1
|
Okonkwo V, Cholet F, Ijaz UZ, Koottatep T, Pussayanavin T, Polpraset C, Sloan WT, Connelly S, Smith CJ. intI1 gene abundance from septic tanks in Thailand using validated intI1 primers. Appl Environ Microbiol 2023; 89:e0107123. [PMID: 37874304 PMCID: PMC10686061 DOI: 10.1128/aem.01071-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 08/22/2023] [Indexed: 10/25/2023] Open
Abstract
IMPORTANCE Antimicrobial resistance is a global crisis, and wastewater treatment, including septic tanks, remains an important source of antimicrobial resistance (AMR) genes. The role of septic tanks in disseminating class 1 integron, and by extension AMR genes, in Thailand, where antibiotic use is unregulated remains understudied. We aimed to monitor gene abundance as a proxy to infer potential AMR from septic tanks in Thailand. We evaluated published intI1 primers due to the lack of consensus on optimal Q-PCR primers and the absence of standardization. Our findings confirmed septic tanks are a source of class 1 integron to the environment. We highlighted the significance of intI1 primer choice, in the context of interpretation of risk associated with AMR spread from septic tanks. We recommend the validated set (F3-R3) for optimal intI1 quantification toward the goal of achieving standardization across studies.
Collapse
Affiliation(s)
- Valentine Okonkwo
- Department of Infrastructure and Environment, James Watt School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Fabien Cholet
- Department of Infrastructure and Environment, James Watt School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Umer Z. Ijaz
- Department of Infrastructure and Environment, James Watt School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Thammarat Koottatep
- School of Environment, Resources and Development, Asian Institute of Technology, Khlong Nueng, Thailand
| | | | - Chongrak Polpraset
- Thammasat School of Engineering, Thammasat University, Bangkok, Thailand
| | - William T. Sloan
- Department of Infrastructure and Environment, James Watt School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Stephanie Connelly
- Department of Infrastructure and Environment, James Watt School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Cindy J. Smith
- Department of Infrastructure and Environment, James Watt School of Engineering, University of Glasgow, Glasgow, United Kingdom
| |
Collapse
|
2
|
Khan A, Akbar S, Okonkwo V, Smith C, Khan S, Ali Shah A, Adnan F, Zeeshan Ijaz U, Ahmed S, Badshah M. Enrichment of the hydrogenotrophic methanogens for, in-situ biogas up-gradation by recirculation of gases and supply of hydrogen in methanogenic reactor. Bioresour Technol 2022; 345:126219. [PMID: 34813923 DOI: 10.1016/j.biortech.2021.126219] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
During in situ biogas up-gradation by supplying hydrogen from an external source and enrichment of hydrogenotrophic methanogens, high pressure of H2 negatively affects hydrolytic and fermentative activities. To overcome this problem, the present study aimed to enrich the hydrogenotrophic methanogens by optimization of various parameters associated with gas recirculation along-with hydrogen supply from the external source. Due to recirculation of gases and supplied hydrogen, methane generation was two-fold higher in the optimal condition than in conventional anaerobic digestion, with the highest methane content of 99%. Additionally, the hydrogenotrophic methanogens were enriched, with a decrease in acetoclastic methanogens and an increase in Bathyarchaeia population, which utilizes H2 and CO2 to produce acetate and lactate as end products. The study concludes that recirculation increases methane production by converting H2 and CO2 into methane and enhances the degradation of organic matter left over undigested in the hydrolytic reactor.
Collapse
Affiliation(s)
- Alam Khan
- Sustainable Bioenergy and Biorefinery Laboratory, Department of Microbiology, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Sedrah Akbar
- Sustainable Bioenergy and Biorefinery Laboratory, Department of Microbiology, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Valentine Okonkwo
- Water Engineering Group, School of Engineering, The University of Glasgow, Glasgow, United Kingdom
| | - Cindy Smith
- Water Engineering Group, School of Engineering, The University of Glasgow, Glasgow, United Kingdom; Department of Microbiology, School of Natural Sciences, National University of Ireland Galway, Galway H91 TK33, Ireland
| | - Samiullah Khan
- Sustainable Bioenergy and Biorefinery Laboratory, Department of Microbiology, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Aamer Ali Shah
- Sustainable Bioenergy and Biorefinery Laboratory, Department of Microbiology, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Fazal Adnan
- Atta-ur-Rahman School of Applied Biosciences, National University of Sciences & Technology, Islamabad, Pakistan
| | - Umer Zeeshan Ijaz
- Water Engineering Group, School of Engineering, The University of Glasgow, Glasgow, United Kingdom
| | - Safia Ahmed
- Sustainable Bioenergy and Biorefinery Laboratory, Department of Microbiology, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Malik Badshah
- Sustainable Bioenergy and Biorefinery Laboratory, Department of Microbiology, Quaid-i-Azam University, Islamabad 45320, Pakistan.
| |
Collapse
|