细菌叶绿素a高产菌株的选育和发酵工艺优化

The breeding and fermentation optimization of high-yield strains for producing bacteriochlorophyll a

目的结合各种诱变手段,获得细菌叶绿素a(bacteriochlorophyll a,Bchla)的高产菌株,并优化其发酵工艺,提高产量。方法以球红假单胞菌ATCC17023为出发菌株,通过紫外、ARTP(常压室温等离子体)及亚硝基胍单独诱变或组合诱变,结合含氯化胆碱的抗性平板进行筛选。调整发酵培养基中碳氮源组分和比例,优化种龄、接种量、发酵pH、摇瓶装量、转速及温度等发酵培养条件。结果通过多轮筛选,得到突变高产菌株,其发酵单位达到285.7μg/mL,为原始出发菌株的114倍。采用优化后的发酵工艺,经50L发酵罐放大培养,最高效价单位达到296.6μg/mL。结论获得Bchla的高产菌株和摇瓶发酵工艺,并经50L发酵罐放大验证,为大规模商业化生产奠定了良好的基础。

Objective To obtain high-yield strains of bacteriochlorophyll a(Bchla)using various kinds of mutation methods.To achieve higher productivity by optimizing the fermentation technology.Methods The strain Rhodopseudomonas sphaeroides ATCC17023 was used as the original strain.After being mutated by a means of single or combination of UV,atmospheric and room temperature plasma(ARTP),and NTG,strains were screened in choline chloride tolerance plates.Then applicable carbon and nitrogen sources were selected,and the concentrations of which were adjusted for fermentation media,the fermentation conditions(i.e.seed age,inoculation quantity,media pH,bottle loading volume,rotation speed,and incubation temperature)were further optimized to improve productivity.Results The high-yield mutant strains were obtained after several rounds of breeding.The fermentation potency reached 285.7μg/mL.The productivity was 114 times improved compared with the original strain ATCC17023.After optimizing the fermentation technology,the potency reached 296.6μg/mL with running in 50 L fermenter.Conclusion High-yield strains were obtained and fermentation process was optimized,which were verified in 50 L fermenter and laid a good foundation for industry production of bacteriochlorophyll a.