Microorganisms and fermentation of traditional foods Fermentation is one of the oldest technologies for processing of food and beverages to improve qualities such as extended shelf life and organoleptic properties. Fermented foods usually have an improved microbial stability and safety alongwith acceptable taste and some products can be stored even at ambient temperatures. The common microorganisms used in food fermentations are bacteria yeasts and molds. The lactic acid bacteria notably lactobacilli and streptococci are the most commonly found microorganisms in fermented foods having the ability to produce lactic acid from carbohydrates. Other important bacteria in fermented foods are the acetic acid producing Acetobacter and the Bacillus species. The most important benefi cial yeasts in terms of desirable food fermentations belong to the Saccharomyces family especially S. cerevisiae. These yeasts play a crucial role in the food industry as they produce enzymes that bring about various desirable biochemical reactions involved in the production of alcoholic beverages. Also few fungi are usually used to produce a great number of popular cheeses