Department of Microbiology, College of Basic Sciences & Humanities, Chaudhary Charan Singh Haryana Agricultural University, Hisar, 125004, Haryana, India.
Microb Ecol. 2023 Nov;86(4):2282-2292. doi: 10.1007/s00248-023-02238-2. Epub 2023 May 13.
Sulphur, available in the form of sulphate, is one of the essential nutrients that is required by plants. Bacteria capable of oxidizing reduced forms of sulphur to sulphate play an important role in sulphur nutrition for plants. The present study was conducted to isolate, screen, and characterize sulphur-oxidizing bacteria from different soil samples collected from mustard rhizosphere and fly ash mixed soil. A total of 33 sulphur-oxidizing bacterial isolates (HMSOB1-33) were retrieved from soil and further screened for sulphur-oxidizing ability. Maximum solubilization index (3.76), pH reduction (3.93), and sulphate production (173.61 µg/ml) were observed for the isolate HMSOB2 which on the basis of 16S rDNA sequencing was identified as Pantoea dispersa with sequence similarity 98.22%. Four other selected bacterial isolates were identified as Bacillus megaterium, Bacillus tropicus, Bacillus velezensis, and Bacillus cereus. Sulphate solubilization index (SSI) correlated positively (r = 0.91) with sulphate production; however, pH showed negative correlation (r = - 0.82) with SSI as well as sulphate production after 120 h of incubation. These promising bacterial isolates could be further explored as bioinoculant after assessing plant growth traits.
硫磺以硫酸盐的形式存在，是植物所需的必需营养物质之一。能够将还原态硫磺氧化为硫酸盐的细菌在植物的硫磺营养中起着重要作用。本研究从芥菜根际和粉煤灰混合土壤中采集的不同土壤样本中分离、筛选和鉴定了硫氧化细菌。从土壤中回收了 33 株硫氧化细菌（HMSOB1-33），并进一步筛选其硫氧化能力。分离株 HMSOB2 的最大溶解指数（3.76）、pH 值降低（3.93）和硫酸盐生成量（173.61µg/ml）最高，根据 16S rDNA 测序鉴定为泛菌属（Pantoea dispersa），相似度为 98.22%。其他 4 株选定的细菌分离株鉴定为巨大芽孢杆菌、热带芽孢杆菌、韦氏芽孢杆菌和蜡样芽孢杆菌。硫酸盐溶解指数（SSI）与硫酸盐生成量呈正相关（r=0.91）；然而，pH 值与 SSI 以及 120 小时培养后的硫酸盐生成量呈负相关（r=-0.82）。这些有前途的细菌分离株在评估植物生长特性后，可以进一步作为生物接种剂进行探索。
