Department of Microbiology, Kohat University of Science & Technology, Kohat, Pakistan.
Department of Biology, University of Haripur, Haripur, Pakistan.
J Basic Microbiol. 2022 Jan;62(1):48-62. doi: 10.1002/jobm.202100512. Epub 2021 Dec 10.
The need to increase food production and to reduce the pollution caused by synthetic chemicals has led to a search for biocontrol agents against plant pathogens. In the present study, a total of 37 chitinolytic bacteria were isolated from the rhizospheric soil of tomatoes using a chitin agar medium. In vitro bacterial isolates, that is, TD9, TD11, TD15, and TD24 showed strong antagonistic and enzymatic activities against Rhizoctonia (8%-55%), Fusarium (31%-48%), Colletotrichum (24%-49%), and Aspergillus on a dual culture plate and enzyme assay. Furthermore, these putative antagonistic bacterial isolates were identified as Pantoea agglomerans (TD9), Bacillus subtilis (TD11), Bacillus cereus (TD15 and TD24) using 16S rRNA sequence analysis. Additionally, in culture filtrate in vivo assay, the isolates TD11 and TD15 inhibited the growth of Rhizoctonia solani about 40% and Fusarium oxysporum about 80%. However, in the pot trials, these two bacterial isolates (TD11 and TD15) considerably suppressed the disease rate in tomatoes caused by Fusarium and Rhizoctonia fungal species. Moreover, it was concluded that B. subtilis (TD11) was found to be the most promising putative biocontrol agent, inhibiting the fungal diseases of tomatoes by 50% and showing versatile antagonistic potential.
为了增加粮食产量和减少合成化学品造成的污染，人们开始寻找防治植物病原菌的生物防治剂。本研究采用几丁质琼脂培养基，从番茄根际土壤中分离出 37 株几丁质分解细菌。在体外，细菌分离株 TD9、TD11、TD15 和 TD24 在双层平板和酶活测定中对 Rhizoctonia（8%-55%）、Fusarium（31%-48%）、Colletotrichum（24%-49%）和 Aspergillus 表现出强烈的拮抗和酶活性。此外，通过 16S rRNA 序列分析，这些假定的拮抗细菌分离株被鉴定为成团泛菌（TD9）、枯草芽孢杆菌（TD11）、蜡样芽孢杆菌（TD15 和 TD24）。此外，在体内培养滤液测定中，分离株 TD11 和 TD15 抑制了约 40%的 Rhizoctonia solani 和 80%的 Fusarium oxysporum 的生长。然而，在盆栽试验中，这两个细菌分离株（TD11 和 TD15）显著抑制了番茄上由真菌 Fusarium 和 Rhizoctonia 引起的病害发生率。此外，研究结果表明，枯草芽孢杆菌（TD11）是最有前途的生物防治剂，可抑制番茄真菌病害达 50%，具有多种拮抗潜力。
