College of Chemistry and Life Science, Zhejiang Normal University, Zhejiang, 321004, P. R. China.
J Microbiol. 2019 Jul;57(7):597-605. doi: 10.1007/s12275-019-8330-5. Epub 2019 Jun 27.
To screen for Aspergillus activity against Xanthomonas oryzae pv. oryzae and analyse the antimicrobial components involved, 60 Aspergillus spp. were isolated and purified from fruits, soil and other habitats. As-75, an Aspergillus strain that can antagonize Xanthomonas oryzae pv. oryzae, was identified based on the zone of inhibition formed during co-culture. According to morphological, ITS rDNA gene sequencing and phylogenetic tree results, the strain showed close homology to Aspergillus sclerotiorum. The biochemical characterization tests showed that the fermentation broth of strain As-75 exhibited a high capacity for environmental adaptation. The results of the antimicrobial spectrum experiments demonstrated that As-75 exhibited fairly strong antagonistic activity against five plant pathogenic fungi and six plant pathogenic bacteria in vitro. The fermentation broth of strain As-75 displayed maximum stability under fluorescent illumination at temperatures below 60°C at pH 6.5. A substance with antagonistic activity was obtained from strain As-75 via fractional extraction, silica gel column chromatography and thin-layer chromatography. Through mass spectrometry, nuclear magnetic resonance and electrospray ionization mass spectrometry (ESI-MS) analyses, the target compound was identified as (2Z)-2-butenedioic acid-2-(1-methylethenyl)-4-methyl ester; its molecular weight of 170.06 daltons and formula of CHO identify it as a novel compound. Trials of the preventative and curative effects demonstrated that compound S1 exhibited a better control efficiency than the control against rice bacterial blight. Additionally, the M1 processing method was better, and the efficiency of compound S1 in preventing rice bacterial blight in six rice varieties, TN1, IR24, ZF802, Zhonghua 11, Wuyunjing 21, and Nipponbare, was 78.3%, 77.5%, 74.2%, 75.3%, 70.9%, and 72.1%, respectively.
为了筛选对稻黄单胞菌具有拮抗作用的曲霉活性并分析涉及的抗菌成分，从水果、土壤和其他生境中分离和纯化了 60 株曲霉属。根据共培养过程中形成的抑菌圈，鉴定出一株能拮抗稻黄单胞菌的曲霉属菌株 As-75。根据形态学、ITS rDNA 基因测序和系统发育树结果，该菌株与尖孢镰孢菌密切同源。生化特性测试表明，菌株 As-75 的发酵液具有较强的环境适应能力。抗菌谱实验结果表明，As-75 在体外对 5 种植物病原真菌和 6 种植物病原细菌表现出较强的拮抗活性。在 pH 值为 6.5 时，温度低于 60°C，菌株 As-75 的发酵液在荧光照射下表现出最大的稳定性。通过对菌株 As-75 进行分步提取、硅胶柱层析和薄层层析，获得具有拮抗活性的物质。通过质谱、核磁共振和电喷雾电离质谱（ESI-MS）分析，确定目标化合物为（2Z）-2-丁烯二酸-2-（1-亚甲基乙基）-4-甲酯；其分子量为 170.06 道尔顿，分子式为 CHO，鉴定为一种新型化合物。预防和治疗效果试验表明，化合物 S1 的防治效果优于对照药剂对水稻细菌性条斑病的防治效果。此外，M1 处理方式更好，化合物 S1 对六个水稻品种 TN1、IR24、ZF802、中华 11、乌云金 21 和日本晴的防治效果分别为 78.3%、77.5%、74.2%、75.3%、70.9%和 72.1%。
