Characteristics and Mechanism of Ammonia Nitrogen Removal by Heterotrophic Nitrification Bacterium <i>Klebsiella pneumoniae</i> LCU1 and Its Application in Wastewater Treatment
In this study, a novel strain exhibiting heterotrophic nitrification was screened; subsequently, the strain was identified as <i>Klebsiella pneumoniae</i> LCU1 using 16S rRNA gene sequencing. The aim of the study was to investigate the effects of external factors on the NH<sub>4<...
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| Main Authors: | , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
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| Series: | Microorganisms |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-2607/13/2/297 |
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| Summary: | In this study, a novel strain exhibiting heterotrophic nitrification was screened; subsequently, the strain was identified as <i>Klebsiella pneumoniae</i> LCU1 using 16S rRNA gene sequencing. The aim of the study was to investigate the effects of external factors on the NH<sub>4</sub><sup>+</sup>-N removal efficiency of strain LCU1 in order to elucidate the optimal conditions for NH<sub>4</sub><sup>+</sup>-N removal by the strain and improve the removal efficiency. The findings indicated that the NH<sub>4</sub><sup>+</sup>-N removal efficiency of the strain exceeded 80% under optimal conditions (sodium succinate carbon source, C/N ratio of 10, initial pH of 8.0, temperature of 30 °C, and speed of 180 rpm). The genome analysis of strain LCU1 showed that key genes involved in nitrogen metabolism, including <i>nar</i>GHI, <i>nir</i>B, <i>nxr</i>AB, and <i>nas</i>AB, were successfully annotated; <i>hao</i> and <i>amo</i> were absent, but the nitrogen properties analysis determined that the strain had a heterotrophic nitrification ability. After 120 h, the NH<sub>4</sub><sup>+</sup>-N removal efficiency of strain LCU1 was 34.5% at a high NH<sub>4</sub><sup>+</sup>-N concentration of 2000 mg/L. More importantly, the NH<sub>4</sub><sup>+</sup>-N removal efficiency of this strain was above 34.13% at higher Cu<sup>2+</sup>, Mn<sup>2+</sup>, and Zn<sup>2+</sup> ion concentrations. Furthermore, strain LCU1 had the highest NH<sub>4</sub><sup>+</sup>-N removal efficiency of 34.51% for unsterilised (LCU1-OC) aquaculture wastewater. This suggests that with intensive colonisation treatment, the strain has promising application potential in real wastewater treatment. |
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| ISSN: | 2076-2607 |