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Herath HMLPB, de Silva WRM, Dassanayake RS, Gunawardene YINS, Jayasingha JRP, Gayashan MK, Afonso LOB, de Silva KMN. Validation and calibration of a novel GEM biosensor for specific detection of Cd 2+, Zn 2+, and Pb 2. BMC Biotechnol 2023; 23:52. [PMID: 38066557 PMCID: PMC10709830 DOI: 10.1186/s12896-023-00820-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 10/31/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND In this study, we designed a novel genetic circuit sensitive to Cd2+, Zn2+ and Pb2+ by mimicking the CadA/CadR operon system mediated heavy metal homeostasis mechanism of Pseudomonas aeruginosa. The regular DNA motifs on natural operon were reconfigured and coupled with the enhanced Green Fluorescent Protein (eGFP) reporter to develop a novel basic NOT type logic gate CadA/CadR-eGFP to respond metal ions mentioned above. A Genetically Engineered Microbial (GEM)-based biosensor (E.coli-BL21:pJET1.2-CadA/CadR-eGFP) was developed by cloning the chemically synthesised CadA/CadR-eGFP gene circuit into pJET1.2-plasmid and transforming into Escherichia coli (E. coli)-BL21 bacterial cells. RESULTS The GEM-based biosensor cells indicated the reporter gene expression in the presence of Cd2+, Zn2+ and Pb2+ either singly or in combination. Further, the same biosensor cells calibrated for fluorescent intensity against heavy metal concentration generated linear graphs for Cd2+, Zn2+ and Pb2+ with the R2 values of 0.9809, 0.9761 and 0.9758, respectively as compared to non-specific metals, Fe3+ (0.0373), AsO43- (0.3825) and Ni2+ (0.8498) making our biosensor suitable for the detection of low concentration of the former metal ions in the range of 1-6 ppb. Furthermore, the GEM based biosensor cells were growing naturally within the concentration range of heavy metals, at 37 °C and optimum pH = 7.0 in the medium, resembling the characteristics of wildtype E.coli. CONCLUSION Finally, the novel GEM based biosensor cells developed in this study can be applied for detection of targeted heavy metals in low concentration ranges (1-6 ppb) at normal bacterial physiological conditions.
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Affiliation(s)
- H M L P B Herath
- Centre for Advanced Materials and Devices (CAMD), Department of Chemistry, Faculty of Science, University of Colombo, Colombo, 00300, Sri Lanka
- School of Life and Environmental Sciences, Faculty of Science, Engineering and Built Environment, Deakin University, Geelong, Australia
| | - W R M de Silva
- Centre for Advanced Materials and Devices (CAMD), Department of Chemistry, Faculty of Science, University of Colombo, Colombo, 00300, Sri Lanka
| | - R S Dassanayake
- Centre for Advanced Materials and Devices (CAMD), Department of Chemistry, Faculty of Science, University of Colombo, Colombo, 00300, Sri Lanka
| | - Y I N S Gunawardene
- Molecular Medicine Unit, Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka
| | - J R P Jayasingha
- Centre for Advanced Materials and Devices (CAMD), Department of Chemistry, Faculty of Science, University of Colombo, Colombo, 00300, Sri Lanka
| | - M K Gayashan
- Centre for Advanced Materials and Devices (CAMD), Department of Chemistry, Faculty of Science, University of Colombo, Colombo, 00300, Sri Lanka
| | - L O B Afonso
- School of Life and Environmental Sciences, Faculty of Science, Engineering and Built Environment, Deakin University, Geelong, Australia.
| | - K M N de Silva
- Centre for Advanced Materials and Devices (CAMD), Department of Chemistry, Faculty of Science, University of Colombo, Colombo, 00300, Sri Lanka.
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Manogaran M, Halmi MIE, Othman AR, Yasid NA, Gunasekaran B, Shukor MYA. Decolorization of Reactive Red 120 by a novel bacterial consortium: Kinetics and heavy metal inhibition study. AIMS ENVIRONMENTAL SCIENCE 2023; 10:424-445. [DOI: 10.3934/environsci.2023024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
<abstract><p>Juru River is one of the most polluted rivers in Malaysia. A dye-degrading bacterial consortium has been isolated from the river's sediment. This consortium JR3 consists of <italic>Pseudomonas aeruginosa</italic> MM01, <italic>Enterobacter</italic> sp. MM05 and <italic>Serratia marcescens</italic> MM06, which were able to decolorize up to 700 ppm of the Reactive Red 120 (RR120) dye under optimal conditions with limited substrate available. Substrate inhibition kinetics were investigated, and, based on the best model, Aiba, the maximum growth rate was 0.795 h<sup>–1</sup>, while the saturation constant and inhibitory constant were 0.185% and 0.14%, respectively. In addition, the influence of various metal ions on the growth and decolorization rate of this bacterial consortium on RR120 was investigated. Chromium showed the weakest effect on the decolorization of 200 ppm RR120, with 73.5% removal and bacterial growth of 11.461 log CFU mL<sup>–1</sup>. Zinc yielded the second weakest effect, followed by silver and lead, with percentages of RR120 decolorization of 63.8%, 54.6% and 50.5%, respectively. Meanwhile, cadmium, arsenic and copper reduced the decolorization of RR120 in consortium JR3 by half. Mercury strongly inhibited decolorization by 32.5%. Based on the least inhibited heavy metal in RR120 decolorization activity of consortium JR3, the best inhibitory kinetic model was Levenspiel, with a maximum growth rate of 0.632 h<sup>–1</sup>, while the saturation constant and inhibitory constants were 15.08% and 0.5783%, respectively. The metal-tolerant azo dye-degrading bacterial consortium will be very useful in dye remediation in metal-laden polluted environments.</p></abstract>
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Affiliation(s)
- Motharasan Manogaran
- Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor D.E., Malaysia
| | - Mohd Izuan Effendi Halmi
- Department of Land Management, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor D.E., Malaysia
| | - Ahmad Razi Othman
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor D.E., Malaysia
| | - Nur Adeela Yasid
- Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor D.E., Malaysia
| | - Baskaran Gunasekaran
- Faculty of Applied Sciences, UCSI University Kuala Lumpur (South Wing), No.1, Jalan Menara Gading, UCSI Heights 56000 Cheras, Kuala Lumpur, Malaysia
| | - Mohd Yunus Abd Shukor
- Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor D.E., Malaysia
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Gallardo-Benavente C, Campo-Giraldo JL, Castro-Severyn J, Quiroz A, Pérez-Donoso JM. Genomics Insights into Pseudomonas sp. CG01: An Antarctic Cadmium-Resistant Strain Capable of Biosynthesizing CdS Nanoparticles Using Methionine as S-Source. Genes (Basel) 2021; 12:genes12020187. [PMID: 33514061 PMCID: PMC7912247 DOI: 10.3390/genes12020187] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 01/20/2021] [Accepted: 01/22/2021] [Indexed: 12/23/2022] Open
Abstract
Here, we present the draft genome sequence of Pseudomonas sp. GC01, a cadmium-resistant Antarctic bacterium capable of biosynthesizing CdS fluorescent nanoparticles (quantum dots, QDs) employing a unique mechanism involving the production of methanethiol (MeSH) from methionine (Met). To explore the molecular/metabolic components involved in QDs biosynthesis, we conducted a comparative genomic analysis, searching for the genes related to cadmium resistance and sulfur metabolic pathways. The genome of Pseudomonas sp. GC01 has a 4,706,645 bp size with a 58.61% G+C content. Pseudomonas sp. GC01 possesses five genes related to cadmium transport/resistance, with three P-type ATPases (cadA, zntA, and pbrA) involved in Cd-secretion that could contribute to the extracellular biosynthesis of CdS QDs. Furthermore, it exhibits genes involved in sulfate assimilation, cysteine/methionine synthesis, and volatile sulfur compounds catabolic pathways. Regarding MeSH production from Met, Pseudomonas sp. GC01 lacks the genes E4.4.1.11 and megL for MeSH generation. Interestingly, despite the absence of these genes, Pseudomonas sp. GC01 produces high levels of MeSH. This is probably associated with the metC gene that also produces MeSH from Met in bacteria. This work is the first report of the potential genes involved in Cd resistance, sulfur metabolism, and the process of MeSH-dependent CdS QDs bioproduction in Pseudomonas spp. strains.
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Affiliation(s)
- Carla Gallardo-Benavente
- Programa de Doctorado en Ciencias de Recursos Naturales, Universidad de La Frontera, 4780000 Temuco, Chile;
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente (CIBAMA), Facultad de Ingeniería y Ciencias, Universidad de La Frontera, 4780000 Temuco, Chile
| | - Jessica L. Campo-Giraldo
- BioNanotechnology and Microbiology Lab, Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, 8320000 Santiago, Chile;
| | - Juan Castro-Severyn
- Laboratorio de Microbiología Aplicada y Extremófilos, Facultad de Ingeniería y Ciencias Geológicas, Universidad Católica del Norte, 1240000 Antofagasta, Chile;
| | - Andrés Quiroz
- Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente (CIBAMA), Facultad de Ingeniería y Ciencias, Universidad de La Frontera, 4780000 Temuco, Chile
- Departamento de Ciencias Químicas y Recursos Naturales, Facultad de Ingeniería y Ciencias, Universidad de La Frontera, 4780000 Temuco, Chile
- Correspondence: (A.Q.); (J.M.P.-D.)
| | - José M. Pérez-Donoso
- BioNanotechnology and Microbiology Lab, Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, 8320000 Santiago, Chile;
- Correspondence: (A.Q.); (J.M.P.-D.)
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