一株拮抗放线菌NMG8-2的抑菌特性

Antibacterial Characteristics of Actinomycete Strain NMG8-2

为研究拮抗放线菌NMG8-2的抑菌活性,评价其在植物病害防治中的开发应用价值,对该菌株及其发酵液的抑菌活性、发酵液稳定性进行了研究。试验采用平板对峙法、抑制菌丝生长速率法和杯碟法测定拮抗放线菌NMG8-2菌株及其发酵液对18种植物病原真菌和6种细菌的抑制作用。结果表明:NMG8-2菌株及其发酵液对苜蓿茄镰孢根腐病菌、立枯丝核菌等16种植物病原真菌和胡萝卜软腐欧文氏菌、马铃薯环腐棒杆菌、青枯雷尔氏菌、蜡状芽孢杆菌、金黄色葡萄球菌5种细菌具有较强的抑菌作用;发酵液能抑制苜蓿茄镰孢根腐病菌的分生孢子萌发和芽管伸长。不同条件下的稳定性测定结果表明:该菌株发酵液的抑菌作用对碱、紫外线、高温和蛋白酶均比较稳定,但在强酸条件下稳定性较差;连续传接10代,抑菌活性仍然稳定。

In order to evaluate the development and application value of actinomycete NMG8-2 in plant disease control,we studied the antimicrobial activity and stability of the strain and its aseptic broth.The antibacterial effects of marine actinomycete NMG8-2 and its aseptic broth on 18 botanic pathogenic fungi and 6 bacteria were studied by means of antagonistic effect and cylinder-plate assay.The result indicated that both of NMG8-2 and its aseptic broth strongly inhibited the growth of 16 pathogenic fungi,such as Fusarium solani,Rhizoctonia solani,etc.,and 5 bacteria,named Erwinia carotovora subsp.carotovora,Clavibacter michiganensis subsp.sepedonicus,Ralstonia solanacearum,Bacillus cereus,Staphylococcus aureus.The fermentation broth could inhibit the spore germination and the bud elongation of Fusarium solani.The result of stability evaluation of fermentation broth at different conditions indicated that the antibacterial was stable to acid/alkali and proteinase,but was sensitive to UV and high temperature.When the strain actinomycete NMG8-2 was transferred for 10 generations,the activity of its fermentation broth was also stable.