微生物多糖结冷胶的发酵过程优化

利用玉米浆和尿素作为廉价氮源进行结冷胶的发酵生产,通过对发酵过程中的初糖浓度、通气量和搅拌转速进行优化,获得具有生产成本优势的新工艺。结果表明:结冷胶发酵的最佳初糖浓度和通气量分别为40g/L和1 vvm;最佳的搅拌转速控制策略为延滞期(0～12 h)400 r/min,对数期(12～32 h)800 r/min,稳定期(32～40 h)400 r/min。在上述条件下,结冷胶产量、黏均分子量和发酵液表观黏度分别为16.7 g/L、625.8 kDa和7495 cP。

Optimization of fermentation process of microbial polysaccharide-gellan gum

Gellan gum,a kind of microbial polysaccharide with great property of forming gel,can be widely used in food,pharmaceutical and other industries.However,the high cost limits its widespread applications.In this study,corn steep liquor and urea were used as cheap nitrogen sources for the fermentation of gellan gum,and initial glucose concentration,aeration and agitation were optimized to develop a new process with cost advantage.The results showed that the optimal initial glucose concentration and aeration for gellan gum fermentation were 40 g/L and 1vvm,and the optimal agitation control strategy was 400 r/min for lag phase(0-12 h),800 r/min for exponential phase(12-32 h),and 400 r/min for stationary phase(32-40 h).Under these conditions,the yield,weight-average and viscosity of gellan gum were 16.7 g/L,625.8 kDa and 7.495 Pa·s,respectively.