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Song F, Zhang G, Xu X, Polyak SW, Zhang K, Li H, Yang N. Role of intracellular energy metabolism in Mn(Ⅱ) removal by the novel bacterium Stenotrophomonas sp. MNB17. Chemosphere 2022; 308:136435. [PMID: 36113658 DOI: 10.1016/j.chemosphere.2022.136435] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 08/07/2022] [Accepted: 09/10/2022] [Indexed: 06/15/2023]
Abstract
Microorganism-mediated Mn(Ⅱ) removal has gained increasing attention as a valuble bioremediation approach. In this study, a novel strain Stenotrophomonas sp. MNB17 - obtained from marine sediments - was found to show Mn(Ⅱ) removal efficiencies of 98.51-99.38% within 7 days and 92.24% within 20 days at Mn(Ⅱ) concentrations of 10-40 mM and 50 mM, respectively. On day 7, 80.44% of 50 mM Mn(Ⅱ) was oxidized to Mn(Ⅲ/Ⅳ), whereas only 2.11-2.86% of 10-40 mM Mn(Ⅱ) was oxidized. This difference in the proportion of Mn-oxides suggested that the strain MNB17 could remove soluble Mn(Ⅱ) via distinct mechanisms under different Mn(Ⅱ) concentrations. At 10 mM Mn(Ⅱ), indirect mechanisms were employed by strain MNB17 to remove Mn(Ⅱ). The sufficient energy generated by increased cellular respiration led to enhanced ammonification, and MnCO3 was the main component of the Mn-precipitates (97.27%). Meanwhile, intracellular fatty acids were degraded and served as an important carbon source for respiration. At 50 mM Mn(Ⅱ), most of the soluble Mn(Ⅱ) was oxidized, and Mn-oxides dominated the Mn-precipitates (80.44%). Mn(Ⅱ) oxidation likely contributed to electrons for energy production, as the down-regulation of respiratory pathways resulted in a deficit of electron supply, which warrants futher study. The exogenous addition of tricarboxylic acid cycle substrates (malate, α-ketoglutarate, oxaloacetate, succinate, and fumarate) was found to accelerate Mn(Ⅱ) removal as MnCO3 at a concentration of 50 mM. Overall, this study reports a novel strain MNB17 with the biotechnological potential of Mn(Ⅱ) removal and elucidates the function of cellular energy metabolism during the Mn(Ⅱ) removal process. In addition, it demonstrates the potential of aerobic respiration-related substrates in accelerating the removal of high concentrations of Mn(Ⅱ) for the first time.
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Affiliation(s)
- Fuhang Song
- School of Light Industry, Beijing Technology and Business University, 11 Fucheng Road, Beijing, 100048, China
| | - Guoliang Zhang
- Center of Deep Sea Research, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China
| | - Xiuli Xu
- School of Ocean Sciences, China University of Geosciences, 29 Xueyuan Road, Beijing, 100083, China
| | - Steven W Polyak
- UniSA Clinical and Health Sciences, University of South Australia, Adelaide, 5005, Australia
| | - Kai Zhang
- School of Light Industry, Beijing Technology and Business University, 11 Fucheng Road, Beijing, 100048, China
| | - Honghua Li
- School of Light Industry, Beijing Technology and Business University, 11 Fucheng Road, Beijing, 100048, China
| | - Na Yang
- CAS Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 1 Wenhai Road, Qingdao, 266237, China.
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