Organic acids: microbial sources, production, and applications

Microorganisms play a prominent role in generating a variety of products that have applications in different areas, such as energy, food, chemicals, diagnostics, and pharmaceuticals. They are the source of enzymes, organic acids, amino acids, antibiotics, vitamins, single-cell proteins, and other commodity chemicals of commercial importance. The advances in microbial fermentation techniques have led to the development of ecofriendly processes to replace some of the conventional chemical processes. Organic acids are traditional products of food technology and biotechnology. At the same time, organic acids are among the most promising future products of industrial microbiology, owing to their possible use as building block chemicals. The production of organic acid through microbial fermentations using less expensive raw material is also one of the major achievements of industrial microbiology. This review mainly focuses on the microbial sources and production methods of different organic acids (citric acid, gluconic acid, fumaric acid, and lactic acid) used mainly in the food industry.