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Fan K, Wang F, Xu X, Shi J, Wang W, Xing D, Ren N, Lee DJ, Chen C. Enterobacter sp. HIT-SHJ4 isolated from wetland with carbon, nitrogen and sulfur co-metabolism and its implication for bioremediation. ENVIRONMENTAL RESEARCH 2024; 260:119593. [PMID: 39002634 DOI: 10.1016/j.envres.2024.119593] [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: 04/29/2024] [Revised: 07/04/2024] [Accepted: 07/09/2024] [Indexed: 07/15/2024]
Abstract
Both autotrophic and heterotrophic denitrification are known as important bioprocesses of microbe-mediated nitrogen cycle in natural ecosystems. Actually, mixotrophic denitrification co-driven by organic matter and reduced sulfur substances are also common, especially in hypoxic environments such as estuarine sediments. However, carbon, nitrogen and sulfur co-metabolism during mixotrophic denitrification in natural water ecosystems has rarely been reported in detail. Therefore, this study investigated the co-metabolism of carbon, nitrogen and sulfur using samples collected from four distinct natural water ecosystems. Results demonstrated that samples from various sources all exhibited the ability for co-metabolism of carbon, nitrogen and sulfur. Microbial community analysis showed that Pseudomonas and Paracoccus were dominant bacteria ranging from 65.6% to 75.5% in mixotrophic environment. Enterobacter sp. HIT-SHJ4, a mixotrophic denitrifying strain which owned the capacity for co-metabolism of carbon, nitrogen and sulfur, was isolated and reported here for the first time. The strain preferred methanol as its carbon source and demonstrated remarkable efficiency for removing sulfide and nitrate with below 100 mg/L sulfide. Under weak acid conditions (pH 6.5-7.0), it exhibited enhanced capability in converting sulfide to elemental sulfur. Its bioactivity was evident within a temperature from 25 °C to 40 °C and C/N ratios from 0.75 to 3. This study confirmed the widespread presence of microbial-mediated synergistic carbon, nitrogen and sulfur metabolism in natural aquatic ecosystems. HIT-SHJ4 emerges as a novel strain, shedding light on carbon, nitrogen and sulfur co-metabolism in natural water bodies. Furthermore, it also serves as a promising candidate microorganism for in-situ ecological remediation, particularly in dealing with contamination posed by nitrate, sulfide, and organic matter.
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Affiliation(s)
- Kaili Fan
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China
| | - Fei Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China
| | - Xijun Xu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China
| | - Jia Shi
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China
| | - Wei Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China.
| | - Defeng Xing
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China
| | - Nanqi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China
| | - Duu-Jong Lee
- Department of Mechanical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China; Department of Chemical Engineering, National Taiwan University, Taipei, 106, Taiwan
| | - Chuan Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province, 150090, China.
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Chen MX, Li YJ, Wu L, Lv XY, Li Y, Ru J, Yi Y. Optimal conditions and nitrogen removal performance of aerobic denitrifier Comamonas sp. pw-6 and its bioaugmented application in synthetic domestic wastewater treatment. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2024; 89:3007-3020. [PMID: 38877627 DOI: 10.2166/wst.2024.176] [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: 02/22/2024] [Accepted: 05/07/2024] [Indexed: 06/16/2024]
Abstract
To assess the possibility of using aerobic denitrification (AD) bacteria with high NO2--N accumulation for nitrogen removal in wastewater treatment, conditional optimization, as well as sole and mixed nitrogen source tests involving AD bacterium, Comamonas sp. pw-6 was performed. The results showed that the optimal carbon source, pH, C/N ratio, rotational speed, and salinity for this strain were determined to be succinate, 7, 20, 160 rpm, and 0%, respectively. Further, this strain preferentially utilized NH4+-N, NO3--N, and NO2--N, and when NO3--N was its sole nitrogen source, 92.28% of the NO3--N (150 mg·L-1) was converted to NO2--N. However, when NH4+-N and NO3--N constituted the mixed nitrogen source, NO3--N utilization by this strain was significantly lower (p < 0.05). Therefore, a strategy was proposed to combine pw-6 bacteria with traditional autotrophic nitrification to achieve the application of pw-6 bacteria in NH4+-N-containing wastewater treatment. Bioaugmented application experiments showed significantly higher NH4+-N removal (5.96 ± 0.94 mg·L-1·h-1) and lower NO3--N accumulation (2.52 ± 0.18 mg·L-1·h-1) rates (p < 0.05) than those observed for the control test. Thus, AD bacteria with high NO2--N accumulation can also be used for practical applications, providing a basis for expanding the selection range of AD strains for wastewater treatment.
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Affiliation(s)
- Maoxia X Chen
- School of New Energy Materials and Chemistry, Leshan Normal University, Leshan 614000, China; South Sichuan Pollution Control and Resource Recovery Research Center, Leshan Normal University, Leshan 614000, China E-mail:
| | - Yanjun J Li
- South Sichuan Pollution Control and Resource Recovery Research Center, Leshan Normal University, Leshan 614000, China
| | - Liang Wu
- School of New Energy Materials and Chemistry, Leshan Normal University, Leshan 614000, China; South Sichuan Pollution Control and Resource Recovery Research Center, Leshan Normal University, Leshan 614000, China
| | - Xiaoyu Y Lv
- South Sichuan Pollution Control and Resource Recovery Research Center, Leshan Normal University, Leshan 614000, China
| | - Yang Li
- School of New Energy Materials and Chemistry, Leshan Normal University, Leshan 614000, China; South Sichuan Pollution Control and Resource Recovery Research Center, Leshan Normal University, Leshan 614000, China
| | - Jing Ru
- School of New Energy Materials and Chemistry, Leshan Normal University, Leshan 614000, China; South Sichuan Pollution Control and Resource Recovery Research Center, Leshan Normal University, Leshan 614000, China
| | - Yan Yi
- School of New Energy Materials and Chemistry, Leshan Normal University, Leshan 614000, China; South Sichuan Pollution Control and Resource Recovery Research Center, Leshan Normal University, Leshan 614000, China
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Zhao Y, Yuan Z, Wang S, Wang H, Chao Y, Sederoff RR, Sederoff H, Yan H, Pan J, Peng M, Wu D, Borriss R, Niu B. Gene sdaB Is Involved in the Nematocidal Activity of Enterobacter ludwigii AA4 Against the Pine Wood Nematode Bursaphelenchus xylophilus. Front Microbiol 2022; 13:870519. [PMID: 35602027 PMCID: PMC9121001 DOI: 10.3389/fmicb.2022.870519] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 03/25/2022] [Indexed: 11/13/2022] Open
Abstract
Bursaphelenchus xylophilus, a plant parasitic nematode, is the causal agent of pine wilt, a devastating forest tree disease. Essentially, no efficient methods for controlling B. xylophilus and pine wilt disease have yet been developed. Enterobacter ludwigii AA4, isolated from the root of maize, has powerful nematocidal activity against B. xylophilus in a new in vitro dye exclusion test. The corrected mortality of the B. xylophilus treated by E. ludwigii AA4 or its cell extract reached 98.3 and 98.6%, respectively. Morphological changes in B. xylophilus treated with a cell extract from strain AA4 suggested that the death of B. xylophilus might be caused by an increased number of vacuoles in non-apoptotic cell death and the damage to tissues of the nematodes. In a greenhouse test, the disease index of the seedlings of Scots pine (Pinus sylvestris) treated with the cells of strain AA4 plus B. xylophilus or those treated by AA4 cell extract plus B. xylophilus was 38.2 and 30.3, respectively, was significantly lower than 92.5 in the control plants treated with distilled water and B. xylophilus. We created a sdaB gene knockout in strain AA4 by deleting the gene that was putatively encoding the beta-subunit of L-serine dehydratase through Red homologous recombination. The nematocidal and disease-suppressing activities of the knockout strain were remarkably impaired. Finally, we revealed a robust colonization of P. sylvestris seedling needles by E. ludwigii AA4, which is supposed to contribute to the disease-controlling efficacy of strain AA4. Therefore, E. ludwigii AA4 has significant potential to serve as an agent for the biological control of pine wilt disease caused by B. xylophilus.
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Affiliation(s)
- Yu Zhao
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Zhibo Yuan
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Shuang Wang
- Administrative Office of the Summer Palace, Beijing Municipal Administration Center of Parks, Beijing, China
| | - Haoyu Wang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Yanjie Chao
- The Center for Microbes, Development and Health (CMDH), Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Ronald R. Sederoff
- Forest Biotechnology Group, Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, United States
| | - Heike Sederoff
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
| | - He Yan
- Center for Biological Disaster Prevention and Control, National Forestry and Grassland Administration, Shenyang, China
| | - Jialiang Pan
- Center for Biological Disaster Prevention and Control, National Forestry and Grassland Administration, Shenyang, China
| | - Mu Peng
- College of Biological Science and Technology, Hubei Minzu University, Enshi, China
| | - Di Wu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Rainer Borriss
- Nord Reet UG, Greifswald, Germany
- Institute of Marine Biotechnology e.V. (IMaB), Greifswald, Germany
- *Correspondence: Rainer Borriss,
| | - Ben Niu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
- Ben Niu,
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Jerin I, Rahi MS, Sultan T, Islam MS, Sajib SA, Hoque KMF, Reza MA. Diesel degradation efficiency of Enterobacter sp., Acinetobacter sp., and Cedecea sp. isolated from petroleum waste dumping site: a bioremediation view point. Arch Microbiol 2021; 203:5075-5084. [PMID: 34302508 DOI: 10.1007/s00203-021-02469-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 06/27/2021] [Accepted: 06/29/2021] [Indexed: 10/20/2022]
Abstract
Bioremediation through biodegradation is applied for cleaning up several environmental pollutions including petroleum oil spill containing petrol, diesel, mobil, kerosene, lubricating, etc. which have devastated several endangered terrestrial and aquatic ecosystems. Therefore, the current research was aimed to isolate and identify diesel degrading bacteria from the petroleum waste dumping site and determined their degrading efficiency. The bacterial strains were isolated through a minimum salt medium supplemented with 2% diesel as the sole carbon source. The bacteria were identified by morphological, biochemical characterization, and 16S rRNA gene sequencing. The optimized growth pattern was evaluated by utilization of a wide range of temperatures (25, 30, 35, and 40 °C) and pH (5,6,7 and 8) as well as different concentrations of diesel (2, 3, 5and 7%). Finally, the degradation rate was determined by measuring the residual diesel after 7, 14, and 21 days of incubation. The study isolated Enterobacter ludwigii, Enterobacter mori, Acinetobacter baumannii, and Cedecea davisae where all are gram-negative rod-shaped bacilli. All the bacterial strains utilized the diesel at their best at 30 °C and pH 7, among them, A. baumannii and C. davisae exhibited the best degrading efficiency at all applied concentrations. Finally, the determination of degradation rate (%) through gravimetrical analysis has confirmed the potency of A. Baumannii and C. davisae where the degradation rate was around 61 and 52% respectively after 21 days of incubation period with 10% diesel. The study concludes that all of those isolated bacterial consortiums, especially A. baumannii and C. davisae could be allocated as active agents used for bioremediation to detoxify the diesel-containing contaminated sites in a cost-effective and eco-friendly way.
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Affiliation(s)
- Israt Jerin
- Molecular Biology and Protein Science Laboratory, Department of Genetic Engineering and Biotechnology, Rajshahi University, Rajshahi, 6205, Bangladesh
| | - Md Sifat Rahi
- Molecular Biology and Protein Science Laboratory, Department of Genetic Engineering and Biotechnology, Rajshahi University, Rajshahi, 6205, Bangladesh.,Department of Genetic Engineering and Biotechnology, Jashore University of Science and Technology, Jashore, 7408, Bangladesh
| | - Tanjia Sultan
- Molecular Biology and Protein Science Laboratory, Department of Genetic Engineering and Biotechnology, Rajshahi University, Rajshahi, 6205, Bangladesh
| | - Md Shihabul Islam
- Molecular Biology and Protein Science Laboratory, Department of Genetic Engineering and Biotechnology, Rajshahi University, Rajshahi, 6205, Bangladesh
| | - Salek Ahmed Sajib
- Molecular Biology and Protein Science Laboratory, Department of Genetic Engineering and Biotechnology, Rajshahi University, Rajshahi, 6205, Bangladesh
| | - Kazi Md Faisal Hoque
- Molecular Biology and Protein Science Laboratory, Department of Genetic Engineering and Biotechnology, Rajshahi University, Rajshahi, 6205, Bangladesh
| | - Md Abu Reza
- Molecular Biology and Protein Science Laboratory, Department of Genetic Engineering and Biotechnology, Rajshahi University, Rajshahi, 6205, Bangladesh.
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Sustainable Approach to Eradicate the Inhibitory Effect of Free-Cyanide on Simultaneous Nitrification and Aerobic Denitrification during Wastewater Treatment. SUSTAINABILITY 2019. [DOI: 10.3390/su11216180] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Simultaneous nitrification and aerobic denitrification (SNaD) is a preferred method for single stage total nitrogen (TN) removal, which was recently proposed to improve wastewater treatment plant design. However, SNaD processes are prone to inhibition by toxicant loading with free cyanide (FCN) possessing the highest inhibitory effect on such processes, rendering these processes ineffective. Despite the best efforts of regulators to limit toxicant disposal into municipal wastewater sewage systems (MWSSs), FCN still enters MWSSs through various pathways; hence, it has been suggested that FCN resistant or tolerant microorganisms be utilized for processes such as SNaD. To mitigate toxicant loading, organisms in SNaD have been observed to adopt a diauxic growth strategy to sequentially degrade FCN during primary growth and subsequently degrade TN during the secondary growth phase. However, FCN degrading microorganisms are not widely used for SNaD in MWSSs due to inadequate application of suitable microorganisms (Chromobacterium violaceum, Pseudomonas aeruginosa, Thiobacillus denitrificans, Rhodospirillum palustris, Klebsiella pneumoniae, and Alcaligenes faecalis) commonly used in single-stage SNaD. This review expatiates the biological remedial strategy to limit the inhibition of SNaD by FCN through the use of FCN degrading or resistant microorganisms. The use of FCN degrading or resistant microorganisms for SNaD is a cost-effective method compared to the use of other methods of FCN removal prior to TN removal, as they involve multi-stage systems (as currently observed in MWSSs). The use of FCN degrading microorganisms, particularly when used as a consortium, presents a promising and sustainable resolution to mitigate inhibitory effects of FCN in SNaD.
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Liu D, Li J, Li C, Deng Y, Zhang Z, Ye Z, Zhu S. Poly(butylene succinate)/bamboo powder blends as solid-phase carbon source and biofilm carrier for denitrifying biofilters treating wastewater from recirculating aquaculture system. Sci Rep 2018; 8:3289. [PMID: 29459646 PMCID: PMC5818489 DOI: 10.1038/s41598-018-21702-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 02/08/2018] [Indexed: 11/09/2022] Open
Abstract
In this study, Poly(butylene succinate)/bamboo powder (PBS/BP) was newly applied and tested for 8 months as the carbon source in two moving bed reactors for nitrate removal in real RAS wastewater (fresh/sea water), with the purposes of simultaneous reducing the cost of PBS packing and effluent DOC. Fast start-ups were obtained in both reactors, in which high denitrification rates were observed (0.68 ± 0.03 and 0.83 ± 0.11 kg [Formula: see text]-N m-3 d-1 for fresh and sea water, respectively) with no nitrite and low ammonia accumulation. Reduced DOC concentrations in the effluents were also observed compared to pure PBS. The freezing of PBS/BP showed a further slower release of DOC, which might be beneficial to the life of the PBS/BP for the denitrification process, however, microbial activity, especially in high salinity wastewater, was observed to have declined. Illumina sequencing revealed that the autotrophic genus arcobacter was discovered first time in solid-phase denitrification system with salinity. Redundancy analysis (RDA) was used to reveal the relationships between environmental factors and the microbial community. In overall, PBS/BP blends were proven to be an economically attractive carbon source for nitrate removal in RAS.
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Affiliation(s)
- Dezhao Liu
- Institute of Agricultural Bio-Environmental Engineering, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Jiawei Li
- Institute of Agricultural Bio-Environmental Engineering, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Changwei Li
- Institute of Agricultural Bio-Environmental Engineering, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Yale Deng
- Aquaculture and Fisheries Group, Department of Animal Sciences, Wageningen University, 6708 WD, Wageningen, The Netherlands
| | - Zeqing Zhang
- Institute of Agricultural Bio-Environmental Engineering, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Zhangying Ye
- Institute of Agricultural Bio-Environmental Engineering, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China.
| | - Songming Zhu
- Institute of Agricultural Bio-Environmental Engineering, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
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Mekuto L, Ntwampe SKO, Mudumbi JBN. Microbial communities associated with the co-metabolism of free cyanide and thiocyanate under alkaline conditions. 3 Biotech 2018; 8:93. [PMID: 29430355 PMCID: PMC5796949 DOI: 10.1007/s13205-018-1124-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 01/16/2018] [Indexed: 11/26/2022] Open
Abstract
This study focused on the identification of free cyanide (CDO) and thiocyanate (TDO) degrading microbial communities using a culture-dependent and independent approach. Culturable microbial species were isolated from the CDOs (n = 13) and TDOs (n = 18). The CDOs were largely dominated by Bacillus sp. while the TDOs were dominated by Bacillus sp., Klebsiella oxytoca, Providencia sp. and Pseudomonas sp. However, 16S rRNA amplicon gene-sequencing revealed the complexity and diversity of the microbial communities in contrast to the organisms that were detected using culture-dependent technique. Overall, the organisms were mainly dominated by Myroides odoratimimus and Proteus sp. at 37.82 and 30.5% for CDOs, and 35.26 and 17.58% for TDOs, respectively. The co-culturing of the CDOs and TDOs resulted in biochemical changes of key metabolic enzymes, and this resulted in the complete degradation of CN- and SCN- simultaneously; a phenomenon which has not been witnessed, especially under alkaline conditions. Current ongoing studies are focused on the application of these organisms for the biodegradation of CN- and SCN- in a continuous system, under changing operational parameters, to assess their effectiveness in the biodegradation of CN- and SCN-.
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Affiliation(s)
- Lukhanyo Mekuto
- Department of Biotechnology, Bioresource Engineering Research Group (BioERG), Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000 South Africa
| | - Seteno Karabo Obed Ntwampe
- Department of Biotechnology, Bioresource Engineering Research Group (BioERG), Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000 South Africa
| | - John Baptist N. Mudumbi
- Department of Biotechnology, Bioresource Engineering Research Group (BioERG), Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000 South Africa
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Liu C, Xie J, Song M, Gao Z, Zheng D, Liu X, Ning G, Cheng X, Bruning H. Nitrogen removal performance and microbial community changes in subsurface wastewater infiltration systems (SWISs) at low temperature with different bioaugmentation strategies. BIORESOURCE TECHNOLOGY 2018; 250:603-610. [PMID: 29216573 DOI: 10.1016/j.biortech.2017.11.089] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 11/23/2017] [Accepted: 11/27/2017] [Indexed: 06/07/2023]
Abstract
Poor nitrogen removal efficiency (mainly nitrate, NO3--N) at low temperatures strongly limits application of subsurface wastewater infiltration systems (SWISs). Seven psychrophilic strains (heterotrophic nitrifying bacteria and aerobic denitrifying bacteria) were isolated and added to SWISs to investigate the effect of embedding and direct-dosing bioaugmentation strategies on sewage treatment performance at low temperature. Both bioaugmentation strategies improved ammonium (NH4+-N) removal efficiencies, and the embedding strategy also exhibited satisfactory NO3--N and total nitrogen (TN) removal efficiencies. Pyrosequencing results of the bacterial 16S rRNA gene indicated that the embedding strategy significantly decreased the indigenous soil microbial diversity (p < .05) and altered the bacterial community structure, significantly increasing the relative abundance of Clostridia, which have good nitrate-reducing activity.
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Affiliation(s)
- Chunjing Liu
- College of Resources and Environmental Science, Hebei Agricultural University, Baoding 071000, PR China; Key Laboratory for Farmland Eco-Environment of Hebei Province, 071000 Baoding, PR China
| | - Jianzhi Xie
- College of Resources and Environmental Science, Hebei Agricultural University, Baoding 071000, PR China; Key Laboratory for Farmland Eco-Environment of Hebei Province, 071000 Baoding, PR China.
| | - Manli Song
- College of Resources and Environmental Science, Hebei Agricultural University, Baoding 071000, PR China
| | - Zhiling Gao
- College of Resources and Environmental Science, Hebei Agricultural University, Baoding 071000, PR China; Key Laboratory for Farmland Eco-Environment of Hebei Province, 071000 Baoding, PR China
| | - Dongxing Zheng
- College of Resources and Environmental Science, Hebei Agricultural University, Baoding 071000, PR China
| | - Xia Liu
- College of Resources and Environmental Science, Hebei Agricultural University, Baoding 071000, PR China; Key Laboratory for Farmland Eco-Environment of Hebei Province, 071000 Baoding, PR China
| | - Guohui Ning
- College of Resources and Environmental Science, Hebei Agricultural University, Baoding 071000, PR China; Key Laboratory for Farmland Eco-Environment of Hebei Province, 071000 Baoding, PR China
| | - Xu Cheng
- Laboratory of Molecular Biology, Department of Plant Science, Wageningen University, Wageningen, The Netherlands
| | - Harry Bruning
- Sub-department of Environmental Technology, Wageningen University, Wageningen, The Netherlands
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Mekuto L, Alegbeleye OO, Ntwampe SKO, Ngongang MM, Mudumbi JB, Akinpelu EA. Co-metabolism of thiocyanate and free cyanide by Exiguobacterium acetylicum and Bacillus marisflavi under alkaline conditions. 3 Biotech 2016; 6:173. [PMID: 28330245 PMCID: PMC4990519 DOI: 10.1007/s13205-016-0491-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 08/05/2016] [Indexed: 12/01/2022] Open
Abstract
The continuous discharge of cyanide-containing effluents to the environment has necessitated for the development of environmentally benign treatment processes that would result in complete detoxification of the cyanide-containing wastewaters, without producing additional environmental toxicants. Since biological detoxification of hazardous chemical compounds has been renowned for its robustness and environmental-friendliness, the ability of the Exiguobacterium acetylicum (GenBank accession number KT282229) and Bacillus marisflavi (GenBank accession number KR016603) to co-metabolise thiocyanate (SCN−) and free cyanide (CN−) under alkaline conditions was evaluated. E. acetylicum had an SCN− degradation efficiency of 99.9 % from an initial SCN− concentration of 150 mg SCN−/L, but the organism was unable to degrade CN−. Consequently, B. marisflavi had a CN− degradation efficiency of 99 % from an initial concentration of 200 mg CN−/L. Similarly, the organism was unable to degrade SCN−; hence, this resulted in the evaluation of co-metabolism of SCN− and CN− by the two microbial species. Optimisation of operational conditions was evaluated using response surface methodology (RSM). A numeric optimisation technique was used to evaluate the optimisation of the input variables i.e. pH, temperature, SCN− and CN− concentrations. The optimum conditions were found to be as follows: pH 9.0, temperature 34 °C, 140 mg SCN−/L and 205 mg CN−/L under which complete SCN− and CN− degradation would be achieved over a 168-h period. Using the optimised data, co-metabolism of SCN− and CN− by both E. acetylicum and B. marisflavi was evaluated, achieving a combined degradation efficiency of ≥99.9 %. The high degradative capacity of these organisms has resulted in their supplementation on an active continuous biological degradation system that is treating both SCN− and CN−.
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Affiliation(s)
- Lukhanyo Mekuto
- Bioresource Engineering Research Group, Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa.
| | - Oluwadara Oluwaseun Alegbeleye
- Bioresource Engineering Research Group, Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa
| | - Seteno Karabo Obed Ntwampe
- Bioresource Engineering Research Group, Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa
| | - Maxwell Mewa Ngongang
- Bioresource Engineering Research Group, Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa
- Department of Microbiology, Agricultural Research Council, Private Bag X5026, Stellenbosch, 7599, South Africa
| | - John Baptist Mudumbi
- Bioresource Engineering Research Group, Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa
| | - Enoch A Akinpelu
- Bioresource Engineering Research Group, Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa
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10
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Mekuto L, Ntwampe SKO, Akcil A. An integrated biological approach for treatment of cyanidation wastewater. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 571:711-720. [PMID: 27424119 DOI: 10.1016/j.scitotenv.2016.07.040] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/04/2016] [Accepted: 07/06/2016] [Indexed: 06/06/2023]
Abstract
The cyanidation process has been, and still remains, a profitable and highly efficient process for the recovery of precious metals from ores. However, this process has contributed to environmental deterioration and potable water reserve contamination due to the discharge of poorly treated, or untreated, cyanide containing wastewater. The process produces numerous cyanide complexes in addition to the gold cyanocomplex. Additionally, the discharge constituents also include hydrogen cyanide (HCN) - metallic complexes with iron, nickel, copper, zinc, cobalt and other metals; thiocyanate (SCN); and cyanate (CNO). The fate of these complexes in the environment dictates the degree to which these species pose a threat to living organisms. This paper reviews the impact that the cyanidation process has on the environment, the ecotoxicology of the cyanidation wastewater and the treatment methods that are currently utilised to treat cyanidation wastewater. Furthermore, this review proposes an integrated biological approach for the treatment of the cyanidation process wastewater using microbial consortia that is insensitive and able to degrade cyanide species, in all stages of the proposed process.
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Affiliation(s)
- Lukhanyo Mekuto
- Bioresource Engineering Research Group (BioERG), Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town 8000, South Africa
| | - S K O Ntwampe
- Bioresource Engineering Research Group (BioERG), Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town 8000, South Africa.
| | - Ata Akcil
- Mineral-Metal Recovery and Recycling (MMR&R) Research Group, Mineral Processing Div., Dept. of Mining Eng., Suleyman Demirel University, TR32260 Isparta, Turkey
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