Isolation and Identification of Agrobacterium and Azotobacter Species Capable of Producing Curdlan and Alginate Biopolymers

Curdlan is an important homopolysaccharide, while Alginate is a naturally occurring polymer. Numerous bacteria species have the potential to produce these biopolymers.In this study, Agrobacterium and Azotobacter species capable of producing these polymers were isolated and identified. Soil samples from different legume and cereal farms were inoculated unto mannitol glutamate agar containing aniline blue dyes, Nitrogen free Jensen’s agar medium and Asby agar medium for isolation of the bacteria,The isolates obtained were subjected to biochemical tests and 16S rRNA sequencing for identification. Result showed that 5 species of Agrobaterium grew on aneline blue mannitol glutamate agar (aMGA) exhibiting blue coloration; 2 Azotobacter spp grew on Jensen nitrogen free agar; Agrobaterium and Azotobacter species appeared as Gram negative rods; Agrobaterium spp were KOH sensitive, urease, catalase,citrate positive, hydrolyze starch while Azotobacter spp were positive for methly red, indole, catalase, urease, citrate utilization, starch hydrolysis, and hydrogen sulfide production. Molecular identification showed a band of 1500bp product of 16S rRNA gene of Agrobacterium spp on gel electrophoresis. Result further showed that the Agrobacterium species isolates were capable of producing Curdlan while Azotobacter vinelandii demonstrated Alginate biopolymer production. these findings provide suitable indigenous bacterial strains that will enhance biopolymer production.