Chowdhury Soumitra Paul, Schmid Michael, Hartmann Anton, Tripathi Anil Kumar
School of Biotechnology, Banaras Hindu University, Varanasi 221005, India.
Microb Ecol. 2007 Jul;54(1):82-90. doi: 10.1007/s00248-006-9174-1. Epub 2007 Jan 31.
Lasiurus sindicus is a highly nutritive, drought-tolerant, perennial grass that is endemic to the Thar Desert of Rajasthan, India. Analysis of 16S rRNA coding genes of the bacterial isolates enriched in nitrogen-free semisolid medium, from the surface-sterilized roots of L. sindicus, showed predominance of Gram-negative over Gram-positive bacteria. According to comparative sequence analysis of 16S rDNA sequence data, Gram-positive bacteria with low GC content (Staphylococcus warneri and Bacillus sp.) and high GC content (Micrococcus luteus, Microbacterium sp.) were identified. Gram-negative bacteria included Azospirillum sp., Rhizobium sp., Agrobacterium tumefaciens, and Inquilinus limosus (alpha-proteobacteria); Ralstonia sp., Variovorax paradoxus, and Bordetella petrii (beta-proteobacteria); and Pseudomonas pseudoalcaligenes, Stenotrophomonas sp. (gamma-proteobacteria). The occurrence of nifH sequences in Azospirillum sp., Rhizobium sp., and P. pseudoalcaligenes showed the possibility of supplying biologically fixed nitrogen by the root-associated diazotrophs to the host plant.
印度狐蝠草是一种营养丰富、耐旱的多年生草本植物，原产于印度拉贾斯坦邦的塔尔沙漠。对从印度狐蝠草表面消毒的根部在无氮半固体培养基中富集的细菌分离物的16S rRNA编码基因进行分析，结果显示革兰氏阴性菌比革兰氏阳性菌占优势。根据16S rDNA序列数据的比较序列分析，鉴定出了低GC含量的革兰氏阳性菌（华纳葡萄球菌和芽孢杆菌属）和高GC含量的革兰氏阳性菌（藤黄微球菌、微杆菌属）。革兰氏阴性菌包括固氮螺菌属、根瘤菌属、根癌土壤杆菌和寄居菌属（α-变形菌纲）；雷尔氏菌属、贪铜菌属和皮氏博德特氏菌（β-变形菌纲）；以及假产碱假单胞菌、嗜麦芽窄食单胞菌（γ-变形菌纲）。固氮螺菌属、根瘤菌属和假产碱假单胞菌中nifH序列的出现表明，与根相关的固氮菌有可能为宿主植物提供生物固氮。
