Evaluation of protective effect of animal-free freeze-drying protective agent on Streptococcus pneumoniae during freeze-drying
10.13200/j.cnki.cjb.004378
- VernacularTitle:肺炎球菌无动物源性冻干保护剂对肺炎球菌冷冻干燥过程中的保护作用评价
- Author:
WANG Yanyan
- Publication Type:Journal Article
- Keywords:
Streptococcus pneumoniae(Spn);
Animal-free materials;
YTG freeze-drying protective agent;
Acceleration stability;
Production applicability
- From:
Chinese Journal of Biologicals
2024;37(12):1415-1420+1427
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the protective effect of YTG, an animal-free freeze-drying protective agent for pneumococcal strains, on Streptococcus pneumoniae(Spn) during freeze-drying.Methods First, the freeze-drying procedure was determined by analyzing the eutectic point and plait point of YTG freeze-drying protective agent, then the protective effect of YTG freeze-drying protective agent on pneumococcus during freeze-drying and preservation was preliminarily determined by freeze-drying survival rate and accelerated stability test of the strains. Furthermore, the effect on the characteristics of strain and polysaccharide antigen gene sequence was judged by strain verification and capsular polysaccharide antigen gene sequence analysis. Finally, the freeze-dried strains with YTG freeze-drying protective agent were used for fermentation culture according to the production procedure, and the culture situation, the yield and quality of capsular polysaccharide antigen were analyzed to determine the production applicability of YTG freeze-drying protective agent.Results The survival rate of freeze-drying was 50%-90%, and the number of viable bacteria tended to 1. 2 × 10~9CFU/branch in the accelerated stability test. There was no difference in strain appearance and antigen gene sequence compared with the control(sheep blood freeze-dried strain). After the fermentation of the freeze-dried strain with YTG, the growth of bacteria and the yield of capsular polysaccharide increased slightly, and the related verification indexes of capsular polysaccharide were in line with the standards of Chinese Pharmacopoeia(Volume Ⅲ, 2020 edition).Conclusion YTG freeze-drying protective agent has good applicability and can be used for freeze-drying protection of pneumococcus.
