Abstract: After using a simple but efficient mini-bioreactor (2L) we equipped to study the effects of carbon source, nitrogensource and initial pH of fermentation broth on the production of microbial transglutaminase (MTG) by a new potent strain,Streptomyces sp. WZFF.L-M168 isolated from soil and preserved in our laboratories. The incubation conditions were established.The production was scaled up to 20 L and 200 L jar-fermenters through the utilization of on-line control techniques, and then thetechniques for batch fermentation of MTG were set up. The experimental results showed that the optimal processing param-eters achieved were 1.5% glucose and 1.0% soluble starch for the carbon source, 2.0% multi-peptone for the nitrogen source,initial pH 7.0, inoculum ratios of 5%-10%, that the following conditions were suitable during the MTG production with on-linecontrolled supervision: temperature 30℃±0.5℃, pH 6.6～6.9, aeration rate 0.8～1.1 vvm and agitation speed 300～400r/min.Under these conditions, the L-M168 strain could stably produce MTG higher than 2.75U/ml.

Key words: transglutaminase, Streptomyces sp., batch fermentation, on-line control #, the corresponding author