基于NRPS功能基因筛选鉴定盐生海芦笋内生细菌的研究
Isolation and identification of endophytic bacteria based on NRPS functional gene from Salicornia bigelovii.Torr
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摘要: 本研究从盐生海芦笋中分离得到两株具有抑菌活性的内生细菌YK-7、YK-10,利用形态学观察、分子生物学方法与生理生化实验对其进行鉴定,并对其发酵产物进行了预测与验证。结果表明两株菌株分别为解淀粉芽胞杆菌亚种(Bacillus amyloliquefaciens subsp.Plantarum)以及阿氏芽孢杆菌(Bacillus aryabhattai)。通过PCR扩增非核糖体多肽合成酶(NRPS)基因,发现菌株YK-7含有NRPS基因片段,经系统发育树分析,预测该菌株可能产生环脂肽类化合物Surfactin,进一步对该菌株发酵产物进行电喷雾质谱(Electrospray mass,ESI-MS)分析证实了预测结果。该研究结果证实了从基因预测化合物的结构类型对于定向筛选有价值的化合物具有重要意义。Abstract: In this study,two endophytic bacteria coded YK-7 and YK-10 with significant antimicrobial activities,were isolated from halophyte Salicornia bigelovii.Torr,and identified their genera status by morphological characters and molecular biology method coupled with the physiological and biochemical experiments,as well as predicted and verified their fermentation products.The results showed that the two strains were characterized as Bacillus amyloliquefaciens subsp.Plantarum and Bacillus aryabhattai,respectively.The strain YK-7 was found to contain the non-ribosomal peptide compounds synthetase( NRPS) gene fragment after the PCR amplification of NRPS gene.YK-7 had the capability to of produce cyclic-lipopeptide Surfactin by the analysis of NRPS phylogenetic tree. The result was further confirmed by the detection of its fermentation product using an electrospray ionization mass spectrometry( ESI-MS) analysis.This study highlights the advantage of phylogeny-guided pipeline for the screening of bioactive compound from gene type to chemical type by a predication procedure.