pH is one of the most important environmental factors for cell growth and product formation. Batch microbial transglutaminase (MTG) fermentation by Streptoverticillium mobaraense WSH-Z2 at various pH values ranging from 5.0 to 8.5 was studied. A pH-shift strategy was developed to maximize MTG production in batch MTG fermentation. Based on time courses of the specific cell growth rate and specific MTG formation rate, a two-stage pH-shift strategy in which pH 7.0 was controlled at first 13 h, and then switched to 6.5 after 13 h was developed. By applying this pH-shift strategy in MTG fermentation, the maximal MTG activity and productivity had a significant improvement and reached 3.40u/ml and 81.4u/l/h, respectively, compared to those of constant pH operation (2.90u/ml and 61.4u/l/h).