Department of Biotechnology, Junagadh Agricultural University, Junagadh, Gujarat, India.
Crop Improvement Section, ICAR - Directorate of Groundnut Research, Junagadh, Gujarat, India.
Sci Rep. 2024 Jul 8;14(1):15704. doi: 10.1038/s41598-024-63581-z.
Halophiles are one of the classes of extremophilic microorganisms that can flourish in environments with very high salt concentrations. In this study, fifteen bacterial strains isolated from various crop rhizospheric soils of agricultural fields along the Southwest coastline of Saurashtra, Gujarat, and identified by 16S rRNA gene sequencing as Halomonas pacifica, H. stenophila, H. salifodinae, H. binhaiensis, Oceanobacillus oncorhynchi, and Bacillus paralicheniformis were investigated for their potentiality to produce extremozymes and compatible solute. The isolates showed the production of halophilic protease, cellulase, and chitinase enzymes ranging from 6.90 to 35.38, 0.004-0.042, and 0.097-0.550 U ml, respectively. The production of ectoine-compatible solute ranged from 0.01 to 3.17 mg l. Furthermore, the investigation of the ectoine-compatible solute production at the molecular level by PCR showed the presence of the ectoine synthase gene responsible for its biosynthesis in the isolates. Besides, it also showed the presence of glycine betaine biosynthetic gene betaine aldehyde dehydrogenase in the isolates. The compatible solute production by these isolates may be linked to their ability to produce extremozymes under saline conditions, which could protect them from salt-induced denaturation, potentially enhancing their stability and activity. This correlation warrants further investigation.
嗜盐菌是一类极端微生物,可以在高盐浓度的环境中旺盛生长。本研究从古吉拉特邦索拉什特拉西南沿海农业田地的各种作物根际土壤中分离出 15 株细菌菌株,通过 16S rRNA 基因测序鉴定为盐单胞菌属、盐生密螺旋体、盐生盐杆菌、海洋芽孢杆菌和副地衣芽孢杆菌,研究了它们产生极端酶和相容溶质的潜力。这些分离株表现出产生嗜盐蛋白酶、纤维素酶和几丁质酶的能力,酶活分别为 6.90-35.38、0.004-0.042 和 0.097-0.550 U/ml。此外,还通过 PCR 对胞外多胺相容溶质的产生进行了分子水平的研究,结果表明,这些分离株中存在负责其生物合成的胞外多胺合成酶基因。此外,这些分离株中还存在甜菜碱醛脱氢酶基因,用于合成甘氨酸甜菜碱。这些分离株产生的相容溶质可能与其在盐度条件下产生极端酶的能力有关,这可以保护它们免受盐诱导的变性,潜在地提高它们的稳定性和活性。这种相关性值得进一步研究。