Open access peer-reviewed chapter

Technological Advances in Synthetic Biology for Cellulosic Ethanol Production

Written By

Antonio Luiz Fantinel, Rogério Margis, Edson Talamini and Homero Dewes

Submitted: July 23rd, 2021Reviewed: September 3rd, 2021Published: October 16th, 2021

DOI: 10.5772/intechopen.100292

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The resurgence of biofuels in the recent past has brought new perspectives for renewable energy sources. Gradually the optimistic scenarios were being challenged by the competition for raw materials dedicated to direct or indirect human food. Second-generation biorefineries have emerged as technological alternatives to produce biofuels from lignocellulosic biomass. The third generation of biorefineries uses alternative raw materials like algae and microalgae. Despite the technical feasibility, these biorefineries were indebted for their economic performance. Synthetic biology has provided new microbial platforms that are increasingly better adapted to industrial characteristics to produce biofuels and fine chemicals. Synthetic biology bioengineers microorganisms to take advantage of the low-cost and less-noble raw materials like lignocellulosic biomass, carbon dioxide, and waste as a sustainable alternative for bioenergy generation using bio-substrates. In this chapter, we analyze the innovations in synthetic biology as applied to cellulosic ethanol production based on registered patents issued over the last twenty years (1999–2019). Using Questel-Orbit Intelligence, we recovered a total of 298 patent families, from which we extracted the key concepts and technology clusters, the primary technological domains and applications, the geographical distribution of patents, and the leading patents assignees. Besides, we discuss the perspectives for future research and innovations and the market and policy opportunities for innovation in this technological field. We conclude that the patented technologies serve as a proxy for the development of synthetic biotechnology applied in cellulosic ethanol production by the fourth generation of biorefineries.


  • Metabolic engineering
  • microorganisms
  • advanced biofuels
  • genetic engineering

1. Introduction

The transition from a fossil resource-based economy to a bio-based economy necessarily goes using synthetic biotechnologies [1, 2, 3]. Synthetic biology has been evolving and positively affecting human life by providing the opportunity to design and build new biological parts, devices, and systems that do not exist or redesign existing biological systems [4, 5] to produce biofuels and other chemicals [6, 7].

The overlap between synthetic biology and bioeconomy occurs when we consider the latter part of the economy that uses new biological knowledge for commercial and industrial purposes, improving human well-being [8]. This perception intensifies when we ponder the sustainable use of biomass for non-food-biofuel production [9, 10].

Currently, ethanol produced from sugarcane in Brazil [11] and corn in the US [12] is the main alternative in the global supply chain of renewable fuels as a substitute for gasoline. However, this phenomenon fosters scientific debates about land use and food security, given that these are raw materials based on starch and sugar and that can be intended, directly or indirectly, for human food [13, 14].

In microbial ethanol production from lignocellulosic biomass, the dependence on food-related feedstocks is overcoming, being a sustainable alternative for bioenergy generation using substrates from the bioeconomy world [15, 16]. Lignocellulosic biomass is one of the most abundant feedstocks on the globe [17], with a production of approximately 181.5 billion tons/year [18], and can bring about significant changes in socioeconomic, agricultural, and energy systems when efficiently employed [19].

To overcome critical steps of microbial fermentation processes and to increase yields, technological advances are necessary on synthetic biology tools like metagenomics [20], genetic engineering [21], orthogonal communication systems [22], metaproteomics [23], metabolomics [24], and metabolic engineering [25, 26, 27].

From an industrial point of view, investment in these technological solutions depends upon the technical feasibility of using a particular organism to produce a specific compound and on the economic feasibility that results in profitable activity in the long run. Low yields in industrial processes are still recurrent due to low cell density, slowing down the efficient industrial expansion of this field [28, 29, 30, 31, 32] and are critical for biofuel production. Competitive synthetic biology technologies for ethanol production are estimated to be available in the coming years [33].

In the present chapter, we analyze the applications of synthetic biology tools related to cellulosic ethanol production from registered patents, visualizing the technological trends and their regional, institutional, and R&D markets distribution in the years 1999–2019. Patent analysis is one of the approaches to access innovative technologies and commercial aspects of a specific field [34]. The interest in searching for patents on cellulosic ethanol [35, 36, 37, 38] or synthetic biology [39, 40, 41] is expanded here towards the technological development to future energy needs guided by the sustainable bioeconomy agenda. A total of 298 patent families were retrieved using Questel-Orbit Intelligence software. From them, we provide a high-quality dataset from the Questel-Orbit database that can contribute to formulating strategies and policies geared towards the development of these technologies and their applications in emerging markets, ensuring bioeconomic development for the next generations [33].


2. The evolution of innovations in synthetic biology and cellulosic ethanol

Figure 1 shows the distribution of the 298 synthetic biology patent families related to cellulosic ethanol throughout the twenty-year interval 1999–2019. The values correspond to the total frequencies following the International Patent Classification (IPC). In the eight-year interval 1999–2006, the annual number of published patents was negligible, with the first patent application occurring only in 2001. From 2007 to 2011, the number of applications on this topic showed a considerable increase, peaking in 2010 and 2011. Subsequently, applications decreased in 2012, before temporarily recovering in 2013 and 2014. After that year, the applications decreased considerably, as observed through the trend line of synthetic biology patent applications for cellulosic ethanol. Thus, from 2015 there is a decline and subsequent stabilization, which we can understand as a transition from growth to maturity [42] or a consequence of time lag between patent application and patent grant.

Figure 1.

Frequency of synthetic biology patents related to cellulosic ethanol. Source: Research data from Questel-orbit platform.

2.1 Key concepts and technology clusters

The distribution of the main concepts among the retrieved patent families is presented in Figure 2. Nine semantic clusters regularly used by patent applicants were identified (Figure 2A). Most of these patents are related to the use of microorganisms (yeast and gram-negative bacteria), enzymatic activity, biomass, fermentation product, and biofuel production. As for the application of the technologies, we found the predominance of raw materials from biomass, such as agricultural residues (corn straw, wheat, rice, sugarcane bagasse, and switchgrass) and their main fermentable sugars (xylose, hemicellulose, and arabinose) for ethanol production. In the first years, the term “xylose” appeared more prominently than the others (Figure 2B), followed by “corn stover” and “lignocellulosic biomass”. In the sequence, these terms were accompanied by the words “ethyl alcohol” given that the field includes this focus.

Figure 2.

Prevailing concepts in the retrieved patent families. 2A provides an overview of the content of this portfolio formed from the 298 synthetic biology patent families for cellulosic ethanol. 2B shows the distribution of these concepts concerning the complete portfolio over the twenty years surveyed. Source: Research data from Questel-orbit platform.

Therefore, by identifying the concepts commonly employed in the field of synthetic biology concerning cellulosic ethanol, we can propose insights for the development or identification of protected technologies in an emerging technological field with a view to its industrial application.

2.2 Major technological domains and applications

To elucidate the main technological domains and applications of the patent families, we analyzed the codes predominantly used to classify them (Table 1) following the structure proposed by IPC [43]. Approximately 40% of synthetic biology patent families related to cellulosic ethanol belong to the C12P classes. This class contemplates inventions concerning fermentation processes or using enzymes to synthesize a desired chemical composition or compound or to separate optical isomers of a racemic mixture. Within this class, group C12P-007, related to the preparation of organic compounds, represents 37% of the patents. Next in importance is class C12N (30% of the patent families), which deals with microorganisms or enzymes, or compositions thereof; propagation, preservation, or maintenance of microorganisms; genetic or mutation engineering; and culture media. Group C12N-001 accounts for 20% of the patents in this class, concerning processes for propagation, maintenance, or preservation of microorganisms or their compositions, or preparation, isolation of compositions containing a microorganism, and culture media for such.

IPC CodesCode descriptionFamily frequency
C12P-007/06Preparation of oxygen-containing organic compounds [2006.01]
• containing a hydroxy group [2006.01]
•• acyclic [2006.01]
••• Ethanol, i.e. non-beverage [2006.01]
C12P-007/10•••• produced as by-product or from waste or cellulosic material substrate [2006.01]
••••• substrate containing cellulosic material [2006.01]
C12N-001/21• Bacteria; Culture media therefor [2006.01]
•• modified by introduction of foreign genetic material [2006.01]
C12P-007/16••• Butanols [2006.01]13
C12N-001/20• Bacteria; Culture media therefor [2006.01]10
C12N-015/81• Recombinant DNA-technology [2006.01]
•• Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression [2006.01]
••• Vectors or expression systems specially adapted for eukaryotic hosts [2006.01]
•••• for fungi [2006.01]
••••• for yeasts [2006.01]
C12P-007/18••• polyhydric [2006.01]9
C12P-007/14•••• Multiple stages of fermentation; Multiple types of microorganisms or reuse for microorganisms [2006.01]9
C12N-001/19• Fungi (culture of mushrooms A01G 18/00; as new plants A01H 15/00); Culture media therefor [2006.01]
•• Yeasts; Culture media therefor [2006.01]
••• modified by introduction of foreign genetic material [2006.01]
C12N-001/22• Processes using, or culture media containing, cellulose or hydrolysates thereof [2006.01]7

Table 1.

Leading IPC codes for synthetic biology patent families for cellulosic ethanol.

Source: research data from Questel-Orbit platform.

When analyzed separately for each of the predominant codes (Table 1), we see the prominence of code C12P-007/06 (29 patent families). This code is related to the preparation of organic compounds containing oxygen, such as fuel ethanol, whose preponderant claims include yeast capable of fermenting xylose in the presence of glucose [44, 45], development of pretreated biomass [46, 47], use of yeast and bacteria in the presence of glycerol [48]. Among other technologies, we identified inventions related to methods for engineering Thermoanaerobacterium saccharolyticum[48], bioprocessing using recombinant Clostridium[48], methods for ethanol and hydrogen production using microorganisms [49], methods for propagation of microorganisms for hydrolysate fermentation [50], development of fermentation processes using transketolase/thiaminapyrophosphate enzymes [51], and hydrolysis of cellulosic material augmented with an enzyme composition [52].

Accordingly, code C12P-007/10 specifically addresses waste or cellulosic material or substrate containing cellulosic material for ethanol production and accounts for twenty (20) major patent families. These inventions relate to the development of microorganisms fermenting xylose and arabinose into ethanol [53], co-fermentation of pretreated lignocellulosic biomass [54, 55], wet oxidation methods of biomass [56], use of genetic engineering in microorganisms and enzymes [57].

The development of bacteria and culture mediums modified by the introduction of exogenous genetic material is classified by codes C12N-001/20 and C12N-001/21, which together represent twenty-three (23) major patent families. The inventions relate to the development and adaptation of Zymomonas mobilisstrains [58], C. thermocellum[59, 60], E. coli[60], and anaerobic thermophilic bacteria [61, 62] for ethanol production. In addition, we verified the existence of technologies for the removal or inactivation of microbial inhibitors in biomass hydrolysates [63] and the conversion of xylose [64, 65] and arabinose [65] into ethanol.

Preparation of oxygen-containing organic compounds to produce butanol (C12P-007/16) features ten (10) patent families. The technologies pertinent to this code are related to recombinant microbial host cells of S. cerevisiaecapable of converting hemicellulosic material into butanol-like alcohols [66], separation of undissolved solids after liquefaction [66] co-production of biofuels [66], microorganisms using protein and carbohydrate hydrolysates from biomass [67], and genetic engineering in bacteria [67] and yeast [68].

The use of recombinant DNA technologies via vectors and expression regulation in yeast and fungi categorized by code C12N-015/81 presents ten (10) main patent families. These patents target the development of yeast cells with xylose isomerase activity [69], culture medium and bioreactors [70], L-arabinose transporter polypeptide (I) from Pichia stipitis[70], gene transcription control [70], glycerol-free ethanol production using recombinant yeast [71, 72], microbial cells capable of transporting xylo-oligosaccharides [72], and yeast cells with a reduced enzyme activity for NADH-dependent glycerol synthesis [72].

The preparation of organic compounds containing at least two hydroxyl groups (C12P-007/18) features nine (9) main patent families. In this code, inventions are directed to the development of non-native pentose metabolic pathways in yeast cells [73], yeast genes encoding enzymes in the pentose pathway [74], genetically modified thermophilic or mesophilic microorganism [74], S. cerevisiaestrains with reduced glycerol productivity [74] and fermentation microorganism propagation [75].

New forms of fermentation through multiple stages, different types of microorganisms, or reuse of microorganisms represented by code C12P-007/14 present nine (9) main patent families. The technologies are related to the production of syrups enriched with C5 and C6 sugars [75], ethanol production from lignocellulosic biomass [76] and xylitol production from biomass with enriched pentose component [77]. Methods for pectin degradation [78], pretreated cellulosic material [78], biocatalyst development [79] and microorganism propagation [80] for ethanol production are also checked in this code.

Yeast modification by introducing exogenous genetic material represented by C12N-001/19 features eight (8) main patent families. The inventions relate to the use of metabolic engineering for the elimination of the glycerol pathway [78], joint utilization of xylose and glucose [78], and rapid fermentation of xylose [78] in yeast. Methods for enhanced expression of a glycolytic system enzyme [78], glycerol transport [81] and alpha-ketoisovalerate conversion to isobutyraldehyde [81] also integrate this code.

The tenth code with seven (7) patent families relates to processes using culture medium containing cellulose or hydrolysates (C12N-001/22). The inventions concern continuous xylose growth using Zymomonas[81], oligosaccharide degradation by recombinant host cells [82] and lignocellulose bioprocessing employing recombinant Clostridium[83]. Methods for glycerol reduction in biomass fermentative processes [83], increasing tolerance to acetate toxicity in recombinant microbial host cells [84] and controlling contamination during fermentation [84] also integrate this code.

The knowledge present in these technological domains and their applications allows researchers to identify potential fields of development of new cellulosic ethanol production routes using synthetic biology as a technical platform.

2.3 The geographical distribution of innovations

Next, we analyzed the geographical distribution of synthetic biology patent families related to cellulosic ethanol, according to priority country (Figure 3). We found only 14 priority countries holding this technology. The lead-in technological innovation in this field is the USA (Figure 3) since approximately 67% of the patents recovered are in the name of American applicants. The main technological applications patented by American inventors are focused on the production of ethanol from biomass by-products or wastes (C12P-007/10; C12P-007/06), as well as modification of bacteria (C12N-001/21) and fungi (C12N-001/19) by introducing endogenous genetic material as applications to overcome the current barriers to the conversion of biomass to ethanol [85, 86]. Following at a distance is the European Patent Organization, followed by Japan and China, which account for 13%, 6%, and 3% of patent families, respectively. The remaining patent families, which total 11%, are distributed among ten other countries.

Figure 3.

Distribution of priority patent applications in the various offices over the last 20 years (1999–2019). Source: Research data from Questel-orbit platform.

The global distribution of patent families protected in the various offices can be seen in Figure 4. The data corroborates the identification of target markets and demonstrates the patenting strategies of the applicant countries. The illustration confirms that demand is concentrated in the United States, with 49% of patent families, followed by the European Patent Organization (37% of families), India (33% of families), Brazil (30% of families), and China (29% of patent families).

Figure 4.

Worldwide distribution of patents under protection by national patent offices over the last 20 years (1999–2019). Source: Research data from Questel-orbit platform.

Through this data, the strategies for patent protection used by applicants in the sector studied are identified. The preference for registration in patent offices in certain countries indicates the potential of the markets from the viewpoint of the need for commercial protection of new industrial technologies.

2.4 Leading patent assignees

The main assignees of patents in synthetic biology associated with cellulosic ethanol production encompass both private companies and educational and research institutions. The applicants were analyzed by the number of active patents, the average size of these families, generality index, and originality (Table 2). The number of patents and the average size of patent families refer to active patents and their breadth, respectively. In turn, the generality index is defined by Hall et al. [87] as the range of fields of future citations of a given patent. Future citations can be used to assess the subsequent generations of an invention that have benefited from an issued patent by measuring the range of technology fields and, consequently, of industries that cite that patent [88, 89]. On the other hand, the originality index measures the range of technological fields in which a patent is based [89, 90].

AssigneesActive patent familiesAverage family sizeIndicators
Du Pont De Nemours188,70,870,87
Butamax Advanced Biofuels179,30,900,88
University of Florida61,70,840,87
Toray Industries97,10,920,84
DSM Ip Assets77,40,830,78
University of California32,70,860,88

Table 2.

Patent families by assignees and value indicators.

Source: research data from Questel-Orbit platform.

Novozymes, the largest patent holder (27 patent families), is a Danish company that develops and markets enzymes for industrial use. We also highlight the American companies DuPont De Nemours (18 families of patents) and Butamax Advanced Biofuels (17 families). Butamax emerged from the partnership of DuPont and BP, so that in 2017, it acquired the company Nesika Energy LLC, installing an ethanol production plant in Scandia County in the state of Kansas-US, to add to this unit the production of bio-isobutanol. The top five global companies holding patents on the analyzed technology include Canadian Lallemand with 14 patent families and the Dutch company DSM, which has 12 patent families. Regarding the average family size of patents, Butamax Advanced Biofuels is configured with the largest average family size, about 9.3, followed by DuPont De Nemours (8.7) and Danisco (8.6).

Butamax Advanced Biofuels (0.88), Danisco (0.88), the University of California (0.88), Novozymes (0.87), and Du Pont De Nemours (0.87) have the highest patent generality indices and, consequently, tend to account for the most relevant applications. Toray Industries (0.92) and Novozymes (0.91) show the highest scores for the originality index. The importance of the companies cited for inventions and subsequent innovations in the technological field analyzed is undeniable.

We emphasize that, except for Butamax Advanced Biofuels that aims at the production and commercialization of bio-isobutanol, the other companies aim at developing and commercializing enzymes, yeasts, and catalysts for the production of advanced biofuels.


3. Perspectives for future research and innovations

The present study gathers evidence of technological opportunities for ethanol production from raw materials derived from the bioeconomy. As evidenced in our findings, the development of innovations in this field requires multidisciplinary knowledge, providing solutions for industrial applications, which employ S. cerevisiae, E. coli, and Z. mobilis[91]. However, these potentially usable microorganisms in these fermentative processes are not naturally adaptable to extreme industrial conditions [92] or do not tolerate high concentrations of inhibitory compounds released during biomass fermentation [93]. Thus, to overcome these barriers, different synthetic biology and metabolic engineering approaches are employed to microorganisms to make them robust living factories adapted to the industrial activities required for biomass fermentation into ethanol [5, 94, 95]. These insights about synthetic biology may allow folding and probing the genome at different length and time scales, making it possible to understand gene positioning and functions [96]. Nevertheless, we check the prospect of new unconventional yeasts and bacteria such as P. stipitisfor fermentation of lignocellulosic biomass.

Because the yeast S. cerevisiae, commonly used in ethanol fermentation of sugar-based feedstocks, is not a natural degrader of arabinose [97] and xylose [98, 99], making the fermentation processes accessible to these sugars requires pathway engineering [100, 101]. Ye et al. [102] integrated a heterologous fungal arabinose pathway into S. cerevisiae, with the deletion of the PHO13 phosphatase gene, increasing the rate of arabinose consumption and ethanol production under aerobic conditions. In Cunha et al. [103], two pathways (XR/XDH or XI) of xylose assimilation by S. cerevisiaewere compared in ethanol production under different fermentation conditions, demonstrating satisfactory results for the feasibility of this fuel from non-detoxified hemicellulosic hydrolysates. Meanwhile, Mitsui et al. [104] developed a novel genome shuffling method using CRISPR-Cas to improve stress tolerance in S. cerevisiae yeast. Regarding E. coli, its main disadvantages refer to the narrow growth range of neutral pH (6.0–8.0), in addition to ethanol not being a core product for this bacterium. However, Sun et al. [105] successfully developed an efficient bioprocess using an E. colistrain for ethanol production and xylose recovery from corn cob hydrolysate. Strains of this bacterium with regulated glucose utilization showed efficient metabolism of mixed sugars in lignocellulosic hydrolysates, and higher ethanol production yields [106]. In the same perspective, metabolic engineering has been studied to provide simultaneous utilization of glucose and xylose in this bacterial culture [107].

High cellulosic ethanol yields are achieved using Z. mobilisstrains due to their unique physiology [108, 109]. It is possible to employ other substrates, mitigating the socio-environmental challenges for expanding ethanol production [30, 110]. Different approaches have been tested in Z. mobilisto improve the fermentation of lignocellulosic biomass substrates into ethanol [111, 112].

One critical step in developing methods of the microbial fermentation process of lignocellulosic biomass is its pre-treatment to increase the digestibility of the available sugars. Lignocellulosic biomass consists of highly crystalline cellulose and a hemicellulose sheath wrapped in a lignin network. This structure causes recalcitrance in fermentation processes [113, 114]. Recalcitrance is the main obstacle to using lignocellulosic biomass for ethanol production. It determines the rest of the fermentation and the overall efficiency of the process [115]. Biological pre-treatment has been employed for the deconstruction of this biomass because of its wide application, lower energy consumption, no generation of toxic substances, and higher yield [116].

Co-fermentation of different sugars from lignocellulosic biomass and its residues enables ethanol production processes to become economically viable [117]. The potential of using a blend of E. colistrains and yeasts to rapidly ferment all sugars in pretreated biomass at high ethanol rates is presented by Wang et al. [118]. In the same perspective, Amoah et al. [119] developed a yeast with xylose assimilation capable of co-fermenting xylose and glucose in ionic liquid for ethanol production from lignocellulosic biomass. Advances are also in attempting to overcome obstacles and perturbations present in the degradation of lignin [120] and cellulose [121] using microbial consortium and genetic engineering via RNA-guided Cas9 in S. cerevisiae[21], Candida glycerinogenes[122], Rhodosporidium toruloides[123]. The results denote significant increases in stress tolerance of microorganisms in severe fermentative processes.


4. Market and policy opportunities for innovation

The continued development of synthetic biology R&D for cellulosic ethanol production depends on both the technical and economic feasibility of the solutions presented. In the analyzed period, approximately US$ 820 million was invested in synthetic biology research aimed at the development of advanced biofuels and bioproducts from microbial systems [124].

Despite being the second-largest ethanol producer in the world, Brazil does not own priority patents registered in synthetic biology for cellulosic ethanol production, becoming only a target market for other countries holding these technologies, like the USA. In Brazil, the unit cost per protected patent is very high, corresponding to approximately US$ 13,000 per patent. Besides the poor institutional environment for innovation, the unit cost of protection may be one of the reasons for the lack of patent applications by Brazilian assignees. According to Cicogna et al. [125], Brazil is an example of an infant industry that is slowly reaching maturity. In the same perspective, Kang et al. [126] point to the need for government policies that facilitate the development of promising renewable technologies, in addition to offering incentives for their commercialization.

In an attempt to change this situation, in 2017 a new national policy for biofuels was enacted by the Brazilian government, the RenovaBio, aiming to promote ethanol and biodiesel production from various sources available in the country [127]. Brazil, in the future, could become the largest producer of bio-based products when economic, logistical, regulatory, and political barriers are overcome [128]. Its territorial extension and diverse regional edaphoclimatic characteristics enable the country an intensive production of biomass for industrial biotechnology at a relatively lower cost compared to other locations that prospect synthetic microbial cells. Moreover, it is one of the world’s leading food producers with agroindustry generating a significant amount of waste with potential for transformation into bioenergy, providing a new pathway for biofuel production not competing with food but biomass and agricultural waste [129].

The knowledge applied to the creation of new technologies in synthetic biology related to cellulosic ethanol comes mainly from companies that work in the development of enzymes and microorganisms for the transformation of biomass into ethanol and also in the production and commercialization of this biofuel. Companies seek, through patents, the commercial exploitation of these new technologies as they maximize their competitive advantages [130]. Industries operate in complex technological environments. Their technical knowledge is highly relevant to gain a competitive advantage. Therefore, companies cannot rely solely on their internal R&D units but also need to seek support from external sources of technology. To protect their inventions from third-party misuse, innovative companies seek patent protection [131, 132].


5. Concluding remarks

In this chapter, we examined the developments and applications of synthetic biology tools related to cellulosic ethanol by analyzing patents to investigate the current stage and dynamics of this technological field and its role as a proxy for a sustainable bioeconomy using non-food feedstocks. The findings are not necessarily only involved in the field of synthetic biology, but also in its numerous approaches that could circumscribe the development of cellulosic ethanol production worldwide. Our analyses provide a compilation of relevant patents, allowing us to understand, track, and project the role of synthetic biology in fostering solutions for the emerging sustainable bioeconomy, and enabling socio-market scenarios with this orientation.

Thinking about sustainable bioeconomy for energy generation, the use of synthetic biology tools may provide new living factories increasingly adapted to industrial processing technology, despite the decrease in the search for patent applications. Using the results from this study, synthetic or bioenergy engineers will be able to choose robust microorganisms capable of performing optimized fermentation processes or biomass processing methods, alleviating a bottleneck that limits the yields of bioenergy research. As these efforts mature, they can be expanded into biofuel production based on bioeconomic-nonfood substrates.

Overall, the research has provided approach for evaluating synthetic biology R&D performance related to cellulosic ethanol and bioeconomy. The results can help researchers quickly integrate into the field as they will easily understand the technological frontiers. The study also provides references for future energy research and policies that could proxy for a world focused on a more sustainable bioeconomy using non-food feedstocks. In addition, the text illustrated the importance of knowledge spillovers in R&D and signaled possibilities for future work. Deepening the understanding of cellular systems can raise the yield of low-cost carbon sources for cellulosic ethanol production. Integration of different generations of technologies may be an alternative to improve the total yields and make cellulosic ethanol economically viable.



A.L.F., R.M., and E.T. are grateful for supporting received from the Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq, and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). This study was carried out with financial fellowship supports 309586/2019-4, 303956/2019-4, and 141259/2016-7 from the Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq.


Conflict of interest

The authors inform they have no conflict of interest to declare.


  1. Lorenzo, V, Schmidt, M. Biological standards for the Knowledge-Based BioEconomy: What is at stake. New Biotechnology. 2018; 40:170-180. DOI: 10.1016/j.nbt.2017.05.001
  2. 2.French, KE. Harnessing synthetic biology for sustainable development. Nature Sustainability. 2019;2(4):250-252. DOI: 10.1038/s41893-019-0270-x
  3. 3.Srivastava, A, Villalobos, MB, Singh, RK. Engineering Photosynthetic Microbes for Sustainable Bioenergy Production, in: Contemporary Environmental Issues and Challenges in Era of Climate Change; 2020. pp. 183-198. DOI: 10.1007/978-981-32-9595-7_10
  4. 4.Benner, SA, Sismour, AM. Synthetic biology. Nature Reviews Genetics. 2005;6(7):533-543. DOI: 10.1038/nrg1637
  5. 5.Ren, J, Lee, J, Na, D. Recent advances in genetic engineering tools based on synthetic biology. Journal of Microbiology. 2020;58(1):1-10. DOI: 10.1007/s12275-020-9334-x
  6. 6.Nielsen, J, Keasling, JD. Synergies between synthetic biology and metabolic engineering. Nature Biotechnology. 2011;29(8):693-695. DOI: 10.1038/nbt.1937
  7. 7.Chownk, M, Thakur, K, Purohit, A, Vashisht, A, Kumar, S. Applications and Future Perspectives of Synthetic Biology Systems, in: Current Developments in Biotechnology and Bioengineering; 2019. P. 393-412. DOI: 10.1016/b978-0-444-64085-7.00016-2
  8. 8.Zilberman, D, Kim, E, Kirschner, S, Kaplan, S, Reeves, J. Technology and the future bioeconomy. Agricultural Economics (United Kingdom). 2013;44(s1):95-102. DOI: 10.1111/agec.12054
  9. 9.Aro, EM. From first generation biofuels to advanced solar biofuels. Ambio. 2016;45(1):24-31. DOI: 10.1007/s13280-015-0730-0
  10. 10.Dupont-Inglis, J, Borg, A. Destination bioeconomy – The path towards a smarter, more sustainable future. New Biotechnology. 2018;40:140-143. DOI: 10.1016/j.nbt.2017.05.010
  11. 11.Rudorff, BFT, de Aguiar, DA, da Silva, WF, Sugawara, LM, Adami, M, Moreira, MA. Studies on the rapid expansion of sugarcane for ethanol production in São Paulo state (Brazil) using Landsat data. Remote Sensing. 2010;2(4): 1057-1076. DOI: 10.3390/rs2041057
  12. 12.Pimentel, D, Patzek, TW. Ethanol production using corn, switchgrass, and wood; biodiesel production using soybean and sunflower, in: Food, Energy, and Society; 2017. DOI: 10.1201/9781420046687
  13. 13.Tomei, J, Helliwell, R. Food versus fuel? Going beyond biofuels. Land Use Policy. 2016;56:320-326. DOI: 10.1016/j.landusepol.2015.11.015
  14. 14.Rulli, MC, Bellomi, D, Cazzoli, A, De Carolis, G, D’Odorico, P. The water-land-food nexus of first-generation biofuels. Scientific Reports. 2016;6:22521. DOI: 10.1038/srep22521
  15. 15.Guerriero, G, Hausman, JF, Strauss, J, Ertan, H, Siddiqui, KS. Lignocellulosic biomass: Biosynthesis, degradation, and industrial utilization. Engineering in Life Sciences. 2016;16(1);1-16. DOI: 10.1002/elsc.201400196
  16. 16.Lara-Flores, AA, Araújo, RG, Rodríguez-Jasso, RM, Aguedo, M, Aguilar, CN, Trajano, HL, Ruiz, HA. Bioeconomy and Biorefinery: Valorization of Hemicellulose from Lignocellulosic Biomass and Potential Use of Avocado Residues as a Promising Resource of Bioproducts. In Waste to Wealth; 2016. p. 141-170. Springer, Singapore. DOI: 10.1007/978-981-10-7431-8_8
  17. 17.Narnoliya, LK, Jadaun, JS, Singh, SP. Management of Agro-industrial Wastes with the Aid of Synthetic Biology. In Biosynthetic Technology and Environmental Challenges; 2018. p. 11-28. DOI: 10.1007/978-981-10-7434-9_2
  18. 18.Paul, S, Dutta, A. Challenges and opportunities of lignocellulosic biomass for anaerobic digestion. Resources, Conservation and Recycling. 2018;130:164-174. DOI: 10.1016/j.resconrec.2017.12.005
  19. 19.Ingle, AP, Ingle, P, Gupta, I, Rai, M. Socioeconomic impacts of biofuel production from lignocellulosic biomass, in: Sustainable Bioenergy, Elsevier; 2019. p. 347-366. DOI: 10.1016/b978-0-12-817654-2.00013-7
  20. 20.Chen, Y, Wang, Y, Chen, TH, Yao, MD, Xiao, WH, Li, BZ, Yuan, YJ. Identification and manipulation of a novel locus to improve cell tolerance to short-chain alcohols inEscherichia coli. Journal of Industrial Microbiology & Biotechnology. 2018;45:589-598. DOI: 10.1007/s10295-017-1996-y
  21. 21.EauClaire, SF, Zhang, J, Rivera, CG, Huang, LL. Combinatorial metabolic pathway assembly in the yeast genome with RNA-guided Cas9. Journal of Industrial Microbiology and Biotechnology. 2016;43(7):1001-1015. DOI: 10.1007/s10295-016-1776-0
  22. 22.Bervoets, I, Van Brempt, M, Van Nerom, K, Van Hove, B, Maertens, J, De Mey, M, Charlier, D. A sigma factor toolbox for orthogonal gene expression inEscherichia coli. Nucleic Acids Research. 2018;46:2133-2144. DOI: 10.1093/nar/gky010
  23. 23.Speda, J, Jonsson, BH, Carlsson, U, Karlsson, M. Metaproteomics-guided selection of targeted enzymes for bioprospecting of mixed microbial communities. Biotechnology for Biofuels. 2017;10(1):128. DOI: 10.1186/s13068-017-0815-z
  24. 24.Pandey, S. Prospects of metagenomic cellulases for converting lignocellulosic biomass into bio-ethanol. Journal of Pure and Applied Microbiology. 2017;11(2):1079-1091. DOI: 10.22207/JPAM.11.2.51
  25. 25.Hollinshead, W, He, L, Tang, YJ. Biofuel production: An odyssey from metabolic engineering to fermentation scale-up. Frontiers in Microbiology. 2014;5: 344. DOI: 10.3389/fmicb.2014.00344
  26. 26.Liao, JC, Mi, L, Pontrelli, S, Luo, S. Fuelling the future: Microbial engineering for the production of sustainable biofuels. Nature Reviews Microbiology. 2016;14(5):288. DOI: 10.1038/nrmicro.2016.32
  27. 27.Duan, G, Wu, B, Qin, H, Wang, W, Tan, Q, Dai, Y, Qin, Y, Tan, F, Hu, G, He, M. Replacing water and nutrients for ethanol production by ARTP derived biogas slurry tolerantZymomonas mobilisstrain. Biotechnology for Biofuels. 2019;12(1): 124. DOI: 10.1186/s13068-019-1463-2
  28. 28.Chisti, Y. Constraints to commercialization of algal fuels. Journal of Biotechnology. 2013;167:201-214. DOI: 10.1016/j.jbiotec.2013.07.020
  29. 29.Rahman, Z, Rashid, N, Nawab, J, Ilyas, M, Sung, BH, Kim, SC.Escherichia colias a fatty acid and biodiesel factory: current challenges and future directions. Environmental Science and Pollution Research. 2013;23:12007-12018. DOI: 10.1007/s11356-016-6367-0
  30. 30.Khetkorn, W, Rastogi, RP, Incharoensakdi, A, Lindblad, P, Madamwar, D, Pandey, A, Larroche, C. Microalgal hydrogen production – A review. Bioresource Technology. 2017;243:1194-1206. DOI: 10.1016/j.biortech.2017.07.085
  31. 31.Xue, C, Zhao, JB, Chen, LJ, Yang, ST, Bai, FW. Recent advances and state-of-the-art strategies in strain and process engineering for biobutanol production byClostridium acetobutylicum. Biotechnology Advances. 2017;35:310-322. DOI: 10.1016/j.biotechadv.2017.01.007
  32. 32.Jullesson, D, David, F, Pfleger, B, Nielsen, J. Impact of synthetic biology and metabolic engineering on industrial production of fine chemicals. Biotechnology Advances. 2015;33(7):1395-1402. DOI: 10.1016/j.biotechadv.2015.02.011
  33. 33.Dehghani Madvar, M, Aslani, A, Ahmadi, MH, Karbalaie Ghomi, NS. Current status and future forecasting of biofuels technology development. International Journal of Energy Research. 2019;43(3):1142-116. DOI: 10.1002/er.4344
  34. 34.Devarapalli, P, Deshpande, N, Hirwani, RR. Xylose utilization in ethanol production: a patent landscape. Biofuels, Bioproducts and Biorefining. 2016;10(5):534-541. DOI: 10.1002/bbb.1664
  35. 35.Gustafsson, R, Kuusi, O; Meyer, M. Examining open-endedness of expectations in emerging technological fields: The case of cellulosic ethanol. Technological Forecasting and Social Change. 2015;91:179-193. DOI: 10.1016/j.techfore.2014.02.008
  36. 36.Kessler, J, Sperling, D. Tracking U.S. biofuel innovation through patents. Energy Policy. 2016;98:97-107. DOI: 10.1016/j.enpol.2016.08.021
  37. 37.Karvonen, M, Klemola, K. Identifying bioethanol technology generations from the patent data. World Patent Information. 2019;57:25-34. DOI: 10.1016/j.wpi.2019.03.004
  38. 38.Toivanen, H, Novotny, M. The emergence of patent races in lignocellulosic biofuels, 2002-2015. Renewable and Sustainable Energy Reviews. 2017;77:318-326. DOI: 10.1016/j.rser.2017.03.089
  39. 39.Van Doren, D, Koenigstein, S, Reiss, T. The development of synthetic biology: A patent analysis. Systems and Synthetic Biology. 2013;7(4):209-220. DOI: 10.1007/s11693-013-9121-7
  40. 40.Carbonell, P, Gök, A, Shapira, P, Faulon, JL. Mapping the patent landscape of synthetic biology for fine chemical production pathways. Microbial Biotechnology. 2016;135:544-554. DOI: 10.1111/1751-7915.12401
  41. 41.Ribeiro, B, Shapira, P. Private and public values of innovation: A patent analysis of synthetic biology. Research Policy. 2020;49(1):103875. DOI: 10.1016/j.respol.2019.103875
  42. 42.Haupt, R, Kloyer, M, Lange, M. Patent indicators for the technology life cycle development. Research Policy. 2007;36(3):387-398. DOI: 10.1016/j.respol.2006.12.004
  43. 43.WIPO. Guide to the International Patent Classification. World Intelectual Property Organization. 2019
  44. 44.WO2009093630A1 - Hexose-pentose cofermenting yeast having excellent xylose fermentability and method of highly efficiently producing ethanol using the same - Google Patents [WWW Document], n.d. URL 1.17.20)
  45. 45.US10301653B2 - Microorganisms that co-consume glucose with non-glucose carbohydrates and methods of use - Google Patents [WWW Document], n.d. URL 1.17.20)
  46. 46.WO2009137804A1 - Yeast cells and mehtods for increasing ethanol production - Google Patents [WWW Document], n.d. URL 1.17.20)
  47. 47.WO2015142399A1 - Preparation of biomass - Google Patents [WWW Document], n.d. URL 1.17.20)
  48. 48.WO2012067510A1 - Yeast strains engineered to produce ethanol from glycerol - Google Patents [WWW Document], n.d. URL 1.17.20)
  49. 49.WO2009124321A1 - Methods and compositions for improving the production of fuels in microorganisms - Google Patents [WWW Document], n.d. URL 1.17.20)
  50. 50.WO2017112475A1 - Methods, systems, and compositions for propagation of a fermentation microorganism - Google Patents [WWW Document], n.d. URL 1.17.20)
  51. 51.WO2010014817A2 - Producing fermentation products - Google Patents [WWW Document], n.d. URL 1.17.20)
  52. 52.WO2010080408A2 - Methods for increasing enzymatic hydrolysis of cellulosic material in the presence of a peroxidase - Google Patents [WWW Document], n.d. URL 1.17.20)
  53. 53.WO2013071112A1 - A genetically modified strain of s. cerevisiae engineered to ferment xylose and arabinose - Google Patents [WWW Document], n.d. URL 1.17.20)
  54. 54.WO2014160402A1 - Co-conversion of carbohydrates to fermentation products in a single fermentation step - Google Patents [WWW Document], n.d. URL 1.17.20)
  55. 55.WO2008124162A2 - Substrate-selective co-fermentation process - Google Patents [WWW Document], n.d. URL 1.17.20)
  56. 56.WO2017049394A1 - Oxydation par voie humide de biomasse - Google Patents [WWW Document], n.d. URL 1.17.20)
  57. 57.WO2011150318A1 - Acetate-resistant yeast strain for the production of a fermentation product - Google Patents [WWW Document], n.d. URL 1.17.20)
  58. 58.BR112013014912A2 - micro-organismo recombinante, zymomonas recombinante, polipeptídeo, métodos para a produção de uma zymomonas recombinantes produtora de etanol e para a produção de etanol - Google Patents [WWW Document], n.d. URL 1.17.20)
  59. 59.WO2014182054A1 - Recombinant microorganism metabolizing 3,6-anhydride-l-galactose and a use thereof - Google Patents [WWW Document], n.d. URL 1.17.20)
  60. 60.WO2011137401A2 - Redirected bioenergetics in recombinant cellulolytic clostridium microorganisms - Google Patents [WWW Document], n.d. URL 1.17.20)
  61. 61.BRPI0712490A2 - cepa bg1 de trehmoanaerobacter mathranii - Google Patents [WWW Document], n.d. URL 1.17.20)
  62. 62.WO2010031793A2 - Thermophilic fermentative bacterium producing butanol and/or hydrogen from glycerol - Google Patents [WWW Document], n.d. URL 1.17.20)
  63. 63.WO2013019822A1 - Removal of microbial fermentation inhibitors from cellulosic hydrolysates or other inhibitor-containing compositions - Google Patents [WWW Document], n.d. URL 1.17.20)
  64. 64.BR112014015565A2 - método de produzir uma célula, célula e método para produzir etanol - Google Patents [WWW Document], n.d. URL 1.17.20)
  65. 65.BR112014015566A2 - célula hospedeira bacteriana recombinante e processo para produção de etanol - Google Patents [WWW Document], n.d. URL 1.17.20)
  66. 66.WO2010059616A2 - Biocatalysts and methods for conversion of hemicellulose hydrolsates to biobased products - Google Patents [WWW Document], n.d. URL 1.17.20)
  67. 67.WO2014047421A1 - Production of renewable hydrocarbon compositions - Google Patents [WWW Document], n.d. URL 1.17.20)
  68. 68.WO2015103001A1 - Expression of a hap transcriptional complex subunit - Google Patents [WWW Document], n.d. URL 1.17.20)
  69. 69.WO2014098939A1 - Expression of xylose isomerase activity in yeast - Google Patents [WWW Document], n.d. URL 1.17.20)
  70. 70.WO2011123715A1 - Metabolically engineered yeasts for the production of ethanol and other products from xylose and cellobiose - Google Patents [WWW Document], n.d. URL 1.17.20)
  71. 71.WO2019063542A1 - Improved glycerol free ethanol production - Google Patents [WWW Document], n.d. URL 1.17.20)
  72. 72.WO2019063543A1 - Improved glycerol free ethanol production - Google Patents [WWW Document], n.d. URL 1.17.20)
  73. 73.BR112013009157A2 - polipeptídeos com atividade de permease - Google Patents [WWW Document], n.d. URL 1.17.20)
  74. 74.WO2019149789A1 - Yeast cell capable of simultaneously fermenting hexose and pentose sugars - Google Patents [WWW Document], n.d. URL 1.17.20)
  75. 75.WO2017112471A1 - Methods, systems, and compositions for propagation of a fermentation microorganism - Google Patents [WWW Document], n.d. URL 1.17.20)
  76. 76.WO2010075213A2 - Production of ethanol from lignocellulosic biomass - Google Patents [WWW Document], n.d. URL 1.17.20)
  77. 77.WO2014045297A2 - A selective microbial production of xylitol from biomass-based sugar stream with enriched pentose component" - Google Patents [WWW Document], n.d. URL 1.17.20)
  78. 78.WO2010033823A2 - Methods and compositions for degrading pectin - Google Patents [WWW Document], n.d. URL 1.17.20)
  79. 79.WO2015089428A1 - Enhanced efficiency ethanol production and sugar conversion processes - Google Patents [WWW Document], n.d. URL 1.17.20)
  80. 80.WO2018097844A1 - Methods, systems, and compositions for propagation of a fermentation microorganism - Google Patents [WWW Document], n.d. URL 1.17.20)
  81. 81.WO2015028583A2 - Glycerol and acetic acid converting cells with improved glycerol transport - Google Patents [WWW Document], n.d. URL 1.17.20)
  82. 82.WO2007005646A9 - Cellules hotes recombinantes et milieu pour production d’ethanol - Google Patents [WWW Document], n.d. URL 1.17.20)
  83. 83.WO2010063766A1 - Bioprocessing ligno-cellulose into ethanol with recombinant clostridium - Google Patents [WWW Document], n.d. URL 1.17.20)
  84. 84.WO2019058260A1 - Acetate toxicity tolerance in recombinant microbial host cells - Google Patents [WWW Document], n.d. URL 1.17.20)
  85. 85.Gupta, A, Verma, JP. Sustainable bio-ethanol production from agro-residues: A review. Renewable and Sustainable Energy Reviews. 2025;41:550-567. DOI: 10.1016/j.rser.2014.08.032
  86. 86.Sindhu, R, Binod, P, Pandey, A. Biological pretreatment of lignocellulosic biomass - An overview. Bioresource Technology. 2016;199:76-82. DOI: 10.1016/j.biortech.2015.08.030
  87. 87.Hall, BH, Jaffe, AB, Trajtenberg, M. The NBER Patent-Citations Data File: Lessons, Insights, and Methodological Tools. Patents, citations, and innovations: A window on the knowledge economy. 2001;403. DOI: 10.1186/1471-2164-12-148
  88. 88.Bresnahan, TF, Trajtenberg, M. General purpose technologies “Engines of growth”? Journal of Econometrics. 1995;65(1):83-108. DOI: 10.1016/0304-4076(94)01598-T
  89. 89.OECD. Measuring the Technological and Economic Value of Patents, in: Enquires Into Intellectual Property’s Economic Impact. 2015
  90. 90.Trajtenberg, M, Henderson, R, Jaffe, A. University versus corporate patents: A window on the basicness of invention. Economics of Innovation and New Technology. 1997;5(1):19-50. DOI: 10.1080/10438599700000006
  91. 91.Akinosho, H, Yee, K, Close, D, Ragauskas, A. The emergence of Clostridium thermocellum as a high utility candidate for consolidated bioprocessing applications. Frontiers in Chemistry. 2014;2:66. DOI: 10.3389/fchem.2014.00066
  92. 92.Radecka, D, Mukherjee, V, Mateo, RQ, Stojiljkovic, M, Foulquié-Moreno, MR, Thevelein, JM. Looking beyondSaccharomyces: The potential of non-conventional yeast species for desirable traits in bioethanol fermentation. FEMS Yeast Research. 2015;15. DOI: 10.1093/femsyr/fov053
  93. 93.Hasunuma, T, Sanda, T, Yamada, R, Yoshimura, K, Ishii, J, Kondo, A. Metabolic pathway engineering based on metabolomics confers acetic and formic acid tolerance to a recombinant xylose-fermenting strain of Saccharomyces cerevisiae. Microbial Cell Factories. 2011;10(1):2. DOI: 10.1186/1475-2859-10-2
  94. 94.Shen, W, Zhang, J, Geng, B, Qiu, M, Hu, M, Yang, Q, Bao, W, Xiao, Y, Zheng, Y, Peng, W, Zhang, G, Ma, L, Yang, S. Establishment and application of a CRISPR-Cas12a assisted genome-editing system inZymomonas mobilis. Microbial Cell Factories. 2019;18(1):162. DOI: 10.1186/s12934-019-1219-5
  95. 95.Banerjee, S, Mishra, G, Roy, A. Metabolic Engineering of Bacteria for Renewable Bioethanol Production from Cellulosic Biomass. Biotechnology and Bioprocess Engineering. 2019;24(5):713-733. DOI: 10.1007/s12257-019-0134-2
  96. 96.Landhuis, E. Technologies to watch in 2020. Nature. 2020;577:585-587. DOI: 10.1038/d41586-020-00114-4
  97. 97.Buschke, N, Schäfer, R, Becker, J, Wittmann, C. Metabolic engineering of industrial platform microorganisms for biorefinery applications - Optimization of substrate spectrum and process robustness by rational and evolutive strategies. Bioresource Technology. 2013;135:544-554 DOI: 10.1016/j.biortech.2012.11.047
  98. 98.Banerjee, S, Mudliar, S, Sen, R, Giri, B, Satpute, D, Chakrabarti, T, Pandey, RA. Commercializing lignocellulosic bioethanol: Technology bottlenecks and possible remedies. Biofuels, Bioproducts and Biorefining. 2010;4(1):77-93. DOI: 10.1002/bbb.188
  99. 99.Moysés, DN, Reis, VCB, de Almeida, JRM, de Moraes, LMP, Torres, FAG. Xylose fermentation bysaccharomyces cerevisiae: Challenges and prospects. International Journal of Molecular Sciences. 2016;17(3):207. DOI: 10.3390/ijms17030207
  100. 100.Lee, WH, Jin, YS. Evaluation of ethanol production activity by engineeredSaccharomyces cerevisiaefermenting cellobiose through the phosphorolytic pathway in simultaneous saccharification and fermentation of cellulose. Journal of Microbiology and Biotechnology. 2017;27(9):1649-1656. DOI: 10.4014/jmb.1705.05039
  101. 101.Bracher, JM, Verhoeven, MD, Wisselink, HW, Crimi, B, Nijland, JG, Driessen, AJM, Klaassen, P, Van Maris, AJA, Daran, JMG, Pronk, JT. ThePenicillium chrysogenumtransporter PcAraT enables high-affinity, glucose-insensitive l-arabinose transport inSaccharomyces cerevisiae. Biotechnology for Biofuels. 2018;11(1):63. DOI: 10.1186/s13068-018-1047-6
  102. 102.Ye, S, Jeong, D, Shon, JC, Liu, KH, Kim, KH, Shin, M, Kim, SR. Deletion of PHO13 improves aerobic l-arabinose fermentation in engineeredSaccharomyces cerevisiae. Journal of Industrial Microbiology and Biotechnology. 2019;46(12):1725-1731. DOI: 10.1007/s10295-019-02233-y
  103. 103.Cunha, JT, Soares, PO, Romaní, A, Thevelein, JM, Domingues, L. Xylose fermentation efficiency of industrialSaccharomyces cerevisiaeyeast with separate or combined xylose reductase/xylitol dehydrogenase and xylose isomerase pathways. Biotechnology for Biofuels. 2019;12:1-14. DOI: 10.1186/s13068-019-1360-8
  104. 104.Mitsui, R, Yamada, R, Ogino, H. Improved Stress Tolerance ofSaccharomyces cerevisiaeby CRISPR-Cas-Mediated Genome Evolution. Applied Biochemistry and Biotechnology. 2019;10:2637-2650. DOI: 10.1007/s12010-019-03040-y
  105. 105.Sun, J, Wang, J, Tian, K, Dong, Z, Liu, X, Permaul, K, Singh, S, Prior, BA, Wang, Z. A novel strategy for production of ethanol and recovery of xylose from simulated corncob hydrolysate. Biotechnology Letters. 2018a;40:781-788. DOI: 10.1007/s10529-018-2537-0
  106. 106.Sun, J, Tian, K, Wang, J, Dong, Z, Liu, X, Permaul, K, Singh, S, Prior, BA, Wang, Z. Improved ethanol productivity from lignocellulosic hydrolysates byEscherichia coliwith regulated glucose utilization. Microbial Cell Factories. 2018b;17:1-18. DOI: 10.1186/s12934-018-0915-x
  107. 107.Kim, J, Tremaine, M, Grass, JA, Purdy, HM, Landick, R, Kiley, PJ, Reed, JL. Systems Metabolic Engineering ofEscherichia coliImproves Coconversion of Lignocellulose-Derived Sugars. Biotechnology Journal. 2019;14. DOI: 10.1002/biot.201800441
  108. 108.Yang, S, Fei, Q, Zhang, Y, Contreras, LM, Utturkar, SM, Brown, SD, Himmel, ME, Zhang, M.Zymomonas mobilisas a model system for production of biofuels and biochemicals. Microbial Biotechnology. 2016;9:699-717. DOI: 10.1111/1751-7915.12408
  109. 109.Wang, X, He, Q, Yang, Y, Wang, J, Haning, K, Hu, Y, Wu, B, He, M, Zhang, Y, Bao, J, Contreras, LM, Yang, S. Advances and prospects in metabolic engineering ofZymomonas mobilis. Metabolic Engineering. 2018;50:57-73. DOI: 10.1016/j.ymben.2018.04.001
  110. 110.Gonçalves, FA, dos Santos, ES, de Macedo, GR. Alcoholic fermentation ofSaccharomyces cerevisiae,Pichia stipitisandZymomonas mobilisin the presence of inhibitory compounds and seawater. Journal of Basic Microbiology. 2015;55:695-708. DOI: 10.1002/jobm.201400589
  111. 111.Yang, Y, Hu, M, Tang, Y, Geng, B, Qiu, M, He, Q, Chen, S, Wang, X, Yang, S. Progress and perspective on lignocellulosic hydrolysate inhibitor tolerance improvement inZymomonas mobilis. Bioresources and Bioprocessing. 2018;5:1-12. DOI: 10.1186/s40643-018-0193-9
  112. 112.Zhang, K, Lu, X, Li, Y, Jiang, X, Liu, L, Wang, H. New technologies provide more metabolic engineering strategies for bioethanol production inZymomonas mobilis. Applied Microbiology and Biotechnology. 2019;103:2087-2099. DOI: 10.1007/s00253-019-09620-6
  113. 113.Himmel, ME, Ding, SY, Johnson, DK, Adney, WS, Nimlos, MR, Brady, JW, Foust, TD. Biomass recalcitrance: Engineering plants and enzymes for biofuels production. Science. 2007;316:982-982. DOI: 10.1126/science.1137016
  114. 114.Somerville, C, Youngs, H, Taylor, C, Davis, SC, Long, SP. Feedstocks for lignocellulosic biofuels. Science. 2010;329:790-792. DOI: 10.1126/science.1189268
  115. 115.Moreno, AD, Alvira, P, Ibarra, D, Tomás-Pejó, E. Production of Ethanol from Lignocellulosic Biomass. In Production of Platform Chemicals from Sustainable Resources; 2017. p. 375-410. Springer, Singapore. DOI: 10.1007/978-981-10-4172-3_12
  116. 116.Sharma, HK, Xu, C, Qin, W. Biological Pretreatment of Lignocellulosic Biomass for Biofuels and Bioproducts: An Overview. Waste and Biomass Valorization. 2019;10:235-251. DOI: 10.1007/s12649-017-0059-y
  117. 117.Ko, JK, Um, Y, Woo, HM, Kim, KH, Lee, SM. Ethanol production from lignocellulosic hydrolysates using engineeredSaccharomyces cerevisiaeharboring xylose isomerase-based pathway. Bioresource Technology. 2016;209:290-296. DOI: 10.1016/j.biortech.2016.02.124
  118. 118.Wang, L, York, SW, Ingram, LO, Shanmugam, KT. Simultaneous fermentation of biomass-derived sugars to ethanol by a co-culture of an engineeredEscherichia coliandSaccharomyces cerevisiae. Bioresource Technology. 2019;273:269-276. DOI: 10.1016/j.biortech.2018.11.016
  119. 119.Amoah, J, Ogura, K, Schmetz, Q, Kondo, A, Ogino, C. Co-fermentation of xylose and glucose from ionic liquid pretreated sugar cane bagasse for bioethanol production using engineered xylose assimilating yeast. Biomass and Bioenergy. 2019;128:105283. DOI: 10.1016/j.biombioe.2019.105283
  120. 120.Sadalage, PS, Dar, MA, Chavan, AR, Pawar, KD. Formulation of synthetic bacterial consortia and their evaluation by principal component analysis for lignocellulose rich biomass degradation. Renewable Energy. 2019;31:517-535. DOI: 10.1016/j.renene.2019.10.053
  121. 121.Carver, SM, Lepistö, R, Tuovinen, OH. Effect of the type and concentration of cellulose and temperature on metabolite formation by a fermentative thermophilic consortium. International Journal of Hydrogen Energy. 2019;44: 17248-17259. DOI: 10.1016/j.ijhydene.2019.02.177
  122. 122.Zhu, M, Sun, L, Lu, X, Zong, H, Zhuge, B. Establishment of a transient CRISPR-Cas9 genome editing system inCandida glycerinogenesfor co-production of ethanol and xylonic acid. Journal of Bioscience and Bioengineering. 2019;128:283-289. DOI: 10.1016/j.jbiosc.2019.03.009
  123. 123.Schultz, JC, Cao, M, Zhao, H. Development of a CRISPR/Cas9 system for high efficiency multiplexed gene deletion inRhodosporidium toruloides. Biotechnology and Bioengineering. 2019;116:2103-2109. DOI: 10.1002/bit.27001
  124. 124.Si, T, Zhao, H. A brief overview of synthetic biology research programs and roadmap studies in the United States. Synthetic and Systems Biotechnology. 2016;1;258-264. DOI: 10.1016/j.synbio.2016.08.003
  125. 125.Cicogna, MPV, Khanna, M, Zilberman, D. Prospects for Biofuel Production in Brazil: Role of Market and Policy Uncertainties. In Handbook of Bioenergy Economics and Policy; 2017. p. 89-117. Springer, New York, NY. DOI: 10.1007/978-1-4939-6906-7_5
  126. 126.Kang, JS, Kholod, T, Downing, S. Analysis of Russia’s biofuel knowledge base: A comparison with Germany and China. Energy Policy. 2015;85:182-193. DOI: 10.1016/j.enpol.2015.06.002
  127. 127.MME. RenovaBio [WWW Document]. Petróleo, gás natural e biocombustíveis, 2019
  128. 128.Portugal-Pereira, J, Soria, R, Rathmann, R, Schaeffer, R, Szklo, A. Agricultural and agro-industrial residues-to-energy: Techno-economic and environmental assessment in Brazil. Biomass and Bioenergy. 2015;81:521-533. DOI: 10.1016/j.biombioe.2015.08.010
  129. 129.Maitan-Alfenas, GP, Visser, EM, Guimarães, VM. Enzymatic hydrolysis of lignocellulosic biomass: Converting food waste in valuable products. Current Opinion in Food Science. 2015;1:44-49. DOI: 10.1016/j.cofs.2014.10.001
  130. 130.Leu, HJ, Wu, CC, Lin, CY. Technology exploration and forecasting of biofuels and biohydrogen energy from patent analysis, in: International Journal of Hydrogen Energy; 2012. p. 15719-15725. DOI: 10.1016/j.ijhydene.2012.04.143
  131. 131.Lin, BW, Chen, WC, Chu, PY. Mergers and acquisitions strategies for industry leaders, challengers, and niche players: Interaction effects of technology positioning and industrial environment. IEEE Transactions on Engineering Management, 2015; 62(1), 80-88. DOI: 10.1109/TEM.2014.2380822
  132. 132.Caviggioli, F, De Marco, A, Scellato, G, Ughetto, E. Corporate strategies for technology acquisition: evidence from patent transactions. Management Decision. 2017;55(6):1163-1181. DOI: 10.1108/MD-04-2016-0220

Written By

Antonio Luiz Fantinel, Rogério Margis, Edson Talamini and Homero Dewes

Submitted: July 23rd, 2021Reviewed: September 3rd, 2021Published: October 16th, 2021