Isolation and identification of the molybdenum-resistant strain Raoultella ornithinolytica A1 and its effect on MoO42- in the environment

The mining and leakage of molybdenum (Mo) can cause environmental contamination which has not been realized until recently. Bacteria that can mitigate Mo-contamination was enriched and isolated. The low temperature and different pH conditions were considered to analysis its feasibility in Northern China which suffers from a long time of low temperatures every year. The result showed that the removal rate of MoO42- by Raoultella ornithinolytica A1 reached 30.46% at 25 & DEG;C and pH 7.0 in Luria-Bertani medium (LB). Meanwhile, A1 also showed some efficiency in the reduction of MoO42- in low phosphate molybdate medium (LPM), which reached optimum at the MoO42- concentration of 10 mM. The results of FTIR indicated that the cell wall performed an essential role in the MoO42- removal process, which was illustrated by the distribution of Mo in A1 (Mo bound to cell wall accounted for 92.29% of the total MoO42- removed). In addition, low temperature (10 & DEG;C) effect the removal rate of MoO42- by - 8.38 to 11.66%, indicating the potential for the in-situ microbial remediation of Mo-contaminated environments in low temperature areas.