Methionine is a dietary essential amino acid secreted by various microorganisms and can be supplemented in food and feed for enhancing the growth and body functions of the mammals. Methionine is frequently a limiting factor in utilization of dietary proteins and according to FAO nutritional report, 22g of methionine should be present in per kg of dietary protein for the successful synthesis of tissue proteins. The primary protein aminoacids like methionine are all manufactured on an industrial scale by three main processes: extraction from protein hydrolysates, fermentation processes and chemical synthesis. Chemical synthesis and extraction from protein hydrolysates for methionine production are either expensive or undesirable. Hence production of methionine through microorganisms for various applications gain importance. The book focus on the isolation and screening of efficient methionine producing microorganisms and optimization of their growth conditions to enhance the amino acid production.