潜在植物根际促生菌副地衣芽孢杆菌HMPM220325生物膜培养条件优化

Optimization of culture conditions for biofilm formation of the potential plant growth-promoting rhizobacterial strain Bacillus paralicheniformis HMPM220325

摘要:

副地衣芽孢杆菌(Bacillus paralicheniformis)是一种革兰氏阳性、兼性厌氧、运动杆状的内生孢子形成细菌，其可作为潜在植物根际促生菌使用。本研究团队从水果发酵乳中分离出一株副地衣芽孢杆菌HMPM220325，该菌株在静置培养过程中可在气-液界面形成生物膜。【目的】 探究不同环境因子对副地衣芽孢杆菌HMPM220325生物膜生物量的影响，为后期将其作为植物根际促生菌剂的开发利用提供数据支撑。【方法】 采用结晶紫染色法定量检测不同环境因素和营养物质对副地衣芽孢杆菌生物膜形成的影响，并结合正交试验优化副地衣芽孢杆菌生物膜形成的最佳条件。【结果】 副地衣芽孢杆菌生物膜形成的最佳环境条件是温度50 ℃、pH值9.0、培养36 h；最适培养基组成为麦芽糖15.0 g/L、尿素10.0 g/L、硫酸镁20.0 mmol/L、磷酸氢二钠2.5 g/L、牛心浸粉17.5 g/L。优化后的培养条件使得生物膜产量相较原培养条件提高约58.28%。【结论】 本研究对副地衣芽孢杆菌在多种环境中的生物膜形成能力进行了深入探讨，并优化出该菌株生物膜培养的最佳条件，为其进一步作为植物根际促生菌剂的开发提供实验基础。

Abstract:

Bacillus paralicheniformis, a Gram-positive, facultative anaerobic, motile rod-shaped endospore-forming bacterium, can be used as a species of potential plant growth-promoting rhizobacteria (PGPR). In this study, B. paralicheniformis HMPM220325 was isolated from the fruit fermented milk. This strain can form biofilms at the gas-liquid interface during static cultivation. [Objective] To study the effects of different environmental factors on the biofilm biomass of B. paralicheniformis HMPM220325 and provide data support for the later development and application of HMPM220325 as a PGPR strain. [Methods] effects of different environmental factors and nutrients on the biofilm formation of B. paralicheniformis HMPM220325 were quantitatively detected by crystal violet staining, and the optimal conditions for the biofilm formation of the strain were optimized by orthogonal experiments. [Results] The optimal environmental conditions for the biofilm formation of B. paralicheniformis HMPM220325 were incubation at 50 ℃ and pH 9.0 for 36 h. The optimal medium was composed of maltose 15.0 g/L, urea 10.0 g/L, magnesium sulphate 20.0 mmol/L, disodium hydrogen phosphate 2.5 g/L, and bovine heart infusion 17.5 g/L. The optimized culture conditions increased the biofilm biomass by 58.28% compared with the original culture conditions. [Conclusion] This study explored the biofilm formation of B. paralicheniformis in a variety of environments and optimized the culture conditions for biofilm formation of this strain, providing an experimental basis for further development of PGPR.