外源添加氨基酸对兽疫链球菌产透明质酸的影响  

Effect of addition of amino acids on production of hyaluronic acid by Streptococcus zooepidemicus

作　　者：朱丽雅 吴善善 欧阳水平 唐硕[1] 李鑫[1] ZHU Liya;WU Shanshan;OUYANG Shuiping;TANG Shuo;LI Xin(College of Chemical Engineering, Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]南京林业大学化学工程学院,南京210037

出　　处：《林业工程学报》2019年第3期74-79,共6页Journal of Forestry Engineering

基　　金：江苏高校优势学科建设工程资助项目(PAPD);青海省重点研发与转化计划项目(2016-HZ-819)

摘　　要：兽疫链球菌(Streptococcus zooepidemicus)是一种营养缺陷型菌株,其生长代谢需要外源添加各类营养因子。通过在兽疫链球菌发酵对数生长初期外源添加氨基酸的方式研究其对透明质酸生产的影响。结果表明,外源添加氨基酸对透明质酸的生产具有显著的促进作用。笔者初步研究了当添加质量浓度为0.5 g/L时,18种常见氨基酸对透明质酸产量的影响。在此基础上,在18种氨基酸中选取苯丙氨酸和丝氨酸对透明质酸合成进行浓度优化实验,结合细胞生长和代谢产物分析,更进一步研究氨基酸对透明质酸合成的影响。结果表明,苯丙氨酸和丝氨酸添加质量浓度分别为0.5 g/L和0.5 g/L时,透明质酸产量提高最大,与对照相比分别提高了18.05%和17.44%,菌体浓度均没有增加,但是乳酸浓度分别降低了9.93%和15.80%,说明氨基酸的添加不是通过增加菌体量来提高透明质酸产量,而是改变了碳源流向,减少了乳酸积累,使得透明质酸产量显著提高。本研究为高产透明质酸的发酵工艺提供了借鉴与依据。Streptococcus zooepidemicus is an auxotrophic strain, which requires the exogenous addition of various nutrient factorsduring their growth and metabolism. In this study, the effect of exogenous amino acid addition in the early stage of the logarithmic growth of Streptococcus zooepidemicus on the production of hyaluronic acid was investigated. The results showed that the exogenously added amino acids had a significant effect on the production of hyaluronic acid. The authors initially explored the effect of 18 common amino acids on the production of hyaluronic acid when the mass concentration was 0.5 g/L.Studies found that the exogenous addition of phenylalanine and serine had a strong promoting effect on HA synthesis, while the exogenous addition of threonine and tyrosine had a certain inhibitory effect on HA synthesis. On this basis, phenylalanine and serine were selected from 18 amino acids for concentration optimization experiments of hyaluronic acid synthesis. Lactic acid was the main by-product of hyaluronic acid synthesis. Hyaluronic acid was the main component of bacterial capsules. Therefore, combined with cell growth and lactic acid metabolism analysis, the effect of amino acids on hyaluronic acid synthesis was further investigated. The results showed that, when the mass concentrations of phenylalanine and serine were 0.5 g/L and 0.5 g/L, respectively, the production of hyaluronic acid was increased by 18.05% and 17.44%, respectively, compared with the control. At this case, the concentration of the bacteria did not increase, but the concentration of lactic acid decreased by 9.93% and 15.80%, respectively, indicating that the addition of amino acids did not increase the yield of hyaluronic acid by increasing the bacteria, but changed the flow of carbon sources and reduced the accumulation of lactic acid. The carbon source flowed to the direction of hyaluronic acid synthesis, thereby increasing its yield. At the same time, it was found that the addition of amino acid did not change the consumption rate of

关 键 词：透明质酸 兽疫链球菌 发酵 氨基酸 外源添加 

分 类 号：Q815[生物学—生物工程]