Screening and optimization of the freeze-dried protectants for the lyophilized Vibrio-qinghaiensis of direct vat set

In order to obtain the best protectants for Vibrioqinghaiensis sp.-Q67 of direct vat set, the freeze-dried protectants was firstly screened by single factor and then optimized by response surface analysis.The study indicated that in many substances the skim milk, saccharose, soluble starch and sodium glutamate have outstanding protective effect.In response to the relative light unit (RLU) of the lyophilized Vibrioqinghaiensis sp.-Q67 after the regeneration for 30min, when taken skim milk 7.68%, sucrose 2%, soluble starch 0.25%, sodium glutamate 1% as the combined optimal formula, the relative light unit (RLU) could reach 1382.87%;when the volume of protectants was equal to the strain and the response time was 30min, the relative light unit (RLU) could achieve 1356%.