Chryseobacterium indologenes A Novel Root Nodule Endophyte in Vigna radiata

Abstract

Endophytic non rhizobial bacterial stain AM2 was isolated from root nodules of Vigna radiate. The bacterium was Gram-negative, yellow pigmented, nonspore forming, motile and oxidase positive. Phylogeny of 16S rRNA gene sequences revealed that the strain belonged to the genus Chryseobacterium, a member of family Flavobacteriaceae. Closest phylogenetic relatives to it were Chryseobacterium indologenes strain LMG8337 and Chryseobacterium indologenes strain NBRC 14944, respectively was showing 97% and 95% 16S rRNA gene sequence similarity. Strain showed presence of nifH gene of ~380 bp. It also exhibit nitrogen fixation ability around 19.55mg N g-1 of glucose consumed with indole acetic acid producing capability of 87.04 µg ml-1. However, phosphate solubilization and siderophore production was absent. 1-Aminocyclopropane-1- carboxylate deaminase activity was also present. In present study, to the best of our knowledge and literature surveyed endophytic non rhizobial C. indologenes AM2 isolated first time from root nodules of mungbean possessing plant growth promoting attributes.