Bacillus spp. can promote the growth of plants and reduce plant disease incidence or severity by triggering induced systemic resistance to plant pathogens. In addition, bacteria of this genus are chitinase enzyme producers. Chitinase inhibits the growth of fungi by breaking down the chitin-containing cell wall of plant pathogenic fungi. In this study, 270 native Bacillus spp., isolated from various habitats in Kayseri and Adana, Turkey, were screened by PCR for the chitinase gene and 66 of them were found to have this gene. Nine Bacillus thuringiensis (Bt) isolates showing high insecticidal activity against insect pests in our previous studies were selected from 66 isolates containing the chitinase gene. Chitinases with different molecular weights ranging from ~ 40 to 113 kDa were determined by SDS-PAGE. To determine the antagonistic effects against plant pathogenic fungi (Fusarium oxysporum f.sp. niveum, Verticillium dahliae and Aspergillus niger), a dual culture assay was used with nine native and two standard strains of Bt, and radial growth inhibition was calculated as a percentage. Of all the tested isolates, SY33.3 showed the strongest antagonistic activity and thus, can be used as an effective biological control agent against plant pathogenic fungi.

芽孢杆菌属 可以通过引发对植物病原体的诱导系统抗性来促进植物的生长并降低植物病害的发生率或严重程度。此外，该属细菌是几丁质酶的生产者。几丁质酶通过分解植物病原真菌含有几丁质的细胞壁来抑制真菌的生长。在这项研究中，从土耳其开塞利和阿达纳的不同栖息地分离的270 种天然芽孢杆菌属通过 PCR 筛选几丁质酶基因，其中 66 种被发现具有该基因。苏云金九号芽孢杆菌（Bt) 在我们之前的研究中对害虫表现出高杀虫活性的分离株是从含有几丁质酶基因的 66 个分离株中选出的。具有不同分子量的几丁质酶通过 SDS-PAGE 测定，范围从 ~ 40 到 113 kDa。为了确定针对植物病原真菌的拮抗效应（尖镰孢病菌niveum，黄萎病和黑曲霉），双培养测定用9天然和两个标准菌株使用的Bt，和径向生长抑制计算为百分比. 在所有受试分离株中，SY33.3 显示出最强的拮抗活性，因此可作为一种有效的植物病原真菌生物防治剂。