Part of the book: Management of Organic Waste
Part of the book: Biomass Now
Winemaking produces annually millions of tons of grape marc as a byproduct, which is a revaluable resource having many potential uses, including a nutrient‐rich organic soil amendment. However, its application as untreated raw material can damage crops owing to the release of phytotoxic polyphenols. This agronomic problems can be minimized by vermicomposting, as earthworms can partly digest polyphenols. This chapter reports the results obtained in the processing of grape marc derived from white wine through vermicomposting on an industrial scale to yield both a high quality organic, polyphenol‐free fertilizer and grape seeds as a source of bioactive compounds. Vermicomposting reduced substantially the residue biomass. In a very short‐term, the process yielded a nutrient‐rich, microbiologically active and stabilized peat‐like material that can be easily separated from the seeds by sieving. The isolation of the seeds eliminates the polyphenol‐associated phytotoxicity from the vermicompost and left those seeds prepared to be easily processed to get different bioactive compounds, mainly rich‐polyphenols extracts but also rich‐fatty acids seed oil. The procedure described is effective, simple, environmental‐friendly and economical, and can easily be scaled up for industrial application yielding a variety of added‐value products from the initial grape marc.
Part of the book: Grape and Wine Biotechnology
Vermicomposting, the conversion of organic waste into vermicompost, is mediated by the combined action of earthworms and microorganisms. This interesting and attractive alternative to regular composting turns organic waste into a substrate that can be used as a soil amendment and as a growing medium for use in horticulture. Soil is not required in vermicomposting as the organic matter acts as both the substrate and food, and therefore only epigeic earthworms can be used in the process. Several earthworm species have been evaluated for their potential use in vermicomposting, including Eisenia fetida (Savigny), Eisenia andrei (Bouché), Dendrobaena veneta (Rosa), Dendrobaena hortensis (Michaelsen) Eudrilus eugeniae (Kinberg), and Perionyx excavatus (Perrier). The species most commonly used in vermicomposting and vermiculture facilities worldwide are Eisenia andrei and Eisenia fetida. This chapter reviews and updates the controversy surrounding the taxonomic differentiation between E. andrei and E. fetida, and between D. veneta and D. hortensis, showing that these are all different species and emphasizing the importance of maintaining pure cultures in vermicomposting systems. In the final section, methods of cultivating epigeic earthworms to ensure high rates of growth and reproduction are described.
Part of the book: Earthworms