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Genomic Characterization of Bacillus safensis Isolated from Mine Tailings in Peru and Evaluation of Its Cyanide-Degrading Enzyme CynD. Appl Environ Microbiol 2022; 88:e0091622. [PMID: 35762789 PMCID: PMC9317851 DOI: 10.1128/aem.00916-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Understanding the biochemistry and metabolic pathways of cyanide degradation is necessary to improve the efficacy of cyanide bioremediation processes and industrial requirements. We have isolated and sequenced the genome of a cyanide-degrading Bacillus strain from water in contact with mine tailings from Lima, Peru. This strain was classified as Bacillus safensis based on 16S rRNA gene sequencing and core genome analyses and named B. safensis PER-URP-08. We searched for possible cyanide-degradation enzymes in the genome of this strain and identified a putative cyanide dihydratase (CynD) gene similar to a previously characterized CynD from Bacillus pumilus C1. Sequence analysis of CynD from B. safensis and B. pumilus allow us to identify C-terminal residues that differentiate both CynDs. We then cloned, expressed in Escherichia coli, and purified recombinant CynD from B. safensis PER-URP-08 (CynDPER-URP-08) and showed that in contrast to CynD from B. pumilus C1, this recombinant CynD remains active at up to pH 9. We also showed that oligomerization of CynDPER-URP-08 decreases as a function of increased pH. Finally, we demonstrated that transcripts of CynDPER-URP-08 in B. safensis PER-URP-08 are strongly induced in the presence of cyanide. Our results suggest that the use of B. safensis PER-URP-08 and CynDPER-URP-08 as potential tool for cyanide bioremediation warrants further investigation. IMPORTANCE Despite being of environmental concern around the world due to its toxicity, cyanide continues to be used in many important industrial processes. Thus, searching for cyanide bioremediation methods is a matter of societal concern and must be present on the political agenda of all governments. Here, we report the isolation, genome sequencing and characterization of cyanide degradation capacity of a bacterial strain isolated from an industrial mining site in Peru. We characterize a cyanide dehydratase (CynD) homolog from one of these bacteria, Bacillus safensis PER-URP-08.
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Malmir N, Zamani M, Motallebi M, Fard NA, Mekuto L. Cyanide Biodegradation by Trichoderma harzianum and Cyanide Hydratase Network Analysis. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27103336. [PMID: 35630813 PMCID: PMC9143735 DOI: 10.3390/molecules27103336] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 05/13/2022] [Accepted: 05/14/2022] [Indexed: 11/23/2022]
Abstract
Cyanide is a poisonous and dangerous chemical that binds to metals in metalloenzymes, especially cytochrome C oxidase and, thus, interferes with their functionalities. Different pathways and enzymes are involved during cyanide biodegradation, and cyanide hydratase is one of the enzymes that is involved in such a process. In this study, cyanide resistance and cyanide degradation were studied using 24 fungal strains in order to find the strain with the best capacity for cyanide bioremediation. To confirm the capacity of the tested strains, cyano-bioremediation and the presence of the gene that is responsible for the cyanide detoxification was assessed. From the tested organisms, Trichoderma harzianum (T. harzianum) had a significant capability to resist and degrade cyanide at a 15 mM concentration, where it achieved an efficiency of 75% in 7 days. The gene network analysis of enzymes that are involved in cyanide degradation revealed the involvement of cyanide hydratase, dipeptidase, carbon–nitrogen hydrolase-like protein, and ATP adenylyltransferase. This study revealed that T. harzianum was more efficient in degrading cyanide than the other tested fungal organisms, and molecular analysis confirmed the experimental observations.
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Affiliation(s)
- Narges Malmir
- National Institute of Genetic Engineering and Biotechnology (NIGEB), Shahrak-e Pajoohesh km 15, Tehran-Karaj Highway, Tehran P.O. Box 14965/161, Iran; (N.M.); (M.Z.); (M.M.); (N.A.F.)
- Department of Chemical Engineering, University of Johannesburg, Johannesburg 2028, South Africa
| | - Mohammadreza Zamani
- National Institute of Genetic Engineering and Biotechnology (NIGEB), Shahrak-e Pajoohesh km 15, Tehran-Karaj Highway, Tehran P.O. Box 14965/161, Iran; (N.M.); (M.Z.); (M.M.); (N.A.F.)
- Department of Chemical Engineering, University of Johannesburg, Johannesburg 2028, South Africa
| | - Mostafa Motallebi
- National Institute of Genetic Engineering and Biotechnology (NIGEB), Shahrak-e Pajoohesh km 15, Tehran-Karaj Highway, Tehran P.O. Box 14965/161, Iran; (N.M.); (M.Z.); (M.M.); (N.A.F.)
- Department of Chemical Engineering, University of Johannesburg, Johannesburg 2028, South Africa
| | - Najaf Allahyari Fard
- National Institute of Genetic Engineering and Biotechnology (NIGEB), Shahrak-e Pajoohesh km 15, Tehran-Karaj Highway, Tehran P.O. Box 14965/161, Iran; (N.M.); (M.Z.); (M.M.); (N.A.F.)
- Department of Chemical Engineering, University of Johannesburg, Johannesburg 2028, South Africa
| | - Lukhanyo Mekuto
- Department of Chemical Engineering, University of Johannesburg, Johannesburg 2028, South Africa
- Correspondence: ; Tel.: +27-(0)-11-559-9212
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Ahmed EM, F Alsanie W, Alhomrani M. Cyanide removal from aqueous environment by resting cells and PTFE immobilized cells of Sphingobacterium spp. J Basic Microbiol 2021; 62:444-454. [PMID: 34870865 DOI: 10.1002/jobm.202100292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 11/02/2021] [Accepted: 11/13/2021] [Indexed: 11/11/2022]
Abstract
Microbial detoxification of cyanide offered an inexpensive, safe, and viable alternative to physiochemical processes for the treatment of cyanide in industrial effluents or contaminated sites. This study involved isolation of novel strain with high resistance against cyanide toxicity and able to degrade the cyanide radical. The strain was isolated from rocky area and identified as Sphingobacterium multivorium using 16S ribosomal RNA. Resting pregrown cells were used in simple reaction mixture to avoid the complication associated with the media. One-gram fresh weight of this bacteria was able to remove 98.5% from 1.5 g/L cyanide which is a unique result. Factor affecting the biochemical process such as pH, temperature, agitation, glucose concentration was examined. The optimum conditions were, pH 6-7, 30-40°C, and 100-150 rpm shaking speed and 0.25% glucose. Furthermore, the cells were used after immobilization in polytetrafluoroethylene (PTFE) polymer. The PTFE is very safe carrier and the cells withstand the entrapment process and were able to remove 92% (1 g/L cyanide). The immobilized cells were used for six successive cycles with about 50% removal efficiency. The storage life extended to 14 days. No previous work studied the cyanide removal by Sphingobacterium spp. The strain showed good applicable characters.
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Affiliation(s)
- Essam M Ahmed
- Microbial Products Department, National Research Centre, Dokki, Egypt
| | - Walaa F Alsanie
- Clinical Laboratory Sciences Department, College of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
| | - Majid Alhomrani
- Clinical Laboratory Sciences Department, College of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
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Zaveri P, Iyer AR, Patel R, Munshi NS. Uncovering Competitive and Restorative Effects of Macro- and Micronutrients on Sodium Benzoate Biodegradation. Front Microbiol 2021; 12:634753. [PMID: 33815319 PMCID: PMC8009979 DOI: 10.3389/fmicb.2021.634753] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 02/01/2021] [Indexed: 11/13/2022] Open
Abstract
A model aromatic compound, sodium benzoate, is generally used for simulating aromatic pollutants present in textile effluents. Bioremediation of sodium benzoate was studied using the most abundant bacteria, Pseudomonas citronellolis, isolated from the effluent treatment plants of South Gujarat, India. Multiple nutrients constituting the effluent in actual conditions are proposed to have interactive effects on biodegradation which needs to be analyzed strategically for successful field application of developed bioremediation process. Two explicitly different sets of fractional factorial designs were used to investigate the interactive influence of alternative carbon, nitrogen sources, and inorganic micronutrients on sodium benzoate degradation. The process was negatively influenced by the co-existence of other carbon sources and higher concentration of KH2PO4 whereas NH4Cl and MgSO4 exhibited positive effects. Optimized concentrations of NH4Cl, MgSO4, and KH2PO4 were found to be 0.35, 1.056, and 0.3 mg L–1 respectively by central composite designing. The negative effect of high amount of KH2PO4 could be ameliorated by increasing the amount of NH4Cl in the biodegradation milieu indicating the possibility of restoration of the degradation capability for sodium benzoate degradation in the presence of higher phosphate concentration.
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Affiliation(s)
- Purvi Zaveri
- Institute of Science, Nirma University, Ahmedabad, India
| | | | - Rushika Patel
- Institute of Science, Nirma University, Ahmedabad, India
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Sustainable Approach to Eradicate the Inhibitory Effect of Free-Cyanide on Simultaneous Nitrification and Aerobic Denitrification during Wastewater Treatment. SUSTAINABILITY 2019. [DOI: 10.3390/su11216180] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Simultaneous nitrification and aerobic denitrification (SNaD) is a preferred method for single stage total nitrogen (TN) removal, which was recently proposed to improve wastewater treatment plant design. However, SNaD processes are prone to inhibition by toxicant loading with free cyanide (FCN) possessing the highest inhibitory effect on such processes, rendering these processes ineffective. Despite the best efforts of regulators to limit toxicant disposal into municipal wastewater sewage systems (MWSSs), FCN still enters MWSSs through various pathways; hence, it has been suggested that FCN resistant or tolerant microorganisms be utilized for processes such as SNaD. To mitigate toxicant loading, organisms in SNaD have been observed to adopt a diauxic growth strategy to sequentially degrade FCN during primary growth and subsequently degrade TN during the secondary growth phase. However, FCN degrading microorganisms are not widely used for SNaD in MWSSs due to inadequate application of suitable microorganisms (Chromobacterium violaceum, Pseudomonas aeruginosa, Thiobacillus denitrificans, Rhodospirillum palustris, Klebsiella pneumoniae, and Alcaligenes faecalis) commonly used in single-stage SNaD. This review expatiates the biological remedial strategy to limit the inhibition of SNaD by FCN through the use of FCN degrading or resistant microorganisms. The use of FCN degrading or resistant microorganisms for SNaD is a cost-effective method compared to the use of other methods of FCN removal prior to TN removal, as they involve multi-stage systems (as currently observed in MWSSs). The use of FCN degrading microorganisms, particularly when used as a consortium, presents a promising and sustainable resolution to mitigate inhibitory effects of FCN in SNaD.
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Li Q, Lu H, Yin Y, Qin Y, Tang A, Liu H, Liu Y. Synergic effect of adsorption and biodegradation enhance cyanide removal by immobilized Alcaligenes sp. strain DN25. JOURNAL OF HAZARDOUS MATERIALS 2019; 364:367-375. [PMID: 30384247 DOI: 10.1016/j.jhazmat.2018.10.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 08/08/2018] [Accepted: 10/02/2018] [Indexed: 06/08/2023]
Abstract
A high efficiency and stability polyurethane-foam (PUF)-immobilized cell system was constructed to remove cyanide based on simultaneous adsorption and biodegradation (SAB). The performance of the PUF-immobilized system was evaluated by comparison with the freely suspended cell system. The SAB system exhibited more effective and robust, and could still remain degradation activity even at 40 °C or pH 11.0. The SAB system completely removed 500 mg CN-/L within 8 h at 30 °C, pH 8.0, and 120 rpm, whereas 12 h were required for the free cells system. Moreover, the SAB system showed apparent superiority in removing higher concentration cyanide up to 1200 mg CN-/L. A continuously stirred tank bioreactor (CSTR) was successfully designed and steadily operated with approximately 85% of the total average removal efficiency for 52 days at an influent cyanide concentration of 100-200 mg/L, which demonstrated a favorable reliability. Cyanide removal process could be well described using a pseudo first-order model, and the higher apparent rate constants (k) of the immobilized cells showed the synergic effect of adsorption and biodegradation significantly enhanced cyanide removal. Preliminarily, it was found that the foam characteristic might play a not negligible role on the cyanide-degrading enzyme expression of strain DN25 in the SAB system.
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Affiliation(s)
- Qingyun Li
- College of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, Guangxi, PR China; Guangxi Key Laboratory of Biorefining, Nanning, 530003, Guangxi, PR China
| | - Hui Lu
- College of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, Guangxi, PR China
| | - Yexing Yin
- College of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, Guangxi, PR China
| | - Yiming Qin
- College of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, Guangxi, PR China
| | - Aixing Tang
- College of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, Guangxi, PR China
| | - Haibo Liu
- College of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, Guangxi, PR China
| | - Youyan Liu
- College of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, Guangxi, PR China; Guangxi Key Laboratory of Biorefining, Nanning, 530003, Guangxi, PR China; Guangxi Colleges and Universities Key Laboratory of New Technology and Application in Resource Chemical Engineering, Guangxi University, Nanning, 530004, Guangxi, PR China.
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Chahuki FF, Aminzadeh S, Jafarian V, Tabandeh F, Khodabandeh M. Hyaluronic acid production enhancement via genetically modification and culture medium optimization in Lactobacillus acidophilus. Int J Biol Macromol 2018; 121:870-881. [PMID: 30342141 DOI: 10.1016/j.ijbiomac.2018.10.112] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/17/2018] [Accepted: 10/14/2018] [Indexed: 01/16/2023]
Abstract
Hyaluronic acid (HA) is a natural polymer with various molecular weights that specify multiple biological roles. Traditionally, HA is obtained from animal waste and conventional pathogenic streptococci. However, there are challenges in these processes such as the presence of exotoxins, hyaluronidase, and viral contamination. In order to reduce these problems, this study was conducted to produce HA using recombinant bacterium that is generally recognized as safe (GRAS), and thereafter increase production through experimental design. At first, some lactic acid bacteria were screened and evaluated for HA production. Accordingly, among the selected bacteria, Lactobacillus acidophilus PTCC1643 produced about 0.25 g HA/L in the 48th hour of cultivation, and was thus selected as an alternative host for heterologous HA production. An expression vector containing HA synthase genes was transformed into L. acidophilus by electroporation. Consequently, HA production increased to 0.4 g/L. Eventually, response surface method (RSM) was used, which increased HA production to 1.7 g/L. This is approximately 7-fold higher than that produced at first. The resulting HA was characterized by FTIR spectroscopy and its molecular weight was estimated using agarose gel electrophoresis. In conclusion, L. acidophilus could be a safe, effective, and novel HA producer with industrial potential and commercial prospects.
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Affiliation(s)
- Fatemeh Fotouhi Chahuki
- National Institute for Genetic Engineering and Biotechnology (NIGEB), Institute of Industrial and Environmental Biotechnology, Bioprocess Engineering Research Group, Shahrak-e Pajoohesh km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran; Department of Biology, Faculty of Sciences, University of Zanjan, Iran
| | - Saeed Aminzadeh
- National Institute for Genetic Engineering and Biotechnology (NIGEB), Institute of Industrial and Environmental Biotechnology, Bioprocess Engineering Research Group, Shahrak-e Pajoohesh km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran.
| | - Vahab Jafarian
- Department of Biology, Faculty of Sciences, University of Zanjan, Iran
| | - Fatemeh Tabandeh
- National Institute for Genetic Engineering and Biotechnology (NIGEB), Institute of Industrial and Environmental Biotechnology, Bioprocess Engineering Research Group, Shahrak-e Pajoohesh km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran
| | - Mahvash Khodabandeh
- National Institute for Genetic Engineering and Biotechnology (NIGEB), Institute of Industrial and Environmental Biotechnology, Bioprocess Engineering Research Group, Shahrak-e Pajoohesh km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran
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