摘要
L-氨基酸氧化酶可以催化L-氨基酸生成酮酸等化学品,具有重要的应用前景。本研究成功将来源于红球菌(Rhodococcus opacus)的氨基酸氧化酶在大肠杆菌中表达,并首次用于生物催化合成5-氨基戊酸。结果表明:L-氨基酸氧化酶诱导表达最适温度为25℃,最适诱导剂浓度0.5 mmol/L,最适诱导时间为7 h,诱导时最佳细胞量为0.246 g/L。催化合成5-氨基戊酸时,最适底物L-赖氨酸(Lys)浓度17 mmol/L,最适p H为7.0,最适温度为37℃,最适时间为24 h,最适补加0.5%H_2O_2,添加酶与黄素腺嘌呤二核苷酸(FAD)的最适摩尔比为1∶1,最终5-氨基戊酸产量达到16.71 mmol/L。本研究成功的实现了单酶(LAAO)合成5-氨基戊酸,为简便生物合成5-氨基戊酸奠定基础。
L-amino acid oxidase,which catalyze the biosynthesis of keto acid and other chemicals from L-amino acid,is applied in many fields of industry.The LAAO from Rhodococcus opacus was cloned and heterologous expressed in Escherichia coli, followed the investigation of induced conditions and biosynthesis of 5-aminovaleric acid.The results showed that the optimum induction temperature of L-amino acid oxidase was 25 ℃,The optimal concentration of inducing agent, induction time, the cell mass were 0.5 mmol/L, 7 h, 0.246 g/L, respectively. Meanwhile,biocatalytic conditions were optimized to improve the production of 5-aminovaleric acid.The optimal substrate molar concentration of biosynthesis of 5-aminovaleric acid was 17 mmol/L,furthermore,the optimal pH, temperature,time,supplemented with H202,addition of the enzyme and FAD molar ratio were 7.0,37 ℃,24 h, 0.5%, 1：1, respectively.As a result, a 5-aminovaleric acid concentration of 16.71 mmol/L was achieved.This study successfully realized the single enzyme （LAAO） synthesis of 5- aminovaleric acid, to lay the foundation for the simple biosynthesis of 5-aminovaleric acid.
出处
《食品工业科技》
CAS
CSCD
北大核心
2016年第7期153-158,共6页
Science and Technology of Food Industry
基金
江苏省产学研联合创新资金(BY2014005)
863计划"2014AA021703"
国家自然科学基金(31440024)
