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Tulloch CL, Cotterell BM, Pântea I, Jones DL, Golyshin PN. Selective microbial attachment to LDPE plastic beads during passage through the wastewater network. CHEMOSPHERE 2024; 362:142618. [PMID: 38880260 DOI: 10.1016/j.chemosphere.2024.142618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 06/11/2024] [Accepted: 06/13/2024] [Indexed: 06/18/2024]
Abstract
Urban wastewater treatment plants (WWTP) represent key point-source discharges of microplastics (MP) into the environment, however, little is known about the microbial carrying capacity of plastics travelling through them. The purpose of this study was to quantify the number of cells that become associated with MP at different locations within a WWTP, and to assess differences in microbiome communities. We conducted a field experiment incubating low density polyethylene (LDPE) MP beads in WWTP influent and effluent, as well as tracking free floating beads during passage in wastewater from a large municipal hospital to an urban WWTP, where they were subsequently recovered. Using two cell counting methods - automated flow cytometric true absolute cell counts and indirect cell quantification via protein content based on a model E. coli cell - we quantified cell attachment to LDPE beads. LDPE associated counts ranged from 350 x 103 cells cm-2 after incubation in wastewater effluent, and 990 x 103 cells cm-2 after incubation in wastewater influent. 16S rRNA gene amplicon sequencing was used to determine the bacterial community structure of the plastic-associated microbiomes. Our results showed that distinct bacterial communities developed on the LDPE MP following exposure to each wastewater type. Influent (untreated) wastewater LDPE-associated microbiomes were dominated by Bacillota whereas the microbes that attached in wastewater effluent (tertiary treated) were dominated by Pseudomonadota. In conclusion, this study provides clear evidence that microplastics migrating through the sewer network and WWTP rapidly accumulate microbiomes with unique microbial community structures varying from sewage influent to effluent. These findings demonstrate the differential microbiological risk from MP associated with routine wastewater discharges to those released from intermittent combined sewer overflows (CSOs) during storm events.
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Affiliation(s)
- Constance L Tulloch
- Centre for Environmental Biotechnology, School of Environmental and Natural Sciences, Bangor University, Bangor, LL57 2UW, UK.
| | - Benjamin M Cotterell
- Centre for Environmental Biotechnology, School of Environmental and Natural Sciences, Bangor University, Bangor, LL57 2UW, UK
| | - Igor Pântea
- Centre for Environmental Biotechnology, School of Environmental and Natural Sciences, Bangor University, Bangor, LL57 2UW, UK
| | - Davey L Jones
- Centre for Environmental Biotechnology, School of Environmental and Natural Sciences, Bangor University, Bangor, LL57 2UW, UK; Food Futures Institute, Murdoch University, Perth, WA 6150, Australia
| | - Peter N Golyshin
- Centre for Environmental Biotechnology, School of Environmental and Natural Sciences, Bangor University, Bangor, LL57 2UW, UK
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Kita K, Yoshida S, Masuo S, Nakamura A, Ishikawa S, Yoshida KI. Genes encoding a novel thermostable bacteriocin in the thermophilic bacterium Aeribacillus pallidus PI8. J Appl Microbiol 2023; 134:lxad293. [PMID: 38040658 DOI: 10.1093/jambio/lxad293] [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: 06/13/2023] [Revised: 11/10/2023] [Accepted: 11/30/2023] [Indexed: 12/03/2023]
Abstract
AIM Aeribacillus pallidus PI8 is a Gram-positive thermophilic bacterium that produces thermostable antimicrobial substances against several bacterial species, including Geobacillus kaustophilus HTA426. In the present study, we sought to identify genes of PI8 with antibacterial activity. METHODS AND RESULTS We isolated, cloned, and characterized a thermostable bacteriocin from A. pallidus PI8 and named it pallidocyclin. Mass spectrometric analyses of pallidocyclin revealed that it had a circular peptide structure, and its precursor was encoded by pcynA in the PI8 genome. pcynA is the second gene within the pcynBACDEF operon. Expression of the full-length pcynBACDEF operon in Bacillus subtilis produced intact pallidocyclin, whereas expression of pcynF in G. kaustophilus HTA426 conferred resistance to pallidocyclin. CONCLUSION Aeribacillus pallidus PI8 possesses the pcynBACDEF operon to produce pallidocyclin. pcynA encodes the pallidocyclin precursor, and pcynF acts as an antagonist of pallidocyclin.
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Affiliation(s)
- Kyosuke Kita
- Department of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Sanako Yoshida
- Department of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Shunsuke Masuo
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572 Ibaraki, Japan
- Microbiology Research Center for Sustainability, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572 Ibaraki, Japan
| | - Akira Nakamura
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572 Ibaraki, Japan
- Microbiology Research Center for Sustainability, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572 Ibaraki, Japan
| | - Shu Ishikawa
- Department of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Ken-Ichi Yoshida
- Department of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
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Kita K, Yoshida S, Ishikawa S, Yoshida KI. Functional analysis of a gene cluster for putative bacteriocin deduced from the genome sequence of Aeribacillus pallidus PI8. J GEN APPL MICROBIOL 2022; 68:87-94. [PMID: 35418540 DOI: 10.2323/jgam.2021.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bacteriocins are a large family of peptides synthesized ribosomally by a variety of bacterial species. The genome of one of the thermophilic Gram-positive bacteria, Aeribacillus pallidus PI8, was found to possess an operon comprising five genes possibly involved in the production of a putative bacteriocin that was named pcnABCDE for the production of "pallidocyclicin." This study investigated the function of the pcn operon experimentally. The heterologous expression of the entire pcn operon from the plasmid was toxic to Escherichia coli but not to Bacillus subtilis. However, when the entire pcn operon was expressed constitutively, even the growth of B. subtilis was impaired, and at least pcnA was implied to serve as the precursor of pallidocyclicin. In addition, a strain of B. subtilis expressing the entire pcn operon from the plasmid showed toxicity to another thermophilic species, Geobacillus kaustophilus, at elevated temperatures, whereas another strain lacking pcnE alone from the pcn operon lost the toxicity, suggesting that pcnE might be involved in the biosynthesis of pallidocyclicin when it is produced in B. subtilis.
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Affiliation(s)
- Kyosuke Kita
- Department of Science, Technology and Innovation, Kobe University
| | | | - Shu Ishikawa
- Department of Science, Technology and Innovation, Kobe University.,Department of Agrobioscience, Kobe University
| | - Ken-Ichi Yoshida
- Department of Science, Technology and Innovation, Kobe University.,Department of Agrobioscience, Kobe University
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Mahfooz S, Shankar G, Narayan J, Singh P, Akhter Y. Simple sequence repeat insertion induced stability and potential 'gain of function' in the proteins of extremophilic bacteria. Extremophiles 2022; 26:17. [PMID: 35511349 DOI: 10.1007/s00792-022-01265-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 04/11/2022] [Indexed: 11/26/2022]
Abstract
Here, we analysed the genomic evolution in extremophilic bacteria using long simple sequence repeats (SSRs). Frequencies of occurrence, relative abundance (RA) and relative density (RD) of long SSRs were analysed in the genomes of extremophilic bacteria. Thermus aquaticus had the most RA and RD of long SSRs in its coding sequences (110.6 and 1408.3), followed by Rhodoferax antarcticus (77.0 and 1187.4). A positive correlation was observed between G + C content and the RA-RD of long SSRs. Geobacillus kaustophilus, Geobacillus thermoleovorans, Halothermothrix orenii, R. antarcticus, and T. aquaticus preferred trinucleotide repeats within their genomes, whereas others preferred a higher number of tetranucleotide repeats. Gene enrichment showed the presence of these long SSRs in metabolic enzyme encoding genes related to stress tolerance. To analyse the functional implications of SSR insertions, three-dimensional protein structure modelling of SSR containing diguanylate cyclase (DGC) gene encoding protein was carried out. Removal of SSR sequence led to an inappropriate folding and instability of the modelled protein structure.
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Affiliation(s)
- Sahil Mahfooz
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow, Uttar Pradesh, 226025, India
| | - Gauri Shankar
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow, Uttar Pradesh, 226025, India
| | - Jitendra Narayan
- CSIR-Institute of Genomics and Integrative Biology, South Campus, Mathura Road, New Delhi, 110025, India
| | - Pallavi Singh
- Department of Biotechnology, Dr. A.P.J. Abdul Kalam Technical University, Lucknow, Uttar Pradesh, 226031, India
| | - Yusuf Akhter
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow, Uttar Pradesh, 226025, India.
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