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Bai M, He J, Zheng F, Lv S, Wang Z, Hrynsphan D, Savitskaya T, Chen J. Gene cloning, expression and performance validation of nitric oxide dismutase. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 935:173455. [PMID: 38782282 DOI: 10.1016/j.scitotenv.2024.173455] [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: 03/25/2024] [Revised: 05/20/2024] [Accepted: 05/20/2024] [Indexed: 05/25/2024]
Abstract
Nitrous oxide (N2O) is a significant contributor to global warming and possesses an ozone-depleting impact nearly 298 times that of CO2. To reduce N2O emissions, the newly-discovered nod gene which can directly convert NO into N2 and O2 was successfully cloned from the anaerobic denitrification sludge. The recombinant plasmid containing the nod gene was built, and the expression of nod gene in Escherichia coli was determined, leading to the construction of recombinant engineering bacteria. Results showed that the recombinant engineering bacteria E. coli BL21 (DE3)-pET28a-nod could autonomously degrade NO, with a degradation rate of 72 % within 48 h, and could produce 2479.72 ppm of N2 and 75.12 mL of O2. The cumulative O2 production of the sludge sample and recombinant E. coli within 8 h was 1.75 mL and 8.45 mL, respectively. The cumulative O2 production of recombinant E. coli was at least 4.82 times higher than that of the sludge sample. The investigation proposed a new biodegradation pathway for nitrogen pollution.
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Affiliation(s)
- Mengwei Bai
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jiamei He
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Fengzhen Zheng
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou 310015, China
| | - Sini Lv
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Zeyu Wang
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou 310015, China
| | - Dzmitry Hrynsphan
- Research Institute of Physical and Chemical Problems, Belarusian State University, Minsk 220030, Belarus
| | - Tatsiana Savitskaya
- Research Institute of Physical and Chemical Problems, Belarusian State University, Minsk 220030, Belarus
| | - Jun Chen
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou 310015, China.
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2
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Xu C, Xu Y, Chen J, Huang S, Zhou B, Song M. Spatio-temporal efficiency of fiscal environmental expenditure in reducing CO 2 emissions in China's cities. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 334:117479. [PMID: 36780813 DOI: 10.1016/j.jenvman.2023.117479] [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: 10/29/2022] [Revised: 01/28/2023] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
Although market-based CO2 emission control measures (e.g., carbon tax and carbon trading market) have been deeply discussed, government-based measures have received limited attention. This has led to increased uncertainty regarding the formulation of targeted emission reduction policies. Using a unique dataset, the non-radial directional distance function, a proposed spatial meta-frontier analysis method, and the log t convergence model, this study comprehensively investigates the spatio-temporal trends in fiscal environmental expenditure efficiency (FE) and corresponding causes for in a case study for 106 Chinese cities over 2007-2019. The results show that city-level FE presented a slow upward trend at a relatively low level, with a clearly skewed distribution. The technology gap effect between city groups and the overall best production technology, and the efficiency gap effect within city groups were the main drivers widening the overall FE gap. Convergence analysis indicated that three convergence clubs of FE were found, which were distributed across the country. This study highlights that, when constructing fiscal environmental expenditure policies, the government should focus on balancing the regional gap of FE while comprehensively improving FE.
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Affiliation(s)
- Chong Xu
- School of Public Administration, Southwestern University of Finance and Economics, Chengdu, China
| | - Yiyin Xu
- Business School of Chengdu University, Chengdu University, Chengdu, China
| | - Jiandong Chen
- School of Public Administration, Southwestern University of Finance and Economics, Chengdu, China
| | - Shuo Huang
- School of Public Administration, Southwestern University of Finance and Economics, Chengdu, China
| | - Bo Zhou
- School of Finance, Nanjing University of Finance and Economics, Nanjing, China
| | - Malin Song
- School of Statistics and Applied Mathematics, Anhui University of Finance and Economics, Bengbu, China.
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3
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Kim JY, Cho KS. Inoculation effect of Pseudomonas sp. TF716 on N 2O emissions during rhizoremediation of diesel-contaminated soil. Sci Rep 2022; 12:13018. [PMID: 35906374 PMCID: PMC9338077 DOI: 10.1038/s41598-022-17356-z] [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: 04/04/2022] [Accepted: 07/25/2022] [Indexed: 11/17/2022] Open
Abstract
The demand for rhizoremediation technology that can minimize greenhouse gas emissions while effectively removing pollutants in order to mitigate climate change has increased. The inoculation effect of N2O-reducing Pseudomonas sp. TF716 on N2O emissions and on remediation performance during the rhizoremediation of diesel-contaminated soil planted with tall fescue (Festuca arundinacea) or maize (Zea mays) was investigated. Pseudomonas sp. TF716 was isolated from the rhizosphere soil of tall fescue. The maximum N2O reduction rate of TF716 was 18.9 mmol N2O g dry cells−1 h−1, which is superior to the rates for previously reported Pseudomonas spp. When Pseudomonas sp. TF716 was added to diesel-contaminated soil planted with tall fescue, the soil N2O-reduction potential was 2.88 times higher than that of soil with no inoculation during the initial period (0–19 d), and 1.08–1.13 times higher thereafter. However, there was no enhancement in the N2O-reduction potential for the soil planted with maize following inoculation with strain TF716. In addition, TF716 inoculation did not significantly affect diesel degradation during rhizoremediation, suggesting that the activity of those microorganisms involved in diesel degradation was unaffected by TF716 treatment. Analysis of the dynamics of the bacterial genera associated with N2O reduction showed that Pseudomonas had the highest relative abundance during the rhizoremediation of diesel-contaminated soil planted with tall fescue and treated with strain TF716. Overall, these results suggest that N2O emissions during the rhizoremediation of diesel-contaminated soil using tall fescue can be reduced with the addition of Pseudomonas sp. TF716.
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Affiliation(s)
- Ji-Yoon Kim
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Kyung-Suk Cho
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul, 03760, Republic of Korea.
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4
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Sun S, Bi X, Yang B, Zhang W, Zhang X, Sun S, Xiao J, Yang Y, Huang Z. Nitrite removal by Acinetobacter sp.TX: a candidate of curbing N 2O emission. ENVIRONMENTAL TECHNOLOGY 2022; 43:2300-2309. [PMID: 33427603 DOI: 10.1080/09593330.2021.1874543] [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: 09/18/2020] [Accepted: 01/01/2021] [Indexed: 06/12/2023]
Abstract
The nitrite removal pathway in Acinetobacter sp. TX5 was explored through the key gene identification and the corresponding enzyme purification, after which the capability to reduce nitrite by immobilized beads was investigated in a fixed-bed reactor. Results revealed that a nosZ gene encoding nitrous oxide reductase (N2OR) exists in TX5 cells, and a N2OR responsible for the reduction of N2O to N2 was purified successfully with a molecular weight of 70.05 kDa, a purification fold of 16.30 and a recovery rate of 5.17%. For TX5 immobilization, the optimal values of polyvinyl alcohol (PVA), spent mushroom substrate (SMS) and Aci (TX5) obtained by response surface methodology (RSM) were 6.32%, 2.92% and 4.57%, respectively. In a fixed-bed reactor packed with immobilized TX5, the removal efficiency (RE) achieved 90% (at 50 h) for NO2--N and 85% (at 96 h) for total nitrogen (TN). On the basis of these results, a nitrite removal pathway in TX5 was proposed. Overall, Acinetobacter sp. TX5 might be a promising candidate for nitrite removal with an ability to suppress N2O accumulation.
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Affiliation(s)
- Shuqian Sun
- College of Life Science, Fujian Agriculture and Forestry University, Fuhzou, People's Republic of China
| | - Xiaohui Bi
- College of Life Science, Fujian Agriculture and Forestry University, Fuhzou, People's Republic of China
| | - Bin Yang
- College of Life Science, Fujian Agriculture and Forestry University, Fuhzou, People's Republic of China
| | - Weihong Zhang
- College of Life Science, Fujian Agriculture and Forestry University, Fuhzou, People's Republic of China
| | - Xinyu Zhang
- College of Life Science, Fujian Agriculture and Forestry University, Fuhzou, People's Republic of China
| | - Shujing Sun
- College of Life Science, Fujian Agriculture and Forestry University, Fuhzou, People's Republic of China
| | - Jibo Xiao
- College of Life and Environmental Science, Wenzhou University, Wenzhou, People's Republic of China
- Wenzhou Chuangyuan Environment Technology Co. Ltd., Wenzhou, People's Republic of China
| | - Yunlong Yang
- College of Life and Environmental Science, Wenzhou University, Wenzhou, People's Republic of China
| | - Zhida Huang
- Wenzhou Institute of Industry & Science, Wenzhou, People's Republic of China
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Zafar A, Hamid A, Peng L, Wang Y, Aftab MN. Enzymatic hydrolysis of lignocellulosic biomass using a novel, thermotolerant recombinant xylosidase enzyme from Clostridium clariflavum: a potential addition for biofuel industry. RSC Adv 2022; 12:14917-14931. [PMID: 35702232 PMCID: PMC9115876 DOI: 10.1039/d2ra00304j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 04/13/2022] [Indexed: 11/28/2022] Open
Abstract
The present study describes the cloning, expression, purification and characterization of the xylosidase gene (1650 bp) from a thermophilic bacterium Clostridium clariflavum into E. coli BL21 (DE3) using the expression vector pET-21a(+) for utilization in biofuel production. The recombinant xylosidase enzyme was purified to homogeneity by heat treatment and immobilized metal ion affinity chromatography. SDS-PAGE determined that the molecular weight of purified xylosidase was 60 kDa. This purified recombinant xylosidase showed its maximum activity at a temperature of 37 °C and pH 6.0. The purified recombinant xylosidase enzyme remains stable up to 90 °C for 4 h and retained 54.6% relative activity as compared to the control. The presence of metal ions such as Ca2+ and Mg2+ showed a positive impact on xylosidase enzyme activity whereas Cu2+ and Hg2+ inhibit its activity. Organic solvents did not considerably affect the stability of the purified xylosidase enzyme while DMSO and SDS cause the inhibition of enzyme activity. Pretreatment experiments were run in triplicate for 72 h at 30 °C using 10% NaOH. Saccharification experiment was performed by using 1% substrate (pretreated plant biomass) in citrate phosphate buffer of pH 6.5 loaded with 150 U mL−1 of purified recombinant xylosidase enzyme along with ampicillin (10 μg mL−1). Subsequent incubation was carried out at 50 °C and 100 rpm in a shaking incubator for 24 h. Saccharification potential of the recombinant xylosidase enzyme was calculated against both pretreated and untreated sugarcane bagasse and wheat straw as 9.63% and 8.91% respectively. All these characteristics of the recombinant thermotolerant xylosidase enzyme recommended it as a potential candidate for biofuel industry. The present study describes the cloning, expression, purification and characterization of a xylosidase gene from Clostridium clariflavum into E. coli BL21 (DE3) using the expression vector pET-21a(+) for utilization in biofuel production.![]()
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Affiliation(s)
- Asma Zafar
- Faculty of Life Sciences, University of Central Punjab Lahore Pakistan
| | - Attia Hamid
- Institute of Industrial Biotechnology, Government College University Lahore 54000 Pakistan +92 99213341 +92 3444704190
| | - Liangcai Peng
- Biomass and Bioenergy Research Center, Huazhong Agriculture University Wuhan China
| | - Yanting Wang
- Biomass and Bioenergy Research Center, Huazhong Agriculture University Wuhan China
| | - Muhammad Nauman Aftab
- Institute of Industrial Biotechnology, Government College University Lahore 54000 Pakistan +92 99213341 +92 3444704190
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6
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Hu L, Wang X, Chen C, Chen J, Wang Z, Chen J, Hrynshpan D, Savitskaya T. NosZ gene cloning, reduction performance and structure of Pseudomonas citronellolis WXP-4 nitrous oxide reductase. RSC Adv 2022; 12:2549-2557. [PMID: 35425296 PMCID: PMC8979117 DOI: 10.1039/d1ra09008a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/08/2022] [Indexed: 11/24/2022] Open
Abstract
Nitrous oxide reductase (N2OR) is the only known enzyme that can reduce the powerful greenhouse gas nitrous oxide (N2O) to harmless nitrogen at the final step of bacterial denitrification. To alleviate the N2O emission, emerging approaches aim at microbiome biotechnology. In this study, the genome sequence of facultative anaerobic bacteria Pseudomonas citronellolis WXP-4, which efficiently degrades N2O, was obtained by de novo sequencing for the first time, and then, four key reductase structure coding genes related to complete denitrification were identified. The single structural encoding gene nosZ with a length of 1914 bp from strain WXP-4 was cloned in Escherichia coli BL21(DE3), and the N2OR protein (76 kDa) was relatively highly efficiently expressed under the optimal inducing conditions of 1.0 mM IPTG, 5 h, and 30 °C. Denitrification experiment results confirmed that recombinant E. coli had strong denitrification ability and reduced 10 mg L−1 of N2O to N2 within 15 h under the optimal conditions of pH 7.0 and 40 °C, its corresponding N2O reduction rate was almost 2.3 times that of Alcaligenes denitrificans strain TB, but only 80% of that of wild strain WXP-4, meaning that nos gene cluster auxiliary gene deletion decreased the activity of N2OR. The 3D structure of N2OR predicted on the basis of sequence homology found that electron transfer center CuA had only five amino acid ligands, and the S2 of the catalytically active center CuZ only bound one CuI atom. The unique 3D structure was different from previous reports and may be closely related to the strong N2O reduction ability of strain WXP-4 and recombinant E. coli. The findings show a potential application of recombinant E. coli in alleviating the greenhouse effect and provide a new perspective for researching the relationship between structure and function of N2OR. Nitrous oxide reductase (N2OR) is the only known enzyme that can reduce the powerful greenhouse gas nitrous oxide (N2O) to harmless nitrogen at the final step of bacterial denitrification. The recombinant E. coli and wild strain WXP-4 demonstrate strong N2O reduction ability.![]()
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Affiliation(s)
- Liyong Hu
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Xiaoping Wang
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Cong Chen
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Jianmeng Chen
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Zeyu Wang
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou, 310015, China
| | - Jun Chen
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou, 310015, China
| | - Dzmitry Hrynshpan
- Research Institute of Physical and Chemical Problems, Belarusian State University, Minsk, 220030, Belarus
| | - Tatsiana Savitskaya
- Research Institute of Physical and Chemical Problems, Belarusian State University, Minsk, 220030, Belarus
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7
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Fang F, Xu RZ, Huang YQ, Luo JY, Xie WM, Ni BJ, Cao JS. Exploring the feasibility of nitrous oxide reduction and polyhydroxyalkanoates production simultaneously by mixed microbial cultures. BIORESOURCE TECHNOLOGY 2021; 342:126012. [PMID: 34571328 DOI: 10.1016/j.biortech.2021.126012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/18/2021] [Accepted: 09/20/2021] [Indexed: 06/13/2023]
Abstract
Nitrous oxide (N2O), as a powerful greenhouse gas, has drawn increasing attention in recent years and different strategies for N2O reduction were explored. In this study, a novel strategy for valuable polyhydroxyalkanoates (PHA) production coupling with N2O reduction by mixed microbial cultures (MMC) using different substrates was evaluated. Results revealed that N2O was an effective electron acceptor for PHA production. The highest PHA yield (0.35 Cmmol PHA/Cmmol S) and PHA synthesis rate (227.47 mg PHA/L/h) were obtained with acetic acid as substrate. Low temperature (15℃) and pH of 8.0 were beneficial for PHA accumulation. Results of the thermogravimetric analysis showed that PHA produced with N2O as electron acceptor has better thermal stability (melting temperature of 99.4℃ and loss 5% weight temperature of 211.4℃). Our work opens up new avenues for simultaneously N2O reduction and valuable bioplastic production, which is conducive to resource recovery and climate protection.
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Affiliation(s)
- Fang Fang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
| | - Run-Ze Xu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Yan-Qiu Huang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment of the People's Republic of China, Nanjing 210042, PR China
| | - Jing-Yang Luo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Wen-Ming Xie
- School of Environment, Nanjing Normal University, Nanjing 210046, China
| | - Bing-Jie Ni
- Centre for Technology in Water and Wastewater (CTWW), School of Civil and Environmental Engineering, University of Technology Sydney (UTS), Sydney, NSW 2007, Australia
| | - Jia-Shun Cao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
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8
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Research on the Efficiency of China’s Fiscal Expenditure Structure under the Goal of Inclusive Green Growth. SUSTAINABILITY 2021. [DOI: 10.3390/su13179725] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Inclusive Green Growth is a sustainable development mode that pays attention to the coordinated growth of the economy, society, and ecology. With the intensification of the contradiction between fiscal revenue and expenditure, adopting the goal of adjusting the fiscal expenditure structure is conducive to improving the efficiency of fiscal funds. This paper establishes a theoretical model of the efficiency of the fiscal expenditure structure under the goal of Inclusive Green Growth, and on this basis, it constructs an index system of Inclusive Green Growth. Then, it applies a DEA-Malmquist model to analyze the efficiency of the fiscal expenditure structure. The results show that from 2007 to 2018, the growth rate of Inclusive Green Growth index showed a downward trend, which was mainly due to the decline in the growth rate of economic development. It rebounded after 2016, and the growth of the inclusiveness level played a major role. In time and space, the development resources tend to the unbalanced development trend of the eastern region; the average total factor productivity of the fiscal expenditure structure in space is the lowest in the east. The fiscal expenditure should be inclined to social expenditure and green expenditure, the western region should be inclined to economic expenditure, and the allocation of the expenditure structure in the central region should imitate the high-efficiency areas. In order to achieve the comprehensive development goal, this paper provides an analytical idea for the adjustment of the fiscal expenditure structure.
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Cloning Method for Stress-Resistant Gene of Conringia planisiliqua under Drought Stress. JOURNAL OF HEALTHCARE ENGINEERING 2021; 2021:3517002. [PMID: 34221296 PMCID: PMC8219435 DOI: 10.1155/2021/3517002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/01/2021] [Accepted: 06/03/2021] [Indexed: 11/18/2022]
Abstract
The low temperature, drought, high salt, and other environments influence crop production and development directly, so the gene cloning method has become an effective biological means. In order to effectively improve the cloning effect, a gene cloning method for Conringia planisiliqua based on mRNA differential display technology was proposed. Based on mRNA differential display technology, the gene of Conringia planisiliqua was transcribed. The present study expects gene cloning to be better than the traditional method. This will lay the basis for gene cloning and functional verification of the transcription and disease-resistant proteins in Conringia planisiliqua. According to homologous identification results, the homologous drought-resistant genes were determined and screened. The data of Conringia planisiliqua in the existing biological database were used to extract ESTs data of Conringia planisiliqua. Then, the heating environment was established and the concept of integral function was introduced to express the influence of growth environment of different genomes. The mass, momentum, energy, and turbulent flow situation of stress-resistant gene of Conringia planisiliqua during the growth were satisfied. Finally, the data search was carried out in the NCBI database and gene cloning was achieved by ESTs data sequence. Experimental results show that the proposed method can effectively reduce the gene data fitting and improve the quantity of gene fragments cloned in a cycle, so the overall cloning effect is better.
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Isolation, purification, gene cloning and expression of antifungal protein from Bacillus amyloliquefaciens MG-3. Food Chem 2021; 349:129130. [PMID: 33540220 DOI: 10.1016/j.foodchem.2021.129130] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 09/21/2020] [Accepted: 01/14/2021] [Indexed: 11/20/2022]
Abstract
The antifungal protein MG-3A was isolated from Bacillus amyloliquefaciens MG-3, and was purified and identified. The results showed that antifungal protein MG-3A was likely a serine protease with a molecular weight of ~48 kDa. The serine protease exhibited a broad antifungal spectrum and effectively extended the shelf-life of loquat fruit up to 25 d. The antifungal protein MG-3A showed good stabilities to temperature, pH and protease K. Primers were designed according to the mass spectrum of antifungal protein and the comparison with proteins in the NCBI database. The serine protease gene MG-3A from B. amyloliquefaciens genome was isolated and cloned using PCR. The prokaryotic expression plasmid pET28a-MG-3A was constructed and used to express the antimicrobial protein in vitro. The SDS-PAGE results showed that the recombinant protein expressed in Escherichia coli BL21 (DE3) was highly soluble. Affinity chromatography was used to purify the recombinant protein and its antifungal activity was evaluated.
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Chen C, Wang Y, Liu H, Chen Y, Yao J, Chen J, Hrynsphanb D, Tatsianab S. Heterologous expression and functional study of nitric oxide reductase catalytic reduction peptide from Achromobacter denitrificans strain TB. CHEMOSPHERE 2020; 253:126739. [PMID: 32464773 DOI: 10.1016/j.chemosphere.2020.126739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/21/2020] [Accepted: 04/04/2020] [Indexed: 06/11/2023]
Abstract
Biological denitrification is a promising and green technology for air pollution control. To investigate the nitric oxide reductase (NOR) that dominates NO reduction efficiency in biological purification, the heterologous prokaryotic expression system of the norB gene, which encodes the core peptide of the catalytic reduction structure in the NOR from Achromobacter denitrificans strain TB, was constructed in Escherichia coli BL21 (DE3). Results showed that the 1218 bp-long norB gene was expressed at the highest level under 1.0 mM IPTG for 5 h at 30 °C, and the relative expression abundance of norB in recombinant E. coli was increased by 16.6 times compared with that of the wild-type TB. However, the NO reduction efficiency and NOR activity of strain TB was 2.7 and 1.83 times higher than those of recombinant E. coli, respectively. On the basis of genomic reassembly and protein structure modeling, the core peptide of the NOR catalytic reduction structure from Achromobacter sp. TB can independently exert NO reduction. The low NO degradation efficiency of recombinant E. coli may be due to the lack of a NorC-like structure that increases the enzyme activity of the NorB protein. The results of this study can be used as basis for further research on the structure and function of NOR.
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Affiliation(s)
- Cong Chen
- College of Environmental, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Yu Wang
- College of Environmental, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Huan Liu
- College of Environmental, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Yi Chen
- College of Environmental, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Jiachao Yao
- College of Biological and Environmental Engineering, Zhejiang Shuren University, Hangzhou, 310021, PR China
| | - Jun Chen
- College of Biological and Environmental Engineering, Zhejiang Shuren University, Hangzhou, 310021, PR China.
| | - Dzmitry Hrynsphanb
- Research Institute of Physical and Chemical Problems, Belarusian State University, Minsk, 220030, Belarus
| | - Savitskaya Tatsianab
- Research Institute of Physical and Chemical Problems, Belarusian State University, Minsk, 220030, Belarus
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12
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Ou X, Peng F, Wu X, Xu P, Zong M, Lou W. Efficient protein expression in a robust Escherichia coli strain and its application for kinetic resolution of racemic glycidyl o-methylphenyl ether in high concentration. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107573] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Pan X, Li M, Guo S, Pu C. Research on the competitive effect of local government's environmental expenditure in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 718:137238. [PMID: 32086088 DOI: 10.1016/j.scitotenv.2020.137238] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 02/08/2020] [Accepted: 02/08/2020] [Indexed: 05/16/2023]
Abstract
Local government's environmental expenditure (LGEE) is critical to ecological protection and environmental governance, and it has not played its due role. By constructing a theoretical model of the competitive effect of LGEE under the intervention of central government, this study used the spatial econometric model to analyze the competitive effect of LGEE based on the data of 30 provinces in China from 2007 to 2016. The main results show that (1) from the perspective of the national area, LGEE shows a U-shaped development model together with economic growth; (2) a significant positive spatial effect in interprovincial LGEE is observed in eastern region, indicating that local government tends to adopt the competitive strategy of mutual imitation. Local government will not reduce environmental expenditure as fiscal decentralization increases; (3) the coefficient of the spatial effect in LGEE is significantly negative in central and western regions, which is manifested as a competitive strategy of mutual substitution. The coefficient of fiscal decentralization is significantly negative, indicating that LGEE relies mainly on the transfer payments from central government, and the essence of interprovincial competition regarding environmental expenditure is the competition for the transfer payments from central government.
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Affiliation(s)
- Xiongfeng Pan
- School of Economics and Management, Dalian University of Technology, Dalian 116024, China
| | - Mengna Li
- School of Economics and Management, Dalian University of Technology, Dalian 116024, China.
| | - Shucen Guo
- School of Economics and Management, Dalian University of Technology, Dalian 116024, China
| | - Chenxi Pu
- School of Economics and Management, Dalian University of Technology, Dalian 116024, China
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Duo Y, Wang X, He J, Zhang S, Pan H, Chen J, Chen J. Simultaneous removal of SO 2 and NO by Fe II(EDTA) solution: promotion of Mn powder and mechanism of reduction. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:28808-28816. [PMID: 31377926 DOI: 10.1007/s11356-019-06067-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 07/25/2019] [Indexed: 06/10/2023]
Abstract
The effect of Mn powder addition on the simultaneous removal of SO2 and NO coupled with FeII(EDTA) absorption was investigated in this work. In the NO absorption system with FeII(EDTA), SO2 reduced FeII(EDTA)-NO to FeII(EDTA) with a reduction efficiency reaching 88.5% under the conditions of 4000 mg/m3 SO2, pH 8.0, 44 °C, and the flow rate of 1.2 L/min within 60 min. Introducing 0.1 M Mn powder with SO2 increased the FeII(EDTA)-NO reduction efficiency to 96.8% within 5 min. SO2 was also removed by reducing FeII(EDTA)-NO and converted into SO42- at a removal efficiency of 100%. After adding Mn powder, NO was removed through the following reaction: [Formula: see text]. Mn powder functioned as a reductant to regenerate the absorption of solution, and the coordinated NO in FeII(EDTA)-NO was reduced to NH4+. The resource utilization rate of N reached approximately 77.2%. The integrated technology is a potential solution for flue gas treatment in industrial sectors with coal-fired power plants and industrial boiler. Graphical abstract.
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Affiliation(s)
- Yankai Duo
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Xiaoping Wang
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Jinjia He
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Shihan Zhang
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Hua Pan
- College of Biological and Environmental Engineering, Zhejiang Shuren University, Hangzhou, 30021, People's Republic of China
| | - Jianmeng Chen
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Jun Chen
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China.
- College of Biological and Environmental Engineering, Zhejiang Shuren University, Hangzhou, 30021, People's Republic of China.
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15
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Wei Z, Yu S, Huang Z, Xiao X, Tang M, Li B, Zhang X. Simultaneous removal of elemental mercury and NO by mercury induced thermophilic community in membrane biofilm reactor. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 176:170-177. [PMID: 30927638 DOI: 10.1016/j.ecoenv.2019.03.082] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 03/14/2019] [Accepted: 03/19/2019] [Indexed: 06/09/2023]
Abstract
Thermophilic membrane biofilm reactor (TMBR) for elemental mercury (Hg0) and NO removal in simulated flue gas was investigated at oxygen content of 6% and 60 °C. The performance, the microbial community structures, gene function and the mechanism for Hg0 and NO removal in the TMBR were evaluated. TMBR achieved effective simultaneous Hg0 and NO removal in 210 days of operation, Hg0 and NO removal efficiency were up to 88.9% and 85.3%, respectively. Mercury induced thermophilic community had been formed significantly. Comamonas, Pseudomonas, Desulfomicrobium, Burkholderia and Halomonas were thermophilic mercury resistant bacteria. Brucella, Paracoccus, Tepidiphilus, Proteobacteria, Pseudomonas and Symbiobacterium were nitrifying/denitrifying genera, and had functional genes of mercury and nitrogen metabolism, as shown by16S rDNA and metagenomic sequencing. The biofilm in TMBR was characterized by XPS, HPLC. XPS and HPLC spectra indicate the formation of a mercuric species (Hg2+) from mercury oxidation. TMBR used oxygen as electron acceptor, NO and Hg0 as electron donor in nitrification; O2, NO and NO3- could be used as electron acceptor and Hg0 as electron donor in denitrification.
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Affiliation(s)
- Zaishan Wei
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275, China.
| | - Shan Yu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275, China
| | - Zaishan Huang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275, China
| | - Xiaoliang Xiao
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275, China
| | - Meiru Tang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275, China
| | - Bailong Li
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275, China
| | - Xiao Zhang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275, China
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16
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Liu Y, Yuan X, Liu Z. Optimization, purification, and characterization of hydroxylamine oxidoreductase from Acinetobacter sp. Y1. Biotechnol Appl Biochem 2019; 66:494-501. [PMID: 30905079 DOI: 10.1002/bab.1745] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 03/11/2019] [Indexed: 01/14/2023]
Abstract
Hydroxylamine oxidoreductase (HAO) is a key enzyme involved in ammonium removal pathway. To further study the enzyme, HAO was purified from heterotrophic nitrifier Acinetobacter sp. Y1 and its property was investigated. Results of single-factor experiments showed that the optimal carbon source, nitrogen source, and C/N ratio were trisodium citrate, ammonium sulfate, and 14, respectively, with incubation time of 16 H. DEAE SefinoseTM FF anion-exchange chromatography was used to purify HAO, followed by SefinoseTM CL-6B gel filtration chromatography. SDS-PAGE revealed that a 47 kDa enzyme was purified successfully, with a purification fold of 7.32 and a recovery rate of 19.40%. The optimized enzyme activity of purified HAO was tested at pH 8.0 and 30 °C. The results showed that the activity was increased by 43.78% and 25.64% in the presence of 1 mM Fe2+ and Fe3+ , respectively. HAO activity was increased with the increase of Na+ and K+ , Mn2+ , Zn2+ , Cu2+ , Ca2+ , Ba2+ inhibited the HAO activity at three concentrations. In addition, HAO activity was activated by ethylenediaminetetraacetic acid at 0.4 mM, and a negative effect arose as the dose increased. The purified enzyme from Y1 is different from other reported HAOs. Further study should be conducted to investigate the enzyme.
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Affiliation(s)
- Yuxiang Liu
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, People's Republic of China
| | - Xin Yuan
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, People's Republic of China
| | - Zeying Liu
- Key Laboratory of Coal Science and Technology of Shanxi Province and Ministry of Education, Taiyuan University of Technology, Taiyuan, Shanxi, People's Republic of China
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