枯草芽孢杆菌fmb60菌株非核糖体肽类化合物对铜绿微囊藻生长的抑制作用

Inhibition of Microcystis aeruginosa by Bacillus subtilis fmb60 non-ribosome peptide metabolites

摘要:

铜绿微囊藻是一种分布广泛的水华微藻，可对人类健康和生态环境造成严重危害，而枯草芽孢杆菌作为一种生防微生物可通过非核糖体肽合成酶合成多种生物活性物质。因此，枯草芽孢杆菌fmb60 非核糖体肽 (Non-ribosomal peptide，NRP) 类产物对铜绿微囊藻生长抑制作用的研究在水华治理方面具有重要的意义。利用基因组挖掘技术从枯草芽孢杆菌fmb60中分离鉴定出bacillibactin、表面活性素(Surfactin) 和芬芥素 (Fengycin) 3种NRP类产物，进而通过添加不同浓度的NRP类产物研究其对铜绿微囊藻生长的影响，结果显示其对铜绿微囊藻4 d的半效应浓度值EC50.4 d为26.5 mg/L，且随着样品浓度的增加，枯草芽孢杆菌fmb60的NRP类产物对铜绿微囊藻的抑制作用增强。当向其分别加入50 mg/L的样品时，培养4 d的铜绿微囊藻Fv/Fm、Fv/Fo、Yield参数分别比对照组降低了2.8%、1.7%、2.0%。表明枯草芽孢杆菌fmb60 NRP类产物能够显著抑制铜绿微囊藻的光合作用强度及代谢合成，从而为枯草芽孢杆菌抑藻剂的开发奠定理论基础。

Abstract:

Microcystis aeruginosa, a type of algal bloom microalgae, is widely distributed in water, causing serious deteriorated effects on humans and the ecological environment. As a biocontrol microorganism, Bacillus subtilis can synthesize various bioactive substances through non-ribosomal peptide synthetase, to inhibit the growth of M. aeruginosa. Thus, it is imperative to investigate the non-ribosomal peptide (NRP) metabolites of B. subtilis fmb60. Three NRP metabolites from B. subtilis fmb60 including bacillibactin, surfactin and fengycin were extracted and identified by genome mining technology. The growth inhibition of M. aeruginosa was studied by adding various concentrations of NRP metabolites. The half-effect concentration value (EC50.4 d) of M. aeruginosa was 26.5 mg/L after incubation for 4 days. With the increasing concentration, the inhibitory effects of NRP metabolites of B. subtilis fmb60 on M. aeruginosa was enhanced significantly. Compared with the control group, with the addition of 50 mg/L NRP metabolites to the M. aeruginosa, the content of Fv/Fm, Fv/Fo and Yield parameter after cultured for 4 days were decreased by 2.8%, 1.7% and 2.0%, respectively. Those findings indicate that the NRP metabolites of B. subtilis fmb60 can significantly inhibit the photosynthesis and metabolism of M. aeruginosa, which provides a theoretical foundation for the development of biological algae inhibitor of B. subtilis.