Production of Citric Acid by Fermentation of Sugarcane Juice & Study of Effect of Aeration on Process

Citric acid is ubiquitous in nature and exists as an intermediate in the citric acid cycle when carbohydrates are oxidized to carbon dioxide. It is solid at room temperature, melts at 153ºC and decomposes at higher temperatures into other products. It is responsible for the tart taste of various fruits in which it occurs, i.e. lemons, limes, figs, oranges, pineapples, pears and goose-berries. Because of its high solubility, palatability and low toxicity, it can be used in food, biochemical and pharmaceutical industries. These uses have placed greater stress on increased citric acid production and search for more efficient fermentation process. There are many processes for production of citric acid such as from citrus fruits such as orange, lemon etc.,by fermentation of corn cobs, fermentation of apple juice, sugar molasses. But in all of that citric acid from sugarcane juice or sugar molasses is the most efficient process. Many microorganisms such as fungi and bacteria can produce citric acid. The various fungi, which have been found to accumulate citric acid in their culture media, include strains of Aspergillus niger, A. awamori, Penicillium restrictum, Trichoderma viride, Mucor piriformis and Yarrowia lipolytica. But Aspergillus niger remained the organism of choice for the production of citric acid.