Improvement of MTG Production by Fed-batch Fermentation

• 1、The Key Laboratory of Industrial Biotechnology, Ministry of Education of Jiangnan University
• 2、School of Food Science and Technology of Jiangnan University

Abstract：This paper provides the fed-batch fermentation of Streptomyces hygroscopicus. In Streptomyces, MTG (Microbial Transglutaminase) is secreted and activated during the emergence of aerial hyphae rather than during the vegetative growth. The secretion and activation process were stopped when spores were formed. To obtain high cell density and high yield of MTG by Streptomyces hygroscopicus, the effects of exponential feeding of glucose and the addition of nitrogen source on MTG production were investigated. The results showed that keeping a high specific growth rate (0.15 h-1) in 8-16 h and a relative low specific growth rate (0.10 h-1) during later time could obtain high-cell density, the DCW could reach 36 g/L which was increased by 80% compared to that in batch fermentation mode. The MTG activity reached 5.79 U/mL by adding 50 g/L soybean meal in the initial medium, and was increased by 83%.

Keywords： Streptomyces hygroscopicus high-cell-density culture MTG exponential feeding nitrogen source