OPTIMIZATION OF MICROBIAL TRANSGLUTAMINASE PRODUCTION USING EXPERIMENTAL-DESIGNS

In prokaryotes, transglutaminase (TGase) has been found only in actino mycetes from the genus Streptoverticillium. The role of this TGase, as well as the mechanism regulating the enzyme expression, are still unk nown. In order to improve TGase production by Streptoverticillium cinn amoneum CBS 683.68 and simultaneously elucidate the relationship betwe en growth and TGase activity, we decided to study these two responses using different designs of statistical analysis. Among the five factor s tested? casein, glycerol, peptones, yeast extract and oligoelements, only oligoelements were found to have no effect either on growth or o n TGase production in a complete factorial design. The two factors cas ein and glycerol were found to have a highly significant effect on bot h dry weights and TGase activity in a Box-Behnken design used to impro ve the model. Finally, the TGase activity was increased three times to reach 0.331 +/- 0.038 U/ml with optimum concentrations of casein (38. 4 g/l) and glycerol (31.2 g/l) calculated with the help of a composite design. In the course of these experiments, the two responses varied in the same way, demonstrating that growth and TGase production were t ightly correlated under the conditions described. However, TGase was p roduced during the stationary phase of growth in optimized medium, ind icating that the enzyme production could be induced.