Abstract

This work highlighted a putative link between the physiological activity and genetic diversity of Methylobacterium species and the association with sugarcane roots and rhizoplane. In total, 40 isolates previously described as pink-pigmented facultative methylotrophic bacteria (PPFMs), were evaluated for their ability to fix nitrogen and solubilize inorganic phosphate, amylase and pectinase activity. This in vitro potential was positively correlated with the community isolated from the root tissues than those from the rhizoplane. Regarding the genomic fingerprinting, the (BOX-PCR) approach revealed a low similarity among the isolates, occurring sole 7 haplotypes harboring more than 70% of similarity among band patterns. These results revealed that the genomic fingerprinting of the isolates recovery from roots is different from the rhizoplane. Besides that, these haplotypes occurred on both sugarcane varieties. Using a phylogenetic sequencing approach based on the 16S rRNA gene, we observed a high abundance of sequences similar to Methylobacterium radiotolerans colonizing both plant tissue and sugarcane varieties were observed. Hence, it was suggested that the plant should select those Methylobacterium spp. with a high biotechnological potential to promote plant growth. Therefore, the bioprospection of specific endophytic bacterial groups comprise an important source of biotechnological potential to improve sugarcane growth and production.

Key words: Pink-pigmented facultative methylotrophic bacteria, plant growth promotion, BOX-PCR, 16S rDNA, Methylobacterium radiotolerans.