Characterization of the anaerobic denitrification bacterium Acinetobacter sp SZ28 and its application for groundwater treatment

Acinetobacter sp. SZ28 exhibited efficient autotrophic denitrification ability using Mn2+ as an electron donor. Sequence amplification identified the presence of the nirS gene. Meteorological chromatography analysis showed that N-2 was produced as an end product. Response surface methodology experiments showed that the maximum removal of nitrate occurred under the following conditions: Mn2+ concentration of 143.56 mg/L, C/N ratio of 6.82, initial pH of 5.17, and temperature of 34.26 degrees C, where the initial Mn2+ concentration produced the largest effect. In the groundwater experiment, nitrate levels decreased from 1.63 mg/L to 0 mg/L. Three-dimensional fluorescence analysis showed a decrease in the peak intensity of the original humus. Humus and the small-molecule amino acid tryptophan were detected. These results demonstrated that strain SZ28 is a suitable candidate for the simultaneous removal of nitrogen and Mn2+ in groundwater treatment. (C) 2015 Elsevier Ltd. All rights reserved.