Fermentation is an enzymatically controlled process that breaks down organic substances into simpler substances, including carbon dioxide, alcohol, and organic acid. Organic substances cannot be fully decomposed by microbes, and are able to produce valuable organic acids, such as alpha-ketoglutaric acid, malic acid, fumaric acid, succinic acid, citric acid, pyruvic acid, pantothenic acid, which are intermediates found in the Krebs’ cycle.
