放线菌JSD-1抑菌活性初探及影响其抑菌活性的发酵条件优化

Preliminary Study on Antibacterial Activity of Actinomycete JSD-1 and Optimization of Fermentation Conditions Affecting the Antibacterial Activity of JSD-1

本文初步研究了放线菌JSD-1的抑菌活性,并优化了影响其抑菌活性的发酵条件,从而增强抑菌效果。本研究以致病性大肠杆菌和金黄色葡萄球菌为指示菌,通过稀释涂布、琼脂打孔法和液态共培养法探究菌株JSD-1抑菌活性,并采用单因素试验及正交试验设计对影响JSD-1抑菌活性的发酵培养基及发酵条件进行优化。最终得出影响JSD-1抑菌活性的最适培养基为葡萄糖10.00 g/L,尿素2.50 g/L,最佳发酵条件组合为温度35℃,p H 7.0,接种量5%,培养时间7 d。通过发酵条件优化可明显增强放线菌JSD-1的抑菌活性,抑菌圈直径由优化前的10.08 mm增长至18.63 mm,有利于菌株JSD-1作为拮抗菌的进一步开发利用。研究发现JSD-1在病原细菌的对数生长期、稳定期及衰亡期持续抑制其生长增殖,这表明菌株JSD-1具有很大的抗菌潜力,可作为生防制剂的候选菌株。

The antibacterial activity of actinomycete JSD-1 was preliminarily investigated in this work, and the fermentation conditions that affected its antibacterial activity were optimized to enhance the antibacterial effect. Using pathogenic Escherichia coli and Staphylococcus aureus as indicator bacterias, the antibacterial activity of strain JSD-1 was investigated by dilution coating, agar diffusion method and liquid co-culture method. The fermentation conditions of JSD-1 were optimized by single factor experiment and orthogonal experiment design. The optimized culture medium to affect the antibacterial activity of JSD-1 was composed of glucose 10 g/L,urea 2.5 g/L. The optimal fermentation condition was as follow: culture temperature of 35 ℃ p H 7.0, inoculation amount 3%, culture time 7 d. The antibacterial activity of JSD-1 was significantly improved. The inhibitory zone diameter increased from 10.08 mm to 18.63 mm, which was beneficial to the further development and utilization of JSD-1 as an antagonist. It was found that the growth and proliferation of pathogenic Escherichia coli and Staphylococcus aureus were inhibited by JSD-1 in their logarithmic phase, stable phase and decline phase continuously, indicating that JSD-1 had great antibacterial potential and could be used as a candidate strain for biocontrol preparation.