Non-nodulating pink-pigmented facultative Methylobacterium sp. with a functional nifH gene

Among the 250 Methylobacterium isolates studied, 11 were able to grow in Nitrogen-free methanol mineral salts medium. Out of the eleven isolates, except MV10, 10 isolates had the nodA gene. ARA and presence of nifH gene confirmed the ability of isolate MV10 to fix biological nitrogen. Plant infection tests conducted with Crotalaria sp. confirmed the inability of isolate MV10 to nodulate Crotalaria sp. The presence of a functional nifH gene and absence of a nodA gene differentiate this isolate from the other 15 species so far described in the genus Methylobacterium and suggest that it is a new species.