Isolation and Identification of Uranium Tolerant Phosphate-Solubilizing Bacillus spp. and Their Synergistic Strategies to U(VI) Immobilization
Open Access
- 13 July 2021
- journal article
- research article
- Published by Frontiers Media SA in Frontiers in Microbiology
- Vol. 12, 676391
- https://doi.org/10.3389/fmicb.2021.676391
Abstract
The remediation of uranium (U) through phosphate-solubilizing bacteria (PSB) is an emerging technique as well as an interesting phenomenon for transforming mobile U into stable minerals in the environment. While studies are well needed for in-depth understanding of the mechanism of U(VI) immobilization by PSB. In this study, two PSB were isolated from a U-tailing repository site. These bacterial strains (ZJ-1 and ZJ-3) were identified as Bacillus spp. by the sequence analysis of 16S ribosomal RNA (rRNA) genes. Incubation of PSB in liquid medium showed that the isolate ZJ-3 could solubilize more than 230 mg L–1 P from glycerol-3-phosphate and simultaneously removed over 70% of 50 mg L–1 U(VI) within 1 h. During this process, the rapid appearance of yellow precipitates was observed. The microscopic and spectroscopic analysis demonstrated that the precipitates were associated with U-phosphate compound in the form of saleeite-like substances. Besides, scanning electron microscopy coupled with energy-dispersive X-ray (SEM-EDS) and Fourier transform infrared spectroscopy (FTIR) analysis of the precipitates confirmed that the extracellular polymeric substances (EPS) might also play a key role in U sequestration. Furthermore, SEM and FTIR analysis revealed that part of U(VI) was adsorbed on the bacterial surface through cellular phosphate, hydroxy, carboxyl, and amide groups. This study provides new insights into the synergistic strategies enhancing U immobilization rates by Bacillus spp. that uses glycerol-3-phosphate as the phosphorus source, the process of which contributes to harmful pollutant biodegradation.Funding Information
- National Key Research and Development Program of China
- National Key Research and Development Program of China
- National Key Research and Development Program of China
This publication has 43 references indexed in Scilit:
- Aerobic uranium immobilization by Rhodanobacter A2-61 through formation of intracellular uranium–phosphate complexesMetallomics, 2013
- Uranium Interaction with Two Multi-Resistant Environmental Bacteria: Cupriavidus metallidurans CH34 and Rhodopseudomonas palustrisPLOS ONE, 2012
- Isolation of phosphate solubilizing bacteria and their potential for lead immobilization in soilJournal of Hazardous Materials, 2011
- Extracellular polymeric substances from Shewanella sp. HRCR‐1 biofilms: characterization by infrared spectroscopy and proteomicsEnvironmental Microbiology, 2011
- Uranium and thorium sequestration by a Pseudomonas sp.: Mechanism and chemical characterizationJournal of Hazardous Materials, 2009
- Aerobic uranium (VI) bioprecipitation by metal‐resistant bacteria isolated from radionuclide‐ and metal‐contaminated subsurface soilsEnvironmental Microbiology, 2007
- Induction of σB-dependent general stress genes by amino acid starvation in a spo0H mutant of Bacillus subtilisFEMS Microbiology Letters, 2001
- An efficient microbiological growth medium for screening phosphate solubilizing microorganismsFEMS Microbiology Letters, 1999
- Uranium Bioaccumulation by a Citrobacter sp. as a Result of Enzymically Mediated Growth of Polycrystalline HUO 2 PO 4Science, 1992
- A modified single solution method for the determination of phosphate in natural watersAnalytica Chimica Acta, 1962