Department of Biotechnology, Junagadh Agricultural University, Junagadh, Gujarat, India.
Main Oilseed Research Station, Junagadh Agricultural University, Junagadh, Gujarat, India.
Sci Rep. 2022 Mar 18;12(1):4699. doi: 10.1038/s41598-022-08151-x.
Halophiles are a class of microorganisms that thrive in environments with very high salt concentrations. The coastal regions of Saurashtra Gujarat host a diverse group of microorganisms including halophilic and halotolerant bacteria that may have plant growth promoting characteristics. Microorganisms with plant growth promoting characteristics are of immense importance in the field of agriculture and the present study was conducted to investigate the characteristics of halophilic and halotolerant bacteria isolated from agricultural soils of coastal regions of Junagadh and Porbandar districts of Saurashtra, Gujarat. A total of 15 isolated strains showed indole acetic acid production, solubilization of phosphate and potash, and nitrogen fixing capacity ranging from 18.77-33.48 μg ml, 50.10-106.10%, 180.42-239.92% and 0.170-0.480 g kg of Jensen's agar medium, respectively, while two isolates were also found positive for siderophore production. Besides, nine out of fifteen isolates also showed positive ACC deaminase activity ranging from 0.92-5.78 µM α-ketobutyrate mg h. The isolates were further characterized by physiological, microscopic, and biochemical tests. The halophilic and halotolerant bacterial isolates were identified by 16S rRNA gene sequencing as belonging to Halomonas pacifica, H. stenophila, and Bacillus haynesii, B. licheniformis and Oceanobacillus aidingensis respectively. The 16S rRNA partial gene sequence of two isolates belonging to H. pacifica and H. stenophila were submitted to NCBI with accession number MK955347 and MK961217 respectively. The findings of the present investigation showed that isolated bacterial halophiles possess promising plant growth promoting characteristics. Their potential as bioinoculants to alleviate salinity stress in crops and for bioremediation deserves further investigation.
嗜盐菌是一类能在高盐环境中生长的微生物。古吉拉特邦索拉什特拉的沿海地区拥有多种微生物，包括嗜盐菌和耐盐细菌，它们可能具有促进植物生长的特性。具有促进植物生长特性的微生物在农业领域具有重要意义，本研究旨在调查从古吉拉特邦朱纳加德和波拉达尔地区沿海农业土壤中分离出的嗜盐菌和耐盐菌的特性。总共 15 株分离株表现出吲哚乙酸产生、磷酸盐和钾盐的溶解以及固氮能力，范围分别为 18.77-33.48μg/ml、50.10-106.10%、180.42-239.92%和 0.170-0.480g/kg Jensen 琼脂培养基，同时，有两株分离株也被发现具有产生铁载体的能力。此外，15 株分离株中有 9 株也表现出 ACC 脱氨酶活性，范围为 0.92-5.78μMα-酮丁酸mg h。通过生理、显微镜和生化试验对分离株进行了进一步的特征描述。通过 16S rRNA 基因测序，鉴定出嗜盐菌和耐盐细菌分离株分别属于太平洋盐单胞菌、嗜盐斯坦利菌、解淀粉芽孢杆菌、地衣芽孢杆菌和海洋芽孢杆菌。属于太平洋盐单胞菌和嗜盐斯坦利菌的两个分离株的 16S rRNA 部分基因序列已提交给 NCBI，登录号分别为 MK955347 和 MK961217。本研究的结果表明，分离的细菌嗜盐菌具有有前途的促进植物生长的特性。它们作为生物接种剂缓解作物盐胁迫和生物修复的潜力值得进一步研究。
