비병원성 Erwinia carotovora subsp. carotovora 9-3의 건조 및 저장의 과정에서 생존에 미치는 염 효과

Dry formulation is a limiting step for successful development of microbial bio-pesticides with the antagonistic Gram-negative bactetia because their survival rates are too low during drying and storage. The high concentration of sodium chloride (NaCl) in culture medium that induces osmolyte in bacterial cells is known to increase of survival rate during drying in many Gram-negative bacteria. Effect of NaCl on survival of antagonistic non-pathogenic Envinia carotovora subsp. carotovora 9-3 (Ecc 9-3) during drying and storage was studied. Growth rate of Ecc 9-3 was not much different up to 0.5 M NaCl in NB while it was lower significantly with 0.7 M NaCl. Survival rates were twice and 3 times higher with 0.5 M NaCl than with no additional NaCl during drying at room temperature and freeze-drying, respectively. Survival rate was also higher with high NaCl in culture medium during storage after drying. It was not much different on storage at 4℃ both of drying at room temperature and freeze-drying. However, the survival rate was higher on storage at 27℃ and 37℃ with high NaCl concentration. Among the additives tested, lactose affects most to survival rate both of drying at room temperature and freeze-drying, and dextrin influenced significantly to survival rate of dtying at room temperature.