铜绿假单胞菌发酵条件优化及抗菌物质研究

铜绿假单胞菌(Pseudomonas aeruginosa)及其代谢产物对撑×绿杂交竹梢枯病病原菌暗孢节菱孢菌(Arthrinium phaeospermum (Corda)M.B.Elli)具有较好的拮抗作用。采用单因素试验和正交试验对铜绿假单胞菌的培养基和发酵条件进行优化,并对其产生的抑菌活性物质的特性进行了初步研究。结果显示:优化培养基配方为蔗糖5 g,蛋白胨10 g,氯化钠2.5 g,水1 000 mL; 最佳发酵条件为温度25 ℃,初始pH7.5,接种量1 mL,瓶装量150 mL于300 mL三角瓶中,发酵时间60 h。粗活性物质检测试验表明:其分子质量小于1 000 u; 代谢产物中大分子蛋白质的生物活性远远低于小分子非蛋白成分; 该菌粗提物中具有生物活性的成分大多是极性较小的物质,且在有机溶剂中溶解性较好,三氯甲烷为最佳萃取剂。

Study on optimization of fermentation conditions of Pseudomonas aeruginosa and its antibacterial substances

Pseudomonas aeruginosa can effectively antagonize Arthrinium phaeospermum (Corda)M.B.Elli. Single-factor experiment and orthogonal tests were used to optimize the fermentation medium and culture conditions of Pseudomonas aeruginosa, and the characters of its antibiotic substance were also investigated. According to orthogonal analysis, the optimal formula of fermentation medium was sucrose 5.0 g, peptone 10 g, NaCl 2.5 g, and distilled water 1 000 mL. The optimal fermentation conditions were determined as follows: fermentation for 60 h at 25 ℃ with an initial pH at 7.5, an inoculum size of 1 mL and 150 mL medium volume in 300 mL triangle flask bulk. The molecular tests showed that the molecular weight of its active ingredient was less than 1 000 u; the biological activity of macromolecular proteins in its metabolites was far lower than that of the low-molecular-mass non-proteins; most active constituents in the crude extracts were small polarity substances, which had better solubility in organic phase, and the best extracting agent of which was methenyl chloride.