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Ou Y, Wu M, Yu Y, Liu Z, Zhang T, Zhang X. Low dose phosphorus supplementation is conducive to remediation of heavily petroleum-contaminated soil-From the perspective of hydrocarbon removal and ecotoxicity risk control. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 929:172478. [PMID: 38621545 DOI: 10.1016/j.scitotenv.2024.172478] [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: 12/29/2023] [Revised: 04/02/2024] [Accepted: 04/12/2024] [Indexed: 04/17/2024]
Abstract
Biostimulation by supplementing of nitrogen and phosphorus nutrients is a common strategy for remediation of petroleum-polluted soils. However, the dosage influence of exogenous nitrogen or phosphorus on petroleum hydrocarbon removal and soil ecotoxicity and microbial function remain unclear. In this study, we compared the efficiencies of hydrocarbon degradation and ecotoxicity control by experiment conducted over addition of inorganic nitrogen or phosphorus at C/N ratio of 100/10, C/N/P ratio of 100/10/1, and C/P ratio of 100/1 in a heavily petroleum-contaminated loessal soil with 12,320 mg/kg of total petroleum hydrocarbon (TPH) content. A 90-day incubation study revealed that low-dose of phosphorus addition with the C/P ratio of 100/1 promoted hydrocarbon degradation and reduced soil ecotoxicity. Microbial community composition analysis suggested that phosphorus addition enriched hydrocarbon degrader Gordonia and Mycolicibacterium genus. The key enzymes EC 5.3.3.8, EC 6.2.1.20 and EC 6.4.1.1 which referred to degradation of long-chain hydrocarbons, unsaturated fatty acids and pyruvate metabolism were abundance by phosphorus supplementation. While nitrogen addition at C/N ratio of 100/10 or C/N/P ratio of 100/10/1 inhibited hydrocarbon degradation and exacerbated soil ecotoxicity due to promoting denitrification and coupling reactions with hydrocarbons. Our results suggested that low-dose phosphorus addition served as a favorable strategy to promote crude oil remediation and ecotoxicity risk control in heavily petroleum-contaminated soil. Hence, the application of suitable doses of exogenous biostimulants is an efficient approach to restore the ecological functions of organically contaminated soils.
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Affiliation(s)
- Yawen Ou
- Key Laboratory of Environmental Engineering of Shaanxi Province, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an 710055, China
| | - Manli Wu
- Key Laboratory of Environmental Engineering of Shaanxi Province, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an 710055, China.
| | - Ying Yu
- Key Laboratory of Environmental Engineering of Shaanxi Province, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an 710055, China
| | - Zeliang Liu
- Key Laboratory of Environmental Engineering of Shaanxi Province, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an 710055, China
| | - Ting Zhang
- Key Laboratory of Environmental Engineering of Shaanxi Province, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an 710055, China
| | - Xuhong Zhang
- Key Laboratory of Environmental Engineering of Shaanxi Province, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an 710055, China
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Jin Y, Liu D, Xiong W, Wu Z, Xiao G, Wang S, Su H. Enhancing nitrogen removal performance using immobilized aerobic denitrifying bacteria by modified polyvinyl alcohol/sodium alginate (PVA/SA). CHEMOSPHERE 2024; 357:141954. [PMID: 38615964 DOI: 10.1016/j.chemosphere.2024.141954] [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: 01/08/2024] [Revised: 03/28/2024] [Accepted: 04/07/2024] [Indexed: 04/16/2024]
Abstract
Aerobic denitrification has emerged as a promising and efficient method for nitrogen removal from wastewater. However, the direct application of aerobic denitrifying bacteria has faced challenges such as low nitrogen removal efficiency, bacterial loss, and poor stability. To address these issues, this study developed a novel microbial particle carrier using NaHCO3-modified polyvinyl alcohol (PVA)/sodium alginate (SA) gel (NaHCO3-PVA/SA). This carrier exhibits several advantageous properties, including excellent mass transfer efficiency, favorable biocompatibility, convenient film formation, abundant biomass, and exceptional pollutant treatment capacity. The carrier was modified with 0.3% NaHCO3, 8.0% PVA, and 1.0% SA, resulting in a remarkable 3.4-fold increase in the average pore diameter and a 12.8% improvement in mass transfer efficiency. This carrier was utilized to immobilize the aerobic denitrifying bacterium Stutzerimonas stutzeri W-2 to enhance nitrogen removal (NaHCO3-PVA/SA@W-2), resulting in a NO3--N removal efficiency of 99.06%, which was 21.39% higher than that without modification. Compared with the non-immobilized W-2, the degradation efficiency was improved by 43.70%. After five reuses, the NO3--N and TN removal rates remained at 99% and 93.01%, respectively. These results provide a solid foundation for the industrial application of the modified carrier as an effective tool for nitrogen removal in large-scale wastewater treatment processes.
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Affiliation(s)
- Yu Jin
- Beijing Key Laboratory of Bioprocess, and Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Dan Liu
- Beijing Key Laboratory of Bioprocess, and Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Wei Xiong
- Beijing Key Laboratory of Bioprocess, and Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Zhiqing Wu
- Beijing Key Laboratory of Bioprocess, and Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Gang Xiao
- Beijing Key Laboratory of Bioprocess, and Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Shaojie Wang
- Beijing Key Laboratory of Bioprocess, and Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China.
| | - Haijia Su
- Beijing Key Laboratory of Bioprocess, and Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China.
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Zhou X, Sun Y, Wang T, Tang L, Ling W, Mosa A, Wang J, Gao Y. Remediation potential of an immobilized microbial consortium with corn straw as a carrier in polycyclic aromatic hydrocarbons contaminated soil. JOURNAL OF HAZARDOUS MATERIALS 2024; 469:134091. [PMID: 38513440 DOI: 10.1016/j.jhazmat.2024.134091] [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: 12/26/2023] [Revised: 02/27/2024] [Accepted: 03/18/2024] [Indexed: 03/23/2024]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are widespread in soils and threaten human health seriously. The immobilized microorganisms (IM) technique is an effective and environmentally sound approach for remediating PAH-contaminated soil. However, the knowledge of the remedial efficiency and the way IM operates using natural organic materials as carriers in complex soil environments is limited. In this study, we loaded a functional microbial consortium on corn straw to analyze the effect of IM on PAH concentration and explore the potential remediation mechanisms of IM in PAH-contaminated soil. The findings revealed that the removal rate of total PAHs in the soil was 88.25% with the application of IM after 20 days, which was 39.25% higher than the control treatment, suggesting that IM could more easily degrade PAHs in soil. The findings from high-throughput sequencing and quantitative PCR revealed that the addition of IM altered the bacterial community structure and key components of the bacterial network, enhanced cooperative relationships among bacteria, and increased the abundance of bacteria and functional gene copies such as nidA and nahAc in the soil, ultimately facilitating the degradation of PAHs in the soil. This study enhances our understanding of the potential applications of IM for the treatment of PAH-contaminated soil.
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Affiliation(s)
- Xian Zhou
- Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Yuhao Sun
- Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Tingting Wang
- Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Lei Tang
- Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Wanting Ling
- Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Ahmed Mosa
- Soils Department, Faculty of Agriculture, Mansoura University, 35516 Mansoura, Egypt
| | - Jian Wang
- Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Yanzheng Gao
- Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
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Feng B, Mao Z, Yu J, Wang Y, Zhang Z, Xu L, Lu D. The remediation of polycyclic aromatic hydrocarbon contaminated soil by immobilized microorganisms using distiller's grains. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:21415-21429. [PMID: 38393558 DOI: 10.1007/s11356-024-32399-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 02/03/2024] [Indexed: 02/25/2024]
Abstract
Polycyclic aromatic hydrocarbons are a persistent organic pollutant, and their biodegradation in the soil is often limited due to the limited degradation ability of indigenous bacteria and the low activity of exogenous PAH degrading bacteria. Immobilized microbial technology can protect microorganisms from the impact of harsh environments, and distiller's grains have the potential as carriers for microbial immobilization. This study aims to use distiller's grains as a microbial carrier, investigate the feasibility of immobilized microorganisms using distiller's grains for remediation of PAH contaminated soil; explore the relationship between soil nutrient content, consumption, and PAH degradation rate; and reveal the mechanism of bioremediation from the perspective of soil enzyme activity and microbial community composition. The results showed that after 72 days of remediation, the removal rates of phenanthrene and pyrene in the treatment of immobilized microorganisms in distiller grains reached 91.78% and 58.59%, respectively. Distiller grains can serve as a carrier for microorganisms, providing them with shelter and nutrients to enhance their chance of survival. Additionally, they can regulate the composition of soil particles and improve aeration, thereby increasing the efficiency of PAH degradation in soil.
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Affiliation(s)
- Bo Feng
- School of Environmental Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, 221116, China
| | - Zhen Mao
- School of Environmental Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, 221116, China.
| | - Jinbiao Yu
- School of Environmental Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, 221116, China
| | - Yuqian Wang
- School of Environmental Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, 221116, China
| | - Zheyu Zhang
- School of Environmental Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, 221116, China
| | - Liang Xu
- School of Environmental Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, 221116, China
| | - Dongqiang Lu
- School of Environmental Science and Spatial Informatics, China University of Mining and Technology, Xuzhou, 221116, China
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Rungsihiranrut A, Muangchinda C, Naloka K, Dechsakulwatana C, Pinyakong O. Simultaneous immobilization enhances synergistic interactions and crude oil removal of bacterial consortium. CHEMOSPHERE 2023; 340:139934. [PMID: 37619752 DOI: 10.1016/j.chemosphere.2023.139934] [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: 02/28/2023] [Revised: 07/18/2023] [Accepted: 08/21/2023] [Indexed: 08/26/2023]
Abstract
Oil spillage has serious adverse effects on marine environments. The degradation of crude oil by microorganisms may be an effective and sustainable approach. In this study, the removal of crude oil from seawater by immobilized bacterial consortium was performed and the enhancement of crude oil degradation efficiency by varying immobilization methods and inoculum volume ratio was examined. The nonpathogenic and heavy metal-tolerant bacterial consortium of Sphingobium naphthae MO2-4 and Priestia aryabhattai TL01-2 was immobilized by biofilm formation on aquaporousgels. The simultaneous immobilization of strains MO2-4 and TL01-2 showed better crude oil removal efficiency than independent immobilization, which indicated positive interactions among consortium members in the mixed-culture immobilized systems. Moreover, the immobilized consortium at a 2:1 (MO2-4:TL01-2) inoculum volume ratio showed the best crude oil removal capacity. The immobilized consortium removed 77% of 2000 mg L-1 crude oil in seawater over 7 days. The immobilized consortium maintained crude oil removal efficacy in semicontinuous experiments. In addition, the immobilized consortium was used to remediate seawater contaminated with 1000 mg L-1 crude oil in a 20 L wave tank. After 28 days, the crude oil degradation efficiency of immobilized consortium was approximately 70%, and crude oil degradation through natural attenuation was not observed. Moreover, the genomic features of strains MO2-4 and TL01-2 are reported. Genomic analyses of both strains confirmed the presence of many genes involved in hydrocarbon degradation, heavy metal resistance, biosurfactant synthesis, and biofilm formation, supporting the biodegradation results and characterizing strain properties. The results of this work introduce the potential benefit of simultaneous immobilization of bacterial consortia to improve efficiency of crude oil biodegradation and has motivated further investigations into large-scale remediation of crude oil-contaminated seawater.
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Affiliation(s)
- Adisan Rungsihiranrut
- International Postgraduate Programs in Hazardous Substance and Environmental Management, Graduate School, Chulalongkorn University, Bangkok, 10330, Thailand; Center of Excellence in Microbial Technology for Marine Pollution Treatment (MiTMaPT), Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Chanokporn Muangchinda
- International Postgraduate Programs in Hazardous Substance and Environmental Management, Graduate School, Chulalongkorn University, Bangkok, 10330, Thailand; Center of Excellence in Microbial Technology for Marine Pollution Treatment (MiTMaPT), Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Kallayanee Naloka
- Center of Excellence in Microbial Technology for Marine Pollution Treatment (MiTMaPT), Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand; Research Program on Remediation Technologies for Petroleum Contamination, Center of Excellence on Hazardous Substance Management (HSM), Bangkok, 10330, Thailand
| | | | - Onruthai Pinyakong
- Center of Excellence in Microbial Technology for Marine Pollution Treatment (MiTMaPT), Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand; Research Program on Remediation Technologies for Petroleum Contamination, Center of Excellence on Hazardous Substance Management (HSM), Bangkok, 10330, Thailand.
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6
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Partovinia A, Khanpour-Alikelayeh E, Talebi A, Kermanian H. Improving mass transfer rates in microbial cell immobilization system for environmental applications: Synergistic interaction of cells on crude oil biodegradation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 326:116729. [PMID: 36375423 DOI: 10.1016/j.jenvman.2022.116729] [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: 08/25/2022] [Revised: 10/25/2022] [Accepted: 11/05/2022] [Indexed: 06/16/2023]
Abstract
Among the various techniques used to clean up polluted environments, bioremediation is the most cost-effective and eco-friendly option. The diversity of microbial communities in a consortium can significantly affect the biodegradability of hazardous organic pollutants, particularly for in situ bioremediation processes. This is largely attributed to interactions between members of a consortium. In this study, the effect of internal diffusion limitations in substrate model biodegradation was firstly examined by immobilized bacterial cells at different particle sizes produced by the electrospray technique. According to the obtained results, for particles with large size, the effectiveness factors (η) were about 0.58-0.67, and the resistance to diffusive on the biodegradation rate was significant, while with decreasing the particle size, η increases and approaches about 1. After selection of suitable bead size, heavy crude oil biodegradation was investigated using a consortium consisting of three oil-degrading bacterial strains at different treatment systems. The removal rate in the suspended co-culture system stands at minimum value of 38% with all three strains which is an indicator of negative interactions among consortium members. Independent immobilization of microorganisms minimizes the competition and antagonistic interactions between strains and leads to more crude oil removal, so that, the biodegradation rate reached 60%.
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Affiliation(s)
- Ali Partovinia
- Faculty of New Technologies Engineering, Zirab Campus, Shahid Beheshti University, Tehran, Iran.
| | - Elham Khanpour-Alikelayeh
- Faculty of New Technologies Engineering, Zirab Campus, Shahid Beheshti University, Tehran, Iran; Department of Environment, College of Environment, Karaj, Iran
| | - Ahmad Talebi
- Department of Environment, College of Environment, Karaj, Iran
| | - Hossein Kermanian
- Faculty of New Technologies Engineering, Zirab Campus, Shahid Beheshti University, Tehran, Iran
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Pan X, Li Z, Huang S, Huang Y, Wang Q, Tao Z, Hu W. Mycolicibacterium aurantiacum sp. nov. and Mycolicibacterium xanthum sp. nov., two novel actinobacteria isolated from mangrove sediments. Int J Syst Evol Microbiol 2022; 72. [DOI: 10.1099/ijsem.0.005595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Two novel actinobacteria with the ability to degrade kerosene, designated as B3033T and Y57T, were isolated from mangrove sediments in Tieshan Harbour, South China Sea. Both strains are Gram-staining-positive, non-spore forming, slow-growing, oxidase-positive, non-motile and aerobic. Their major cellular fatty acids were C16 : 0 and C18 : 1ω9c. Analysis of 16S rRNA gene sequences revealed the close relationship of strain B3033T to
Mycobacterium kyogaense
DSM 107316T (99.4 % nucleotide identity) and strain Y57T to
Mycolicibacterium chubuense
ATCC 27278T (98.7 %) and
Mycolicibacterium rufum
JS14T (98.7 %). Whole genome average nucleotide blast identity (ANI) and the digital DNA–DNA hybridization (dDDH) values between the two isolates and the type strains of species of the genus
Mycolicibacterium
were lower than 94 and 45 %, respectively, which were below the threshold values of 95 % (for ANI) and 70 % (for dDDH) recommended for bacterial species differentiation. The genome sequence of B3033T comprised a circular 11.0 Mb chromosome with a DNA G+C content of 68.1 mol%. Y57T had a genome size of 5.6 Mb and a DNA G+C content of 68.7 mol%. Genes involved in degradation of aromatic compounds and copper resistance were identified in the genomes of both strains that could improve their adaptive capacity to the mangrove environment. These results combined with those of chemotaxonomic analyses, MALDI-TOF MS profiles and phenotypic analyses support the affiliation of these strains to two novel species within the genus
Mycolicibacterium
, for which we propose the names Mycolicibacterium aurantiacum sp. nov. B3033T (=KCTC 49712T=MCCC 1K04526T) and Mycolicibacterium xanthum sp. nov. Y57T (=KCTC 49711T=MCCC 1K04875T) as type strains.
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Affiliation(s)
- Xinli Pan
- Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry, Beibu Gulf Marine Research Center, Guangxi Academy of Sciences, Nanning 530007, PR China
| | - Zhe Li
- Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry, Beibu Gulf Marine Research Center, Guangxi Academy of Sciences, Nanning 530007, PR China
| | - Shushi Huang
- Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry, Beibu Gulf Marine Research Center, Guangxi Academy of Sciences, Nanning 530007, PR China
| | - Yuanlin Huang
- Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry, Beibu Gulf Marine Research Center, Guangxi Academy of Sciences, Nanning 530007, PR China
| | - Qiaozhen Wang
- Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry, Beibu Gulf Marine Research Center, Guangxi Academy of Sciences, Nanning 530007, PR China
| | - Zhanhua Tao
- Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry, Beibu Gulf Marine Research Center, Guangxi Academy of Sciences, Nanning 530007, PR China
| | - Wenjin Hu
- National Engineering Research Center for Non-Food Biorefinery, State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Key Laboratory of Bio-refinery, Guangxi Biomass Engineering Technology Research Center, Guangxi Academy of Sciences, Nanning, 530007, PR China
- Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry, Beibu Gulf Marine Research Center, Guangxi Academy of Sciences, Nanning 530007, PR China
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Yang K, Bu H, Zhang Y, Yu H, Huang S, Ke L, Hong P. Efficacy of simultaneous hexavalent chromium biosorption and nitrogen removal by the aerobic denitrifying bacterium Pseudomonas stutzeri YC-34 from chromium-rich wastewater. Front Microbiol 2022; 13:961815. [PMID: 35992714 PMCID: PMC9389319 DOI: 10.3389/fmicb.2022.961815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 07/11/2022] [Indexed: 12/03/2022] Open
Abstract
The impact of high concentrations of heavy metals and the loss of functional microorganisms usually affect the nitrogen removal process in wastewater treatment systems. In the study, a unique auto-aggregating aerobic denitrifier (Pseudomonas stutzeri strain YC-34) was isolated with potential applications for Cr(VI) biosorption and reduction. The nitrogen removal efficiency and denitrification pathway of the strain were determined by measuring the concentration changes of inorganic nitrogen during the culture of the strain and amplifying key denitrification functional genes. The changes in auto-aggregation index, hydrophobicity index, and extracellular polymeric substances (EPS) characteristic index were used to evaluate the auto-aggregation capacity of the strain. Further studies on the biosorption ability and mechanism of cadmium in the process of denitrification were carried out. The changes in tolerance and adsorption index of cadmium were measured and the micro-characteristic changes on the cell surface were analyzed. The strain exhibited excellent denitrification ability, achieving 90.58% nitrogen removal efficiency with 54 mg/L nitrate-nitrogen as the initial nitrogen source and no accumulation of ammonia and nitrite-nitrogen. Thirty percentage of the initial nitrate-nitrogen was converted to N2, and only a small amount of N2O was produced. The successful amplification of the denitrification functional genes, norS, norB, norR, and nosZ, further suggested a complete denitrification pathway from nitrate to nitrogen. Furthermore, the strain showed efficient aggregation capacity, with the auto-aggregation and hydrophobicity indices reaching 78.4 and 75.5%, respectively. A large amount of protein-containing EPS was produced. In addition, the strain effectively removed 48.75, 46.67, 44.53, and 39.84% of Cr(VI) with the initial concentrations of 3, 5, 7, and 10 mg/L, respectively, from the nitrogen-containing synthetic wastewater. It also could reduce Cr(VI) to the less toxic Cr(III). FTIR measurements and characteristic peak deconvolution analysis demonstrated that the strain had a robust hydrogen-bonded structure with strong intermolecular forces under the stress of high Cr(VI) concentrations. The current results confirm that the novel denitrifier can simultaneously remove nitrogen and chromium and has potential applications in advanced wastewater treatment for the removal of multiple pollutants from sewage.
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Yaashikaa PR, Devi MK, Kumar PS. Advances in the application of immobilized enzyme for the remediation of hazardous pollutant: A review. CHEMOSPHERE 2022; 299:134390. [PMID: 35339523 DOI: 10.1016/j.chemosphere.2022.134390] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/03/2022] [Accepted: 03/18/2022] [Indexed: 06/14/2023]
Abstract
Nowadays, ecofriendly, low-cost, and sustainable alternatives techniques have been focused on the effective removal of hazardous pollutants from the water streams. In this context, enzyme immobilization seems to be of specific interest to several researchers to develop novel, effective, greener, and hybrid strategies for the removal of toxic contaminants. Immobilization is a biotechnological tool, anchoring the enzymes on support material to enhance the stability and retain the structural conformation of enzymes for catalysis. Recyclability and reusability are the main merits of immobilized enzymes over free enzymes. Studies showed that immobilized enzyme laccase can be used up to 7 cycles with 66% efficiency, peroxidase can be recycled to 2 cycles with 50% efficiency, and also cellulase to 3 cycles with 91% efficiency. In this review, basic concepts of immobilization, different immobilization techniques, and carriers used for immobilization are summarized. In addition to that, the potential of immobilized enzymes as the bioremediation agents for the effective degradation of pollutants from the contaminated zone and the impact of different operating parameters are summarized in-depth. Further, this review provides future trends and challenges that have to be solved shortly for enhancing the potential of immobilized systems for large-scale industrial wastewater treatment.
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Affiliation(s)
- P R Yaashikaa
- Department of Biotechnology, Saveetha School of Engineering, SIMATS, Chennai, 602105, India
| | - M Keerthana Devi
- Department of Biotechnology, Saveetha School of Engineering, SIMATS, Chennai, 602105, India
| | - P Senthil Kumar
- Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Chennai, 603110, India; Centre of Excellence in Water Research (CEWAR), Sri Sivasubramaniya Nadar College of Engineering, Chennai, 603110, India.
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Physiological changes in Rhodococcus ruber S103 immobilized on biobooms using low-cost media enhance stress tolerance and crude oil-degrading activity. Sci Rep 2022; 12:10474. [PMID: 35729341 PMCID: PMC9213463 DOI: 10.1038/s41598-022-14488-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 06/07/2022] [Indexed: 11/09/2022] Open
Abstract
For economic feasibility, sugarcane molasses (0.5%, w/v) containing K2HPO4 (0.26%, w/v) and mature coconut water, low value byproducts, were used in cultivation of Rhodococcus ruber S103 for inoculum production and immobilization, respectively. Physiological changes of S103 grown in low-cost media, including cell hydrophobicity, saturated/unsaturated ratio of cellular fatty acids and biofilm formation activity, enhanced stress tolerance and crude oil biodegradation in freshwater and even under high salinity (5%, w/v). Biobooms comprised of S103 immobilized on polyurethane foam (PUF) was achieved with high biomass content (1010 colony-forming units g-1 PUF) via a scale-up process in a 5-L modified fluidized-bed bioreactor within 3 days. In a 500-L mesocosm, natural freshwater was spiked with crude oil (72 g or 667 mg g-1 dry biobooms), and a simulated wave was applied. Biobooms could remove 100% of crude oil within only 3 days and simultaneously biodegraded 60% of the adsorbed oil after 7 days when compared to boom control with indigenous bacteria. In addition, biobooms had a long shelf-life (at least 100 days) with high biodegradation activity (85.2 ± 2.3%) after storage in 10% (w/v) skimmed milk at room temperature. This study demonstrates that the low-cost production of biobooms has potential for future commercial bioremediation.
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