Characterization of pink pigmented facultative methylotrophic bacteria isolated from phyllosphere of some plants

Abstract

One hundred eighteen pink-pigmented methylotrophic bacterial isolates were successfully isolated in pure form from the phyllosphere of eleven economical crops. The ability of these isolates to grow in presence of different methanol concentrations (0.5, 1.0, 1.5 & 2.0%) as a sole source of carbon was evaluated. They were also tested for their capability to accumulate and produce poly-β-hydroxy butyrate (PHB) and indole acetic acid (IAA). Results indicated that, among the tested isolates, only eighteen ones were able to grow well at all the tested methanol concentrations and have a good capability to accumulate and produce the PHB and IAA. Quantitative determinations of PHB, IAA and Cytokinin as well as urease activity of these cultures proved that the isolates namely CP3 and M2 gave the highest values. The morphological and physiological studies for the later isolates indicated that these strains are related to members of the genus Methylobacterium. A comparative 16S rRNA gene sequence-based phylogenetic analysis placed the strains in a clade with the species Methylobacterium extorquens and Methylobacterium zatmanii, with which it showed sequence similarities of 98% and 97 %, respectively.