ABSTRACT
Fermentation dates back to prehistoric times when cheese was made in Iraq from cow’s and goat’s milk (6000 BC). Egyptians first discovered the use of yeast to make leavened bread and wine (4000 BC); Sumerians fermented barley to beer (1750 BC); and Chinese used moldy soybean curds as antibiotics (500 BC) (1). A summary of the fermentation events, reported chronologically, is given in Table 3.1. The first half of the twentieth century saw the development of fermentation processes for the industrial production of alcohol, acetic acid, lactic acid, citric acid, gluconic acid, acetone, butanol, and glycerol. It was during this period that anaerobic fermentations were carried out in submerged culture and
aerobic fermentation in surface culture. Continuous demands for increased productivity of aerobic industrial fermentations for baker’s yeast and organic acid production led to the use of deep tank vessels sparged with large quantities of sterile air. Development of the penicillin process during the Second World War reaffirmed the development of industrial fermentation. However, the postwar period resulted in a temporary setback due to the growth of the petrochemical industry, and the availability of inexpensive chemicals for cheaper production of organic acids and solvents by chemical synthesis. Toward the end of the twentieth century, a better understanding of molecular biology led to the development of efficient fermentation systems for production of biochemicals. Presently, fermentation technology has gained increased credence due to the power of microbe design biotechnology, perceived hazards to people and the environment of chemical synthesis, and better economics from use of renewable raw materials.
