ABSTRACT

The aim of this study was to characterize 59 Pseudomonas strains isolated from soil samples in terms of Inducible Beta-Lactamase (IBL), fluorescence production, antibiotic resistance, presence of plasmids and genetic diversity, as well as denitrification functional genes. Fourteen out of fifty-nine (23.7%) Pseudomonas isolates were identified as multidrug-resistant. To evaluate the contribution of denitrification functional genes to genetic diversity, PCR products were screened by RFLP. It was determined that the 18, 6 and 22 out of 59 isolate harbored nirS, nirK and nosZ genes, respectively. It was found that the 37 isolates were nosZ-negative. Thus, these results suggest that nosZ gene-missing pseudomonad denitrifiers are partly contribute to N₂O emission. Moreover, nirS, nirK and nosZ genes were found to be positive with IBL and negatively correlated with fluorescence production. These results suggest that Pseudomonas species have important roles in soil and even in biosphere due to their diversity and genetic factors.

摘要

本研究的目的是在诱导型 β-内酰胺酶 (IBL)、荧光产生、抗生素抗性、质粒的存在和遗传多样性以及反硝化功能基因方面表征从土壤样品中分离的59株假单胞菌。五十九个 (23.7%)假单胞菌分离株中的十四个被鉴定为具有多重耐药性。为了评估反硝化功能基因对遗传多样性的贡献，通过 RFLP 筛选 PCR 产物。确定 59 个分离株中的18、6和 22 个分别含有 nirS、nirK和nosZ基因。发现37个分离株是nosZ阴性的。因此，这些结果表明nosZ基因缺失的假单胞菌反硝化菌是 N ₂ O 排放的部分原因。此外，发现nirS、nirK和nosZ基因与 IBL 呈阳性，而与荧光产生呈负相关。这些结果表明，假单胞菌属物种由于其多样性和遗传因素在土壤甚至生物圈中具有重要作用。