Microorganisms are ubiquitious in nature. These small living variables occur almost everywhere including extreme environmental conditions and exhibits their metabolic activities in aerobic and anaerobic enivornmet as well. Though the microorganisms are very divert in their morphological, biochemical, genetical and physiological characteristics, there are certain inherent and unique properties which make tehm of peculiar interest. Considering these properties, microoraganisms can be used in the agriculture as well as in industries for production. The aims and objectives of the present series is to disseminate the best available information abut the genetical, biochemical, immunological and agriculture related properties of the microorganisms and their possible exploitation in the production of food, vaccines, fermented product, antibiotics, disease resistance crops andother similar areas in the msot efficient and economic manner.