一株假单胞菌SU8抑菌物质的研究初报

Preliminary research of antifungal substances produced by antagonistic Pseudomonas SU8

为了从假单胞菌SU8发酵液中获得抑菌活性物质并明确其种类,采用皿内生测法测定了假单胞菌SU8对水稻纹枯病病菌抑菌活性,研究了其最佳提取溶剂和用量、时间、温度及其部分理化性质。结果表明,乙酸乙酯的提取效果最好,抑菌带宽度达20.05 mm,二氯甲烷次之,抑菌带宽度为6.93 mm,石油醚的提取效果最差,溶剂最佳物料比为2∶1,其抑菌带宽度为15.34 mm,其他比例效果均较差;浸提时间以8 h为最佳,抑菌带宽度为20.01 mm,其余处理抑菌带宽度从宽到窄依次为4、2、32、16 h;提取温度从好到差依次为45℃>25℃>60℃>4℃>80℃。该菌的抑菌物质具有热稳定性,对紫外线不敏感,耐储藏,耐酸能力较强,耐碱能力差;紫外可见全波段扫描发现抑菌物质为吩嗪类物质。

In order to obtain antifungal substances and classification of fungistatic compound of Pseudomonas SUB broth, Rhizoctonia solani was used in culture dish bioassay method as indicator strain. Optimum extraction method and physico- chemical property of fungistatic compound from Pseudomonas SU8 broth were studied. The results showed that ethyl acetate was optimum extraction solvent with inhibition diameter of 20.05 mm, followed by dichloromethane with inhibition diameter of 6.93 mm. Optimum extraction time was 8 h with inhibition diameter of 20.01 mm, followed by that of 4 hours, 2 hours, 32 hours and 16 hours. Optimum extraction temperature was 45 ℃ with inhibition diameter of 16.54 ram, followed by 25 ℃ with inhibition diameter of 11.36 mm. Optimum material ratio was 2：1 with inhibition diameter of 15.34 mm. Besides, extracted compound showed stability under the conditions of heat treatment, UV exposure and long-term storage. It tolerated to acid but sensitive to alkali. Through UV-VIS whole wavelength scanning the compound was tentatively given as phenazines.