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目的从土壤中筛选拮抗能力强且抑菌特性稳定的放线菌菌株。方法采用双层琼脂法筛选出4株拮抗放线菌菌株,然后采用杯碟法测这4株菌株发酵液提取物的抗菌谱、最小抑菌浓度、热稳定性和酸碱稳定性。结果 4株菌株发酵液提取物都能抑制金黄色葡萄球菌、大肠埃希菌、铜绿假单胞菌和白色念珠菌的生长。以金黄色葡萄球菌为指示菌测发酵液提取物的最小抑制浓度,6#和9#拮抗作用较强,发酵液提取物稀释0.125mg/ml仍有抑菌作用。6#菌株在100℃处理30min后仍有40%的抑菌活性。6#菌株发酵液提取物在碱性环境条件下比在酸性环境条件下稳定。结论 4株菌株中6#菌株发酵液提取物具有拮抗能力强、最小抑菌浓度低和在碱性条件下活性较稳定的特点。
Objective To screen actinomyces strains with strong antagonistic ability and stable antibacterial activity from soil. Methods Four antagonistic actinomycetes strains were screened by double agar method. The antibacterial spectrum, the minimum inhibitory concentration, the thermal stability and the acid-base stability of the extracts of the four strains were determined by cup-cup method. Results Four strains of fermentation broth extract could inhibit the growth of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. Staphylococcus aureus as the indicator bacteria to measure the minimum inhibitory concentration of the extract of the fermentation, 6 # and 9 # strong antagonistic effect, fermentation broth extract diluted 0.125mg / ml still antibacterial effect. The 6 # strain still has 40% antibacterial activity after being treated at 100 ° C for 30 min. The fermentation broth extract of strain # 6 was stable under alkaline conditions than under acidic conditions. Conclusion The extract of fermentation broth of strain 6 in 4 strains has the characteristics of strong antagonistic ability, minimum inhibitory concentration and stable activity under alkaline conditions.