拮抗性芽孢杆菌Y1的鉴定及其粗提物抗白色念珠菌特性的研究

Identification of Antagonistic Bacillus Y1 and Its Crude Extract Against Candida Albicans

目的:探讨并确定车前草组织内生拮抗性芽孢杆菌对白色念珠菌抗菌活性。方法:通过该菌株的形态特征、生理生化特征及16SrDNA序列分析对其进行分类鉴定;利用滤纸片法测试了该菌株发酵上清液对白色念珠菌的抑菌活性,在此基础上利用牛津杯法考查了发酵上清液抗菌物质粗提物特性及培养时间对抗菌活性的影响。结果:菌株Y1液体发酵液上清液对白色念珠菌具有明显抑制作用,平均抑菌圈直径达到(20.4±0.5)mm;根据形态特征、生理生化特征及16SrDNA序列比对,该菌株被鉴定为贝莱斯芽孢杆菌;抗菌物质粗提物经不同温度、pH及蛋白酶处理后其抑菌活性发生一些变化,当温度为90℃抑菌活性开始下降,到121℃完全丧失活性;pH>10.0时,粗提物抑菌活性降低;对蛋白水解酶的水解作用稳定性较好,培养到44 h抗菌活性最好。结论:拮抗性贝莱斯芽孢杆菌对白色念珠菌具有明显抑制活性,且其发酵液中存在相对稳定的抗菌活性成分,具有一定的开发潜力。

Objective:To investigate and determine the antibacterial activity of endophytic antagonistic Bacillus against C.albicans in plantain tissue.Methods:The strain was classified and identified by morphological characteristics,physiological and biochemical characteristics and 16SrDNA sequence analysis.The antibacterial activity of the fermented supernatant against Candida albicans was tested by filter paper method.On this basis,the characteristics of crude extracts of the fermented supernatant and the effect of culture time on the antibacterial activity were investigated by Oxford cup method.Results:The supernatant of liquid fermentation broth of strain Y1 had obvious inhibitory effect on C.albicans,and the average diameter of inhibition zone was(20.4±0.5)mm.According to morphological characteristics,physiological and biochemical characteristics and 16SrDNA sequence alignment,the strain was identified as Bacillus velezenisi.The antimicrobial activity of crude extracts of antimicrobial substances changed after being treated with different temperature,pH and protease.When the temperature was 90℃,the antimicrobial activity began to decline and completely lost when the temperature was 121℃.When the pH was greater than 10.0,the antibacterial activity of crude extract decreased.The hydrolysis stability of proteolytic enzyme was good,and the antibacterial activity was the best after 44 h culture.Conclusion:The antagonistic Bacillus velezenisi has obvious inhibitory activity against C.albicans,and there are relatively stable antibacterial active components in its fermentation broth,which has a certain development potential.