Journal of Biotechnology & Biomaterials
Open Access

Abstract

Radiological survey and exploration by Atomic Mineral Division (AMD), Hyderabad, has indicated the presence of rich uranium deposits in the Bhima river belt of Karnataka (Gogi, Shahapur Taluk, Yadagiri district). The radionuclides/metal enriched reserves are under-explored ecosystems in terms of microbial diversity. It is envisaged that, these ecosystems might harbor microbes possessing special characteristics namely, metal-resistance, phosphate solubilization, and radiation resistance, which may be of use in remediating metal contaminated sites. With this background information, the present study was aimed at isolating and characterizing culturable and phosphate solubilizing bacteria from Gogi region (16� 43? N, 76� 44? E). Soil and tube well water samples were collected aseptically from these sites. These samples were analyzed in laboratory for pH, temperature, salinity, radionuclide activities namely K-40, Th-232 and Ra-226 and presence of phosphate solubilizing bacteria (PSB). For the isolation of PSBs, the samples were inoculated on Pikovskaya?s agar and incubated for 10 days. Among 32 isolates obtained on this media, 15 isolates showed clear zone around the colonies with the Solubilization Index > 1. These isolates were further assessed for their solubilization efficiency in Pikovskaya?s broth containing 5 g/L tri-calcium phosphate for 3 days. The phosphate released by the isolates ranged from 200 mg/L to 800 mg/L with proportional decrease in pH of the media which was significantly higher compared to the uninoculated control. The decrease in pH can be attributed to the release of organic acids which play a role in solubilization of insoluble phosphate. Taxonomic identification by 16S rRNA sequencing and phylogenetic analysis revealed that the isolates belonged to eight genera namely Acinetobacter, Curtobacterium, Enterobacter, Leclercia, Pseudomonas, Pantoea, Staphyloccus and Serratia. This study opens scope for in-depth investigation of these natural isolates possessing important characteristics for environmental application.

Biography

Sowmya S has completed Masters degree in Biotechnology and is presently pursuing Ph.D. on the topic of bioremediation of uranium under the guidance of Dr. Arun A.B. in Yenepoya University, Mangalore, Karnataka.