特基拉芽孢杆菌JN-369的分离鉴定及其抑菌物质分析

Isolation and identification of Bacillus tequilensis JN-369 and antimicrobial substance analysis

为筛选可用于防治由稻瘟病菌所致水稻稻瘟病的生防菌株资源,采用稀释涂布平板法,从感病水稻品种湘早籼24号的健康植株茎叶中分离获得了1株拮抗细菌JN-369,结合形态学观察、生理生化鉴定及16S rDNA序列分析对其菌种进行了鉴定,采用平板对峙法研究了JN-369菌株的抑菌谱,并初步测定了JN-369中挥发性有机物(VOCs)、蛋白类粗提物及脂肽类粗提物对稻瘟病菌的抑制作用。结果表明:JN-369菌株为特基拉芽孢杆菌Bacillus tequilensis,其对稻瘟病菌具有显著抑制作用,对菌丝生长的抑制率达80.46%±0.83%;同时该菌株对供试的辣椒胶孢炭疽菌、烟草赤星病菌及黄瓜疫病菌等植物病原真菌和卵菌均有抑制作用;但对供试病原细菌则均无抑制作用;1×10~8 cfu/mL的JN-369菌悬液产生的挥发性有机物对稻瘟病菌的抑制效果最强,抑制率达72.92%±3.01%,1.454 mg/mL的蛋白类提取物和1.026 mg/mL的脂肽类提取物对稻瘟病菌的抑制率分别为24.68%±0.80%和14.34%±1.08%。研究表明,菌株JN-369具有一定的开发应用潜力。

In order to screen the resources of biocontrol bacteria strains for the control of rice blast caused by Magnaporthe oryzae, a bacteria JN-369 was isolated from the healthy rice plants of the susceptible rice cultivar Xiangzaoxian 24 by dilution plate method. And its activity against mycelial growth of M. oryzae was tested by the plate confrontation method. The strain JN-369’s taxonomic status was identified based on morphological characteristics, physiological, biochemical characteristics and16 S rDNA sequence analysis. The antifungal spectrum of strain JN-369 was determined by the dural culture method, the inhibitory effects of volatile organic compounds(VOCs), crude proteins and crude lipopeptides from strain JN-369 against M. oryzae were preliminarily determined. The results showed that the strain JN-369 was identified as Bacillus tequilensis, with the inhibition rate of 80.46% ±0.83% against M. oryzae. It also had obvious antifungal activity against the tested fungi, such as Colletotrichum gloeosporioides, Alternaria alternata, Phytophthora melonis, and the other plant pathogenic fungi and oomycetes, while it exhibited no inhibition effect on the tested pathogenic bacteria. The volatile organic compounds produced by 1 × 10~8 cfu/mL strain JN-369 had the strongest inhibition rate on M. oryzae with the inhibition rate of 72.92% ± 3.01%. The inhibition rate of1.454 mg/mL protein extract and 1.026 mg/mL lipopeptide extract against M. oryzae were only24.68% ± 0.80% and 14.34% ± 1.08%, respectively. These results showed that the strain JN-369 had potential for development and application.