1
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Sáez LP, Rodríguez-Caballero G, Olaya-Abril A, Cabello P, Moreno-Vivián C, Roldán MD, Luque-Almagro VM. Genomic Insights into Cyanide Biodegradation in the Pseudomonas Genus. Int J Mol Sci 2024; 25:4456. [PMID: 38674043 PMCID: PMC11049912 DOI: 10.3390/ijms25084456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/12/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
Molecular studies about cyanide biodegradation have been mainly focused on the hydrolytic pathways catalyzed by the cyanide dihydratase CynD or the nitrilase NitC. In some Pseudomonas strains, the assimilation of cyanide has been linked to NitC, such as the cyanotrophic model strain Pseudomonas pseudoalcaligenes CECT 5344, which has been recently reclassified as Pseudomonas oleovorans CECT 5344. In this work, a phylogenomic approach established a more precise taxonomic position of the strain CECT 5344 within the species P. oleovorans. Furthermore, a pan-genomic analysis of P. oleovorans and other species with cyanotrophic strains, such as P. fluorescens and P. monteilii, allowed for the comparison and identification of the cioAB and mqoAB genes involved in cyanide resistance, and the nitC and cynS genes required for the assimilation of cyanide or cyanate, respectively. While cyanide resistance genes presented a high frequency among the analyzed genomes, genes responsible for cyanide or cyanate assimilation were identified in a considerably lower proportion. According to the results obtained in this work, an in silico approach based on a comparative genomic approach can be considered as an agile strategy for the bioprospection of putative cyanotrophic bacteria and for the identification of new genes putatively involved in cyanide biodegradation.
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Affiliation(s)
- Lara P. Sáez
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain; (L.P.S.); (G.R.-C.); (A.O.-A.); (C.M.-V.); (M.D.R.)
| | - Gema Rodríguez-Caballero
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain; (L.P.S.); (G.R.-C.); (A.O.-A.); (C.M.-V.); (M.D.R.)
| | - Alfonso Olaya-Abril
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain; (L.P.S.); (G.R.-C.); (A.O.-A.); (C.M.-V.); (M.D.R.)
| | - Purificación Cabello
- Departamento de Botánica, Ecología y Fisiología Vegetal, Edificio Celestino Mutis, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain;
| | - Conrado Moreno-Vivián
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain; (L.P.S.); (G.R.-C.); (A.O.-A.); (C.M.-V.); (M.D.R.)
| | - María Dolores Roldán
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain; (L.P.S.); (G.R.-C.); (A.O.-A.); (C.M.-V.); (M.D.R.)
| | - Víctor M. Luque-Almagro
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain; (L.P.S.); (G.R.-C.); (A.O.-A.); (C.M.-V.); (M.D.R.)
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2
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Sun H, Lee Y, Han SO, Hyeon JE. Detoxifying Cyanides Using Cyanase Enzyme Complexes Composed of Carbonic Anhydrase via Irreversible Covalent Bonds. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:5318-5324. [PMID: 38477042 DOI: 10.1021/acs.jafc.3c08071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
Cyanase is a possible solution to reduce the environmental impact of cyanide. However, the enzyme's dependence on HCO3- limits its industrial applications. To overcome this problem, carbonic anhydrase is utilized in this study. Three types of Catcher/Tag systems were introduced into the cyanase (psCYN) from Pseudomonas stutzeri and the carbonic anhydrase (hmCA) from Hydrogenovibrio marinus to construct enzyme complexes via irreversible covalent bonds. Initially, a cyanase complex with the aid of scaffolding proteins was designed. The results of cyanase complexes using scaffolding proteins were similar to or inferior to those of the two free enzymes. To address this, the two enzymes were manipulated to form a direct bioconjugation without the need for scaffolding proteins. The two enzymes forming a direct conjugation showed activity more than 2.5 times higher than that of cyanase alone. In conclusion, this outcome will contribute to solving problems related to residual cyanides in food and the environment.
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Affiliation(s)
- Habin Sun
- Department of Next Generation Applied Sciences, Graduate School, Sungshin Women's University, Seoul 01133, Republic of Korea
| | - YouKyeong Lee
- Department of Next Generation Applied Sciences, Graduate School, Sungshin Women's University, Seoul 01133, Republic of Korea
| | - Sung Ok Han
- Department of Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Jeong Eun Hyeon
- Department of Next Generation Applied Sciences, Graduate School, Sungshin Women's University, Seoul 01133, Republic of Korea
- Department of Food Science and Biotechnology, College of Knowledge-Based Services Engineering, Sungshin Women's University, Seoul 01133, Republic of Korea
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3
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Kosgey K, Zungu PV, Bux F, Kumari S. Biological nitrogen removal from low carbon wastewater. Front Microbiol 2022; 13:968812. [PMID: 36466689 PMCID: PMC9709150 DOI: 10.3389/fmicb.2022.968812] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 10/28/2022] [Indexed: 08/13/2023] Open
Abstract
Nitrogen has traditionally been removed from wastewater by nitrification and denitrification processes, in which organic carbon has been used as an electron donor during denitrification. However, some wastewaters contain low concentrations of organic carbon, which may require external organic carbon supply, increasing treatment costs. As a result, processes such as partial nitrification/anammox (anaerobic ammonium oxidation) (PN/A), autotrophic denitrification, nitritation-denitritation and bioelectrochemical processes have been studied as possible alternatives, and are thus evaluated in this study based on process kinetics, applicability at large-scale and process configuration. Oxygen demand for nitritation-denitritation and PN/A is 25% and 60% lower than for nitrification/denitrification, respectively. In addition, PN/A process does not require organic carbon supply, while its supply for nitritation-denitritation is 40% less than for nitrification/denitrification. Both PN/A and nitritation-denitritation produce less sludge compared to nitrification/denitrification, which saves on sludge handling costs. Similarly, autotrophic denitrification generates less sludge compared to heterotrophic denitrification and could save on sludge handling costs. However, autotrophic denitrification driven by metallic ions, elemental sulfur (S) and its compounds could generate harmful chemicals. On the other hand, hydrogenotrophic denitrification can remove nitrogen completely without generation of harmful chemicals, but requires specialized equipment for generation and handling of hydrogen gas (H2), which complicates process configuration. Bioelectrochemical processes are limited by low kinetics and complicated process configuration. In sum, anammox-mediated processes represent the best alternative to nitrification/denitrification for nitrogen removal in low- and high-strength wastewaters.
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Affiliation(s)
- Kiprotich Kosgey
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban, South Africa
| | | | | | - Sheena Kumari
- Institute for Water and Wastewater Technology, Durban University of Technology, Durban, South Africa
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4
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Daneshian L, Renggli I, Hanaway R, Offermann LR, Schlachter CR, Hernandez Arriaza R, Henry S, Prakash R, Wybouw N, Dermauw W, Shimizu LS, Van Leeuwen T, Makris TM, Grbic V, Grbic M, Chruszcz M. Structural and functional characterization of β-cyanoalanine synthase from Tetranychus urticae. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 142:103722. [PMID: 35063675 DOI: 10.1016/j.ibmb.2022.103722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 06/14/2023]
Abstract
Tetranychus urticae is a polyphagous spider mite that can feed on more than 1100 plant species including cyanogenic plants. The herbivore genome contains a horizontally acquired gene tetur10g01570 (TuCAS) that was previously shown to participate in cyanide detoxification. To understand the structure and determine the function of TuCAS in T. urticae, crystal structures of the protein with lysine conjugated pyridoxal phosphate (PLP) were determined. These structures reveal extensive TuCAS homology with the β-substituted alanine synthase family, and they show that this enzyme utilizes a similar chemical mechanism involving a stable α-aminoacrylate intermediate in β-cyanoalanine and cysteine synthesis. We demonstrate that TuCAS is more efficient in the synthesis of β-cyanoalanine, which is a product of the detoxification reaction between cysteine and cyanide, than in the biosynthesis of cysteine. Also, the enzyme carries additional enzymatic activities that were not previously described. We show that TuCAS can detoxify cyanide using O-acetyl-L-serine as a substrate, leading to the direct formation of β-cyanoalanine. Moreover, it catalyzes the reaction between the TuCAS-bound α-aminoacrylate intermediate and aromatic compounds with a thiol group. In addition, we have tested several compounds as TuCAS inhibitors. Overall, this study identifies additional functions for TuCAS and provides new molecular insight into the xenobiotic metabolism of T. urticae.
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Affiliation(s)
- Leily Daneshian
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Isabella Renggli
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Ryan Hanaway
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Lesa R Offermann
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Caleb R Schlachter
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | | | - Shannon Henry
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Rahul Prakash
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Nicky Wybouw
- Terrestrial Ecology Unit, Department of Biology, Ghent University, Ghent, 9000, Belgium
| | - Wannes Dermauw
- Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Plant Sciences Unit, Merelbeke, 9820, Belgium; Department of Plants and Crops, Ghent University, Ghent, 9000, Belgium
| | - Linda S Shimizu
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | | | - Thomas M Makris
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA; Department of Molecular and Structural Biochemistry, NC State University, Raleigh, NC, 27607, USA
| | - Vojislava Grbic
- Department of Biology, Western University, London, Ontario, N6A 5B7, Canada
| | - Miodrag Grbic
- Department of Biology, Western University, London, Ontario, N6A 5B7, Canada; University of La Rioja, Logrono, Spain
| | - Maksymilian Chruszcz
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA.
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5
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Ika Pratiwi N, Mukimin A, Zen N, Septarina I. Integration of electrocoagulation, adsorption and wetland technology for jewelry industry wastewater treatment. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119690] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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6
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Mahendran R, Bs S, Thandeeswaran M, kG K, Vijayasarathy M, Angayarkanni J, Muthusamy G. Microbial (Enzymatic) Degradation of Cyanide to Produce Pterins as Cofactors. Curr Microbiol 2019; 77:578-587. [PMID: 31111225 DOI: 10.1007/s00284-019-01694-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 04/16/2019] [Indexed: 11/30/2022]
Abstract
Cyanide is one of the most poisonous substances in the environment, which may have originated from natural and anthropogenic sources. There are many enzymes produced by microorganisms which can degrade and utilize cyanide. The major byproducts of cyanide degradation are alanine, glutamic acid, alpha-amino-butyric acid, beta-cyanoalanine, pterin etc. These products have many pharmaceutical and medicinal applications. For the degradation of cyanide, microbes produce necessary cofactors which catalyze the degradation pathways. Pterin is one of the cofactors for cyanide degradation. There are many pathways involved for the degradation of cyanide, cyanate, and thiocyanate. Some of the microorganisms possess resistance to cyanide, since they have developed adaptive alternative pathways for the production of ATP by utilization of cyanide as carbon and nitrogen sources. In this review, we summarized different enzymes, their mechanisms, and corresponding pathways for the degradation of cyanide and production of pterins during cyanide degradation. We aim to enlighten different types of pterin, its classification, and biological significance through this literature review.
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Affiliation(s)
- Ramasamy Mahendran
- Cancer Therapeutics Lab, Department of Microbial Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Sabna Bs
- Cancer Therapeutics Lab, Department of Microbial Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Murugesan Thandeeswaran
- Cancer Therapeutics Lab, Department of Microbial Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Kiran kG
- Cancer Therapeutics Lab, Department of Microbial Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Muthu Vijayasarathy
- Clinical Biotechnology Lab, Department of Microbial Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | - Jayaraman Angayarkanni
- Cancer Therapeutics Lab, Department of Microbial Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.
| | - Gayathri Muthusamy
- Cancer Therapeutics Lab, Department of Microbial Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
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7
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Sharma M, Akhter Y, Chatterjee S. A review on remediation of cyanide containing industrial wastes using biological systems with special reference to enzymatic degradation. World J Microbiol Biotechnol 2019; 35:70. [DOI: 10.1007/s11274-019-2643-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 04/08/2019] [Indexed: 11/24/2022]
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8
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Zhu H, Han Y, Xu C, Han H, Ma W. Overview of the state of the art of processes and technical bottlenecks for coal gasification wastewater treatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 637-638:1108-1126. [PMID: 29801205 DOI: 10.1016/j.scitotenv.2018.05.054] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 05/04/2018] [Accepted: 05/04/2018] [Indexed: 06/08/2023]
Abstract
CGWW is major waste stream resulting from a number of activities of the low/medium temperature gasification unit that occurs during the production of natural gas. The resulting effluent contains a broad spectrum of organic and inorganic contaminants and exerts a negative influence on the environment, mainly due to the presence of toxic and refractory compounds. So far, various technologies have been applied for treatment of CGWW, while few reviews are available in the literature. Thus, this review attempts to offer a comprehensive picture about CGWW. An overview about pretreatment, biological and advanced processes for treatment of CGWW is presented, and the degradation mechanism of toxic and refractory pollutants is also elaborated. Technical bottlenecks existing in the operation of coal chemical industries, including foam proliferation, odors and biotoxicity risk, are detailed analyzed. Finally, the prospects of treatment for CGWW are discussed based on the concept of "wastewater is money". The review can be provided as an effective technical support for the construction and operation of coal gasification industries.
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Affiliation(s)
- Hao Zhu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yuxing Han
- School of Engineering, South China Agriculture University, Guangzhou 510642, China
| | - Chunyan Xu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Hongjun Han
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Weiwei Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
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9
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Virender Kumar, Kumar V, Singh AK, Verma N, Bhalla TC. A Potentiometric Biosensor for Cyanide Detection using Immobilized Whole Cell Cyanide Dihydratase of Flavobacterium indicum MTCC 6936. JOURNAL OF ANALYTICAL CHEMISTRY 2018. [DOI: 10.1134/s1061934818100039] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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10
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Kumar V, Kumar V, Bhalla TC. Alkaline active cyanide dihydratase of Flavobacterium indicum MTCC 6936: Growth optimization, purification, characterization and in silico analysis. Int J Biol Macromol 2018; 116:591-598. [PMID: 29775704 DOI: 10.1016/j.ijbiomac.2018.05.075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 05/03/2018] [Accepted: 05/12/2018] [Indexed: 11/30/2022]
Abstract
The present work explores a rare cyanide dihydratase of Flavobacterium indicum MTCC 6936 for its potential of cyanide degradation. The enzyme is purified to 12 fold with a yield of 76%. SDS and native-PAGE analysis revealed that enzyme was monomer of 40 kDa size. The enzyme works well in mesophilic range at wide array of pH. The thermostability profile of cyanide dihydratase revealed that the enzyme is quite stable at 30 °C and 35 °C with half-life of 6 h 30 min and 5 h respectively. Km and Vmax for cyanide dihydratase of F. indicum was measured to be 4.76 mM and 45 U mg-1 with kcat calculated to be 27.3 s-1 and specificity constant (kcat/Km) to be around 5.67 mM-1 s-1. MALDI-TOF analysis of purified protein revealed that the amino acid sequence has 50% and 43% sequence identity with putative amino acid sequence of F. indicum and earlier reported cyanide dihydratase of Bacillus pumilus respectively. Homology modeling studies of cyanide dihydratase of F. indicum predicted the catalytic triad of the enzyme indicating Cys at 164, Glu at 46 and Lys at 130th position. The purified enzyme has potential applications in bioremediation and analytical sector.
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Affiliation(s)
- Virender Kumar
- Department of Biotechnology, Himachal Pradesh University, Summer Hill, Shimla 171005, India
| | - Vijay Kumar
- Department of Biotechnology, Himachal Pradesh University, Summer Hill, Shimla 171005, India
| | - Tek Chand Bhalla
- Department of Biotechnology, Himachal Pradesh University, Summer Hill, Shimla 171005, India.
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11
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Cyanotrophic and arsenic oxidizing activities of Pseudomonas mendocina P6115 isolated from mine tailings containing high cyanide concentration. Arch Microbiol 2018; 200:1037-1048. [DOI: 10.1007/s00203-018-1514-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/25/2018] [Accepted: 04/04/2018] [Indexed: 10/17/2022]
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12
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Affiliation(s)
| | - B Trevor Sewell
- Structural Biology Research Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town
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13
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Tang R, Wu D, Chen W, Feng C, Wei C. Biocathode denitrification of coke wastewater effluent from an industrial aeration tank: Effect of long-term adaptation. Biochem Eng J 2017. [DOI: 10.1016/j.bej.2017.05.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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14
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Park JM, Trevor Sewell B, Benedik MJ. Cyanide bioremediation: the potential of engineered nitrilases. Appl Microbiol Biotechnol 2017; 101:3029-3042. [PMID: 28265723 DOI: 10.1007/s00253-017-8204-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 02/13/2017] [Accepted: 02/15/2017] [Indexed: 11/29/2022]
Abstract
The cyanide-degrading nitrilases are of notable interest for their potential to remediate cyanide contaminated waste streams, especially as generated in the gold mining, pharmaceutical, and electroplating industries. This review provides a brief overview of cyanide remediation in general but with a particular focus on the cyanide-degrading nitrilases. These are of special interest as the hydrolysis reaction does not require secondary substrates or cofactors, making these enzymes particularly good candidates for industrial remediation processes. The genetic approaches that have been used to date for engineering improved enzymes are described; however, recent structural insights provide a promising new approach.
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Affiliation(s)
- Jason M Park
- Department of Biology, Texas A&M University, College Station, TX, 77843-3258, USA
| | - B Trevor Sewell
- Structural Biology Research Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, 7925, South Africa
| | - Michael J Benedik
- Department of Biology, Texas A&M University, College Station, TX, 77843-3258, USA.
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15
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Crum MA, Sewell BT, Benedik MJ. Bacillus pumilus Cyanide Dihydratase Mutants with Higher Catalytic Activity. Front Microbiol 2016; 7:1264. [PMID: 27570524 PMCID: PMC4981594 DOI: 10.3389/fmicb.2016.01264] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/02/2016] [Indexed: 11/24/2022] Open
Abstract
Cyanide degrading nitrilases are noted for their potential to detoxify industrial wastewater contaminated with cyanide. However, such application would benefit from an improvement to characteristics such as their catalytic activity and stability. Following error-prone PCR for random mutagenesis, several cyanide dihydratase mutants from Bacillus pumilus were isolated based on improved catalysis. Four point mutations, K93R, D172N, A202T, and E327K were characterized and their effects on kinetics, thermostability and pH tolerance were studied. K93R and D172N increased the enzyme’s thermostability whereas E327K mutation had a less pronounced effect on stability. The D172N mutation also increased the affinity of the enzyme for its substrate at pH 7.7 but lowered its kcat. However, the A202T mutation, located in the dimerization or the A surface, destabilized the protein and abolished its activity. No significant effect on activity at alkaline pH was observed for any of the purified mutants. These mutations help confirm the model of CynD and are discussed in the context of the protein–protein interfaces leading to the protein quaternary structure.
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Affiliation(s)
- Mary A Crum
- Department of Biology, Texas A&M University, College Station TX, USA
| | - B Trevor Sewell
- Structural Biology Research Unit, Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town Cape Town, South Africa
| | - Michael J Benedik
- Department of Biology, Texas A&M University, College Station TX, USA
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16
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Optimisation of biodegradation conditions for cyanide removal by Serratia marcescens strain AQ07 using one-factor-at-a-time technique and response surface methodology. RENDICONTI LINCEI-SCIENZE FISICHE E NATURALI 2016. [DOI: 10.1007/s12210-016-0516-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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17
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Park JM, Mulelu A, Sewell BT, Benedik MJ. Probing an Interfacial Surface in the Cyanide Dihydratase from Bacillus pumilus, A Spiral Forming Nitrilase. Front Microbiol 2016; 6:1479. [PMID: 26779137 PMCID: PMC4700190 DOI: 10.3389/fmicb.2015.01479] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 12/08/2015] [Indexed: 11/13/2022] Open
Abstract
Nitrilases are of significant interest both due to their potential for industrial production of valuable products as well as degradation of hazardous nitrile-containing wastes. All known functional members of the nitrilase superfamily have an underlying dimer structure. The true nitrilases expand upon this basic dimer and form large spiral or helical homo-oligomers. The formation of this larger structure is linked to both the activity and substrate specificity of these nitrilases. The sequences of the spiral nitrilases differ from the non-spiral forming homologs by the presence of two insertion regions. Homology modeling suggests that these regions are responsible for associating the nitrilase dimers into the oligomer. Here we used cysteine scanning across these two regions, in the spiral forming nitrilase cyanide dihydratase from Bacillus pumilus (CynD), to identify residues altering the oligomeric state or activity of the nitrilase. Several mutations were found to cause changes to the size of the oligomer as well as reduction in activity. Additionally one mutation, R67C, caused a partial defect in oligomerization with the accumulation of smaller oligomer variants. These results support the hypothesis that these insertion regions contribute to the unique quaternary structure of the spiral microbial nitrilases.
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Affiliation(s)
- Jason M Park
- Department of Biology, Texas A&M University, College Station TX, USA
| | - Andani Mulelu
- Structural Biology Research Unit, Department of Integrative Biomedical Sciences, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town Cape Town, South Africa
| | - B Trevor Sewell
- Structural Biology Research Unit, Department of Integrative Biomedical Sciences, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town Cape Town, South Africa
| | - Michael J Benedik
- Department of Biology, Texas A&M University, College Station TX, USA
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18
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Kandasamy S, Dananjeyan B, Krishnamurthy K, Benckiser G. Aerobic cyanide degradation by bacterial isolates from cassava factory wastewater. Braz J Microbiol 2015; 46:659-66. [PMID: 26413045 PMCID: PMC4568873 DOI: 10.1590/s1517-838246320130516] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Accepted: 11/16/2014] [Indexed: 11/22/2022] Open
Abstract
Ten bacterial strains that utilize cyanide (CN) as a nitrogen source were isolated
from cassava factory wastewater after enrichment in a liquid media containing sodium
cyanide (1 mM) and glucose (0.2% w/v). The strains could tolerate and grow in cyanide
concentrations of up to 5 mM. Increased cyanide levels in the media caused an
extension of lag phase in the bacterial growth indicating that they need some period
of acclimatisation. The rate of cyanide removal by the strains depends on the initial
cyanide and glucose concentrations. When initial cyanide and glucose concentrations
were increased up to 5 mM, cyanide removal rate increased up to 63 and 61 per cent by
Bacillus pumilus and Pseudomonas putida.
Metabolic products such as ammonia and formate were detected in culture supernatants,
suggesting a direct hydrolytic pathway without an intermediate formamide. The study
clearly demonstrates the potential of aerobic treatment with cyanide degrading
bacteria for cyanide removal in cassava factory wastewaters.
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Affiliation(s)
- Sujatha Kandasamy
- Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, India
| | - Balachandar Dananjeyan
- Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, India
| | - Kumar Krishnamurthy
- Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, India
| | - Gero Benckiser
- Institute of Applied Microbiology, Justus Liebig University, Giessen, Germany
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Crum M, Park J, Sewell B, Benedik M. C-terminal hybrid mutant of Bacillus pumilus
cyanide dihydratase dramatically enhances thermal stability and pH tolerance by reinforcing oligomerization. J Appl Microbiol 2015; 118:881-9. [DOI: 10.1111/jam.12754] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 01/06/2015] [Accepted: 01/08/2015] [Indexed: 01/27/2023]
Affiliation(s)
- M.A. Crum
- Department of Biology; Texas A&M University; College Station TX USA
| | - J.M. Park
- Department of Biology; Texas A&M University; College Station TX USA
| | - B.T. Sewell
- Structural Biology Research Unit; Division of Medical Biochemistry; Institute of Infectious Disease and Molecular Medicine; University of Cape Town; Cape Town South Africa
| | - M.J. Benedik
- Department of Biology; Texas A&M University; College Station TX USA
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Nallapan Maniyam M, Sjahrir F, Latif Ibrahim A, Cass AEG. Enzymatic cyanide degradation by cell-free extract of Rhodococcus UKMP-5M. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2015; 50:357-364. [PMID: 25723061 DOI: 10.1080/10934529.2015.987524] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The cell-free extract of locally isolated Rhodococcus UKMP-5M strain was used as an alternative to develop greener and cost effective cyanide removal technology. The present study aims to assess the viability of the cell-free extract to detoxify high concentrations of cyanide which is measured through the monitoring of protein concentration and specific cyanide-degrading activity. When cyanide-grown cells were subjected to grinding in liquid nitrogen which is relatively an inexpressive and fast cell disruption method, highest cyanide-degrading activity of 0.63 mM min(-1) mg(-1) protein was obtained in comparison to enzymatic lysis and agitation with fine glass beads. The cell-free extracts managed to degrade 80% of 20 mM KCN within 80 min and the rate of cyanide consumption increased linearly as the concentration of protein was raised. In both cases, the addition of co-factor was not required which proved to be advantageous economically. The successful formation of ammonia and formate as endproducts indicated that the degradation of cyanide by Rhodococcus UKMP-5M proceeded via the activity of cyanidase and the resulting non-toxic products are safe for disposal into the environment. Further verification with SDS-PAGE revealed that the molecular weight of the active enzyme was estimated to be 38 kDa, which is consistent with previously reported cyanidases. Thus, the utilization of cell-free extracts as an alternative to live microbial in cyanide degradation offers numerous advantageous such as the potential to tolerate and degrade higher concentration of cyanide and total reduction in the overall cost of operation since the requirement for nutrient support is irrelevant.
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Ramteke PW, Maurice NG, Joseph B, Wadher BJ. Nitrile-converting enzymes: an eco-friendly tool for industrial biocatalysis. Biotechnol Appl Biochem 2014; 60:459-81. [PMID: 23826937 DOI: 10.1002/bab.1139] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 06/21/2013] [Indexed: 11/10/2022]
Abstract
Nitriles are organic compounds bearing a − C ≡ N group; they are frequently known to occur naturally in both fauna and flora and are also synthesized chemically. They have wide applicability in the fields of medicine, industry, and environmental monitoring. However, the majority of nitrile compounds are considered to be lethal, mutagenic, and carcinogenic in nature and are known to cause potential health problems such as nausea, bronchial irritation, respiratory distress, convulsions, coma, and skeletal deformities in humans. Nitrile-converting enzymes, which are extracted from microorganisms, are commonly termed nitrilases and have drawn the attention of researchers all over the world to combat the toxicity of nitrile compounds. The present review focuses on the utility of nitrile-converting enzymes, sources, classification, structure, properties, and applications, as well as the future perspective on nitrilases.
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Affiliation(s)
- Pramod W Ramteke
- Department of Biological Sciences, Sam Higginbotom Institute of Agriculture, Technology and Sciences, Allahabad, India
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22
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Nallapan Maniyam M, Sjahrir F, Ibrahim AL, Cass AEG. Biodegradation of cyanide by acetonitrile-induced cells of Rhodococcus sp. UKMP-5M. J GEN APPL MICROBIOL 2014; 59:393-404. [PMID: 24492598 DOI: 10.2323/jgam.59.393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A Rhodococcus sp. UKMP-5M isolate was shown to detoxify cyanide successfully, suggesting the presence of an intrinsic property in the bacterium which required no prior cyanide exposure for induction of this property. However, in order to promote growth, Rhodococcus sp. UKMP-5M was fully acclimatized to cyanide after 7 successive subcultures in 0.1 mM KCN for 30 days. To further shorten the lag phase and simultaneously increase the tolerance towards higher cyanide concentrations, the bacterium was induced with various nitrile compounds sharing a similar degradatory pathway to cyanide. Acetonitrile emerged as the most favored inducer and the induced cells were able to degrade 0.1 mM KCN almost completely within 18 h. With the addition of subsequent aliquots of 0.1 mM KCN a shorter period for complete removal of cyanide was required, which proved to be advantageous economically. Both resting cells and crude enzyme of Rhodococcus sp. UKMP-5M were able to biodegrade cyanide to ammonia and formate without the formation of formamide, implying the identification of a simple hydrolytic cyanide degradation pathway involving the enzyme cyanidase. Further verification with SDS-PAGE revealed that the molecular weight of the active enzyme was estimated to be 38 kDa, which is consistent with previously reported cyanidases. Since the recent advancement in the application of biological methods in treating cyanide-bearing wastewater has been promising, the discovery of this new bacterium will add value by diversifying the existing microbial populations capable of cyanide detoxification.
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Cray JA, Bell ANW, Bhaganna P, Mswaka AY, Timson DJ, Hallsworth JE. The biology of habitat dominance; can microbes behave as weeds? Microb Biotechnol 2013; 6:453-92. [PMID: 23336673 PMCID: PMC3918151 DOI: 10.1111/1751-7915.12027] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 12/03/2012] [Indexed: 02/06/2023] Open
Abstract
Competition between microbial species is a product of, yet can lead to a reduction in, the microbial diversity of specific habitats. Microbial habitats can resemble ecological battlefields where microbial cells struggle to dominate and/or annihilate each other and we explore the hypothesis that (like plant weeds) some microbes are genetically hard-wired to behave in a vigorous and ecologically aggressive manner. These 'microbial weeds' are able to dominate the communities that develop in fertile but uncolonized--or at least partially vacant--habitats via traits enabling them to out-grow competitors; robust tolerances to habitat-relevant stress parameters and highly efficient energy-generation systems; avoidance of or resistance to viral infection, predation and grazers; potent antimicrobial systems; and exceptional abilities to sequester and store resources. In addition, those associated with nutritionally complex habitats are extraordinarily versatile in their utilization of diverse substrates. Weed species typically deploy multiple types of antimicrobial including toxins; volatile organic compounds that act as either hydrophobic or highly chaotropic stressors; biosurfactants; organic acids; and moderately chaotropic solutes that are produced in bulk quantities (e.g. acetone, ethanol). Whereas ability to dominate communities is habitat-specific we suggest that some microbial species are archetypal weeds including generalists such as: Pichia anomala, Acinetobacter spp. and Pseudomonas putida; specialists such as Dunaliella salina, Saccharomyces cerevisiae, Lactobacillus spp. and other lactic acid bacteria; freshwater autotrophs Gonyostomum semen and Microcystis aeruginosa; obligate anaerobes such as Clostridium acetobutylicum; facultative pathogens such as Rhodotorula mucilaginosa, Pantoea ananatis and Pseudomonas aeruginosa; and other extremotolerant and extremophilic microbes such as Aspergillus spp., Salinibacter ruber and Haloquadratum walsbyi. Some microbes, such as Escherichia coli, Mycobacterium smegmatis and Pseudoxylaria spp., exhibit characteristics of both weed and non-weed species. We propose that the concept of nonweeds represents a 'dustbin' group that includes species such as Synodropsis spp., Polypaecilum pisce, Metschnikowia orientalis, Salmonella spp., and Caulobacter crescentus. We show that microbial weeds are conceptually distinct from plant weeds, microbial copiotrophs, r-strategists, and other ecophysiological groups of microorganism. Microbial weed species are unlikely to emerge from stationary-phase or other types of closed communities; it is open habitats that select for weed phenotypes. Specific characteristics that are common to diverse types of open habitat are identified, and implications of weed biology and open-habitat ecology are discussed in the context of further studies needed in the fields of environmental and applied microbiology.
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Affiliation(s)
- Jonathan A Cray
- School of Biological Sciences, MBC, Queen's University BelfastBelfast, BT9 7BL, Northern Ireland, UK
| | - Andrew N W Bell
- School of Biological Sciences, MBC, Queen's University BelfastBelfast, BT9 7BL, Northern Ireland, UK
| | - Prashanth Bhaganna
- School of Biological Sciences, MBC, Queen's University BelfastBelfast, BT9 7BL, Northern Ireland, UK
| | - Allen Y Mswaka
- School of Biological Sciences, MBC, Queen's University BelfastBelfast, BT9 7BL, Northern Ireland, UK
| | - David J Timson
- School of Biological Sciences, MBC, Queen's University BelfastBelfast, BT9 7BL, Northern Ireland, UK
| | - John E Hallsworth
- School of Biological Sciences, MBC, Queen's University BelfastBelfast, BT9 7BL, Northern Ireland, UK
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Luque-Almagro VM, Acera F, Igeño MI, Wibberg D, Roldán MD, Sáez LP, Hennig M, Quesada A, Huertas MJ, Blom J, Merchán F, Escribano MP, Jaenicke S, Estepa J, Guijo MI, Martínez-Luque M, Macías D, Szczepanowski R, Becerra G, Ramirez S, Carmona MI, Gutiérrez O, Manso I, Pühler A, Castillo F, Moreno-Vivián C, Schlüter A, Blasco R. Draft whole genome sequence of the cyanide-degrading bacterium Pseudomonas pseudoalcaligenes CECT5344. Environ Microbiol 2012; 15:253-70. [PMID: 22998548 DOI: 10.1111/j.1462-2920.2012.02875.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 08/15/2012] [Accepted: 08/19/2012] [Indexed: 11/30/2022]
Abstract
Pseudomonas pseudoalcaligenes CECT5344 is a Gram-negative bacterium able to tolerate cyanide and to use it as the sole nitrogen source. We report here the first draft of the whole genome sequence of a P. pseudoalcaligenes strain that assimilates cyanide. Three aspects are specially emphasized in this manuscript. First, some generalities of the genome are shown and discussed in the context of other Pseudomonadaceae genomes, including genome size, G + C content, core genome and singletons among other features. Second, the genome is analysed in the context of cyanide metabolism, describing genes probably involved in cyanide assimilation, like those encoding nitrilases, and genes related to cyanide resistance, like the cio genes encoding the cyanide insensitive oxidases. Finally, the presence of genes probably involved in other processes with a great biotechnological potential like production of bioplastics and biodegradation of pollutants also is discussed.
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Affiliation(s)
- Víctor M Luque-Almagro
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, 14071, Córdoba, Spain
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Estepa J, Luque-Almagro VM, Manso I, Escribano MP, Martínez-Luque M, Castillo F, Moreno-Vivián C, Roldán MD. The nit1C gene cluster of Pseudomonas pseudoalcaligenes CECT5344 involved in assimilation of nitriles is essential for growth on cyanide. ENVIRONMENTAL MICROBIOLOGY REPORTS 2012; 4:326-334. [PMID: 23760796 DOI: 10.1111/j.1758-2229.2012.00337.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A proteomic approach was used to identify several proteins induced by cyanide in the alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344, two of them, NitB and NitG, encoded by genes that belong to the nit1C gene cluster. The predicted products of the nit1C gene cluster are a Fis-like σ(54) -dependent transcriptional activator (NitA), a nitrilase (NitC), an S-adenosylmethionine superfamily member (NitD), an N-acyltransferase superfamily member (NitE), a trifunctional polypeptide of the AIRS/GARS family (NitF), an NADH-dependent oxidoreductase (NitH) and two hypothetical proteins of unknown function (NitB and NitG). RT-PCR analysis suggested that nitBCDEFGH genes were co-transcribed, whereas the regulatory nitA gene was divergently transcribed. Real-time RT-PCR revealed that expression of the nitBCDEFGH genes was induced by cyanide and repressed by ammonium. The P. pseudoalcaligenes CECT5344 nit1C gene cluster was found to be involved in assimilation of free and organic cyanides (nitriles) as deduced for the inability to grow with cyanides showed by the NitA, NitB and NitC mutant strains. The wild-type strain CECT5344 showed a nitrilase activity that allows growth on cyanide or hydroxynitriles. The NitB and NitC mutants only presented low basal levels of nitrilase activity that were not enough to support growth on either free cyanide or aliphatic nitriles, suggesting that nitrilase NitC is specific and essential for cyanide and aliphatic nitriles assimilation.
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Affiliation(s)
- Jessica Estepa
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Edificio Severo Ochoa, 1a Planta, Universidad de Córdoba, 14071, Córdoba, Spain
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27
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Wang L, Watermeyer JM, Mulelu AE, Sewell BT, Benedik MJ. Engineering pH-tolerant mutants of a cyanide dihydratase. Appl Microbiol Biotechnol 2011; 94:131-40. [DOI: 10.1007/s00253-011-3620-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 09/06/2011] [Accepted: 09/29/2011] [Indexed: 10/16/2022]
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Isolation of a strain of Aspergillus fumigatus able to grow in minimal medium added with an industrial cyanide waste. World J Microbiol Biotechnol 2011; 28:165-73. [DOI: 10.1007/s11274-011-0805-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Accepted: 05/26/2011] [Indexed: 10/18/2022]
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29
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Chen WJ, Tang P, Hseu YC, Chen CC, Huang KY, Chen SC. A proteome analysis of the tetracyanonickelate (II) responses in Klebsiella oxytoca. ENVIRONMENTAL MICROBIOLOGY REPORTS 2011; 3:106-111. [PMID: 23761238 DOI: 10.1111/j.1758-2229.2010.00194.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Tetracyanonickelate (II) (TCN) has been proved to be degraded by Klebsiella oxytoca. In order to examine the physiological responses of TCN degradation by this bacterium, two-dimensional (2-DE) electrophoresis approach and Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry allow us to identify 91 proteins spots that were significantly altered in the presence of 1 mM TCN in relative to that in 1 mM ammonia when K. oxytoca grown at the late-log phase. Among them, 43 proteins were successfully identified. Fractions enriched in hydrophobic proteins were obtained with a specific extraction method based on temperature-dependent phase partitioning with Triton X-114, with the successful identification of 26 proteins out of 41 differential proteins. Some proteins were related with TCN metabolism. OsmC-like protein, molecular chaperone DnaK, glutathione S-transferase, alkyl hydroperoxide reductase, DNA protection during starvation conditions and DNA binding ferritin-like protein can counteract the oxidative stress from TCN biodegradation. The nitrogenase had been suggested to participate in TCN degradation by K. oxytoca, and was upregulated in TCN-treated cells as expected. The induction of glutamine synthetase could enhance the assimilation of limited nitrogen source produced from the bioconversion of TCN into ammonia as the alternate nitrogen source for bacteria growth. These findings could provide new insights into the inducible mechanisms underlying the capacity of K. oxytoca to tolerate TCN stress.
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Affiliation(s)
- Wen-Jen Chen
- Department of Biological Science, National Sun Yat-Sen University, Kaohsiung, Taiwan Bioinformatics Center, Chang Gung University, Taoyuan, Taiwan Department of Cosmeceutic, China Medical University, Taichung, Taiwan Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
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Zhang W, Liu W, Lv Y, Li B, Ying W. Enhanced carbon adsorption treatment for removing cyanide from coking plant effluent. JOURNAL OF HAZARDOUS MATERIALS 2010; 184:135-140. [PMID: 20813456 DOI: 10.1016/j.jhazmat.2010.08.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 07/31/2010] [Accepted: 08/06/2010] [Indexed: 05/29/2023]
Abstract
Batch experiments were conducted to determine the effects of metal loading and fixing methods on the capacity of granular activated carbon (GAC) for removing cyanide from KCN (pH 11), K(3)Fe(CN)(6) solutions and several SCP effluent samples. KI fixed carbon (Cu/KI-GAC) was the most effective among the GAC samples tested. Adsorption was the primary mechanism of cyanide removal; catalytic oxidation of the adsorbed cyanide on carbon surface contributed a minor amount of the observed removal. Four small adsorbers containing the base GAC and 0-100% of Cu/KI-GAC were employed for treating a Fenton oxidized/precipitated SCP effluent sample. After the start-up period (<3-week) to establish the effective biological activated carbon (BAC) function in the adsorbers, the effluents became stable and met the discharge limits (COD(Cr)<50mg/L and TCN<0.5mg/L); with >30% Cu/KI-GAC in the adsorber, the effluent would meet the discharge limits during the start-up phase.
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Affiliation(s)
- Wei Zhang
- School of Resources and Environmental Engineering, East China University of Science and Technology, No.130, Mei Long Road, Shanghai 200237, China
| | - Wandong Liu
- School of Resources and Environmental Engineering, East China University of Science and Technology, No.130, Mei Long Road, Shanghai 200237, China
| | - Yan Lv
- School of Resources and Environmental Engineering, East China University of Science and Technology, No.130, Mei Long Road, Shanghai 200237, China
| | - Bingjing Li
- School of Resources and Environmental Engineering, East China University of Science and Technology, No.130, Mei Long Road, Shanghai 200237, China
| | - Weichi Ying
- School of Resources and Environmental Engineering, East China University of Science and Technology, No.130, Mei Long Road, Shanghai 200237, China.
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Özel YK, Gedikli S, Aytar P, Ünal A, Yamaç M, Çabuk A, Kolankaya N. New fungal biomasses for cyanide biodegradation. J Biosci Bioeng 2010; 110:431-5. [DOI: 10.1016/j.jbiosc.2010.04.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 04/21/2010] [Accepted: 04/26/2010] [Indexed: 11/30/2022]
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Huertas MJ, Sáez LP, Roldán MD, Luque-Almagro VM, Martínez-Luque M, Blasco R, Castillo F, Moreno-Vivián C, García-García I. Alkaline cyanide degradation by Pseudomonas pseudoalcaligenes CECT5344 in a batch reactor. Influence of pH. JOURNAL OF HAZARDOUS MATERIALS 2010; 179:72-78. [PMID: 20346583 DOI: 10.1016/j.jhazmat.2010.02.059] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2009] [Revised: 02/18/2010] [Accepted: 02/19/2010] [Indexed: 05/29/2023]
Abstract
Water containing cyanide was biologically detoxified with the bacterial strain Pseudomonas pseudoalcaligenes CECT5344 in a batch reactor. Volatilization of toxic hydrogen cyanide (HCN) was avoided by using an alkaline medium for the treatment. The operational procedure was optimized to assess cyanide biodegradation at variable pH values and dissolved oxygen concentrations. Using an initial pH of 10 without subsequent adjustment allowed total cyanide to be consumed at a mean rate of approximately 2.81 mg CN(-) L(-1) O.D.(-1) h(-1); however, these conditions posed a high risk of HCN formation. Cyanide consumption was found to be pH-dependent. Thus, no bacterial growth was observed with a controlled pH of 10; on the other hand, pH 9.5 allowed up to 2.31 mg CN(-) L(-1) O.D.(-1) h(-1) to be converted. The combination of a high pH and a low dissolved oxygen saturation (10%) minimized the release of HCN. This study contributes new basic knowledge about this biological treatment, which constitutes an effective alternative to available physico-chemical methods for the purification of wastewater containing cyanide or cyano-metal complexes.
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Affiliation(s)
- M J Huertas
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla Avda Américo Vespucio, 49, 41092 Sevilla, Spain.
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Shimomura-Shimizu M, Karube I. Applications of microbial cell sensors. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2010; 118:1-30. [PMID: 20087723 DOI: 10.1007/10_2009_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Since the first microbial cell sensor was studied by Karube et al. in 1977, many types of microbial cell sensors have been developed as analytical tools. The microbial cell sensor utilizes microbes as a sensing element and a transducer. The characteristics of microbial cell sensors as sensing devices are a complete contrast to those of enzyme sensors or immunosensors, which are highly specific for the substrates of interest, although the specificity of the microbial cell sensor has been improved by genetic modification of the microbe used as the sensing element. Microbial cell sensors have the advantages of tolerance to measuring conditions, a long lifetime, and good cost performance, and have the disadvantage of a long response time. In this review, applications of microbial cell sensors are summarized.
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Affiliation(s)
- Mifumi Shimomura-Shimizu
- School of Bioscience and Biotechnology, Tokyo University of Technology, Hachioji, Tokyo 1920982, Japan
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Kaewkannetra P, Imai T, Garcia-Garcia FJ, Chiu TY. Cyanide removal from cassava mill wastewater using Azotobactor vinelandii TISTR 1094 with mixed microorganisms in activated sludge treatment system. JOURNAL OF HAZARDOUS MATERIALS 2009; 172:224-228. [PMID: 19632039 DOI: 10.1016/j.jhazmat.2009.06.162] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2009] [Revised: 04/13/2009] [Accepted: 06/30/2009] [Indexed: 05/28/2023]
Abstract
Cassava mill wastewater has a high organic and cyanide content and is an important economic product of traditional and rural low technology agro-industry in many parts of the world. However, the wastewater is toxic and can pose serious threat to the environment and aquatic life in the receiving waters. The ability of Azotobactor vinelandii TISTR 1094, a N2-fixing bacterium, to grow and remove cyanide in cassava wastewater was evaluated. Results revealed that the cells in the exponential phase reduce the level of cyanide more rapidly than when the cells are at their stationary growth phase. The rate of cyanide removal by A. vinelandii depends on the initial cyanide concentration. As the initial cyanide concentration increased, removal rate increased and cyanide removal of up to 65.3% was achieved. In the subsequent pilot scale trial involving an activated sludge system, the introduction of A. vinelandii into the system resulted in cyanide removals of up to 90%. This represented an improvement of 20% when compared to the activated sludge system which did not incorporate the strain.
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Affiliation(s)
- P Kaewkannetra
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand
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35
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Proteomic Analysis of the Effect of Cyanide on Klebsiella oxytoca. Curr Microbiol 2009; 60:224-8. [DOI: 10.1007/s00284-009-9529-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Accepted: 10/21/2009] [Indexed: 11/27/2022]
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Dash RR, Gaur A, Balomajumder C. Cyanide in industrial wastewaters and its removal: a review on biotreatment. JOURNAL OF HAZARDOUS MATERIALS 2009; 163:1-11. [PMID: 18657360 DOI: 10.1016/j.jhazmat.2008.06.051] [Citation(s) in RCA: 244] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Revised: 06/11/2008] [Accepted: 06/16/2008] [Indexed: 05/26/2023]
Abstract
Cyanides are produced by certain bacteria, fungi, and algae, and may be found in plants and some foods, such as lima beans and almonds. Although cyanides are present in small concentrations in these plants and microorganisms, their large-scale presence in the environment is attributed to the human activities as cyanide compounds are extensively used in industries. Bulk of cyanide occurrence in environment is mainly due to metal finishing and mining industries. Although cyanide can be removed and recovered by several processes, it is still widely discussed and examined due to its potential toxicity and environmental impact. From an economic standpoint, the biological treatment method is cost-effective as compared to chemical and physical methods for cyanide removal. Several microbial species can effectively degrade cyanide into less toxic products. During metabolism, they use cyanide as a nitrogen and carbon source converting it to ammonia and carbonate, if appropriate conditions are maintained. Biological treatment of cyanide under anaerobic as well as aerobic conditions is possible. The present review describes the mechanism and advances in the use of biological treatment for the removal of cyanide compounds and its advantages over other treatment processes. It also includes various microbial pathways for their removal.
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Affiliation(s)
- Rajesh Roshan Dash
- Department of Civil Engineering, National Institute of Technology Hamirpur, Hamirpur 177005, HP, India.
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Thuku R, Brady D, Benedik M, Sewell B. Microbial nitrilases: versatile, spiral forming, industrial enzymes. J Appl Microbiol 2009; 106:703-27. [DOI: 10.1111/j.1365-2672.2008.03941.x] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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38
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Dash RR, Balomajumder C, Kumar A. Treatment of Cyanide Bearing Water/Wastewater by Plain and Biological Activated Carbon. Ind Eng Chem Res 2009. [DOI: 10.1021/ie071299y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rajesh Roshan Dash
- Department of Civil Engineering, NIT Hamirpur, Hamirpur-177005, HP, India, and Department of Chemical Engineering, and Department of Civil Engineering, IIT Roorkee, Roorkee-247667, Uttarakhand, India
| | - Chandrajit Balomajumder
- Department of Civil Engineering, NIT Hamirpur, Hamirpur-177005, HP, India, and Department of Chemical Engineering, and Department of Civil Engineering, IIT Roorkee, Roorkee-247667, Uttarakhand, India
| | - Arvind Kumar
- Department of Civil Engineering, NIT Hamirpur, Hamirpur-177005, HP, India, and Department of Chemical Engineering, and Department of Civil Engineering, IIT Roorkee, Roorkee-247667, Uttarakhand, India
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39
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Roshan Dash R, Balomajumder C, Kumar A. Removal of metal cyanides from aqueous solutions by suspended and immobilized cells ofRhizopus oryzae(MTCC 2541). Eng Life Sci 2009. [DOI: 10.1002/elsc.200700024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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40
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Basile LJ, Willson RC, Sewell BT, Benedik MJ. Genome mining of cyanide-degrading nitrilases from filamentous fungi. Appl Microbiol Biotechnol 2008; 80:427-35. [DOI: 10.1007/s00253-008-1559-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Revised: 05/28/2008] [Accepted: 05/30/2008] [Indexed: 10/21/2022]
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41
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Chen CY, Kao CM, Chen SC. Application of Klebsiella oxytoca immobilized cells on the treatment of cyanide wastewater. CHEMOSPHERE 2008; 71:133-139. [PMID: 18082868 DOI: 10.1016/j.chemosphere.2007.10.058] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Revised: 10/29/2007] [Accepted: 10/29/2007] [Indexed: 05/25/2023]
Abstract
Klebsiella oxytoca, isolated from cyanide-containing industrial wastewater, has been shown to be able to biodegrade cyanide to non-toxic end products. The technology of immobilized cells can be applied in biological treatment to enhance the efficiency and effectiveness of biodegradation. In this study, potassium cyanide was used as the target compound and both alginate and cellulose triacetate techniques were applied for the preparation of immobilized cells. Results from this study show that KCN can be utilized as the sole nitrogen source by K. oxytoca. The free suspension systems reveal that the cell viability was highly affected by initial KCN concentration and pH. Results show that immobilized cell systems could tolerate a higher level of KCN concentration and wider ranges of pH. In the batch experiments, the maximum KCN removal efficiencies using alginate and cellulose triacetate immobilized beads were 0.108 and 0.101mM h(-1) at pH 7, respectively. Results also indicate that immobilized system can support a higher biomass concentration. Complete KCN degradation was observed after the operation of four consecutive degradation experiments with the same batch of immobilized cells. This suggests that the activity of immobilized cells can be maintained and KCN can be used as the nitrogen source throughout KCN degradation experiments. The maximum KCN removal rates using alginate and cellulose triacetate immobilized beads in continuous-column system were 0.224 and 0.192mMh(-1) with initial KCN concentration of 3mM, respectively. Results indicate that the immobilized cells of K. oxytoca would be applicable to the treatment of cyanide-containing wastewaters.
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Affiliation(s)
- C Y Chen
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
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42
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Nakamura H, Shimomura-Shimizu M, Karube I. Development of microbial sensors and their application. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2008; 109:351-394. [PMID: 18004516 DOI: 10.1007/10_2007_085] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Many types of microbial sensors have been developed as analytical tools since the first microbial sensor was studied by Karube et al. in 1977. The microbial sensor consists of a transducer and microbe as a sensing element. The characteristics of the microbial sensors are a complete contrast to those of enzyme sensors or immunosensors, which are highly specific for the substrates of interest, although the specificity of the microbial sensor has been improved by genetic modification of the microbe used as the sensing element. Microbial sensors have the advantages of tolerance to measuring conditions, a long lifetime, and cost performance, and also have the disadvantage of a long response time. In this review, the long history of microbial sensor development is summarized.
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Affiliation(s)
- Hideaki Nakamura
- School of Bionics, Tokyo University of Technology, 1404-1 Katakura, Hachioji, 192-0982 Tokyo, Japan
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43
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Development and Electrochemical Investigations of an EIS- (Electrolyte-Insulator-Semiconductor) based Biosensor for Cyanide Detection. SENSORS 2007. [DOI: 10.3390/s7081415] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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44
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Lalucat J, Bennasar A, Bosch R, García-Valdés E, Palleroni NJ. Biology of Pseudomonas stutzeri. Microbiol Mol Biol Rev 2006; 70:510-47. [PMID: 16760312 PMCID: PMC1489536 DOI: 10.1128/mmbr.00047-05] [Citation(s) in RCA: 325] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Pseudomonas stutzeri is a nonfluorescent denitrifying bacterium widely distributed in the environment, and it has also been isolated as an opportunistic pathogen from humans. Over the past 15 years, much progress has been made in elucidating the taxonomy of this diverse taxonomical group, demonstrating the clonality of its populations. The species has received much attention because of its particular metabolic properties: it has been proposed as a model organism for denitrification studies; many strains have natural transformation properties, making it relevant for study of the transfer of genes in the environment; several strains are able to fix dinitrogen; and others participate in the degradation of pollutants or interact with toxic metals. This review considers the history of the discovery, nomenclatural changes, and early studies, together with the relevant biological and ecological properties, of P. stutzeri.
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Affiliation(s)
- Jorge Lalucat
- Department de Biologia, Microbiologia, Universitat de les Illes Balears, 07122 Palma de Mallorca, Spain.
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45
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Baxter J, Cummings SP. The current and future applications of microorganism in the bioremediation of cyanide contamination. Antonie van Leeuwenhoek 2006; 90:1-17. [PMID: 16683094 DOI: 10.1007/s10482-006-9057-y] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2005] [Accepted: 01/11/2006] [Indexed: 10/24/2022]
Abstract
Inorganic cyanide and nitrile compounds are distributed widely in the environment, chiefly as a result of anthropogenic activity but also through cyanide synthesis by a range of organisms including higher plants, fungi and bacteria. The major source of cyanide in soil and water is through the discharge of effluents containing a variety of inorganic cyanide and nitriles. Here the fate of cyanide compounds in soil and water is reviewed, identifying those factors that affect their persistence and which determine whether they are amenable to biological degradation. The exploitation of cyanides by a variety of taxa, as a mechanism to avoid predation or to inhibit competitors has led to the evolution in many organisms of enzymes that catalyse degradation of a range of cyanide compounds. Microorganisms expressing pathways involved in cyanide degradation are briefly reviewed and the current applications of bacteria and fungi in the biodegradation of cyanide contamination in the field are discussed. Finally, recent advances that offer an insight into the potential of microbial systems for the bioremediation of cyanide compounds under a range of environmental conditions are identified, and the future potential of these technologies for the treatment of cyanide pollution is discussed.
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Affiliation(s)
- Joanne Baxter
- School of Applied Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK
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46
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Fernandez RF, Kunz DA. Bacterial cyanide oxygenase is a suite of enzymes catalyzing the scavenging and adventitious utilization of cyanide as a nitrogenous growth substrate. J Bacteriol 2005; 187:6396-402. [PMID: 16159773 PMCID: PMC1236641 DOI: 10.1128/jb.187.18.6396-6402.2005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2005] [Accepted: 06/27/2005] [Indexed: 11/20/2022] Open
Abstract
Cyanide oxygenase (CNO) from Pseudomonas fluorescens NCIMB 11764 catalyzes the pterin-dependent oxygenolytic cleavage of cyanide (CN) to formic acid and ammonia. CNO was resolved into four protein components (P1 to P4), each of which along with a source of pterin cofactor was obligately required for CNO activity. Component P1 was characterized as a multimeric 230-kDa flavoprotein exhibiting the properties of a peroxide-forming NADH oxidase (oxidoreductase) (Nox). P2 consisted of a 49.7-kDa homodimer that showed 100% amino acid identity at its N terminus to NADH peroxidase (Npx) from Enterococcus faecalis. Enzyme assays further confirmed the identities of both Nox and Npx enzymes (specific activity, 1 U/mg). P3 was characterized as a large oligomeric protein (approximately 300 kDa) that exhibited cyanide dihydratase (CynD) activity (specific activity, 100 U/mg). Two polypeptides of 38 kDa and 43 kDa were each detected in the isolated enzyme, the former believed to confer catalytic activity based on its similar size to other CynD enzymes. The amino acid sequence of an internal peptide of the 43-kDa protein was 100% identical to bacterial elongation factor Tu, suggesting a role as a possible chaperone in the assembly of CynD or a multienzyme CNO complex. The remaining P4 component consisted of a 28.9-kDa homodimer and was identified as carbonic anhydrase (specific activity, 2,000 U/mg). While the function of participating pterin and the roles of Nox, Npx, CynD, and CA in the CNO-catalyzed scavenging of CN remain to be determined, this is the first report describing the collective involvement of these four enzymes in the metabolic detoxification and utilization of CN as a bacterial nitrogenous growth substrate.
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Affiliation(s)
- Ruby F Fernandez
- Division of Biochemistry and Molecular Biology, Department of Biological Sciences, University of North Texas, Denton, Texas 76203-5220, USA
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47
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Jandhyala DM, Willson RC, Sewell BT, Benedik MJ. Comparison of cyanide-degrading nitrilases. Appl Microbiol Biotechnol 2005; 68:327-35. [PMID: 15703908 DOI: 10.1007/s00253-005-1903-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2004] [Revised: 12/21/2004] [Accepted: 12/22/2004] [Indexed: 10/25/2022]
Abstract
Recombinant forms of three cyanide-degrading nitrilases, CynD from Bacillus pumilus C1, CynD from Pseudomonas stutzeri, and CHT from Gloeocercospora sorghi, were prepared after their genes were cloned with C-terminal hexahistidine purification tags and expressed in Escherichia coli, and the enzymes purified using nickel-chelate affinity chromatography. The enzymes were compared with respect to their pH stability, thermostability, metal tolerance, and kinetic constants. The two bacterial genes, both cyanide dihydratases, were similar with respect to pH range, retaining greater than 50% activity between pH 5.2 and pH 8 and kinetic properties, having similar K(m) (6-7 mM) and V(max) (0.1 mmol min(-1) mg(-1)). They also exhibited similar metal tolerances. However, the fungal CHT enzyme had notably higher K(m) (90 mM) and V(max) (4 mmol min(-1) mg(-1)) values. Its pH range was slightly more alkaline (retaining nearly full activity above 8.5), but exhibited a lower thermal tolerance. CHT was less sensitive to Hg(2+) and more sensitive to Pb(2+) than the CynD enzymes. These data describe, in part, the current limits that exist for using nitrilases as agents in the bioremediation of cyanide-containing waste effluent, and may help serve to determine where and under what conditions these nitrilases may be applied.
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Affiliation(s)
- Dakshina M Jandhyala
- Department of Biology and Biochemistry, University of Houston, Houston, TX, 77204-5001, USA
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48
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Sewell BT, Berman MN, Meyers PR, Jandhyala D, Benedik MJ. The cyanide degrading nitrilase from Pseudomonas stutzeri AK61 is a two-fold symmetric, 14-subunit spiral. Structure 2004; 11:1413-22. [PMID: 14604531 DOI: 10.1016/j.str.2003.10.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The quaternary structure of the cyanide dihydratase from Pseudomonas stutzeri AK61 was determined by negative stain electron microscopy and three-dimensional reconstruction using the single particle technique. The structure is a spiral comprising 14 subunits with 2-fold symmetry. Interactions across the groove cause a decrease in the radius of the spiral at the ends and the resulting steric hindrance prevents the addition of further subunits. Similarity to two members of the nitrilase superfamily, the Nit domain of NitFhit and N-carbamyl-D-amino acid amidohydrolase, enabled the construction of a partial atomic model that could be unambiguously fitted to the stain envelope. The model suggests that interactions involving two significant insertions in the sequence relative to these structures leads to the left-handed spiral assembly.
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Affiliation(s)
- B T Sewell
- Electron Microscope Unit, University of Cape Town, Private Bag, 7701 Rondebosch, South Africa.
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Fernandez RF, Dolghih E, Kunz DA. Enzymatic assimilation of cyanide via pterin-dependent oxygenolytic cleavage to ammonia and formate in Pseudomonas fluorescens NCIMB 11764. Appl Environ Microbiol 2004; 70:121-8. [PMID: 14711633 PMCID: PMC321297 DOI: 10.1128/aem.70.1.121-128.2004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2003] [Accepted: 10/02/2003] [Indexed: 11/20/2022] Open
Abstract
Utilization of cyanide as a nitrogen source by Pseudomonas fluorescens NCIMB 11764 occurs via oxidative conversion to carbon dioxide and ammonia, with the latter compound satisfying the nitrogen requirement. Substrate attack is initiated by cyanide oxygenase (CNO), which has been shown previously to have properties of a pterin-dependent hydroxylase. CNO was purified 71-fold and catalyzed the quantitative conversion of cyanide supplied at micromolar concentrations (10 to 50 micro M) to formate and ammonia. The specific activity of the partially purified enzyme was approximately 500 mU/mg of protein. The pterin requirement for activity could be satisfied by supplying either the fully (tetrahydro) or partially (dihydro) reduced forms of various pterin compounds at catalytic concentrations (0.5 micro M). These compounds included, for example, biopterin, monapterin, and neopterin, all of which were also identified in cell extracts. Substrate conversion was accompanied by the consumption of 1 and 2 molar equivalents of molecular oxygen and NADH, respectively. When coupled with formate dehydrogenase, the complete enzymatic system for cyanide oxidation to carbon dioxide and ammonia was reconstituted and displayed an overall reaction stoichiometry of 1:1:1 for cyanide, O(2), and NADH consumed. Cyanide was also attacked by CNO at a higher concentration (1 mM), but in this case formamide accumulated as the major reaction product (formamide/formate ratio, 0.6:0.3) and was not further degraded. A complex reaction mechanism involving the production of isocyanate as a potential CNO monooxygenation product is proposed. Subsequent reduction of isocyanate to formamide, whose hydrolysis occurs as a CNO-bound intermediate, is further envisioned. To our knowledge, this is the first report of enzymatic conversion of cyanide to formate and ammonia by a pterin-dependent oxygenative mechanism.
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Affiliation(s)
- Ruby F Fernandez
- Division of Biochemistry and Molecular Biology, Department of Biological Sciences, University of North Texas, Denton, Texas 76203, USA
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50
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Jandhyala D, Berman M, Meyers PR, Sewell BT, Willson RC, Benedik MJ. CynD, the cyanide dihydratase from Bacillus pumilus: gene cloning and structural studies. Appl Environ Microbiol 2003; 69:4794-805. [PMID: 12902273 PMCID: PMC169136 DOI: 10.1128/aem.69.8.4794-4805.2003] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2002] [Accepted: 05/02/2003] [Indexed: 11/20/2022] Open
Abstract
The cyanide dihydratase in Bacillus pumilus was shown to be an 18-subunit spiral structure by three-dimensional reconstruction of electron micrographs of negatively stained material at its optimum pH, 8.0. At pH 5.4, the subunits rearrange to form an extended left-handed helix. Gel electrophoresis of glutaraldehyde cross-linked enzyme suggests that the fundamental component of the spiral is a dimer of the 37-kDa subunit. The gene was cloned, and the recombinant enzyme was readily expressed at high levels in Escherichia coli. Purification of the recombinant enzyme was facilitated by the addition of a C-terminal six-histidine affinity purification tag. The tagged recombinant enzyme has K(m) and V(max) values similar to those published for the native enzyme. This is the first cyanide dihydratase from a gram-positive bacterium to be sequenced, and it is the first description of the structure of any member of this enzyme class. The putative amino acid sequence shares over 80% identity to the only other sequenced cyanide dihydratase, that of the gram-negative Pseudomonas stutzeri strain AK61, and is similar to a number of other bacterial and fungal nitrilases. This sequence similarity suggests that the novel short spiral structure may be typical of these enzymes. In addition, an active cyanide dihydratase from a non-cyanide-degrading isolate of B. pumilus (strain 8A3) was cloned and expressed. This suggests that cynD, the gene coding for the cyanide dihydratase, is not unique to the C1 strain of B. pumilus and is not a reflection of its origin at a mining waste site.
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Affiliation(s)
- Dakshina Jandhyala
- Department of Biology and Biochemistry. University of Houston, Houston, Texas 77204, USA
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