Ardley Julie Kaye, O'Hara Graham W, Reeve Wayne G, Yates Ron J, Dilworth Michael J, Tiwari Ravi P, Howieson John G
Centre for Rhizobium Studies, School of Biological Sciences and Biotechnology, Murdoch University, Perth, WA, Australia.
Arch Microbiol. 2009 Apr;191(4):311-8. doi: 10.1007/s00203-009-0456-0. Epub 2009 Jan 18.
The South African legumes Lotononis bainesii, L. listii and L. solitudinis are specifically nodulated by highly effective, pink-pigmented bacteria that are most closely related to Methylobacterium nodulans on the basis of 16S rRNA gene homology. Methylobacterium spp. are characterized by their ability to utilize methanol and other C(1) compounds, but 11 Lotononis isolates neither grew on methanol as a sole carbon source nor were able to metabolize it. No product was obtained for PCR amplification of mxaF, the gene encoding the large subunit of methanol dehydrogenase. Searches for methylotrophy genes in the sequenced genome of Methylobacterium sp. 4-46, isolated from L. bainesii, indicate that the inability to utilize methanol may be due to the absence of the mxa operon. While methylotrophy appears to contribute to the effectiveness of the Crotalaria/M. nodulans symbiosis, our results indicate that the ability to utilize methanol is not a factor in the Lotononis/Methylobacterium symbiosis.
南非豆科植物贝恩氏洛托豆、利斯氏洛托豆和孤独洛托豆专门由高效的、呈粉红色的细菌结瘤,基于16S rRNA基因同源性,这些细菌与结瘤甲基杆菌关系最为密切。甲基杆菌属的特点是能够利用甲醇和其他C(1)化合物,但11株洛托豆分离株既不能以甲醇作为唯一碳源生长,也不能代谢甲醇。对编码甲醇脱氢酶大亚基的基因mxaF进行PCR扩增未获得产物。在从贝恩氏洛托豆中分离出的甲基杆菌属菌株4-46的测序基因组中搜索甲基营养基因,结果表明无法利用甲醇可能是由于缺少mxa操纵子。虽然甲基营养似乎有助于猪屎豆属/结瘤甲基杆菌共生的有效性,但我们的结果表明,利用甲醇的能力不是洛托豆属/甲基杆菌共生关系中的一个因素。