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Yu M, Guo W, Liang Y, Xiang H, Xia Y, Feng H. Towards rapid formation of electroactive biofilm: insights from thermodynamics and electric field manipulation. WATER RESEARCH 2024; 261:121992. [PMID: 38971076 DOI: 10.1016/j.watres.2024.121992] [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: 04/03/2024] [Revised: 06/19/2024] [Accepted: 06/21/2024] [Indexed: 07/08/2024]
Abstract
Electroactive biofilm (EAB) has garnered significant attention due to its effectiveness in pollutant remediation, electricity generation, and chemical synthesis. However, achieving precise control over the rapid formation of EAB presents challenges for the practical implementation of bioelectrochemical technology. In this study, we investigated the regulation of EAB formation by manipulating applied electric potential. We developed a modified XDLVO model for the applied electric field and quantitatively assessed the feasibility of existing rapid formation strategies for EAB. Our results revealed that electrostatic (EL) force significantly influenced EAB formation in the presence of the applied electric field, with the potential difference between the electrode and the microbial solution being the primary determinant of EL force. Compared to -0.2 V and 0 V vs.Ag/AgCl, EAB exhibited the highest electrochemical performance at 0.2 V vs.Ag/AgCl, with a maximum current density of 6.044 ± 0.10 A/m2, surpassing that at -0.2 V vs.Ag/AgCl and 0 V vs.Ag/AgCl by 1.73 times and 1.31 times, respectively. Furthermore, EAB demonstrated the highest biomass accumulation, measuring a thickness of 25 ± 2 μm at 0.2 V vs. Ag/AgCl, representing increases of 1.67 and 1.25 times compared to -0.2 V vs.Ag/AgCl and 0 V vs.Ag/AgCl, respectively. The strong electrostatic attraction under the anodic potential promoted the formation of a monolayer of biofilm. Additionally, the hydrophilicity and hydrophobicity of the biofilm were altered following inversion culture. The Lewis acid-base (AB) attraction offset the electrostatic repulsion caused by negative charges, it is beneficial for the formation of biofilms. This study, for the first time, elucidated the difference in the formation of cathode and anode biofilm from a thermodynamic perspective in the context of electric field introduction, laying the theoretical foundation for the directional regulation of the rapid formation of typical electroactive biofilms.
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Affiliation(s)
- Mengfan Yu
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China
| | - Wei Guo
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China
| | - Yuxiang Liang
- College of Environment and Resources, College of Carbon Neutral, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China; Sino-Spain Joint Laboratory for Agricultural Environment Emerging Contaminants of Zhejiang Province, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China
| | - Hai Xiang
- College of Environment and Resources, College of Carbon Neutral, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China; Sino-Spain Joint Laboratory for Agricultural Environment Emerging Contaminants of Zhejiang Province, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China
| | - Yijing Xia
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China
| | - Huajun Feng
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China; College of Environment and Resources, College of Carbon Neutral, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China; Sino-Spain Joint Laboratory for Agricultural Environment Emerging Contaminants of Zhejiang Province, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China.
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2
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Sujiritha PB, Vikash VL, Ponesakki G, Ayyadurai N, Kamini NR. Microbially induced carbonate precipitation with Arthrobacter creatinolyticus: An eco-friendly strategy for mitigation of chromium contamination. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 365:121300. [PMID: 38955041 DOI: 10.1016/j.jenvman.2024.121300] [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: 12/15/2023] [Revised: 04/14/2024] [Accepted: 05/30/2024] [Indexed: 07/04/2024]
Abstract
Chromium contamination from abandoned industrial sites and inadequately managed waste disposal areas poses substantial environmental threat. Microbially induced carbonate precipitation (MICP) has shown promising, eco-friendly solution to remediate Cr(VI) and divalent heavy metals. In this study, MICP was carried out for chromium immobilization by an ureolytic bacterium Arthrobacter creatinolyticus which is capable of reducing Cr(VI) to less toxic Cr(III) via extracellular polymeric substances (EPS) production. The efficacy of EPS driven reduction was confirmed by cellular fraction analysis. MICP carried out in aqueous solution with 100 ppm of Cr(VI) co-precipitated 82.21% of chromium with CaCO3 and the co-precipitation is positively correlated with reduction of Cr(VI). The organism was utilized to remediate chromium spiked sand and found that MICP treatment decreased the exchangeable fraction of chromium to 0.54 ± 0.11% and increased the carbonate bound fraction to 26.1 ± 1.15% compared to control. XRD and SEM analysis revealed that Cr(III) produced during reduction, influenced the polymorph selection of vaterite during precipitation. Evaluation of MICP to remediate Cr polluted soil sample collected from Ranipet, Tamil Nadu also showed effective immobilization of chromium. Thus, A. creatinolyticus proves to be viable option for encapsulating chromium contaminated soil via MICP process, and effectively mitigating the infiltration of Cr(VI) into groundwater and adjacent water bodies.
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Affiliation(s)
- Parthasarathy Baskaran Sujiritha
- Department of Biochemistry and Biotechnology, CSIR - Central Leather Research Institute, Chennai, 600020, Tamil Nadu, India; University of Madras, Chennai, 600005, Tamil Nadu, India
| | - Vijan Lal Vikash
- Department of Biochemistry and Biotechnology, CSIR - Central Leather Research Institute, Chennai, 600020, Tamil Nadu, India
| | - Ganesan Ponesakki
- Department of Biochemistry and Biotechnology, CSIR - Central Leather Research Institute, Chennai, 600020, Tamil Nadu, India
| | - Niraikulam Ayyadurai
- Department of Biochemistry and Biotechnology, CSIR - Central Leather Research Institute, Chennai, 600020, Tamil Nadu, India
| | - Numbi Ramudu Kamini
- Department of Biochemistry and Biotechnology, CSIR - Central Leather Research Institute, Chennai, 600020, Tamil Nadu, India.
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3
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Jia J, Xiao B, Yao L, Zhang B, Ma Y, Wang W, Han Y, Lei Q, Zhao R, Dong J, Wei N, Zhang H. The dominant role of extracellular polymeric substances produced by Achromobacter xylosoxidans BP1 in Cr(VI) microbial reduction. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 947:174464. [PMID: 38964391 DOI: 10.1016/j.scitotenv.2024.174464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 06/12/2024] [Accepted: 07/01/2024] [Indexed: 07/06/2024]
Abstract
Extracellular polymeric substances (EPS) have demonstrated significant benefits for reducing multivalent metal contamination. Using Achromobacter xylosoxidans BP1 isolated from a coal chemical site in China, this study elucidated the contribution of EPS production to Cr (VI) reduction and revealed its biological removal mechanism. BP1 grew at an optimum pH of 8 and the lowest inhibitory concentration of Cr(VI) was 300 mg/L. The spent medium completely removed Cr(VI), whereas resting cells were only able to remove 10.47 % and inactivated cells were nearly incapable of Cr(VI) removal. S-EPS and B-EPS reduced Cr(VI) by 98.59 % and 11.64 %, respectively. SEM-EDS analysis showed that the BP1 cells were stimulated to produce EPS under Cr stress. The XPS results showed that 29.63 % of Cr(VI) was enriched by intracellular bioaccumulation or biosorption and 70.37 % of Cr(VI) was reduced by extracellular enzymes to produce Cr(OH)3 and organic Cr(III) complexes. According to FTIR, EPS with -OH, COO-, and amide groups supplied binding sites and electrons for the reductive adsorption of Cr(VI). Genomic studies showed that BP1 primarily produces extracellular polysaccharides, metabolises sulphur and nitrogen, and reduces reactive oxygen species damage as a result of DNA repair proteases.
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Affiliation(s)
- Jianli Jia
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, People's Republic of China.
| | - Bing Xiao
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, People's Republic of China.
| | - Linying Yao
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, People's Republic of China.
| | - Ben Zhang
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, People's Republic of China.
| | - Yichi Ma
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, People's Republic of China.
| | - Weiran Wang
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, People's Republic of China.
| | - Yuxin Han
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, People's Republic of China.
| | - Qiushuang Lei
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, People's Republic of China; Center for Soil Protection and Landscape Design, Chinese Academy of Environmental Planning, Beijing 100041, People's Republic of China.
| | - Ruofan Zhao
- Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, People's Republic of China.
| | - Jingqi Dong
- Center for Soil Protection and Landscape Design, Chinese Academy of Environmental Planning, Beijing 100041, People's Republic of China.
| | - Nan Wei
- Center for Soil Protection and Landscape Design, Chinese Academy of Environmental Planning, Beijing 100041, People's Republic of China.
| | - Hongzhen Zhang
- Center for Soil Protection and Landscape Design, Chinese Academy of Environmental Planning, Beijing 100041, People's Republic of China.
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Shi J, Yang Y, Zhang S, Lin Q, Sun F, Lin H, Shen C, Su X. New insights into survival strategies and PCB bioremediation potential of resuscitated strain Achromobacter sp. HR2 under combined stress conditions. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133242. [PMID: 38103289 DOI: 10.1016/j.jhazmat.2023.133242] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 12/08/2023] [Accepted: 12/10/2023] [Indexed: 12/19/2023]
Abstract
The resuscitated strains achieved through the addition of resuscitation promoting factor (Rpf) hold significant promise as bio-inoculants for enhancing the bioremediation of polychlorinated biphenyls (PCBs). Nevertheless, the potential of these resuscitated strains to transition into a viable but non-culturable (VBNC) state, along with the specific stressors that initiate this transformation, remains to be comprehensively elucidated. In this study, a resuscitated strain HR2, obtained through Rpf amendment, was employed to investigate its survival strategies under combined stress involving low temperature (LT), and PCBs, in the absence and presence of heavy metals (HMs). Whole-genome analysis demonstrated that HR2, affiliated with Achromobacter, possessed 107 genes associated with the degradation of polycyclic aromatic compounds. Remarkably, HR2 exhibited effective degradation of Aroclor 1242 and robust resistance to stress induced by LT and PCBs, while maintaining its culturability. However, when exposed to the combined stress of LT, PCBs, and HMs, HR2 entered the VBNC state. This state was characterized by significant decreases in enzyme activities and notable morphological, physiological, and molecular alterations compared to normal cells. These findings uncovered the survival status of resuscitated strains under stressful conditions, thereby offering valuable insights for the development of effective bioremediation strategies.
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Affiliation(s)
- Jie Shi
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua 321004, China
| | - Yingying Yang
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua 321004, China
| | - Shusheng Zhang
- The Management Center of Wuyanling National Natural Reserve in Zhejiang, Wenzhou 325500, China
| | - Qihua Lin
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua 321004, China
| | - Faqian Sun
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua 321004, China
| | - Hongjun Lin
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua 321004, China
| | - Chaofeng Shen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xiaomei Su
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua 321004, China.
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5
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Yang Y, Zhang Q, Lin Q, Sun F, Shen C, Lin H, Su X. Unveiling the PCB biodegradation potential and stress survival strategies of resuscitated strain Pseudomonas sp. HR1. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 344:123320. [PMID: 38185359 DOI: 10.1016/j.envpol.2024.123320] [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: 09/30/2023] [Revised: 01/03/2024] [Accepted: 01/04/2024] [Indexed: 01/09/2024]
Abstract
The exploration of resuscitated strains, facilitated by the resuscitation promoting factor (Rpf), has substantially expanded the pool of cultivated degraders, enhancing the screening of bio-inoculants for bioremediation applications. However, it remains unknown whether these resuscitated strains can re-enter the viable but non-culturable (VBNC) state and the specific stress conditions that trigger such a transition. In this work, the whole genome, and polychlorinated biphenyl (PCB)-degrading capabilities of a resuscitated strain HR1, were investigated. Notably, the focus of this exploration was on elucidating whether HR1 would undergo a transition into the VBNC state when exposed to low temperature and PCBs, with and without the presence of heavy metals (HMs). The results suggested that the resuscitated strain Pseudomonas sp. HR1 harbored various functional genes related to xenobiotic biodegradation, demonstrating remarkable efficiency in Aroclor 1242 degradation and strong resistance against stress induced by low temperature and PCBs. Nevertheless, when exposed to the combined stress of low temperature, PCBs, and HMs, HR1 underwent a transition into the VBNC state. This transition was characterized by significant decreases in enzyme activities and notable changes in both morphological and physiological traits when compared to normal cells. Gene expression analysis revealed molecular shifts underlying the VBNC state, with down-regulated genes showed differential expression across multiple pathways and functions, including oxidative phosphorylation, glycolysis, tricarboxylic acid cycle, amino acid metabolism, translation and cytoplasm, while up-regulated genes predominantly associated with transcription regulation, membrane function, quorum sensing, and transporter activity. These findings highlighted the great potential of resuscitated strains as bio-inoculants in bioaugmentation and shed light on the survival mechanisms of functional strains under stressful conditions, which should be carefully considered during bioremediation processes.
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Affiliation(s)
- Yingying Yang
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua, 321004, China
| | - Qian Zhang
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua, 321004, China
| | - Qihua Lin
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua, 321004, China
| | - Faqian Sun
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua, 321004, China
| | - Chaofeng Shen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Hongjun Lin
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua, 321004, China
| | - Xiaomei Su
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua, 321004, China.
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6
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Koşarsoy Ağçeli G. Similarities and differences of nano-sized levan synthesized by Bacillus haynesii at low and high temperatures: Characterization and bioactivity. Int J Biol Macromol 2023; 253:126804. [PMID: 37709216 DOI: 10.1016/j.ijbiomac.2023.126804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 08/01/2023] [Accepted: 09/06/2023] [Indexed: 09/16/2023]
Abstract
Levan is a biopolymer with many different uses. Temperature is an important parameter in biopolymer synthesis. Herein, levan production was carried out from Bacillus haynesii, a thermophilic microorganism, in the temperature range of 4 °C-95 °C. The highest levan production was measured as 10.9 g/L at 37 °C. The synthesized samples were characterized by FTIR and NMR analysis. The particle size of the levan samples varied between 153 and 824.4 nm at different temperatures. In levan samples produced at high temperatures, the water absorption capacity is higher in accordance with the particle size. Irregularities were observed in the surface pores at temperatures of 60 °C and above. The highest emulsion capacity of 83.4 % was measured in the sample synthesized at 4 °C. The antioxidant activity of all levan samples synthesized at different temperatures was measured as 84 % on average. All synthesized levan samples showed antibacterial effect on pathogenic bacteria. In addition, levan synthesized at 45 °C showed the highest antimicrobial effect on E. coli ATCC 35218 with an inhibition zone of 21.3 ± 1.82 mm. Antimicrobial activity against yeast sample C. albicans, was measured only in levan samples synthesized at 80 °C, 90 °C, 95 °C temperatures. Levan synthesized from Bacillus haynesii at low and high temperatures showed differences in characterization and bioactivity.
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Affiliation(s)
- Gözde Koşarsoy Ağçeli
- Hacettepe University, Faculty of Science, Department of Biology, Beytepe Campus, 06800 Ankara, Turkey.
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7
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Li T, Du D, Li C, Zhao J, Guo L, Wang X, Zhao J, Xiang W. Investigation on Cr(VI)-bioreduction mechanism and reduction products by a novel Microbacterium sp. strain NEAU-W11. CHEMOSPHERE 2023; 343:140232. [PMID: 37734508 DOI: 10.1016/j.chemosphere.2023.140232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 08/12/2023] [Accepted: 09/18/2023] [Indexed: 09/23/2023]
Abstract
Cr(VI) widely exists in the environment and has highly toxic, carcinogenic and mutagenic effects on all organisms. Physical/chemical methods to remove chromium pollution are economically expensive and have disadvantages like high reagent consumption, energy requirements and so on, while bioremediation is an eco-friendly, simple and cost-effective way. In this study, a novel Cr(VI)-reducing strain, Microbacterium sp. NEAU-W11, was reported, and its reduction mechanism was investigated. Microbacterium sp. NEAU-W11 could effectively degrade Cr(VI) under the conditions of pH 7-10, 15-35 °C, and the coexistence of metal pollutants such as Pb and Ni, etc. In addition, both Fe3+ and Cu2+ could improve the reducing ability of strain NEAU-W11, and glucose and lactose as electron donors also had promoting effect. Heat treatment of resting cells confirmed that chromium removal was not biological sorption but biological reduction. The active reductase of strain NEAU-W11 to chromium(VI) mainly existed in the cell cytoplasm, which is the first report in the genus Microbacterium. Micro-characterization of strain NEAU-W11 and the reduction products identified the reduction products as Cr(III)-ligand complexes bound to extracellular polymeric substances (EPS). Collectively, this study systematically investigated the degradation mechanism of Microbacterium sp. NEAU-W11 and the distribution of degradation product Cr(III), providing a new reduction mechanism for the genus Microbacterium, providing a new perspective for a comprehensive understanding of the degradation and transport of chromium by bacteria, and providing theoretical reference for the migration of metal ions in environmental governance.
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Affiliation(s)
- Tingting Li
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China
| | - Dandan Du
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China
| | - Chenxu Li
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China
| | - Junlei Zhao
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China
| | - Lifeng Guo
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China
| | - Xiangjing Wang
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China
| | - Junwei Zhao
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China.
| | - Wensheng Xiang
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, 150030, People's Republic of China; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
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8
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Luo Y, Pang J, Peng C, Ye J, Long B, Tong J, Shi J. Cr(VI) Reduction and Fe(II) Regeneration by Penicillium oxalicum SL2-Enhanced Nanoscale Zero-Valent Iron. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023. [PMID: 37474249 DOI: 10.1021/acs.est.3c01390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Nanoscale zero-valent iron (nZVI) faces significant challenges in Cr(VI) remediation through aggregation and passivation. This study identified a Cr(VI)-resistant filamentous fungus (Penicillium oxalicum SL2) for nZVI activation and elucidated the synergistic mechanism in chromium remediation. P. oxalicum SL2 and nZVI synergistically and effectively removed Cr(VI), mainly by extracellular nonenzymatic reduction (89.1%). P. oxalicum SL2 exhibited marked iron precipitate solubilization and Fe(II) regeneration capabilities. The existence of the Fe(II)-Cr(V)-oxalate complex (HCrFeC4O9) indicated that in addition to directly reducing Cr(VI), iron ions generated by nZVI stimulated Cr(VI) reduction by organic acids secreted by P. oxalicum SL2. RNA sequencing and bioinformatics analysis revealed that P. oxalicum SL2 inhibited phosphate transport channels to suppress Cr(VI) transport, facilitated iron and siderophore transport to store Fe, activated the glyoxylate cycle to survive harsh environments, and enhanced organic acid and riboflavin secretion to reduce Cr(VI). Cr(VI) exposure also stimulated the antioxidative system, promoting catalase activity and maintaining the intracellular thiol/disulfide balance. Cr(VI)/Fe(III) reductases played crucial roles in the intracellular reduction of chromium and iron, while nZVI decreased cellular oxidative stress and alleviated Cr(VI) toxicity to P. oxalicum SL2. Overall, the P. oxalicum SL2-nZVI synergistic system is a promising approach for regenerating Fe(II) while reducing Cr(VI).
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Affiliation(s)
- Yating Luo
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jingli Pang
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Cheng Peng
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Jien Ye
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China
| | - Bibo Long
- Institute of Biological and Medical Engineering, Guangdong Academy of Sciences, Guangzhou 510316, China
| | - Jianhao Tong
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jiyan Shi
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
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9
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Wang Y, Fu M, Wu B, Huang M, Ma T, Zang H, Jiang H, Zhang Y, Li C. Insight into biofilm-forming patterns: biofilm-forming conditions and dynamic changes in extracellular polymer substances. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:89542-89556. [PMID: 35852740 DOI: 10.1007/s11356-022-21645-5] [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: 03/16/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
The microbial biofilm adheres to the surface of the carrier, which protects the pollutant-degrading bacteria and resists harsh environments; thus, research on biofilm-forming patterns will help promote the application of biofilms in wastewater treatment. Herein, univariate analysis and response surface methodology (RSM) confirmed that glucose and mannose at 3-5 g/L promoted biofilm formation. Notably, the microplate method demonstrated that compared to trivalent cations, divalent cations could more greatly enhance the activity (especially magnesium) of the biofilm matrix, and the period of biofilm formation in the three strains was divided into the following stages: initial attachment (0-10 h), microcolony (10-24 h), maturation (24-48 h), and dispersion (36-72 h). During maturation, large amounts of extracellular polysaccharides (EPs) and extracellular DNA (eDNA) were distributed in the extracellular and intracellular spaces, respectively, as observed by super-resolution structured illumination microscopy (SR-SIM). This study enhances the understanding of the characteristics and patterns of biofilm formation and can facilitate the application of biofilms in wastewater treatment.
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Affiliation(s)
- Yue Wang
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Meng Fu
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Bowen Wu
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Mingyan Huang
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Tian Ma
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Hailian Zang
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Hanyi Jiang
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Yuting Zhang
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Chunyan Li
- College of Resource and Environment, Northeast Agricultural University, Harbin, 150030, China.
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10
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Feng H, Xu L, Chen R, Ma X, Qiao H, Zhao N, Ding Y, Wu D. Detoxification mechanisms of electroactive microorganisms under toxicity stress: A review. Front Microbiol 2022; 13:1084530. [DOI: 10.3389/fmicb.2022.1084530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 11/14/2022] [Indexed: 11/30/2022] Open
Abstract
Remediation of environmental toxic pollutants has attracted extensive attention in recent years. Microbial bioremediation has been an important technology for removing toxic pollutants. However, microbial activity is also susceptible to toxicity stress in the process of intracellular detoxification, which significantly reduces microbial activity. Electroactive microorganisms (EAMs) can detoxify toxic pollutants extracellularly to a certain extent, which is related to their unique extracellular electron transfer (EET) function. In this review, the extracellular and intracellular aspects of the EAMs’ detoxification mechanisms are explored separately. Additionally, various strategies for enhancing the effect of extracellular detoxification are discussed. Finally, future research directions are proposed based on the bottlenecks encountered in the current studies. This review can contribute to the development of toxic pollutants remediation technologies based on EAMs, and provide theoretical and technical support for future practical engineering applications.
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11
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Oleic Acid Facilitates Cd Excretion by Increasing the Abundance of Burkholderia in Cd-Exposed Mice. Int J Mol Sci 2022; 23:ijms232314718. [PMID: 36499044 PMCID: PMC9741113 DOI: 10.3390/ijms232314718] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/20/2022] [Accepted: 11/23/2022] [Indexed: 11/27/2022] Open
Abstract
As a global pollutant, cadmium (Cd) can easily enter the body through food chains, threatening human health. Most Cd is initially absorbed in the gut, with the gut microbiota playing a pivotal role in reducing Cd absorption and accumulation. This study assessed the effects of three fatty acids on Cd accumulation and toxicity in Cd-exposed mice. The results showed that oleic acid (OA) was the most effective in facilitating Cd excretion in mice among these fatty acids. The use of OA led to reduced Cd accumulation in the organs and increased Cd content in the feces. The metagenomic analysis of the gut microbiota showed that the genus Burkholderia was the most significantly restored by OA in Cd-exposed mice. Burkholderia cepacia, as the type species for the genus Burkholderia, also exhibited strong Cd tolerance after treatment with OA. Furthermore, the electron microscopy analysis showed that most of the Cd was adsorbed on the surface of B. cepacia, where the extracellular polymeric substances (EPSs) secreted by B. cepacia play a key role, displaying a strong capacity for Cd adsorption. The peak at 2355 cm-1 and the total sulfhydryl group content of EPSs showed significant increases following co-treatment with Cd and OA. The results demonstrated the potential roles that gut Burkholderia may play in OA-mediated Cd excretion in mice.
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Xiong L, Ma L, Zhao M, Zhang H, Chen S. Shewanella oneidensis MR-1 for enhanced the reactivity of FA-stabilized nZVI toward Cr(VI) removal. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.122542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Potential Applications of an Exopolysaccharide Produced by Bacillus xiamenensis RT6 Isolated from an Acidic Environment. Polymers (Basel) 2022; 14:polym14183918. [PMID: 36146061 PMCID: PMC9505781 DOI: 10.3390/polym14183918] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/09/2022] [Accepted: 09/15/2022] [Indexed: 11/17/2022] Open
Abstract
The Bacillus xiamenensis RT6 strain was isolated and identified by morphological, biochemical and molecular tests from an extreme acidic environment, Rio Tinto (Huelva). Optimisation tests for exopolysaccharide (EPS) production in different culture media determined that the best medium was a minimal medium with glucose as the only carbon source. The exopolymer (EPSt) produced by the strain was isolated and characterised using different techniques (GC-MS, HPLC/MSMS, ATR-FTIR, TGA, DSC). The molecular weight of EPSt was estimated. The results showed that the average molecular weight of EPSt was approximately 2.71 × 104 Da and was made up of a heteropolysaccharide composed of glucose (60%), mannose (20%) and galactose (20%). The EPSt showed antioxidant capabilities that significantly improved cell viability. Metal chelation determined that EPSt could reduce the concentration of transition metals such as iron at the highest concentrations tested. Finally, the emulsification study showed that EPSt was able to emulsify different natural polysaccharide oils, reaching up to an 80% efficiency (olive and sesame oil), and was a good candidate for the substitution of the most polluting emulsifiers. The EPSt was found to be suitable for pharmaceutical and industrial applications.
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Li H, Wu Y, Tang Y, Fang B, Luo P, Yang L, Jiang Q. A manganese-oxidizing bacterium-Enterobacter hormaechei strain DS02Eh01: Capabilities of Mn(II) immobilization, plant growth promotion and biofilm formation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 309:119775. [PMID: 35843452 DOI: 10.1016/j.envpol.2022.119775] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 07/06/2022] [Accepted: 07/10/2022] [Indexed: 06/15/2023]
Abstract
While biogenic Mn oxides (BioMnOx) generated by Mn(II)-oxidizing bacteria (MOB) have attracted increasing attention, a MOB strain isolated from Mn-polluted sediments was identified and assigned as Enterobacter hormaechei DS02Eh01. Its Mn(II) immobilization activity, plant growth-promoting traits, and biofilm formation capability were investigated. The results showed that strain DS02Eh01 was found to be able to tolerate Mn(II) up to 122 mM. The strain immobilized Mn(II) in aquatic media mainly through extracellular adsorption, bio-oxidation and pH-induced precipitation as well as manganese oxidation. DS02Eh01-derived BioMnOx are negatively charged and have a larger specific surface area (86.70 m2/g) compared to the previously reported BioMnOx. The strain can immobilize Mn(II) at extreme levels, for instance, when it was exposed to 20 mM Mn(II), about 59% of Mn(II) were found immobilized and 17% of Mn(II) were converted to MnOx. The SEM and TEM observation revealed that the DS02Eh01-derived BioMnOx were aggregates doped with granules and microbial pellets. The precipitated Mn(II) and the Mn(III)/Mn(IV) oxides co-existed in BioMnOx, in which Mn(II) and Mn(IV) were found dominant with Mn(II) accounting for 49.6% and Mn(IV) accounting for 41.3%. DS02Eh01 possesses plant growth-promoting traits and biofilm formation capacity even under Mn(II) exposure. Mn(II) exposure at 5 mM was found to stimulate strain DS02Eh01 to form biofilms, from which, the extracted EPS was mainly composed of aromatic proteins. This study reveals that E. hormaechei strain DS02Eh01 possesses the potential in environmental ecoremediation via coupling processes of macrophytes extraction, biochemical immobilization and biosorption.
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Affiliation(s)
- Huilan Li
- Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials & MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China; Key Laboratory of Environmental Protection (Guangxi University), Education Department of Guangxi Zhuang Autonomous Region, Nanning, 530004, China
| | - Yu Wu
- Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials & MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China; Key Laboratory of Environmental Protection (Guangxi University), Education Department of Guangxi Zhuang Autonomous Region, Nanning, 530004, China
| | - Yankui Tang
- Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials & MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China; Key Laboratory of Environmental Protection (Guangxi University), Education Department of Guangxi Zhuang Autonomous Region, Nanning, 530004, China.
| | - Bo Fang
- Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials & MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China; Key Laboratory of Environmental Protection (Guangxi University), Education Department of Guangxi Zhuang Autonomous Region, Nanning, 530004, China
| | - Penghong Luo
- Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials & MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China; Key Laboratory of Environmental Protection (Guangxi University), Education Department of Guangxi Zhuang Autonomous Region, Nanning, 530004, China
| | - Luling Yang
- Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials & MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China; Key Laboratory of Environmental Protection (Guangxi University), Education Department of Guangxi Zhuang Autonomous Region, Nanning, 530004, China
| | - Qiming Jiang
- Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials & MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China; Key Laboratory of Environmental Protection (Guangxi University), Education Department of Guangxi Zhuang Autonomous Region, Nanning, 530004, China
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