While alcoholic fermentation is driven by the presence of yeast and oxygen, and lactic acid fermentation is spurred by the absence of oxygen and dominance of lactic acid bacteria, the factors leading to alkaline fermentation are presence of protein and/or fat source and dominance of Bacillus sp. Therefore, legumes and seeds generally undergo alkaline fermentation., with B. subtilis, B. licheniformis and sometimes B. pumilus being the primary fermenting microorganisms. Many of these fermentations are spontanious, but in many Asian processes, the substrate (often soybean) is inocculated with B. subtilis, which hydrolizes the protein to amino acids and peptides. This extensive hydrolysis causes a raise in pH and release of ammonia. This gives many of the alkaline fermented products a pungent smell. They are most often used as flavourings and condiments. However, as they are rich in protein and amino acids and also often have a meat-like flavour and texture, they are also interesting alternatives for meat and fish.
