Department of Biosciences, Saurashtra University, Rajkot, 360005, Gujarat, India.
Braz J Microbiol. 2022 Dec;53(4):1817-1828. doi: 10.1007/s42770-022-00794-2. Epub 2022 Jul 19.
To explore the in vivo and in vitro plant growth promoting activities, biocatalytic potential, and antimicrobial activity of salt tolerance rhizoactinobacteria, rhizospheric soil of a halotolerant plant Saueda maritima L. was collected from Rann of Tiker, near Little Rann of Kutch, Gujarat (India). The morphology analysis of the isolated strain TSm39 revealed that the strain belonged to the phylum actinobacteria, as it was stained Gram-positive, displayed filamentous growth, showed spore formation and red pigment production on starch casein agar (SCA). It was identified as Georgenia soli based on 16S rRNA gene sequencing. The Georgenia soli strain TSm39 secreted extracellular amylase, pectinase, and protease. It showed in vitro plant growth-promoting (PGP) activities such as indole acetic acid (IAA) production, siderophore production, ammonia production, and phosphate solubilization. In vivo plant growth-promoting traits of strain TSm39 revealed 30% seed germination on water agar and vigor index 374.4. Additionally, a significant increase (p ≤ 0.05) was found in growth parameters such as root length (16.1 ± 0.22), shoot length (15.2 ± 0.17), the fresh weight (g), and dry weight (g) of the roots (0.43 ± 0.42 and 0.32 ± 0.12), shoots (0.62 ± 0.41 and 0.13 ± 0.03), and leaves (0.42 ± 0.161 and 0.14 ± 0.42) in treated seeds of Vigna radiata L. plant with the strain TSm39 compared to control. The antibiotic susceptibility profile revealed resistance of the strain TSm39 to erythromycin, ampicillin, tetracycline, and oxacillin, while it displayed maximum sensitivity to vancomycin (40 ± 0.72), chloramphenicol (40 ± 0.61), clarithromycin (40 ± 1.30), azithromycin (39 ± 0.42), and least sensitivity to teicoplanin (15 ± 0.15). Moreover, the antimicrobial activity of the strain TSm39 was observed against Gram's positive and Gram's negative microorganisms such as Shigella, Proteus vulgaris, and Bacillus subtilis. These findings indicated that the Georgenia soli strain TSm39 has multiple plant-growth-promoting properties and biocatalytic potential that signifies its agricultural applications in the enhancement of crop yield and quality and would protect the plant against plant pathogens.
为了探索耐盐根际放线菌的体内和体外植物生长促进活性、生物催化潜力和抗菌活性，从古吉拉特邦（印度）小拉恩的库奇附近的提克湿地采集了耐盐植物 Saueda maritima L. 的根际土壤。分离株 TSm39 的形态分析表明，该菌株属于放线菌门，因为它被革兰氏染色阳性，显示丝状生长，在淀粉酪蛋白琼脂（SCA）上形成孢子并产生红色色素。基于 16S rRNA 基因测序，它被鉴定为 Georgenia soli。Georgenia soli 菌株 TSm39 分泌细胞外淀粉酶、果胶酶和蛋白酶。它表现出体外植物生长促进 (PGP) 活性，如吲哚乙酸 (IAA) 生产、铁载体生产、氨生产和磷酸盐溶解。菌株 TSm39 的体内植物生长促进特性显示在琼脂水上有 30%的种子发芽和活力指数 374.4。此外，在根长（16.1±0.22）、茎长（15.2±0.17）、鲜重（g）和干重（g）等生长参数方面发现了显著增加（p≤0.05）根（0.43±0.42 和 0.32±0.12）、茎（0.62±0.41 和 0.13±0.03）和叶（0.42±0.161 和 0.14±0.42）在处理过的 Vigna radiata L. 种子中，与对照相比，用菌株 TSm39 处理的种子。抗生素敏感性分析显示，菌株 TSm39 对红霉素、氨苄西林、四环素和苯唑西林具有抗性，而对万古霉素（40±0.72）、氯霉素（40±0.61）、克拉霉素（40±1.30）、阿奇霉素（39±0.42）和替考拉宁（15±0.15）显示最大敏感性。此外，菌株 TSm39 的抗菌活性还观察到对革兰氏阳性和革兰氏阴性微生物如志贺氏菌、普通变形杆菌和枯草芽孢杆菌的抑制作用。这些发现表明，Georgenia soli 菌株 TSm39 具有多种植物生长促进特性和生物催化潜力，这表明它在提高作物产量和质量方面具有农业应用，并能保护植物免受植物病原体的侵害。
