优化有机氮源提高小白链霉菌发酵生产ε-聚赖氨酸效率  

Improvement ofε-poly-L-lysine yield through organic nitrogen optimization by Streptomyces albulus

作　　者：刘宇翔 柳天一 邓玥 王靓[1,2] 张宏建 张建华[1,2] 陈旭升 LIU Yuxiang;LIU Tianyi;DENG Yue;WANG Liang;ZHANG Hongjian;ZHANG Jianhua;CHEN Xusheng(School of Biotechnology,Jiangnan University,Wuxi 214122,China;The Key Laboratory of Industrial Biotechnology,Ministry of Education,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学生物工程学院,江苏无锡214122 [2]工业生物技术教育部重点实验室(江南大学),江苏无锡214122

出　　处：《食品与发酵工业》2022年第13期1-8,共8页Food and Fermentation Industries

基　　金：国家重点研发计划项目(2020YFA0907700);江苏省自然科学基金项目(BK20191332,BK20190585);国家自然科学基金项目(31901622,31671846)。

摘　　要：ε-聚赖氨酸(ε-poly-L-lysine,ε-PL)是小白链霉菌(Streptomyces albulus)分泌产生的一种同型氨基酸聚合物,具有广泛的抑菌活性,目前被多个国家批准使用,是一种优良天然食品防腐剂。为了进一步提高S. albulus GS114的ε-PL发酵产量,对其发酵培养基中有机氮源的种类及浓度进行了系统优化,并对ε-PL产量提高的原因从氨基酸方面进行了初步解析。研究结果显示,S. albulus GS114的最佳有机氮源为酵母浸粉FM760,最佳添加质量浓度为9.27 g/L,在此条件下,摇瓶自然发酵中ε-PL产量达到(2.60±0.02) g/L,较对照有机氮源提高了22.07%;在pH受控的分批发酵中,ε-PL产量达到(6.41±0.23) g/L,较对照提高42.64%;在补料分批发酵中,ε-PL产量达到62.38 g/L,较对照提高了18.80%,葡萄糖转化率提高了25.77%。同时,通过氨基酸添加实验,初步发现酵母浸粉FM760提高ε-PL产量可能与异亮氨酸、亮氨酸和丙氨酸有关。该研究结果对工业发酵生产ε-PL的有机氮源选择具有重要指导意义。ε-poly-L-lysine(ε-PL)is a homopoly(amino acids)produced by Streptomyces albulus,which is currently approved as an excellent natural food preservative in many countries due to its broad antibacterial activity.To improve theε-PL production by S.albulus GS114,twelve commonly used organic nitrogen types and their concentrations were compared and systematically optimized in shake flask,batch and fed-batch fermentation,respectively.The yeast extract FM760,with the addition concentration of 9.27 g/L,was considered as the optimal organic nitrogen forε-PL production.Subsequently,the amino acid composition of FM760 was analyzed and compared with the control to explain the reason for the enhancedε-PL production.The result showed that in shake flask fermentation,the usage of fast-acting organic nitrogen source was more favorable for the biosynthesis ofε-PL.Considering together theε-PL production andε-PL biosynthesis capacity per unit biomass,the organic nitrogen sources FP103,FM760 and FM408 were all better than the control FM902.The highestε-PL production reached(2.60±0.02)g/L by FM760,which was 22.07%higher than that of the control organic nitrogen.In a pH-controlled batch fermentation,theε-PL production,dry weight,yield,glucose conversion rate andε-PL synthesis capacity per unit biomass were compared in a pH-controlled batch fermentation,and FM760 is also turned out to be the best organic nitrogen source forε-PL production in S.albulus GS114 fermentation.Theε-PL production reaching(6.41±0.23)g/L,42.64%higher than that of the control organic nitrogen.In fed-batch fermentation,we optimized the addition concentration of FM760,and determined the optimal addition concentration forε-PL synthesis was 9.27 g/L.Under this condition,theε-PL production and glucose conversion rate reached 62.38 g/L and 9.76%respectively,which was 18.80%and 25.77%higher than those of the control.The above results demonstrated that choosing 9.27 g/L FM760 as the organic nitrogen source not only obtained more than 60 g/L ofε-PL product

关 键 词：Ε-聚赖氨酸 食品防腐剂 有机氮源 氨基酸 链霉菌 

分 类 号：TS202.3[轻工技术与工程—食品科学]