Fermentation is a multi-disciplinary concept that is defined from the perspectives of various disciplines. It connotes different meanings to microbiologist, biochemist, food and nutritionist (rumen modulator/manipulation) and soil scientist. However, the overall is that it results in the breakdown of substrates (organic or inorganic) in the absence of air to yield intermediate by-products including methane gas (loss of feed energy). The concept includes activities bothering on anaerobic and aerobic processes to enhance the breakdown of substrates to produce some useful materials and biogases. Although carbohydrates are often regarded as essential materials for fermentations, organic acids (including amino acids), proteins, fats, and other organic compounds are fermentable substrates for selected microorganisms with the production of total volatile fatty acids and their individual components (i.e. propionates, butyrates and acetates). Today, fermentative process involves the transformation of raw materials, aerobically or anaerobically, to other valuable products through the activities of microorganisms.
Part of the book: Fermentation