天冬氨酸族氨基酸对沼泽红假单胞菌J001辅酶Q_(10)合成的影响(英文)

目的]探讨天冬氨酸族氨基酸对沼泽红假单胞菌J001辅酶Q10合成的影响。方法]通过在对数生长末期添加天冬氨酸族氨基酸来考察了其对沼泽红假单胞菌辅酶Q10合成的影响,以期为微生物发酵法获得大批量天然辅酶Q10的培养基优化和菌种的遗传改造提供依据。结果]蛋氨酸的添加量与辅酶Q10合成呈正相关,蛋氨酸添加量达125mg/L时,辅酶Q10产量达最大值23.8mg/L,比对照提高20.2%;添加低浓度的赖氨酸、苏氨酸、异亮氨酸对辅酶Q10的合成没有影响,但高浓度(赖氨酸浓度达500mg/L以上、苏氨酸400mg/L以上、异亮氨酸400mg/L以上)时,辅酶Q10的合成受到抑制,说明该菌株天冬氨酸激酶受到赖氨酸、苏氨酸以及异亮氨酸的反馈抑制或阻遏而不利于蛋氨酸的合成,进而减少辅酶Q10的产量。结论]可通过菌种遗传改造获得抗赖氨酸、苏氨酸以及异亮氨酸结构类似物的反馈调节型和赖氨酸、苏氨酸以及异亮氨酸营养缺陷型突变体来提高辅酶Q10的产量。

Effects of the Amino Acids of Aspartate Family on the Biosynthesis of CoQ_(10) in Rhodopseudomonas palustris J001

Objective]The study aimed to investigate the effects of the amino acids of aspartate family on the biosynthesis of CoQ10 in Rhodpseudomonas palustris J001.Method]The impacts of amino acids of this family on the biosynthesis of CoQ10 in Rhodopseudomnas palustris J001 were investigated by feeding these amino acids at the end of the logarithmic phase during incubation,which aim was for the optimization of the fermentation medium and genetic improvement of the strain for CoQ10 production.Result]The results showed that feeding proper amount of methione(125 mg/L)could increase CoQ10 production by 20.2%,but feeding of lysine(above 500 mg/L),threonine(above 400 mg/L)and/or isoleucine(above 400 mg/L)repressed the biosynthesis of CoQ10.The results indicated that the aspartate kinase is subject to feedback inhibition or repression by lysine,threonine and isoleucine in the strain,which was unfavorable to the formation of methioine and then caused the decrease of CoQ10 production.Conclusion]Lysine,threonine and isoleucine auxotrophic mutants with resistance to analogues of lysine,threonine and isoleucine could increase the production of CoQ10.