Anotace:
Citric acid is one of the extensively used organic acids in many industries. There is a worldwide demand for citric acid consumption due to their many industrial applications. It is also considered as a Generally Recognized As Safe (GRAS) compound. In this review, current developments in microbial fermentation processes for citric acid production have been discussed. In food, beverages, milk and sugar processing several biodegradable organic waste materials are generated in large quantities. These include sugarcane bagasse, grape pomace, apple pomace, pineapple pomace, vegetables, tapioca, coconut husk, banana peels, citrus peels, whey and decaying fruits are found to be potential substrates for citric acid production. A significant effect of substrate concentration, inorganic salts, initial sugar concentration, moisture and additives etc on citric acid production have been highlighted for further improvement in fermentation process. Recent developments in upstream and downstream processes for citric acid production are also deeply discussed. This review gives insights for future possibilities of cost effective fermentation process for citric acid production from several cheap raw materials. Formation of citric acid as an industrial byproduct will help to tackle waste disposal issue and also reduce the dependency of industry over other citric acid producers. Thus, the industry would be benefitted ecologically and economically.