ABSTRACT
Many organic acids possess a long chain of carbons attached to a carboxyl group and can be produced through microbial bioprocesses with the exception of a few that are produced commercially. Fermentation processes play a major role in the production of most organic acids such as citric, gluconic, itaconic, lactic, fumaric, and malic acids. Most organic acids are produced as intermediate metabolites of the tricarboxylic acid (TCA) cycle whereas other acids can be derived indirectly from the Krebs cycle such as itaconic acid, or directly from glucose. Acetic and lactic acids are formed as end products from pyruvate or ethanol. Many bacteria and fungi have the potential to produce a variety of organic acids with high yields. However, fungi have an intrinsic ability to accumulate many organic acids because of their ability to thrive at acidic pH from 2 to 5 (Goldberg et al. 2006).
