通过阻断调控基因ygrA挖掘海洋链霉菌OUC6819中抗MDR菌活性次级代谢产物  

Mining anti-MDR bacteria compounds from mangrove-derived Streptomyces sp.OUC6819 by inactivation of a regulatory gene ygrA

作　　者：刘晶 李通[1] 刘增智 姚婷婷[1] 夏娟[1] 李花月 车茜[1] 李德海[1] 李静[2] 李文利[1] LIU Jing;LI Tong;LIU Zeng-zhi;YAO Ting-ting;XIA Juan;LI Jing;LI Wen-li;Hua-yue;CHE Qian(Key Laboratory of Marine Drugs, Ministry Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China;College of Marine Life, Ocean University of China, Qingdao 266003, China)

机构地区：[1]中国海洋大学海洋药物教育部重点实验室医药学院,山东青岛266003 [2]中国海洋大学海洋生命学院,山东青岛266003

出　　处：《中国海洋药物》2017年第5期16-22,共7页Chinese Journal of Marine Drugs

基　　金：国家自然科学基金项目(31070072;31570032)资助

摘　　要：目的激活南海红树林来源链霉菌Streptomyces sp.OUC6819菌株中不表达或表达量低的隐性生物合成基因簇,挖掘具有优良多重耐药菌(MDR)抗菌活性的次级代谢产物。方法通过生物信息学分析推测Streptomyces sp.OUC6819基因组中可能的GntR家族调控子,采用PCR-targeting策略敲除其中的ygrA基因,HPLC分析突变株和野生株的发酵产物的差异,并比较粗提物对5株MDR菌抑制活性。结果 HPLC分析结果表明与野生株相比,突变株中化合物1和化合物2产量分别提高了9倍和7倍;突变株发酵液粗提物对其中3株MDR菌抑制活性较野生株明显提高。结论通过阻断GntR家族调控子ygrA激活了Streptomyces sp.OUC6819菌株中具有抗MDR菌活性次级代谢产物合成基因簇的表达,为从中发掘新的抗MDR菌抗生素奠定了必要基础;同时,将为其他海洋链霉菌中隐性基因簇的激活提供重要参考。Objective To activate cryptic biosynthetic gene clusters in mangrove-derived Streptomyces sp.OUC6819,and thus to discover anti-MDR（multi-drug resistant）bacteria secondary metabolites.Methods Genome scanning of Streptomyces sp.OUC6819 disclosed many GntR family regulators,among which ygrAgene was knocked out by using PCR-targeting strategy.The resulting fermentation broths were analyzed by HPLC.In addition,the crude extracts were subjected to bioassay against five MDRB strains.Results HPLC analysis suggested that the yields of compound 1 and 2 were increased by about 9-and 7-fold,respectively,in theΔygrA strain compared to the wild-type strain.The crude extract from the mutant strain exhibited much stronger inhibition activities against three MDRB strains.Conclusion By inactivating the GntR family regulatory gene ygrA,the biosynthetic gene cluster（s）encoding anti-MDRB compounds was（were）activated,thereby laying the foundation for discovery of new anti-MDRB antibiotics.Moreover,our study provided important reference for activation of cryptic gene clusters in other marine-derived Streptomyces stain.

关 键 词：STREPTOMYCES sp.OUC6819 PCR-targeting GntR家族调控基因 多重耐药菌 

分 类 号：R931[医药卫生—生药学]