Cell growth and production were compared at 24 h in the cultures of engineered cells in medium with or without VM-A or NaCl because cell concentration reached maximum at this time in most culture media. Comparison was also made at 42 h to check possible degradation of trehalose because trehalase activity in this culture reached the highest at the stationary phase as mentioned above. In cultures with control medium, cell concentration was maximized (OD600 of 4.3) at 24 h and TLC revealed a weak trehalose spot at 24 h but not at 42 h