Ranjbariyan Ar, Shams-Ghahfarokhi M, Kalantari S, Razzaghi-Abyaneh M
Department of Mycology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran 14115-331, Iran.
Iran J Microbiol. 2011 Sep;3(3):140-6.
To find antagonistic bacteria with potential antifungal activity against some pathogenic fungi, including Aspergillus niger, A. flavus, Fusarium moniliforme and Penicillium marneffei, a total of 148 agricultural soil samples from different sites of Tehran were examined.
Antagonistic soils were selected by screening against A. niger on glucose-yeast extract (GY) agar using a visual agar plate assay method. All growing bacteria were examined for antifungal activity, and antagonistic bacteria identified based on 16S rRNA sequence analysis. Among a total number of 97 bacteria isolated form inhibitory soils (36 samples), 16 bacteria were reported as strong growth inhibitors in co-cultures on GY agar with all tested fungi at variable degrees. Fungal growth inhibitory bacteria were cultured against all fungi and growth inhibition was measured and analyzed between test and control groups by statistical analysis (ANOVA).
Molecular identification of antagonistic bacteria indicated that most bacterial isolates belonged to the genus Bacillus (81.25%), including B. subtilis (5 isolates), B. amyloliquefaciens (6 isolates) and B. valismortis (2 isolates), followed by one isolate (6.25%) from each Streptomyces sp., Pseudomonas chlororaphis and Acinetobacter baumannii. Based on the visual plate assay results, total fungal growth inhibition of all bacteria was reported in the range of 13.2 to 68.3%. P. chlororaphis S105 was reported as the most potent antagonistic bacterium which inhibited the growth of A. niger by 68.3%, followed by F. moniliforme (66.4%), A. flavus (64.7%) and P. marneffei (57.1%).
P. chlororaphis and some other inhibitory bacteria reported in the present study, they may be considered not only as a rich source of useful metabolites with potential application in antifungal drug discovery, but also as potential candidates for biological control programs.
为了寻找对包括黑曲霉、黄曲霉、串珠镰刀菌和马尔尼菲青霉在内的一些致病真菌具有潜在抗真菌活性的拮抗细菌，对来自德黑兰不同地点的总共148份农业土壤样本进行了检测。
采用可视琼脂平板测定法，通过在葡萄糖 - 酵母提取物（GY）琼脂上针对黑曲霉进行筛选来选择拮抗土壤。检查所有生长的细菌的抗真菌活性，并基于16S rRNA序列分析鉴定拮抗细菌。在从抑制性土壤（36个样本）中分离出的总共97株细菌中，有16株细菌在与所有测试真菌在GY琼脂上的共培养中被报告为不同程度的强生长抑制剂。将真菌生长抑制细菌与所有真菌一起培养，并通过统计分析（方差分析）测量和分析测试组与对照组之间的生长抑制情况。
拮抗细菌的分子鉴定表明，大多数细菌分离株属于芽孢杆菌属（81.25%），包括枯草芽孢杆菌（5株）、解淀粉芽孢杆菌（6株）和瓦莱斯芽孢杆菌（2株），其次是链霉菌属、绿针假单胞菌和鲍曼不动杆菌各1株（6.25%）。根据可视平板测定结果，所有细菌对真菌的总生长抑制率在13.2%至68.3%之间。绿针假单胞菌S105被报告为最有效的拮抗细菌，它对黑曲霉生长的抑制率为68.3%，其次是串珠镰刀菌（66.4%）、黄曲霉（64.7%）和马尔尼菲青霉（57.1%）。
本研究中报告的绿针假单胞菌和其他一些抑制细菌，它们不仅可被视为具有在抗真菌药物发现中潜在应用的有用代谢物的丰富来源，还可作为生物防治计划的潜在候选者。
