基于NRPSs基因筛选与鉴定海芦笋内生细菌

摘要

利用形态学观察和分子生物学相结合的方法分离鉴定海芦笋内生细菌,并筛选含有NRPS基因的菌株(nonribosomal peptide synthetase,NRPS),以期获得能够产生环肽化合物的菌株.研究结果表明,共从海芦笋中分离到6株内生细菌Srtli-F1 ～ Srtli-F6,分别鉴定为绿针假单胞菌橙黄亚种(Pseudomonas chlororaphis subsp.aurantiaca)、组氨酸节杆菌(Arthrobacter histidinolovorans)、庆盛芽孢杆菌(Bacillus qingshengii)、类芽孢杆菌羽扇豆根瘤菌(Paenibacillus lupini)、假蕈状芽孢杆菌(Bacillus pseudomycoides)、高山麝病原性阿尔伯蒂埃希氏杆菌(Escherichia albertii),其中菌株Srtli-F5检测到含有NRPS基因,经系统发育树分析,预测该菌株可能产生环肽类化合物,该株菌经过发酵,有机溶剂萃取发酵产物,并用电喷雾质谱ESI-MS (electrospray mass,ESI-MS)分析Srtli-F5能产生环肽化合物——杆菌肽,证实了该预测结果.该研究为定向筛选能够产生环肽类化合物的菌种开拓了新思路.%In the current research,endophytic bacteria were isolated from Salicornia bigelovii.Torr and characterized by morphological observation and molecular methods,and the NRPS gene was screened to obtain the strains that could produce cyclic peptide compounds.The results showed that six endophytic bacteria were isolated and identified as Pseudomonas chlororaphis subsp.Aurantiaca,Arthrobacter histidinolovorans,Bacillus qingshengii,Paenibacillus lupini,Bacillus pseudomycoides,Escherichia albertii,respectively.Among them,the strain Srtli-F5 contained NRPS genes and was predicted to have capability of producing cyclopeptide compounds by phylogenetic tree analysis.It was further confirmed by the detection of fermentation production using ESI-MS (electrospray mass,ESI-MS) that the strain really produced bacitracin.The study provides a new method for directional screening strains with the potential to produce cyclic peptide compounds.