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Wen Q, Wang Z, Liu B, Liu S, Huang H, Chen Z. Enrichment performance and salt tolerance of polyhydroxyalkanoates (PHAs) producing mixed cultures under different saline environments. ENVIRONMENTAL RESEARCH 2024; 251:118722. [PMID: 38499223 DOI: 10.1016/j.envres.2024.118722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 03/08/2024] [Accepted: 03/12/2024] [Indexed: 03/20/2024]
Abstract
The key to the resource recycling of saline wastes in form of polyhydroxyalkanoates (PHA) is to enrich mixed cultures with salt tolerance and PHA synthesis ability. However, the comparison of saline sludge from different sources and the salt tolerance mechanisms of salt-tolerant PHA producers need to be clarified. In this study, three kinds of activated sludge from different salinity environments were selected as the inoculum to enrich salt-tolerant PHA producers under aerobic dynamic feeding (ADF) mode with butyric acid dominated mixed volatile fatty acid as the substrate. The maximum PHA content (PHAm) reached 0.62 ± 0.01, 0.62 ± 0.02, and 0.55 ± 0.03 g PHA/g VSS at salinity of 0.5%, 0.8%, and 1.8%, respectively. Microbial community analysis indicated that Thauera, Paracoccus, and Prosthecobacter were dominant salt-tolerant PHA producers at low salinity, Thauera, NS9_marine, and SM1A02 were dominant salt-tolerant PHA producers at high salinity. High salinity and ADF mode had synergistic effects on selection and enrichment of salt-tolerant PHA producers. Combined correlation network with redundancy analysis indicated that trehalose synthesis genes and betaine related genes had positive correlation with PHAm, while extracellular polymeric substances (EPS) content had negative correlation with PHAm. The compatible solutes accumulation and EPS secretion were the main salt tolerance mechanisms of the PHA producers. Therefore, adding compatible solutes is an effective strategy to improve PHA synthesis in saline environment.
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Affiliation(s)
- Qinxue Wen
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin, 150090, China; School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Zifan Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin, 150090, China; School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Baozhen Liu
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101, China
| | - Shaojiao Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin, 150090, China; School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou, 510006, China
| | - Haolong Huang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin, 150090, China; School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Zhiqiang Chen
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin, 150090, China; School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
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Zhu L, Li W, Huang C, Tian Y, Xi B, Wu W, Yan Y. Contribution of sulfur-containing precursors to release of hydrogen sulfide in sludge composting. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 353:120195. [PMID: 38306858 DOI: 10.1016/j.jenvman.2024.120195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 01/03/2024] [Accepted: 01/20/2024] [Indexed: 02/04/2024]
Abstract
Hydrogen sulfide (H2S) production during composting can impact the environment and human health. Especially during the thermophilic phase, H2S is discharged in large quantities. However, in sludge composting, the contributions of different sulfur-containing precursors to H2S fluxes, key functional microorganisms, and key environmental parameters for reducing H2S flux remain unclear. Analysis of cysteine (Cys), methionine (Met), and sulfate (SO42-) concentrations, multiple stepwise regression analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation analysis of metagenomes showed that Cys was the main contributor to the production of H2S and that Met was among the main sources during the first three days of composting, while the SO42- contribution to H2S was negligible. Fifteen functional genera involved in the conversion of precursors to H2S were identified by co-occurrence network analysis. Only Bacillus showed high temperature resistance (>50 °C) and the ability to reduce H2S. Redundancy analysis showed that total carbon (64.0 %) and pH (23.3 %) had significant effects on functional bacteria. H2S had a quadratic relationship with sulfur-containing precursors. All microbial network sulfur-containing precursors metabolism modules showed a highly significant relationship with Cys.
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Affiliation(s)
- Lin Zhu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Ecological Effect and Risk Assessment of Chemicals, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Wei Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Caihong Huang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Ecological Effect and Risk Assessment of Chemicals, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Yu Tian
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Beidou Xi
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Weixia Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Ecological Effect and Risk Assessment of Chemicals, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541006, China
| | - Yimeng Yan
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Ecological Effect and Risk Assessment of Chemicals, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541006, China
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Liu S, Chen Z, Liu B, Wen Q, Wang Z, Lin X, Wang Y. Ecological succession and community assembly of mixed microbial culture polyhydroxyalkanoate production systems: Drivers of polyhydroxyalkanoate synthesis and Bdellovibrio predation. BIORESOURCE TECHNOLOGY 2024; 394:130204. [PMID: 38104663 DOI: 10.1016/j.biortech.2023.130204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/19/2023]
Abstract
The production of polyhydroxyalkanoate (PHA) by mixed microbial culture (MMC) can reduce the pollution of plastics. Ecophysiological study of the microbial community assembly and succession is helpful for comprehensive understanding the MMC PHA production process. The operation mode of sequential aerobic dynamic discharge - aerobic dynamic feeding (ADD-ADF) was applied and the operation can be divided into acclimation phase and maturation phase. Deterministic process caused by selective pressure dominated the community assembly throughout the operation. In the acclimation phase, the physical selective pressure recovered the settling capacity of the system, and settling ability of the MMC was closely related to function of PHA synthesis. However, in the maturation phase, stochastic process caused sludge bulking, making the settling ability and PHA synthesis function of the MMC independent on each other. Stochastic process led to the succession of the dominant PHA-producing bacteria, for example, the predation of Paracoccus and Thauera by Bdellovibrio.
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Affiliation(s)
- Shaojiao Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Zhiqiang Chen
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Baozhen Liu
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101, China
| | - Qinxue Wen
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; School of Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Zifan Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Xiao Lin
- Beijing General Municipal Engineering Design & Research Institute Co., Ltd, Beijing 100082, China
| | - Yuhan Wang
- China Aviation Planning and Design Institute (Group) Co., Ltd, Beijing 100082, China
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Li D, Wen Q, Chen Z. Effects of Fe/Fe-Mn oxides loaded biochar on anaerobic degradation of typical phenolic compounds in coal gasification wastewater: Performance and mechanism. BIORESOURCE TECHNOLOGY 2024; 394:130308. [PMID: 38199441 DOI: 10.1016/j.biortech.2024.130308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/06/2024] [Accepted: 01/07/2024] [Indexed: 01/12/2024]
Abstract
In this study, two kinds of magnetic biochar (BC) were synthesized by loading Fe (FeBC) and Fe-Mn oxides (FMBC) and their effects on anaerobic phenolics degradation were investigated. Compared with BC/FMBC, FeBC addition achieved the superior phenolics biodegradation even for 3,5-xylenol. Compared with control, FeBC addition enhanced CH4 production by 100.1 % with the lag time shortened from 9.5 days to 6.6 days while it increased to 11.2 days with FMBC addition. FeBC addition activated adsorption-biodegradation and Fe (III) reduction with the improved electron transfer activity, adenosine triphosphate and cytochrome C concentrations. Abundant phenol degrading bacteria, electroactive bacteria, syntrophic partners could be enriched by FeBC addition, contributing to the enhanced benzoyl-CoA and methanogenesis pathways. However, this enhancement was inhibited by FMBC addition owing to the accumulation of reactive oxygen species. This study provided novel insights into the application of magnetic BC to enhanced anaerobic treatment of phenolic wastewater.
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Affiliation(s)
- Da Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090, PR China
| | - Qinxue Wen
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090, PR China
| | - Zhiqiang Chen
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090, PR China.
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