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Patel SKS, Singh D, Pant D, Gupta RK, Busi S, Singh RV, Lee JK. Polyhydroxyalkanoate Production by Methanotrophs: Recent Updates and Perspectives. Polymers (Basel) 2024; 16:2570. [PMID: 39339034 PMCID: PMC11435153 DOI: 10.3390/polym16182570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2024] [Revised: 09/08/2024] [Accepted: 09/09/2024] [Indexed: 09/30/2024] Open
Abstract
Methanotrophs are bacteria that consume methane (CH4) as their sole carbon and energy source. These microorganisms play a crucial role in the carbon cycle by metabolizing CH4 (the greenhouse gas), into cellular biomass and carbon dioxide (CO2). Polyhydroxyalkanoates (PHAs) are biopolymers produced by various microorganisms, including methanotrophs. PHA production using methanotrophs is a promising strategy to address growing concerns regarding plastic pollution and the need for sustainable, biodegradable materials. Various factors, including nutrient availability, environmental conditions, and metabolic engineering strategies, influence methanotrophic production. Nutrient limitations, particularly those of nitrogen or phosphorus, enhance PHA production by methanotrophs. Metabolic engineering approaches, such as the overexpression of key enzymes involved in PHA biosynthesis or the disruption of competing pathways, can also enhance PHA yields by methanotrophs. Overall, PHA production by methanotrophs represents a sustainable and versatile approach for developing biomedical materials with numerous potential applications. Additionally, alternative feedstocks, such as industrial waste streams or byproducts can be explored to improve the economic feasibility of PHA production. This review briefly describes the potential of methanotrophs to produce PHAs, with recent updates and perspectives.
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Affiliation(s)
- Sanjay K S Patel
- Department of Chemical Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
- Department of Biotechnology, Hemvati Nandan Bahuguna Garhwal University (A Central University), Srinagar 246174, Uttarakhand, India
| | - Deepshikha Singh
- Department of Biotechnology, Hemvati Nandan Bahuguna Garhwal University (A Central University), Srinagar 246174, Uttarakhand, India
| | - Diksha Pant
- Department of Biotechnology, Hemvati Nandan Bahuguna Garhwal University (A Central University), Srinagar 246174, Uttarakhand, India
| | - Rahul K Gupta
- Department of Chemical Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Siddhardha Busi
- Department of Microbiology, Pondicherry University, Pondicherry 605014, Kalapet, India
| | - Rahul V Singh
- Department of Chemical Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Jung-Kul Lee
- Department of Chemical Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
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Amabile C, Abate T, Muñoz R, Chianese S, Musmarra D. Production of poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from methane and volatile fatty acids: properties, metabolic routes and current trend. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172138. [PMID: 38582106 DOI: 10.1016/j.scitotenv.2024.172138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 03/21/2024] [Accepted: 03/30/2024] [Indexed: 04/08/2024]
Abstract
Polyhydroxyalkanoates (PHAs) are biobased and biodegradable polymers that could effectively replace fossil-based and non-biodegradable plastics. However, their production is currently limited by the high production costs, mainly due to the costly carbon sources used, low productivity and quality of the materials produced. A potential solution lies in utilizing cheap and renewable carbon sources as the primary feedstock during the biological production of PHAs, paving the way for a completely sustainable and economically viable process. In this review, the opportunities and challenges related to the production of polyhydroxyalkanoates using methane and volatile fatty acids (VFAs) as substrates were explored, with a focus on poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate). The discussion reports the current knowledge about promising Type II methanotrophs, the impact of process parameters such as limiting nutrients, CH4:O2 ratio and temperature, the type of co-substrate and its concentration. Additionally, the strategies developed until now to enhance PHA production yields were also discussed.
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Affiliation(s)
- Claudia Amabile
- Department of Engineering, University of Campania "Luigi Vanvitelli", Via Roma 29, 81031 Aversa, Italy; Institute of Sustainable Processes, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain
| | - Teresa Abate
- Department of Engineering, University of Campania "Luigi Vanvitelli", Via Roma 29, 81031 Aversa, Italy; Institute of Sustainable Processes, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain
| | - Raul Muñoz
- Institute of Sustainable Processes, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain
| | - Simeone Chianese
- Department of Engineering, University of Campania "Luigi Vanvitelli", Via Roma 29, 81031 Aversa, Italy.
| | - Dino Musmarra
- Department of Engineering, University of Campania "Luigi Vanvitelli", Via Roma 29, 81031 Aversa, Italy
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Eam H, Ko D, Lee C, Myung J. Methylosinus trichosporium OB3b bioaugmentation unleashes polyhydroxybutyrate-accumulating potential in waste-activated sludge. Microb Cell Fact 2024; 23:160. [PMID: 38822346 PMCID: PMC11140957 DOI: 10.1186/s12934-024-02442-w] [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: 01/29/2024] [Accepted: 05/27/2024] [Indexed: 06/02/2024] Open
Abstract
BACKGROUND Wastewater treatment plants contribute approximately 6% of anthropogenic methane emissions. Methanotrophs, capable of converting methane into polyhydroxybutyrate (PHB), offer a promising solution for utilizing methane as a carbon source, using activated sludge as a seed culture for PHB production. However, maintaining and enriching PHB-accumulating methanotrophic communities poses challenges. RESULTS This study investigated the potential of Methylosinus trichosporium OB3b to bioaugment PHB-accumulating methanotrophic consortium within activated sludge to enhance PHB production. Waste-activated sludges with varying ratios of M. trichosporium OB3b (1:0, 1:1, 1:4, and 0:1) were cultivated. The results revealed substantial growth and methane consumption in waste-activated sludge with M. trichosporium OB3b-amended cultures, particularly in a 1:1 ratio. Enhanced PHB accumulation, reaching 37.1% in the same ratio culture, indicates the dominance of Type II methanotrophs. Quantification of methanotrophs by digital polymerase chain reaction showed gradual increases in Type II methanotrophs, correlating with increased PHB production. However, while initial bioaugmentation of M. trichosporium OB3b was observed, its presence decreased in subsequent cycles, indicating the dominance of other Type II methanotrophs. Microbial community analysis highlighted the successful enrichment of Type II methanotrophs-dominated cultures due to the addition of M. trichosporium OB3b, outcompeting Type I methanotrophs. Methylocystis and Methylophilus spp. were the most abundant in M. trichosporium OB3b-amended cultures. CONCLUSIONS Bioaugmentation strategies, leveraging M. trichosporium OB3b could significantly enhance PHB production and foster the enrichment of PHB-accumulating methanotrophs in activated sludge. These findings contribute to integrating PHB production in wastewater treatment plants, providing a sustainable solution for resource recovery.
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Affiliation(s)
- Hyerim Eam
- Department of Civil and Environmental Engineering, KAIST, Daejeon, 34141, Republic of Korea
| | - Dayoung Ko
- Department of Civil, Urban, Earth, and Environmental Engineering, UNIST, Ulsan, 44919, Republic of Korea
| | - Changsoo Lee
- Department of Civil, Urban, Earth, and Environmental Engineering, UNIST, Ulsan, 44919, Republic of Korea
| | - Jaewook Myung
- Department of Civil and Environmental Engineering, KAIST, Daejeon, 34141, Republic of Korea.
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Wutkowska M, Tláskal V, Bordel S, Stein LY, Nweze JA, Daebeler A. Leveraging genome-scale metabolic models to understand aerobic methanotrophs. THE ISME JOURNAL 2024; 18:wrae102. [PMID: 38861460 PMCID: PMC11195481 DOI: 10.1093/ismejo/wrae102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/20/2024] [Accepted: 06/10/2024] [Indexed: 06/13/2024]
Abstract
Genome-scale metabolic models (GEMs) are valuable tools serving systems biology and metabolic engineering. However, GEMs are still an underestimated tool in informing microbial ecology. Since their first application for aerobic gammaproteobacterial methane oxidizers less than a decade ago, GEMs have substantially increased our understanding of the metabolism of methanotrophs, a microbial guild of high relevance for the natural and biotechnological mitigation of methane efflux to the atmosphere. Particularly, GEMs helped to elucidate critical metabolic and regulatory pathways of several methanotrophic strains, predicted microbial responses to environmental perturbations, and were used to model metabolic interactions in cocultures. Here, we conducted a systematic review of GEMs exploring aerobic methanotrophy, summarizing recent advances, pointing out weaknesses, and drawing out probable future uses of GEMs to improve our understanding of the ecology of methane oxidizers. We also focus on their potential to unravel causes and consequences when studying interactions of methane-oxidizing bacteria with other methanotrophs or members of microbial communities in general. This review aims to bridge the gap between applied sciences and microbial ecology research on methane oxidizers as model organisms and to provide an outlook for future studies.
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Affiliation(s)
- Magdalena Wutkowska
- Institute of Soil Biology and Biogeochemistry, Biology Centre CAS, 370 05 České Budějovice, Czech Republic
| | - Vojtěch Tláskal
- Institute of Soil Biology and Biogeochemistry, Biology Centre CAS, 370 05 České Budějovice, Czech Republic
| | - Sergio Bordel
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Valladolid 47011, Spain
- Institute of Sustainable Processes, Valladolid 47011, Spain
| | - Lisa Y Stein
- Department of Biological Sciences, Faculty of Science, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Justus Amuche Nweze
- Institute of Soil Biology and Biogeochemistry, Biology Centre CAS, 370 05 České Budějovice, Czech Republic
- Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, 370 05 České Budějovice, Czech Republic
- Department of Science Laboratory Technology, Faculty of Physical Sciences, University of Nigeria, Nsukka 410001, Nigeria
| | - Anne Daebeler
- Institute of Soil Biology and Biogeochemistry, Biology Centre CAS, 370 05 České Budějovice, Czech Republic
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Kim Y, Flinkstrom Z, Candry P, Winkler MKH, Myung J. Resource availability governs polyhydroxyalkanoate (PHA) accumulation and diversity of methanotrophic enrichments from wetlands. Front Bioeng Biotechnol 2023; 11:1210392. [PMID: 37588137 PMCID: PMC10425282 DOI: 10.3389/fbioe.2023.1210392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 07/12/2023] [Indexed: 08/18/2023] Open
Abstract
Aquatic environments account for half of global CH4 emissions, with freshwater wetlands being the most significant contributors. These CH4 fluxes can be partially offset by aerobic CH4 oxidation driven by methanotrophs. Additionally, some methanotrophs can convert CH4 into polyhydroxyalkanoate (PHA), an energy storage molecule as well as a promising bioplastic polymer. In this study, we investigate how PHA-accumulating methanotrophic communities enriched from wetlands were shaped by varying resource availability (i.e., C and N concentrations) at a fixed C/N ratio. Cell yields, PHA accumulation, and community composition were evaluated in high (20% CH4 and 10 mM NH4 +) and low resource (0.2% CH4 and 0.1 mM NH4 +) conditions simulating engineered and environmental settings, respectively. High resource availability decreased C-based cell yields, while N-based cell yields remained stable, suggesting nutrient exchange patterns differed between methanotrophic communities at different resource concentrations. PHA accumulation was only observed in high resource enrichments, producing approximately 12.6% ± 2.4% (m/m) PHA, while PHA in low resource enrichments remained below detection. High resource enrichments were dominated by Methylocystis methanotrophs, while low resource enrichments remained significantly more diverse and contained only a minor population of methanotrophs. This study demonstrates that resource concentration shapes PHA-accumulating methanotrophic communities. Together, this provides useful information to leverage such communities in engineering settings as well as to begin understanding their role in the environment.
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Affiliation(s)
- Yujin Kim
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Zachary Flinkstrom
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, United States
| | - Pieter Candry
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, United States
| | - Mari-Karoliina H. Winkler
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, United States
| | - Jaewook Myung
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
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Sikkema WD, Cal AJ, Hathwaik UI, Orts WJ, Lee CC. Polyhydroxyalkanoate production in Pseudomonas putida from alkanoic acids of varying lengths. PLoS One 2023; 18:e0284377. [PMID: 37471433 PMCID: PMC10358918 DOI: 10.1371/journal.pone.0284377] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 03/29/2023] [Indexed: 07/22/2023] Open
Abstract
Many studies have been conducted to produce microbial polyhydroxyalkanoates (PHA), a biopolymer, from Pseudomonas sp. fed with various alkanoic acids. Because this previous data was collected using methodologies that varied in critical aspects, such as culture media and size range of alkanoic acids, it has been difficult to compare the results for a thorough understanding of the relationship between feedstock and PHA production. Therefore, this study utilized consistent culture media with a wide range of alkanoic acids (C7-C14) to produce medium chain length PHAs. Three strains of Pseudomonas putida (NRRL B-14875, KT2440, and GN112) were used, and growth, cell dry weight, PHA titer, monomer distribution, and molecular weights were all examined. It was determined that although all the strains produced similar PHA titers using C7-C9 alkanoic acids, significant differences were observed with the use of longer chain feedstocks. Specifically, KT2440 and its derivative GN112 produced higher PHA titers compared to B-14875 when fed longer chain alkanoates. We also compared several analytical techniques for determining amounts of PHA and found they produced different results. In addition, the use of an internal standard had a higher risk of calculating inaccurate concentrations compared to an external standard. These observations highlight the importance of considering this aspect of analysis when evaluating different studies.
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Affiliation(s)
- W Dirk Sikkema
- Bioproducts Research Unit, USDA-ARS-WRRC, Albany, CA, United States of America
| | - Andrew J Cal
- Bioproducts Research Unit, USDA-ARS-WRRC, Albany, CA, United States of America
| | - Upul I Hathwaik
- Bioproducts Research Unit, USDA-ARS-WRRC, Albany, CA, United States of America
| | - William J Orts
- Bioproducts Research Unit, USDA-ARS-WRRC, Albany, CA, United States of America
| | - Charles C Lee
- Bioproducts Research Unit, USDA-ARS-WRRC, Albany, CA, United States of America
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Ray S, Jin JO, Choi I, Kim M. Recent trends of biotechnological production of polyhydroxyalkanoates from C1 carbon sources. Front Bioeng Biotechnol 2023; 10:907500. [PMID: 36686222 PMCID: PMC9852868 DOI: 10.3389/fbioe.2022.907500] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 12/06/2022] [Indexed: 01/09/2023] Open
Abstract
Growing concerns over the use of limited fossil fuels and their negative impacts on the ecological niches have facilitated the exploration of alternative routes. The use of conventional plastic material also negatively impacts the environment. One such green alternative is polyhydroxyalkanoates, which are biodegradable, biocompatible, and environmentally friendly. Recently, researchers have focused on the utilization of waste gases particularly those belonging to C1 sources derived directly from industries and anthropogenic activities, such as carbon dioxide, methane, and methanol as the substrate for polyhydroxyalkanoates production. Consequently, several microorganisms have been exploited to utilize waste gases for their growth and biopolymer accumulation. Methylotrophs such as Methylobacterium organophilum produced highest amount of PHA up to 88% using CH4 as the sole carbon source and 52-56% with CH3OH. On the other hand Cupriavidus necator, produced 71-81% of PHA by utilizing CO and CO2 as a substrate. The present review shows the potential of waste gas valorization as a promising solution for the sustainable production of polyhydroxyalkanoates. Key bottlenecks towards the usage of gaseous substrates obstructing their realization on a large scale and the possible technological solutions were also highlighted. Several strategies for PHA production using C1 gases through fermentation and metabolic engineering approaches are discussed. Microbes such as autotrophs, acetogens, and methanotrophs can produce PHA from CO2, CO, and CH4. Therefore, this article presents a vision of C1 gas into bioplastics are prospective strategies with promising potential application, and aspects related to the sustainability of the system.
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Affiliation(s)
- Subhasree Ray
- Research Institute of Cell Culture, Yeungnam University, Gyeongsan, South Korea,Department of Life Science, School of Basic Science and Research, Sharda University, Greater Noida, India,*Correspondence: Myunghee Kim, ; Subhasree Ray,
| | - Jun-O Jin
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, South Korea,Department of Food Science and Technology, Yeungnam University, Gyeongsan, South Korea
| | - Inho Choi
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, South Korea,Department of Food Science and Technology, Yeungnam University, Gyeongsan, South Korea
| | - Myunghee Kim
- Research Institute of Cell Culture, Yeungnam University, Gyeongsan, South Korea,Department of Food Science and Technology, Yeungnam University, Gyeongsan, South Korea,*Correspondence: Myunghee Kim, ; Subhasree Ray,
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Naizabekov S, Hyun SW, Na JG, Yoon S, Lee OK, Lee EY. Comparative genomic analysis of Methylocystis sp. MJC1 as a platform strain for polyhydroxybutyrate biosynthesis. PLoS One 2023; 18:e0284846. [PMID: 37163531 PMCID: PMC10171618 DOI: 10.1371/journal.pone.0284846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 04/06/2023] [Indexed: 05/12/2023] Open
Abstract
Biodegradable polyhydroxybutyrate (PHB) can be produced from methane by some type II methanotroph such as the genus Methylocystis. This study presents the comparative genomic analysis of a newly isolated methanotroph, Methylocystis sp. MJC1 as a biodegradable PHB-producing platform strain. Methylocystis sp. MJC1 accumulates up to 44.5% of PHB based on dry cell weight under nitrogen-limiting conditions. To facilitate its development as a PHB-producing platform strain, the complete genome sequence of Methylocystis sp. MJC1 was assembled, functionally annotated, and compared with genomes of other Methylocystis species. Phylogenetic analysis has shown that Methylocystis parvus to be the closest species to Methylocystis sp. MJC1. Genome functional annotation revealed that Methylocystis sp. MJC1 contains all major type II methanotroph biochemical pathways such as the serine cycle, EMC pathway, and Krebs cycle. Interestingly, Methylocystis sp. MJC1 has both particulate and soluble methane monooxygenases, which are not commonly found among Methylocystis species. In addition, this species also possesses most of the RuMP pathway reactions, a characteristic of type I methanotrophs, and all PHB biosynthetic genes. These comparative analysis would open the possibility of future practical applications such as the development of organism-specific genome-scale models and application of metabolic engineering strategies to Methylocystis sp. MJC1.
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Affiliation(s)
- Sanzhar Naizabekov
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin-si, Gyeonggi-do, Republic of Korea
| | - Seung Woon Hyun
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin-si, Gyeonggi-do, Republic of Korea
| | - Jeong-Geol Na
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, Republic of Korea
| | - Sukhwan Yoon
- Department of Civil & Environmental Engineering, Korea Advanced Institute of Science & Technology, Daejeon, Republic of Korea
| | - Ok Kyung Lee
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin-si, Gyeonggi-do, Republic of Korea
| | - Eun Yeol Lee
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin-si, Gyeonggi-do, Republic of Korea
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Cattaneo CR, Rodríguez Y, Rene ER, García-Depraect O, Muñoz R. Biogas bioconversion into poly(3-hydroxybutyrate) by a mixed microbial culture in a novel Taylor flow bioreactor. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 150:364-372. [PMID: 35914413 DOI: 10.1016/j.wasman.2022.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 07/07/2022] [Accepted: 07/16/2022] [Indexed: 06/15/2023]
Abstract
Biogas-based biopolymer production represents an alternative biogas valorization route with potential to cut down plastic pollution and greenhouse gas emissions. This study investigated for the first time the continuous bioconversion of methane, contained in biogas, into poly(3-hydroxybutyrate) (PHB) by a mixed methanotrophic culture using an innovative high mass-transfer Taylor flow bioreactor. Following a hydrodynamic flow regime mapping, the influence of the gas residence time and the internal gas recirculation on CH4 abatement was assessed under non nutrient limiting conditions. Under optimal operational conditions (gas residence time of 60 min and internal gas recycling ratio of 17), the bioreactor was able to support a CH4 removal efficiency of 63.3%, a robust CH4 elimination capacity (17.2 g-CH4 m-3h-1) and a stable biomass concentration (1.0 g L-1). The simultaneous CH4 abatement and PHB synthesis was investigated under 24-h:24-h nitrogen feast/famine continuous operation. The cyclic nitrogen starvation and the Taylor flow imposed in the bioreactor resulted in a relatively constant biomass concentration of 0.6 g L-1 with PHB contents ranging from 11 to 32% w w-1 (on a dry weight basis), entailing an average PHB productivity of 5.9 g-PHB m-3 d-1 with an associated PHB yield of 19.8 mg-PHB g-CH4-1. Finally, the molecular analysis of the microbial population structure indicated that type II methanotrophs outcompeted non-PHB accumulating type I methanotrophs, with a heterotrophic-methanotrophic consortium enriched in Methylocystis, Hyphomicrobium, Rubinisphaeraceae SH PL14 and Pseudonocardia.
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Affiliation(s)
- Carlos R Cattaneo
- Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Water Supply, Sanitation and Environmental Engineering, IHE Delft Institute for Water Education, Westvest 7, 2611AX Delft, the Netherlands
| | - Yadira Rodríguez
- Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain
| | - Eldon R Rene
- Department of Water Supply, Sanitation and Environmental Engineering, IHE Delft Institute for Water Education, Westvest 7, 2611AX Delft, the Netherlands
| | - Octavio García-Depraect
- Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain
| | - Raúl Muñoz
- Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain.
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Comesaña-Gándara B, García-Depraect O, Santos-Beneit F, Bordel S, Lebrero R, Muñoz R. Recent trends and advances in biogas upgrading and methanotrophs-based valorization. CHEMICAL ENGINEERING JOURNAL ADVANCES 2022. [DOI: 10.1016/j.ceja.2022.100325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Rodríguez Y, García S, Pérez R, Lebrero R, Muñoz R. Optimization of nitrogen feeding strategies for improving polyhydroxybutyrate production from biogas by Methylocystis parvus str. OBBP in a stirred tank reactor. CHEMOSPHERE 2022; 299:134443. [PMID: 35364084 DOI: 10.1016/j.chemosphere.2022.134443] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 03/07/2022] [Accepted: 03/24/2022] [Indexed: 06/14/2023]
Abstract
The design of efficient cultivation strategies to produce bioplastics from biogas is crucial for the implementation of this biorefinery process. In this work, biogas-based polyhydroxybutyrate (PHB) production and CH4 biodegradation performance was investigated for the first time in a stirred tank bioreactor inoculated with Methylocystis parvus str. OBBP. Decreasing nitrogen loading rates in continuous mode and alternating feast:famine regimes of 24 h-cycles, and alternating feast:famine regimes of 24 h:24 h and 24 h:48 h were tested. Continuous N feeding did not support an effective PHB production despite the occurrence of nitrogen limiting conditions. Feast-famine cycles of 24 h:24 h (with 50% stoichiometric nitrogen supply) supported the maximum PHB production (20 g-PHB m-3 d-1) without compromising the CH4-elimination capacity (25 g m-3 h-1) of the system. Feast:famine ratios ≤1:2 entailed the deterioration of process performance at stoichiometric nitrogen inputs ≤60%.
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Affiliation(s)
- Yadira Rodríguez
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011, Valladolid, Spain; Institute of Sustainable Processes, Dr. Mergelina, s/n, 47011, Valladolid, Spain.
| | - Silvia García
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011, Valladolid, Spain; Institute of Sustainable Processes, Dr. Mergelina, s/n, 47011, Valladolid, Spain.
| | - Rebeca Pérez
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011, Valladolid, Spain; Institute of Sustainable Processes, Dr. Mergelina, s/n, 47011, Valladolid, Spain.
| | - Raquel Lebrero
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011, Valladolid, Spain; Institute of Sustainable Processes, Dr. Mergelina, s/n, 47011, Valladolid, Spain.
| | - Raúl Muñoz
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011, Valladolid, Spain; Institute of Sustainable Processes, Dr. Mergelina, s/n, 47011, Valladolid, Spain.
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Tentori EF, Fang S, Richardson RE. RNA Biomarker Trends across Type I and Type II Aerobic Methanotrophs in Response to Methane Oxidation Rates and Transcriptome Response to Short-Term Methane and Oxygen Limitation in Methylomicrobium album BG8. Microbiol Spectr 2022; 10:e0000322. [PMID: 35678574 PMCID: PMC9241951 DOI: 10.1128/spectrum.00003-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 05/21/2022] [Indexed: 11/26/2022] Open
Abstract
Methanotrophs, which help regulate atmospheric levels of methane, are active in diverse natural and man-made environments. This range of habitats and the feast-famine cycles seen by many environmental methanotrophs suggest that methanotrophs dynamically mediate rates of methane oxidation. Global methane budgets require ways to account for this variability in time and space. Functional gene biomarker transcripts are increasingly studied to inform the dynamics of diverse biogeochemical cycles. Previously, per-cell transcript levels of the methane oxidation biomarker pmoA were found to vary quantitatively with respect to methane oxidation rates in the model aerobic methanotroph Methylosinus trichosporium OB3b. In the present study, these trends were explored for two additional aerobic methanotroph pure cultures grown in membrane bioreactors, Methylocystis parvus OBBP and Methylomicrobium album BG8. At steady-state conditions, per-cell pmoA mRNA transcript levels strongly correlated with per-cell methane oxidation across the three methanotrophs across many orders of magnitude of activity (R2 = 0.91). The inclusion of both type I and type II aerobic methanotrophs suggests a universal trend between in situ activity level and pmoA RNA biomarker levels which can aid in improving estimates of both subsurface and atmospheric methane. Additionally, genome-wide expression data (obtained by transcriptome sequencing [RNA-seq]) were used to explore transcriptomic responses of steady-state M. album BG8 cultures to short-term CH4 and O2 limitation. These limitations induced regulation of genes involved in central carbon metabolism (including carbon storage), cell motility, and stress response. IMPORTANCE Methanotrophs are naturally occurring microorganisms capable of oxidizing methane, having an impact on global net methane emissions. Additionally, they have also gained interest for their biotechnological applications in single-cell protein production, biofuels, and bioplastics. Having better ways of measuring methanotroph activity and understanding how methanotrophs respond to changing conditions is imperative for both optimization in controlled-growth applications and understanding in situ methane oxidation rates. In this study, we explored the applicability of methane oxidation biomarkers as a universal indicator of methanotrophic activity and explored methanotroph transcriptomic response to short-term changes in substrate availability. Our results contribute to better understanding the activity of aerobic methanotrophs, their core metabolic pathways, and their stress responses.
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Affiliation(s)
- Egidio F. Tentori
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, USA
| | - Shania Fang
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, USA
| | - Ruth E. Richardson
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, USA
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13
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Yáñez L, Rodríguez Y, Scott F, Vergara-Fernández A, Muñoz R. Production of (R)-3-hydroxybutyric acid from methane by in vivo depolymerization of polyhydroxybutyrate in Methylocystis parvus OBBP. BIORESOURCE TECHNOLOGY 2022; 353:127141. [PMID: 35405209 DOI: 10.1016/j.biortech.2022.127141] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 06/14/2023]
Abstract
Methylocystis parvus OBBP accumulates polyhydroxybutyrate (PHB) using methane as the sole carbon and energy source. In this work, the feasibility of producing (R)-3-hydroxybutyric acid (R3HBA) via intracellularly accumulated PHB through depolymerization (in-vivo) was investigated. Results showed that a PHB to R3HBA conversion of 77.2 ± 0.9% (R3HBA titer of 0.153 ± 0.002 g L-1) can be attained in a mineral medium containing 1 g L-1 KNO3 at 30 °C with shaking at 200 rpm and a constant pH of 11 for 72 h. Nitrogen deprivation and neutral or acidic pHs strongly reduced the excreted R3HBA concentration. Reduced oxygen availability negatively affected the R3HBA yield, which decreased to 73.6 ± 4.9% (titer of 0.139 ± 0.01 g L-1) under microaerobic conditions. Likewise, the presence of increasing concentrations of R3HBA in the medium before the onset of PHB depolymerization reduced the initial R3HBA release rate and R3HBA yield.
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Affiliation(s)
- Luz Yáñez
- Institute of Sustainable Processes, Universidad de Valladolid, Doctor Mergelina s/n, 47011, Spain; Green Technology Research Group, Facultad de Ingeniería y Ciencias Aplicadas, Universidad de Los Andes, 7550000, Chile.
| | - Yadira Rodríguez
- Institute of Sustainable Processes, Universidad de Valladolid, Doctor Mergelina s/n, 47011, Spain.
| | - Felipe Scott
- Green Technology Research Group, Facultad de Ingeniería y Ciencias Aplicadas, Universidad de Los Andes, 7550000, Chile.
| | - Alberto Vergara-Fernández
- Green Technology Research Group, Facultad de Ingeniería y Ciencias Aplicadas, Universidad de Los Andes, 7550000, Chile.
| | - Raúl Muñoz
- Institute of Sustainable Processes, Universidad de Valladolid, Doctor Mergelina s/n, 47011, Spain.
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14
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Poly(3-hydroxybutyrate) Production From Methane in Bubble Column Bioreactors: Process Simulation and Design Optimization. N Biotechnol 2022; 70:39-48. [DOI: 10.1016/j.nbt.2022.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 02/20/2022] [Accepted: 04/17/2022] [Indexed: 11/17/2022]
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15
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Kulkarni PP, Chavan SB, Deshpande MS, Sagotra D, Kumbhar PS, Ghosalkar AR. Enrichment of Methylocystis dominant mixed culture from rice field for PHB production. J Biotechnol 2022; 343:62-70. [PMID: 34838616 DOI: 10.1016/j.jbiotec.2021.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/16/2021] [Accepted: 11/20/2021] [Indexed: 11/16/2022]
Abstract
Presence of methanotrophs in diverse environmental habitats helps to reduce emissions of greenhouse gas like methane. Isolation and culture of undiscovered wealth of methanotrophic organisms can help in exploitation of these organisms in value added products. The present study focuses on the enrichment of methanotroph dominated mixed microbial community by use of three stage strategy of revival, proliferation, and segregation. During the enrichment process amplicon sequencing of 16 s rRNA V3-V4 region showed relative abundance of mixed culture comprising single methanotrophic species of Methylocystis genus (88.92%) along with only three other species. Methylocystis dominant mixed culture (MMI-11) was observed to produce polyhydroxyalkanoates (PHA). During studies to identify favourable culture conditions, nitrate was found to be preferred nitrogen source for growth and PHA production. Cell growth ability to produce PHA was also evaluated at 14 L fermentor by supplying gas using continuous bubbling and through pressurization in the headspace. The mixed methanotrophic culture was found to accumulate maximum of 22.20% polyhydroxybutyrate (PHB) under nitrate limited condition. The molecular weight of PHB was found to be 2.221 × 105 g mol-1 with polydispersity of 1.82.
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Affiliation(s)
- Pranav P Kulkarni
- Department of Technology, Savitribai Phule Pune University, Pune, India; Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Sambhaji B Chavan
- Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Mandar S Deshpande
- Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Dhanishta Sagotra
- Department of Technology, Savitribai Phule Pune University, Pune, India
| | - Pramod S Kumbhar
- Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Anand R Ghosalkar
- Department of Technology, Savitribai Phule Pune University, Pune, India; Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India.
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16
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In vivo quantification of polyhydroxybutyrate (PHB) in the alphaproteobacterial methanotroph, Methylocystis sp. Rockwell. Appl Microbiol Biotechnol 2021; 106:811-819. [PMID: 34921330 DOI: 10.1007/s00253-021-11732-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 11/29/2021] [Accepted: 12/05/2021] [Indexed: 10/19/2022]
Abstract
Methane is a common industrial by-product that can be used as feedstock for production of the biopolymer polyhydroxybutyrate (PHB) by alphaproteobacterial methanotrophs. In vivo assessment of PHB production would shed light on the biosynthesis process and guide design of improved production strategies, but it is currently difficult to perform efficiently. In this study, the alphaproteobacterial methanotroph Methylocystis sp. Rockwell was grown on methane with three different nitrogen sources (ammonium, nitrate, and atmospheric nitrogen), and biomass samples were harvested at defined time points during lag, exponential, and stationary growth phases. PHB cell content was analyzed at these sampling points via a standard gas chromatography-flame ionization detector method, which requires hydrolysis of PHB and esterification of the resulting monomer under acidic conditions, and a novel, rapid, cost-effective approach based on fixation and staining of bacterial cells via Nile Blue A fluorescent dye enabling differential staining of cell membranes and intracellular PHB granules for single-cell analysis through fluorescence microscopy. Overall, the two PHB quantification approaches were in agreement at all stages of growth and in all three growing conditions tested. The PHB cell content was greatest with atmospheric nitrogen as a nitrogen source, followed by ammonium and nitrate. Under atmospheric nitrogen and ammonium conditions, PHB cell content decreased with growth progression, while under nitrate conditions PHB cell content remained unchanged in all growth phases. In addition to presenting a rapid, efficient method enabling in vivo quantification of PHB production, the present study highlights the impact of nitrogen source on PHB production by Methylocystis sp. Rockwell. KEY POINTS: • A novel fluorescence microscopy method to quantify PHB in single cells was developed • The microscopy method was validated by the derivation/gas chromatography method • Methylocystis sp. Rockwell synthesizes PHB granules without nutrient stress.
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17
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Jo SY, Son J, Sohn YJ, Lim SH, Lee JY, Yoo JI, Park SY, Na JG, Park SJ. A shortcut to carbon-neutral bioplastic production: Recent advances in microbial production of polyhydroxyalkanoates from C1 resources. Int J Biol Macromol 2021; 192:978-998. [PMID: 34656544 DOI: 10.1016/j.ijbiomac.2021.10.066] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/04/2021] [Accepted: 10/09/2021] [Indexed: 12/18/2022]
Abstract
Since the 20th century, plastics that are widely being used in general life and industries are causing enormous plastic waste problems since improperly discarded plastics barely degrade and decompose. Thus, the demand for polyhydroxyalkanoates (PHAs), biodegradable polymers with material properties similar to conventional petroleum-based plastics, has been increased so far. The microbial production of PHAs is an environment-friendly solution for the current plastic crisis, however, the carbon sources for the microbial PHA production is a crucial factor to be considered in terms of carbon-neutrality. One‑carbon (C1) resources, such as methane, carbon monoxide, and carbon dioxide, are greenhouse gases and are abundantly found in nature and industry. C1 resources as the carbon sources for PHA production have a completely closed carbon loop with much advances; i) fast carbon circulation with direct bioconversion process and ii) simple fermentation procedure without sterilization as non-preferable nutrients. This review discusses the biosynthesis of PHAs based on C1 resource utilization by wild-type and metabolically engineered microbial host strains via biorefinery processes.
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Affiliation(s)
- Seo Young Jo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Jina Son
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Yu Jung Sohn
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Seo Hyun Lim
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Ji Yeon Lee
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Jee In Yoo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Se Young Park
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Jeong-Geol Na
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, Republic of Korea.
| | - Si Jae Park
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, 03760, Republic of Korea.
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18
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Oshkin IY, Danilova OV, Suleimanov RZ, Tikhonova EN, Malakhova TV, Murashova IA, Pimenov NV, Dedysh SN. Thermotolerant Methanotrophic Bacteria from Sediments of the River Chernaya, Crimea, and Assessment of Their Growth Characteristics. Microbiology (Reading) 2021. [DOI: 10.1134/s0026261721050131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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19
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Nguyen TT, Lee EY. Methane-based biosynthesis of 4-hydroxybutyrate and P(3-hydroxybutyrate-co-4-hydroxybutyrate) using engineered Methylosinus trichosporium OB3b. BIORESOURCE TECHNOLOGY 2021; 335:125263. [PMID: 34020156 DOI: 10.1016/j.biortech.2021.125263] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 06/12/2023]
Abstract
4-Hydroxybutyric acid (4-HB) is a key platform chemical that serves as a precursor in a wide variety of industrial applications including 1,4-butanediol and bioplastics production. In this study, we reconstructed 4-HB biosynthetic pathway including CoA-dependent succinate semialdehyde dehydrogenase and NADPH-dependent succinate semialdehyde reductase in Type II methanotrophs, Methylosinus trichosporium OB3b, to synthesize 4-HB. These engineered strains were able to synthesize 4-HB from methane via tricarboxylic acid cycle. 4-HB synthesis was further improved to 10.5 mg/L by overexpressing phosphoenolpyruvate carboxylase, isocitrate dehydrogenase and 2-oxoglutarate dehydrogenase genes in M. trichosporium OB3b. We combined the native poly(3-hydroxybutyrate) metabolic pathway and reconstructed 4-HB biosynthetic pathway to synthesize P(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer from structurally unrelated substrate methane as a single carbon source. These engineered strains could synthesize P(3HB-co-4HB) copolymer with 3.08 mol% 4-HB from methane. This study provides several engineering strategies to synthesize polyhydroxyalkanoates and their monomers from methane.
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Affiliation(s)
- Thu Thi Nguyen
- Department of Chemical Engineering (Integrated Engineering), Kyung Hee University, Yongin-si, Gyeonggi-do 17104, Republic of Korea
| | - Eun Yeol Lee
- Department of Chemical Engineering (Integrated Engineering), Kyung Hee University, Yongin-si, Gyeonggi-do 17104, Republic of Korea.
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20
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Lazic M, Sugden S, Sauvageau D, Stein LY. Metabolome profiles of the alphaproteobacterial methanotroph Methylocystis sp. Rockwell in response to carbon and nitrogen source. FEMS Microbiol Lett 2021; 368:6055661. [PMID: 33378457 DOI: 10.1093/femsle/fnaa219] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 12/28/2020] [Indexed: 01/23/2023] Open
Abstract
Methanotrophs use methane as a sole carbon source and thus play a critical role in its global consumption. Intensified interest in methanotrophs for their low-cost production of value-added products and large-scale industrialization has led to investigations of strain-to-strain variation in parameters for growth optimization and metabolic regulation. In this study, Methylocystis sp. Rockwell was grown with methane or methanol as a carbon source and ammonium or nitrate as a nitrogen source. The intracellular metabolomes and production of polyhydroxybutyrate, a bioplastic precursor, were compared among treatments to determine how the different combinations of carbon and nitrogen sources affected metabolite production. The methane-ammonium condition resulted in the highest growth, followed by the methane-nitrate, methanol-nitrate and methanol-ammonium conditions. Overall, the methane-ammonium and methane-nitrate conditions directed metabolism toward energy-conserving pathways, while methanol-ammonium and methanol-nitrate directed the metabolic response toward starvation pathways. Polyhydroxybutyrate was produced at greater abundances in methanol-grown cells, independent of the nitrogen source. Together, the results revealed how Methylocystis sp. Rockwell altered its metabolism with different combinations of carbon and nitrogen source, with implications for production of industrially relevant metabolites.
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Affiliation(s)
- Marina Lazic
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Scott Sugden
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Dominic Sauvageau
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
| | - Lisa Y Stein
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
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21
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Wang S, Liu Q, Li J, Wang Z. Methane in wastewater treatment plants: status, characteristics, and bioconversion feasibility by methane oxidizing bacteria for high value-added chemicals production and wastewater treatment. WATER RESEARCH 2021; 198:117122. [PMID: 33865027 DOI: 10.1016/j.watres.2021.117122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 02/23/2021] [Accepted: 04/02/2021] [Indexed: 06/12/2023]
Abstract
Methane is a type of renewable fuel that can generate many types of high value-added chemicals, however, besides heat and power production, there is little methane utilization in most of the wastewater treatment plants (WWTPs) all round the world currently. In this review, the status of methane production performance from WWTPs was firstly investigated. Subsequently, based on the identification and classification of methane oxidizing bacteria (MOB), the key enzymes and metabolic pathway of MOB were presented in depth. Then the production, extraction and purification process of high value-added chemicals, including methanol, ectoine, biofuel, bioplastic, methane protein and extracellular polysaccharides, were introduced in detail, which was conducive to understand the bioconversion process of methane. Finally, the use of methane in wastewater treatment process, including nitrogen removal, emerging contaminants removal as well as resource recovery was extensively explored. These findings could provide guidance in the development of sustainable economy and environment, and facilitate biological methane conversion by using MOB in further attempts.
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Affiliation(s)
- Shuo Wang
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu Engineering Laboratory for Biomass Energy and Carbon Reduction Technology, Wuxi 214122, China; Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou 215009, China
| | - Qixin Liu
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China
| | - Ji Li
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu Engineering Laboratory for Biomass Energy and Carbon Reduction Technology, Wuxi 214122, China; Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou 215009, China.
| | - Zhiwu Wang
- Department of Civil and Environmental Engineering, Virginia Tech, Manassas, VA 20110, USA.
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22
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Guerrero-Cruz S, Vaksmaa A, Horn MA, Niemann H, Pijuan M, Ho A. Methanotrophs: Discoveries, Environmental Relevance, and a Perspective on Current and Future Applications. Front Microbiol 2021; 12:678057. [PMID: 34054786 PMCID: PMC8163242 DOI: 10.3389/fmicb.2021.678057] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 04/12/2021] [Indexed: 11/13/2022] Open
Abstract
Methane is the final product of the anaerobic decomposition of organic matter. The conversion of organic matter to methane (methanogenesis) as a mechanism for energy conservation is exclusively attributed to the archaeal domain. Methane is oxidized by methanotrophic microorganisms using oxygen or alternative terminal electron acceptors. Aerobic methanotrophic bacteria belong to the phyla Proteobacteria and Verrucomicrobia, while anaerobic methane oxidation is also mediated by more recently discovered anaerobic methanotrophs with representatives in both the bacteria and the archaea domains. The anaerobic oxidation of methane is coupled to the reduction of nitrate, nitrite, iron, manganese, sulfate, and organic electron acceptors (e.g., humic substances) as terminal electron acceptors. This review highlights the relevance of methanotrophy in natural and anthropogenically influenced ecosystems, emphasizing the environmental conditions, distribution, function, co-existence, interactions, and the availability of electron acceptors that likely play a key role in regulating their function. A systematic overview of key aspects of ecology, physiology, metabolism, and genomics is crucial to understand the contribution of methanotrophs in the mitigation of methane efflux to the atmosphere. We give significance to the processes under microaerophilic and anaerobic conditions for both aerobic and anaerobic methane oxidizers. In the context of anthropogenically influenced ecosystems, we emphasize the current and potential future applications of methanotrophs from two different angles, namely methane mitigation in wastewater treatment through the application of anaerobic methanotrophs, and the biotechnological applications of aerobic methanotrophs in resource recovery from methane waste streams. Finally, we identify knowledge gaps that may lead to opportunities to harness further the biotechnological benefits of methanotrophs in methane mitigation and for the production of valuable bioproducts enabling a bio-based and circular economy.
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Affiliation(s)
- Simon Guerrero-Cruz
- Catalan Institute for Water Research (ICRA), Girona, Spain
- Universitat de Girona, Girona, Spain
| | - Annika Vaksmaa
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, ’t Horntje, Netherlands
| | - Marcus A. Horn
- Institute of Microbiology, Leibniz Universität Hannover, Hannover, Germany
| | - Helge Niemann
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, ’t Horntje, Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, Netherlands
- Centre for Arctic Gas Hydrate, Environment and Climate, Department of Geosciences, UiT the Arctic University of Norway, Tromsø, Norway
| | - Maite Pijuan
- Catalan Institute for Water Research (ICRA), Girona, Spain
- Universitat de Girona, Girona, Spain
| | - Adrian Ho
- Institute of Microbiology, Leibniz Universität Hannover, Hannover, Germany
- Division of Applied Life Sciences, Gyeongsang National University, Jinju, South Korea
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23
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Salem R, Soliman M, Fergala A, Audette GF, ElDyasti A. Screening for Methane Utilizing Mixed Communities with High Polyhydroxybutyrate (PHB) Production Capacity Using Different Design Approaches. Polymers (Basel) 2021; 13:1579. [PMID: 34069256 PMCID: PMC8157138 DOI: 10.3390/polym13101579] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/08/2021] [Accepted: 05/11/2021] [Indexed: 12/04/2022] Open
Abstract
With the adverse environmental ramifications of the use of petroleum-based plastic outweighing the challenges facing the industrialization of bioplastics, polyhydroxyalkanoate (PHA) biopolymer has gained broad interest in recent years. Thus, an efficient approach for maximizing polyhydroxybutyrate (PHB) polymer production in methanotrophic bacteria has been developed using the methane gas produced in the anaerobic digestion process in wastewater treatment plants (WWTPS) as a carbon substrate and an electron donor. A comparison study was conducted between two experimental setups using two different recycling strategies, namely new and conventional setups. The former setup aims to recycle PHB producers into the system after the PHB accumulation phase, while the latter recycles the biomass back into the system after the exponential phase of growth or the growth phase. The goal of this study was to compare both setups in terms of PHB production and other operational parameters such as growth rate, methane uptake rate, and biomass yield using two different nitrogen sources, namely nitrate and ammonia. The newly proposed setup is aimed at stimulating PHB accumulating type II methanotroph growth whilst enabling other PHB accumulators to grow simultaneously. The success of the proposed method was confirmed as it achieved highest recorded PHB accumulation percentages for a mixed culture community in both ammonia- and nitrate-enriched media of 59.4% and 54.3%, respectively, compared to 37.8% and 9.1% for the conventional setup. Finally, the sequencing of microbial samples showed a significant increase in the abundance of type II methanotrophs along with other PHB producers, confirming the success of the newly proposed technique in screening for PHB producers and achieving higher PHB accumulation.
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Affiliation(s)
- Rana Salem
- Civil Engineering Department, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada; (R.S.); (M.S.)
| | - Moomen Soliman
- Civil Engineering Department, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada; (R.S.); (M.S.)
| | - Ahmed Fergala
- Department of Biotechnology, Delft University of Technology, Mekelweg 5, 2628 CD Delft, The Netherlands;
| | - Gerald F. Audette
- Chemistry Department, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada;
| | - Ahmed ElDyasti
- Civil Engineering Department, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada; (R.S.); (M.S.)
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24
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Nguyen DTN, Lee OK, Nguyen TT, Lee EY. Type II methanotrophs: A promising microbial cell-factory platform for bioconversion of methane to chemicals. Biotechnol Adv 2021; 47:107700. [PMID: 33548453 DOI: 10.1016/j.biotechadv.2021.107700] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 12/04/2020] [Accepted: 01/20/2021] [Indexed: 10/22/2022]
Abstract
Methane, the predominant element in natural gas and biogas, represents a promising alternative to carbon feedstocks in the biotechnological industry due to its low cost and high abundance. The bioconversion of methane to value-added products can enhance the value of gas and mitigate greenhouse gas emissions. Methanotrophs, methane-utilizing bacteria, can make a significant contribution to the production of various valuable biofuels and chemicals from methane. Type II methanotrophs in comparison with Type I methanotrophs have distinct advantages, including high acetyl-CoA flux and the co-incorporation of two important greenhouse gases (methane and CO2), making it a potential microbial cell-factory platform for methane-derived biomanufacturing. Herein, we review the most recent advances in Type II methanotrophs related to multi-omics studies and metabolic engineering. Representative examples and prospects of metabolic engineering strategies for the production of suitable products are also discussed.
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Affiliation(s)
- Diep Thi Ngoc Nguyen
- Department of Chemical Engineering (Integrated Engineering), Kyung Hee University, Gyeonggi-do 17104, Republic of Korea
| | - Ok Kyung Lee
- Department of Chemical Engineering (Integrated Engineering), Kyung Hee University, Gyeonggi-do 17104, Republic of Korea
| | - Thu Thi Nguyen
- Department of Chemical Engineering (Integrated Engineering), Kyung Hee University, Gyeonggi-do 17104, Republic of Korea
| | - Eun Yeol Lee
- Department of Chemical Engineering (Integrated Engineering), Kyung Hee University, Gyeonggi-do 17104, Republic of Korea.
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Tveit AT, Schmider T, Hestnes AG, Lindgren M, Didriksen A, Svenning MM. Simultaneous Oxidation of Atmospheric Methane, Carbon Monoxide and Hydrogen for Bacterial Growth. Microorganisms 2021; 9:microorganisms9010153. [PMID: 33445466 PMCID: PMC7827875 DOI: 10.3390/microorganisms9010153] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 11/16/2022] Open
Abstract
The second largest sink for atmospheric methane (CH4) is atmospheric methane oxidizing-bacteria (atmMOB). How atmMOB are able to sustain life on the low CH4 concentrations in air is unknown. Here, we show that during growth, with air as its only source for energy and carbon, the recently isolated atmospheric methane-oxidizer Methylocapsa gorgona MG08 (USCα) oxidizes three atmospheric energy sources: CH4, carbon monoxide (CO), and hydrogen (H2) to support growth. The cell-specific CH4 oxidation rate of M. gorgona MG08 was estimated at ~0.7 × 10−18 mol cell−1 h−1, which, together with the oxidation of CO and H2, supplies 0.38 kJ Cmol−1 h−1 during growth in air. This is seven times lower than previously assumed necessary to support bacterial maintenance. We conclude that atmospheric methane-oxidation is supported by a metabolic flexibility that enables the simultaneous harvest of CH4, H2 and CO from air, but the key characteristic of atmospheric CH4 oxidizing bacteria might be very low energy requirements.
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Affiliation(s)
- Alexander Tøsdal Tveit
- Department of Arctic and Marine Biology, UiT, The Arctic University of Norway, 9037 Tromsø, Norway; (T.S.); (A.G.H.); (A.D.); (M.M.S.)
- Correspondence:
| | - Tilman Schmider
- Department of Arctic and Marine Biology, UiT, The Arctic University of Norway, 9037 Tromsø, Norway; (T.S.); (A.G.H.); (A.D.); (M.M.S.)
| | - Anne Grethe Hestnes
- Department of Arctic and Marine Biology, UiT, The Arctic University of Norway, 9037 Tromsø, Norway; (T.S.); (A.G.H.); (A.D.); (M.M.S.)
| | - Matteus Lindgren
- CAGE—Centre for Arctic Gas Hydrate, Environment and Climate, Department of Geosciences, UiT, The Arctic University of Norway, 9010 Tromsø, Norway;
| | - Alena Didriksen
- Department of Arctic and Marine Biology, UiT, The Arctic University of Norway, 9037 Tromsø, Norway; (T.S.); (A.G.H.); (A.D.); (M.M.S.)
| | - Mette Marianne Svenning
- Department of Arctic and Marine Biology, UiT, The Arctic University of Norway, 9037 Tromsø, Norway; (T.S.); (A.G.H.); (A.D.); (M.M.S.)
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Rumah BL, Stead CE, Claxton Stevens BH, Minton NP, Grosse-Honebrink A, Zhang Y. Isolation and characterisation of Methylocystis spp. for poly-3-hydroxybutyrate production using waste methane feedstocks. AMB Express 2021; 11:6. [PMID: 33409745 PMCID: PMC7788130 DOI: 10.1186/s13568-020-01159-4] [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: 08/28/2020] [Accepted: 12/07/2020] [Indexed: 11/10/2022] Open
Abstract
Waste plastic and methane emissions are two anthropogenic by-products exacerbating environmental pollution. Methane-oxidizing bacteria (methanotrophs) hold the key to solving these problems simultaneously by utilising otherwise wasted methane gas as carbon source and accumulating the carbon as poly-3-hydroxybutyrate, a biodegradable plastic polymer. Here we present the isolation and characterisation of two novel Methylocystis strains with the ability to produce up to 55.7 ± 1.9% poly-3-hydroxybutyrate of cell dry weight when grown on methane from different waste sources such as landfill and anaerobic digester gas. Methylocystis rosea BRCS1 isolated from a recreational lake and Methylocystis parvus BRCS2 isolated from a bog were whole genome sequenced using PacBio and Illumina genome sequencing technologies. In addition to potassium nitrate, these strains were also shown to grow on ammonium chloride, glutamine and ornithine as nitrogen source. Growth of Methylocystis parvus BRCS2 on Nitrate Mineral Salt (NMS) media with 0.1% methanol vapor as carbon source was demonstrated. The genetic tractability by conjugation was also determined with conjugation efficiencies up to 2.8 × 10–2 and 1.8 × 10–2 for Methylocystis rosea BRCS1 and Methylocystis parvus BRCS2 respectively using a plasmid with ColE1 origin of replication. Finally, we show that Methylocystis species can produce considerable amounts of poly-3-hydroxybutyrate on waste methane sources without impaired growth, a proof of concept which opens doors to their use in integrated bio-facilities like landfills and anaerobic digesters.
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Cal AJ, Kibblewhite RE, Sikkema WD, Torres LF, Hart-Cooper WM, Orts WJ, Lee CC. Production of polyhydroxyalkanoate copolymers containing 4-hydroxybutyrate in engineered Bacillus megaterium. Int J Biol Macromol 2020; 168:86-92. [PMID: 33290766 DOI: 10.1016/j.ijbiomac.2020.12.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 11/18/2020] [Accepted: 12/03/2020] [Indexed: 11/15/2022]
Abstract
Despite being used as a common platform for the commercial production of many biochemicals, Bacilli are often overlooked as a source of industrial polyhydroxyalkanoates (PHAs), biodegradable plastic replacements. In addition to having a robust expression system, the lack of lipopolysaccharides and ease of lysis make Bacilli an attractive host for the production of PHAs. In this work, a Bacillus megaterium strain was engineered to generate poly(3-hydroxybutyrate-co-4-hydroxybutryate) (P[3HB-co-4HB]) copolymers, which are among the most useful and industrially-relevant copolymers. These copolymers had lower modulus and increased toughness, thus making the copolymer suitable for a broader range of applications. Due to high metabolic flux through succinate, the engineered B. megaterium strain produced P(3HB-co-4HB) with >10% mol fraction 4HB from glucose, without the use of highly regulated and expensive precursors or potentially damaging truncation of central biochemical pathways.
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Affiliation(s)
- Andrew J Cal
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA
| | - Rena E Kibblewhite
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA
| | - W Dirk Sikkema
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA
| | - Lennard F Torres
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA
| | - William M Hart-Cooper
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA
| | - William J Orts
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA
| | - Charles C Lee
- USDA-ARS-Western Regional Research Center, Bioproducts Research Unit, 800 Buchanan St., Albany, CA 94710, USA.
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Cai Y, Zhou X, Shi L, Jia Z. Atmospheric Methane Oxidizers Are Dominated by Upland Soil Cluster Alpha in 20 Forest Soils of China. MICROBIAL ECOLOGY 2020; 80:859-871. [PMID: 32803363 DOI: 10.1007/s00248-020-01570-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 08/03/2020] [Indexed: 05/25/2023]
Abstract
Upland soil clusters alpha and gamma (USCα and USCγ) are considered a major biological sink of atmospheric methane and are often detected in forest and grassland soils. These clusters are phylogenetically classified using the particulate methane monooxygenase gene pmoA because of the difficulty of cultivation. Recent studies have established a direct link of pmoA genes to 16S rRNA genes based on their isolated strain or draft genomes. However, whether the results of pmoA-based assays could be largely represented by 16S rRNA gene sequencing in upland soils remains unclear. In this study, we collected 20 forest soils across China and compared methane-oxidizing bacterial (MOB) communities by high-throughput sequencing of 16S rRNA and pmoA genes using different primer sets. The results showed that 16S rRNA gene sequencing and the semi-nested polymerase chain reaction (PCR) of the pmoA gene (A189/A682r nested with a mixture of mb661 and A650) consistently revealed the dominance of USCα (accounting for more than 50% of the total MOB) in 12 forest soils. A189f/A682r successfully amplified pmoA genes (mainly RA14 of USCα) in only three forest soils. A189f/mb661 could amplify USCα (mainly JR1) in several forest soils but showed a strong preferential amplification of Methylocystis and many other type I MOB groups. A189f/A650 almost exclusively amplified USCα (mainly JR1) and largely discriminated against Methylocystis and most of the other MOB groups. The semi-nested PCR approach weakened the bias of A189f/mb661 and A189f/A650 for JR1 and balanced the coverage of all USCα members. The canonical correspondence analysis indicated that soil NH4+-N and pH were the main environmental factors affecting the MOB community of Chinese forest soils. The RA14 of the USCα group prefers to live in soils with low pH, low temperature, low elevation, high precipitation, and rich in nitrogen. JR1's preferences for temperature and elevation were opposite to RA14. Our study suggests that combining the deep sequencing of 16S rRNA and pmoA genes to characterize MOB in forest soils is the best choice.
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Affiliation(s)
- Yuanfeng Cai
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, Jiangsu Province, China
| | - Xue Zhou
- College of agricultural science and engineering, Hohai University, Nanjing, 210098, Jiangsu Province, China
| | - Limei Shi
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, Jiangsu Province, China
| | - Zhongjun Jia
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, Jiangsu Province, China.
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Semrau JD, DiSpirito AA, Obulisamy PK, Kang-Yun CS. Methanobactin from methanotrophs: genetics, structure, function and potential applications. FEMS Microbiol Lett 2020; 367:5804726. [PMID: 32166327 DOI: 10.1093/femsle/fnaa045] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 03/11/2020] [Indexed: 12/12/2022] Open
Abstract
Aerobic methane-oxidizing bacteria of the Alphaproteobacteria have been found to express a novel ribosomally synthesized post-translationally modified polypeptide (RiPP) termed methanobactin (MB). The primary function of MB in these microbes appears to be for copper uptake, but MB has been shown to have multiple capabilities, including oxidase, superoxide dismutase and hydrogen peroxide reductase activities, the ability to detoxify mercury species, as well as acting as an antimicrobial agent. Herein, we describe the diversity of known MBs as well as the genetics underlying MB biosynthesis. We further propose based on bioinformatics analyses that some methanotrophs may produce novel forms of MB that have yet to be characterized. We also discuss recent findings documenting that MBs play an important role in controlling copper availability to the broader microbial community, and as a result can strongly affect the activity of microbes that require copper for important enzymatic transformations, e.g. conversion of nitrous oxide to dinitrogen. Finally, we describe procedures for the detection/purification of MB, as well as potential medical and industrial applications of this intriguing RiPP.
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Affiliation(s)
- Jeremy D Semrau
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI, USA 48109-2125
| | - Alan A DiSpirito
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA 50011
| | | | - Christina S Kang-Yun
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI, USA 48109-2125
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Rodríguez Y, Firmino PIM, Pérez V, Lebrero R, Muñoz R. Biogas valorization via continuous polyhydroxybutyrate production by Methylocystis hirsuta in a bubble column bioreactor. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 113:395-403. [PMID: 32585559 DOI: 10.1016/j.wasman.2020.06.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/25/2020] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
Creating additional value out of biogas during waste treatment has become a priority in past years. Biogas bioconversion into valuable bioproducts such as biopolymers has emerged as a promising strategy. This work assessed the operational feasibility of a bubble column bioreactor (BCB) implemented with gas recirculation and inoculated with a polyhydroxybutyrate (PHB)-producing strain using biogas as substrate. The BCB was initially operated at empty bed residence times (EBRTs) ranging from 30 to 120 min and gas recirculation ratios (R) from 0 to 30 to assess the gas-to-liquid mass transfer and bioconversion of CH4. Subsequently, the BCB was continuously operated at a R of 30 and an EBRT of 60 min under excess of nitrogen and nitrogen feast-famine cycles of 24 h:24 h to trigger PHB synthesis. Gas recirculation played a major role in CH4 gas-liquid transfer, providing almost fourfold higher CH4 elimination capacities (~41 g CH4 m-3 h-1) at the highest R and EBRT of 60 min. The long-term operation under N excess conditions entailed nitrite accumulation (induced by O2 limiting conditions) and concurrent methanotrophic activity inhibition above ~60 mg N-NO2- L-1. Adjusting the N-NO3- supply to match microbial N demand successfully prevented nitrite accumulation. Finally, the N feast-famine 24 h:24 h strategy supported a stable CH4 conversion with a removal efficiency of 70% along with a continuous PHB production, which yielded PHB accumulations of 14.5 ± 2.9% (mg PHB mg-1 total suspended solids × 100). These outcomes represent the first step towards the integration of biogas biorefineries into conventional anaerobic digestion plants.
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Affiliation(s)
- Yadira Rodríguez
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain; Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain
| | - Paulo Igor Milen Firmino
- Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Víctor Pérez
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain; Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain
| | - Raquel Lebrero
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain; Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain
| | - Raúl Muñoz
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain; Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain.
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Complete Genome Sequence of Methylosinus sp. Strain C49, a Methane-Oxidizing Bacterium Harboring phaABC Genes for Polyhydroxyalkanoate Synthesis. Microbiol Resour Announc 2020; 9:9/27/e00113-20. [PMID: 32616630 PMCID: PMC7330232 DOI: 10.1128/mra.00113-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report a complete genome sequence of Methylosinus sp. strain C49, a methane-oxidizing bacterium (MOB) in the class Alphaproteobacteria, isolated from MOB-enriched biomass. The genome encodes the functional genes for methane oxidation (pmoA) and polyhydroxyalkanoate (PHA) biosynthesis (phaABC). Deciphering the genome will help research toward PHA production by MOB.
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Yasuda S, Toyoda R, Agrawal S, Suenaga T, Riya S, Hori T, Lackner S, Hosomi M, Terada A. Exploration and enrichment of methane-oxidizing bacteria derived from a rice paddy field emitting highly concentrated methane. J Biosci Bioeng 2020; 130:311-318. [PMID: 32487498 DOI: 10.1016/j.jbiosc.2020.04.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 04/06/2020] [Accepted: 04/20/2020] [Indexed: 12/11/2022]
Abstract
Methane-oxidizing bacteria (MOB) possess the metabolic potential to assimilate the highly potent greenhouse gas, CH4, and can also synthesize valuable products. Depending on their distinct and fastidious metabolic pathways, MOB are mainly divided into Type I and Type II; the latter are known as producers of polyhydroxyalkanoate (PHA). Despite the metabolic potential of MOB to synthesize PHA, the ecophysiology of MOB, especially under high CH4 flux conditions, is yet to be understood. Therefore, in this study, a rice paddy soil receiving a high CH4 flux from underground was used as an inoculum to enrich MOB using fed-batch operation, then the enriched Type II MOB were characterized. The transitions in the microbial community composition and CH4 oxidation rates were monitored by 16S rRNA gene amplicon sequencing and degree of CH4 consumption. With increasing incubation time, the initially dominant Methylomonas sp., affiliated with Type I MOB, was gradually replaced with Methylocystis sp., Type II MOB, resulting in a maximum CH4 oxidation rate of 1.40 g-CH4/g-biomass/day. The quantification of functional genes encoding methane monooxygenase, pmoA and PHA synthase, phaC, by quantitative PCR revealed concomitant increases in accordance with the Type II MOB enrichment. These increases in the functional genes underscore the significance of Type II MOB to mitigate greenhouse gas emission and produce PHA.
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Affiliation(s)
- Shohei Yasuda
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan.
| | - Risako Toyoda
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan.
| | - Shelesh Agrawal
- Department of Civil and Environmental Engineering Science, Institute IWAR, Chair of Wastewater Engineering, Technische Universität Darmstadt, Franziska-Braun-Straße 7, 64287 Darmstadt, Germany.
| | - Toshikazu Suenaga
- Global Innovation Research Institute, Tokyo University of Agriculture and Technology, 3-8-1 Harumi-cho, Fuchu, Tokyo 185-8538, Japan.
| | - Shohei Riya
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan.
| | - Tomoyuki Hori
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan.
| | - Susanne Lackner
- Department of Civil and Environmental Engineering Science, Institute IWAR, Chair of Wastewater Engineering, Technische Universität Darmstadt, Franziska-Braun-Straße 7, 64287 Darmstadt, Germany.
| | - Masaaki Hosomi
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan.
| | - Akihiko Terada
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan; Global Innovation Research Institute, Tokyo University of Agriculture and Technology, 3-8-1 Harumi-cho, Fuchu, Tokyo 185-8538, Japan.
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Wang S, An Z, Wang ZW. Bioconversion of methane to chemicals and fuels by methane-oxidizing bacteria. ADVANCES IN BIOENERGY 2020. [DOI: 10.1016/bs.aibe.2020.04.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Luangthongkam P, Strong PJ, Syed Mahamud SN, Evans P, Jensen P, Tyson G, Laycock B, Lant PA, Pratt S. The effect of methane and odd-chain fatty acids on 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) synthesis by a Methylosinus-dominated mixed culture. BIORESOUR BIOPROCESS 2019. [DOI: 10.1186/s40643-019-0285-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
AbstractA methanotrophic community was enriched in a semi-continuous reactor under non-aseptic conditions with methane and ammonia as carbon and nitrogen source. After a year of operation, Methylosinus sp., accounted for 80% relative abundance of the total sequences identified from potential polyhydroxyalkanoates (PHAs) producers, dominated the methane-fed enrichment. Prior to induction of PHA accumulation, cells harvested from the parent reactor contained low level of PHA at 4.0 ± 0.3 wt%. The cells were later incubated in the absence of ammonia with various combinations of methane, propionic acid, and valeric acid to induce biosynthesis of poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). Previous studies reported that methanotrophic utilization of odd-chain fatty acids for the production of PHAs requires reducing power from methane oxidation. However, our findings demonstrated that the PHB-containing methanotrophic enrichment does not require methane availability to generate 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV)—when odd-chain fatty acids are presented. The enrichment yielded up to 14 wt% PHA with various mole fractions of 3HV monomer depending on the availability of methane and odd-fatty acids. Overall, the addition of valeric acid resulted in a higher PHA content and a higher 3HV fraction. The highest 3HV fraction (up to 65 mol%) was obtained from the methane–valeric acid experiment, which is higher than those previously reported for PHA-producing methanotrophic mixed microbial cultures.
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Pérez R, Casal J, Muñoz R, Lebrero R. Polyhydroxyalkanoates production from methane emissions in Sphagnum mosses: Assessing the effect of temperature and phosphorus limitation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 688:684-690. [PMID: 31254834 DOI: 10.1016/j.scitotenv.2019.06.296] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 06/10/2019] [Accepted: 06/19/2019] [Indexed: 06/09/2023]
Abstract
The isolation of highly efficient methanotrophic communities is crucial for the optimization of methane bioconversion into products with a high market value such as polyhydroxyalkanoates (PHA). The research here presented aimed at enriching a methanotrophic consortium from two different inocula (Sphagnum peat moss (Sp) and Sphagnum and activated sludge (M)) able to accumulate PHA while efficiently oxidizing CH4. Moreover, the effect of the temperature and phosphorus limitation on the biodegradation rate of CH4 and the PHA accumulation potential was investigated. Higher CH4 degradation rates were obtained under P availability at increasing temperature (25, 30 and 37 °C). The biomass enriched from the mixed inoculum always exhibited a superior biodegradation performance regardless of the temperature (a maximum value of 84.3 ± 8.4 mg CH4 h-1 g biomass-1 was recorded at 37 °C). The results of the PHB production showed that phosphorus limitation is required to promote PHB accumulation, the highest PHB content being observed with the Sphagnum inoculum at 25 °C (13.6 ± 5.6%). The differential specialization of the microbial communities depending on the enrichment temperature supported the key role of this parameter on the results obtained. In all cases after the completion of the enrichment process and of the P limitation tests, Methylocystis, a type II methanotroph known for its ability to accumulate PHA, was the genus that became dominant (reaching percentages from 16 to 46% depending on the enrichment temperature). Thus, the results here obtained demonstrated for the first time the relevance of the temperature used for the enrichment of the methanotrophic bacteria to boost PHA production yields under P limiting condition, highlighting the importance of optimizing culture conditions to improve the cost-efficiency of bioprocesses based on using methane as the primary feedstock for the PHA industrial market.
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Affiliation(s)
- Rebeca Pérez
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, Valladolid University, Prado de la Magdalena, 5, Valladolid, Spain; Institute of Sustainable Processes, Valladolid University, Spain.
| | - Jesús Casal
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, Valladolid University, Prado de la Magdalena, 5, Valladolid, Spain
| | - Raúl Muñoz
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, Valladolid University, Prado de la Magdalena, 5, Valladolid, Spain; Institute of Sustainable Processes, Valladolid University, Spain
| | - Raquel Lebrero
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, Valladolid University, Prado de la Magdalena, 5, Valladolid, Spain; Institute of Sustainable Processes, Valladolid University, Spain
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36
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Venkiteshwaran K, Benn N, Seyedi S, Zitomer D. Methane yield and lag correlate with bacterial community shift following bioplastic anaerobic co-digestion. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.biteb.2019.100198] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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37
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Carere CR, McDonald B, Peach HA, Greening C, Gapes DJ, Collet C, Stott MB. Hydrogen Oxidation Influences Glycogen Accumulation in a Verrucomicrobial Methanotroph. Front Microbiol 2019; 10:1873. [PMID: 31474959 PMCID: PMC6706786 DOI: 10.3389/fmicb.2019.01873] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 07/29/2019] [Indexed: 11/23/2022] Open
Abstract
Metabolic flexibility in aerobic methane oxidizing bacteria (methanotrophs) enhances cell growth and survival in instances where resources are variable or limiting. Examples include the production of intracellular compounds (such as glycogen or polyhydroxyalkanoates) in response to unbalanced growth conditions and the use of some energy substrates, besides methane, when available. Indeed, recent studies show that verrucomicrobial methanotrophs can grow mixotrophically through oxidation of hydrogen and methane gases via respiratory membrane-bound group 1d [NiFe] hydrogenases and methane monooxygenases, respectively. Hydrogen metabolism is particularly important for adaptation to methane and oxygen limitation, suggesting this metabolic flexibility may confer growth and survival advantages. In this work, we provide evidence that, in adopting a mixotrophic growth strategy, the thermoacidophilic methanotroph, Methylacidiphilum sp. RTK17.1 changes its growth rate, biomass yields and the production of intracellular glycogen reservoirs. Under nitrogen-fixing conditions, removal of hydrogen from the feed-gas resulted in a 14% reduction in observed growth rates and a 144% increase in cellular glycogen content. Concomitant with increases in glycogen content, the total protein content of biomass decreased following the removal of hydrogen. Transcriptome analysis of Methylacidiphilum sp. RTK17.1 revealed a 3.5-fold upregulation of the Group 1d [NiFe] hydrogenase in response to oxygen limitation and a 4-fold upregulation of nitrogenase encoding genes (nifHDKENX) in response to nitrogen limitation. Genes associated with glycogen synthesis and degradation were expressed constitutively and did not display evidence of transcriptional regulation. Collectively these data further challenge the belief that hydrogen metabolism in methanotrophic bacteria is primarily associated with energy conservation during nitrogen fixation and suggests its utilization provides a competitive growth advantage within hypoxic habitats.
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Affiliation(s)
- Carlo R. Carere
- Department of Chemical and Process Engineering, University of Canterbury, Christchurch, New Zealand
| | - Ben McDonald
- Scion, Te Papa Tipu Innovation Park, Rotorua, New Zealand
| | - Hanna A. Peach
- Geomicrobiology Research Group, Department of Geothermal Sciences, GNS Science, Taupō, New Zealand
| | - Chris Greening
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
| | | | | | - Matthew B. Stott
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
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Luangthongkam P, Laycock B, Evans P, Lant P, Pratt S. Thermophilic production of poly(3-hydroxybutyrate-co-3-hydrovalerate) by a mixed methane-utilizing culture. N Biotechnol 2019; 53:49-56. [PMID: 31276815 DOI: 10.1016/j.nbt.2019.06.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 06/23/2019] [Accepted: 06/30/2019] [Indexed: 11/24/2022]
Abstract
The production of polyhydroxyalkanoates (PHAs) from methane is limited to mesophiles and thus suffers from high energy requirements for cooling. To address this issue, the use of thermophilic processes is gaining interest, as this strategy may deliver improved economic feasibility for PHA production. This study reports the first thermophilic PHA-producing culture grown on methane at 55 °C in fill-and-draw batch reactors. Harvested cells were incubated with various combinations of methane, propionic acid and valeric acid to assess their capacity for the synthesis of poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). Only PHB was produced when fed with methane alone. The addition of odd-carbon-number fatty acids resulted in higher PHA content with 3 HV fractions in the range of 15-99 mol%, depending on the types of fatty acids added. Acetic acid addition enhanced the synthesis of 3HB monomer, but not of 3 HV. On increasing the temperature to 58 °C, PHA productivity was not significantly affected.
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Affiliation(s)
- Pawarisa Luangthongkam
- School of Chemical Engineering, The University of Queensland, St. Lucia, Brisbane, Queensland, 4072, Australia
| | - Bronwyn Laycock
- School of Chemical Engineering, The University of Queensland, St. Lucia, Brisbane, Queensland, 4072, Australia
| | - Paul Evans
- The Australian Centre for Ecogenomics (ACE), The University of Queensland, St. Lucia, Brisbane, Queensland, 4072, Australia
| | - Paul Lant
- School of Chemical Engineering, The University of Queensland, St. Lucia, Brisbane, Queensland, 4072, Australia
| | - Steven Pratt
- School of Chemical Engineering, The University of Queensland, St. Lucia, Brisbane, Queensland, 4072, Australia.
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Bordel S, Rojas A, Muñoz R. Reconstruction of a Genome Scale Metabolic Model of the polyhydroxybutyrate producing methanotroph Methylocystis parvus OBBP. Microb Cell Fact 2019; 18:104. [PMID: 31170985 PMCID: PMC6554988 DOI: 10.1186/s12934-019-1154-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 06/01/2019] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Methylocystis parvus is a type II methanotroph characterized by its high specific methane degradation rate (compared to other methanotrophs of the same family) and its ability to accumulate up to 50% of its biomass in the form of poly-3-hydroxybutyrate (PHB) under nitrogen limiting conditions. This makes it a very promising cell factory. RESULTS This article reports the first Genome Scale Metabolic Model of M. parvus OBBP. The model is compared to Genome Scale Metabolic Models of the closely related methanotrophs Methylocystis hirsuta and Methylocystis sp. SC2. Using the reconstructed model, it was possible to predict the biomass yield of M. parvus on methane. The prediction was consistent with the observed experimental yield, under the assumption of the so called "redox arm mechanism" for methane oxidation. The co-consumption of stored PHB and methane was also modeled, leading to accurate predictions of biomass yields and oxygen consumption rates and revealing an anaplerotic role of PHB degradation. Finally, the model revealed that anoxic PHB consumption has to be coupled to denitrification, as no fermentation of PHB is allowed by the reconstructed metabolic model. CONCLUSIONS The "redox arm" mechanism appears to be a general characteristic of type II methanotrophs, versus type I methanotrophs that use the "direct coupling" mechanism. The co-consumption of stored PHB and methane was predicted to play an anaplerotic role replenishing the serine cycle with glyoxylate and the TCA cycle with succinyl-CoA, which allows the withdrawal of metabolic precursors for biosynthesis. The stored PHB can be also used as an energy source under anoxic conditions when coupled to denitrification.
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Affiliation(s)
- Sergio Bordel
- Departamento de Ingeniería Química y Tecnología del medio ambiente, Escuela de Ingenierías Industriales, Universidad de Valladolid, Valladolid, Spain.
- Institute of Sustainable Processes, Universidad de Valladolid, Valladolid, Spain.
| | - Antonia Rojas
- Biopolis S.L., Parc Cientific Universitat de Valencia, Paterna, Spain
| | - Raúl Muñoz
- Departamento de Ingeniería Química y Tecnología del medio ambiente, Escuela de Ingenierías Industriales, Universidad de Valladolid, Valladolid, Spain
- Institute of Sustainable Processes, Universidad de Valladolid, Valladolid, Spain
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Tveit AT, Hestnes AG, Robinson SL, Schintlmeister A, Dedysh SN, Jehmlich N, von Bergen M, Herbold C, Wagner M, Richter A, Svenning MM. Widespread soil bacterium that oxidizes atmospheric methane. Proc Natl Acad Sci U S A 2019; 116:8515-8524. [PMID: 30962365 PMCID: PMC6486757 DOI: 10.1073/pnas.1817812116] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The global atmospheric level of methane (CH4), the second most important greenhouse gas, is currently increasing by ∼10 million tons per year. Microbial oxidation in unsaturated soils is the only known biological process that removes CH4 from the atmosphere, but so far, bacteria that can grow on atmospheric CH4 have eluded all cultivation efforts. In this study, we have isolated a pure culture of a bacterium, strain MG08 that grows on air at atmospheric concentrations of CH4 [1.86 parts per million volume (p.p.m.v.)]. This organism, named Methylocapsa gorgona, is globally distributed in soils and closely related to uncultured members of the upland soil cluster α. CH4 oxidation experiments and 13C-single cell isotope analyses demonstrated that it oxidizes atmospheric CH4 aerobically and assimilates carbon from both CH4 and CO2 Its estimated specific affinity for CH4 (a0s) is the highest for any cultivated methanotroph. However, growth on ambient air was also confirmed for Methylocapsa acidiphila and Methylocapsa aurea, close relatives with a lower specific affinity for CH4, suggesting that the ability to utilize atmospheric CH4 for growth is more widespread than previously believed. The closed genome of M. gorgona MG08 encodes a single particulate methane monooxygenase, the serine cycle for assimilation of carbon from CH4 and CO2, and CO2 fixation via the recently postulated reductive glycine pathway. It also fixes dinitrogen and expresses the genes for a high-affinity hydrogenase and carbon monoxide dehydrogenase, suggesting that atmospheric CH4 oxidizers harvest additional energy from oxidation of the atmospheric trace gases carbon monoxide (0.2 p.p.m.v.) and hydrogen (0.5 p.p.m.v.).
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Affiliation(s)
- Alexander T Tveit
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, 9037 Tromsoe, Norway
| | - Anne Grethe Hestnes
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, 9037 Tromsoe, Norway
| | - Serina L Robinson
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, 9037 Tromsoe, Norway
| | - Arno Schintlmeister
- Center of Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria
| | - Svetlana N Dedysh
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of Russian Academy of Sciences, 117312 Moscow, Russia
| | - Nico Jehmlich
- Department of Molecular Systems Biology, Helmholtz Centre for Environmental Research-UFZ, 04318 Leipzig, Germany
| | - Martin von Bergen
- Department of Molecular Systems Biology, Helmholtz Centre for Environmental Research-UFZ, 04318 Leipzig, Germany
- Faculty of Life Sciences, Institute of Biochemistry, University of Leipzig, 04109 Leipzig, Germany
| | - Craig Herbold
- Center of Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria
| | - Michael Wagner
- Center of Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria
| | - Andreas Richter
- Center of Microbiology and Environmental Systems Science, Division of Terrestrial Ecosystem Research, University of Vienna, 1090 Vienna, Austria
| | - Mette M Svenning
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, 9037 Tromsoe, Norway;
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Bio-conversion of methane into high profit margin compounds: an innovative, environmentally friendly and cost-effective platform for methane abatement. World J Microbiol Biotechnol 2019; 35:16. [PMID: 30617555 DOI: 10.1007/s11274-018-2587-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 12/31/2018] [Indexed: 01/04/2023]
Abstract
Despite the environmental relevance of CH4 and forthcoming stricter regulations, the development of cost-efficient and environmentally friendly technologies for CH4 abatement is still limited. To date, one of the most promising solutions for the mitigation of this important GHG consists of the bioconversion of CH4 into bioproducts with a high profit margin. In this context, methanotrophs have been already proven as cell-factories of some of the most expensive products synthesized by microorganisms. In the case of ectoine (1000 $ kg-1), already described methanotrophic genera such as Methylomicrobium can accumulate up to 20% (ectoine wt-1) using methane as the only carbon source. Moreover, α-methanotrophs, such as Methylosynus and Methylocystis, are able to store bioplastic concentrations up to 50-60% of their total cell content. More than that, methanotrophs are one of the greatest potential producers of methanol and exopolysaccharides. Although this methanotrophic factory could be enhanced throughout metabolic engineering, the valorization of CH4 into valuable metabolites has been already consistently demonstrated under continuous and discontinuous mode, producing more than one compound in the same bioprocess, and using both, single strains and specific consortia. This review states the state-of-the-art of this innovative biotechnological platform by assessing its potential and current limitations.
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Zhang T, Zhou J, Wang X, Zhang Y. Poly-β-hydroxybutyrate Production by Methylosinus trichosporium OB3b at Different Gas-phase Conditions. IRANIAN JOURNAL OF BIOTECHNOLOGY 2019; 17:e1866. [PMID: 31457042 PMCID: PMC6697861 DOI: 10.21859/ijb.1866] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND The utilization of methane for production of Poly-β-hydroxybutyrate (PHB) not only cuts the emissions of greenhouse gases but also greatly reduces PHB production cost. OBJECTIVES The aim of this study was to determine the effects of gas-phase conditions on PHB production by Methylosinus trichosporium OB3b. MATERIALS AND METHODS Bacterial cultivation and PHB production were conducted in a series of sealed serum bottles. Nitrogen-free mineral salts medium was used to induce PHB production in the presence or absence of N2 in the headspace. RESULTS In the absence of N2, the highest PHB content (i.e., 52.9% of the dry cell weight with a PHB concentration of 814.3 mg.L-1) was obtained at a ratio of CH4:O2=2:1. Further study at different O2 concentrations with a fixed CH4 partial pressure in absence of N2 showed that PHB accumulation by methanotroph could be tolerated high oxygen partial pressure and its respond to the variation of the oxygen concentration depends on the methane partial pressure. In presence of N2, with headspace gas replenished only when oxygen was almost depleted, the degradation of intracellular PHB has appeared. In the regimen of updating headspace gas at the point when the PHB content began to decrease, the highest PHB content (i.e., 55.5% of the dry cell weight with 901.8 mg.L-1 PHB concentration and 12.5 mg.L-1.h-1PHB productivity) was obtained at 0.2 atm O2 and PHB accumulation was depressed with an oxygen concentration greater than 0.3 atm. CONCLUSIONS The methanotroph responses differentially to the increase in the oxygen partial pressure with regard to PHB accumulation either in the presence or in the absence of N2.
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Affiliation(s)
- Tingting Zhang
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, China
| | - Jiti Zhou
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science and Technology, Dalian University of Technology, Dalian, China
| | - Xiaowei Wang
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, China
| | - Yu Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science and Technology, Dalian University of Technology, Dalian, China
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Catalán AI, Malan AK, Ferreira F, Gill PR, Batista S. Propionic acid metabolism and poly-3-hydroxybutyrate-co-3-hydroxyvalerate production by a prpC mutant of Herbaspirillum seropedicae Z69. J Biotechnol 2018; 286:36-44. [DOI: 10.1016/j.jbiotec.2018.09.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 09/14/2018] [Accepted: 09/17/2018] [Indexed: 01/25/2023]
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La H, Hettiaratchi JPA, Achari G, Dunfield PF. Biofiltration of methane. BIORESOURCE TECHNOLOGY 2018; 268:759-772. [PMID: 30064899 DOI: 10.1016/j.biortech.2018.07.043] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/06/2018] [Accepted: 07/08/2018] [Indexed: 06/08/2023]
Abstract
The on-going annual increase in global methane (CH4) emissions can be largely attributed to anthropogenic activities. However, as more than half of these emissions are diffuse and possess a concentration less than 3% (v/v), physical-chemical treatments are inefficient as an abatement technology. In this regard, biotechnologies, such as biofiltration using methane-oxidizing bacteria, or methanotrophs, are a cost-effective and efficient means of combating diffuse CH4 emissions. In this review, a number of abiotic factors including temperature, pH, water content, packing material, empty-bed residence time, inlet gas flow rate, CH4 concentration, as well biotic factors, such as biomass development, are reviewed based on empirical findings on CH4 biofiltration studies that have been performed in the last decades.
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Affiliation(s)
- Helen La
- Department of Civil Engineering, Center for Environmental Engineering Research and Education (CEERE), University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4 Canada
| | - J Patrick A Hettiaratchi
- Department of Civil Engineering, Center for Environmental Engineering Research and Education (CEERE), University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4 Canada
| | - Gopal Achari
- Department of Civil Engineering, Center for Environmental Engineering Research and Education (CEERE), University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4 Canada.
| | - Peter F Dunfield
- Department of Biological Sciences, University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4 Canada
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45
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Yu WJ, Lee JW, Nguyen NL, Rhee SK, Park SJ. The characteristics and comparative analysis of methanotrophs reveal genomic insights into Methylomicrobium sp. enriched from marine sediments. Syst Appl Microbiol 2018; 41:415-426. [DOI: 10.1016/j.syapm.2018.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 05/04/2018] [Accepted: 05/04/2018] [Indexed: 10/16/2022]
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46
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Zaldívar Carrillo JA, Stein LY, Sauvageau D. Defining Nutrient Combinations for Optimal Growth and Polyhydroxybutyrate Production by Methylosinus trichosporium OB3b Using Response Surface Methodology. Front Microbiol 2018; 9:1513. [PMID: 30072960 PMCID: PMC6058025 DOI: 10.3389/fmicb.2018.01513] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/18/2018] [Indexed: 11/19/2022] Open
Abstract
Methane and methanol are common industrial by-products that can be used as feedstocks for the production of value-added products by methylotrophic bacteria. Alphaproteobacterial methanotrophs are known to produce and accumulate the biopolymer polyhydroxybutyrate (PHB) under conditions of nutrient starvation. The present study determined optimal production of biomass and PHB by Methylosinus trichosporium OB3b as a function of carbon source (methane or methanol), nitrogen source (ammonium or nitrate), and nitrogen-to-carbon ratio during growth. Statistical regression analysis with interactions was performed to assess the importance of each factor, and their respective interactions, on biomass and PHB production. Higher biomass concentrations were obtained with methane as carbon source and with ammonium as nitrogen source. The nitrogen source that favored PHB production was ammonium for methane-grown cells and nitrate for methanol-grown cells. Response surface methodology (RSM) was used to determine conditions leading to optimal biomass and PHB production. As an example, the optimal PHB concentration was predicted to occur when a mixture of 30% methane and 70% methanol (molar basis) was used as carbon source with nitrate as nitrogen source and a nitrogen-to-carbon molar ratio of 0.017. This was confirmed experimentally, with a PHB concentration of 48.7 ± 8.3 mg/L culture, corresponding to a cell content of 52.5 ± 6.3% (cell dry weight basis). Using RSM to simultaneously interrogate multiple variables toward optimized growth and production of biopolymer serves as a guide for establishing more efficient industrial conditions to convert single-carbon feedstocks into value-added products.
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Affiliation(s)
| | - Lisa Y Stein
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Dominic Sauvageau
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
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Methanotrophy across a natural permafrost thaw environment. ISME JOURNAL 2018; 12:2544-2558. [PMID: 29955139 PMCID: PMC6155033 DOI: 10.1038/s41396-018-0065-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 01/08/2018] [Accepted: 01/09/2018] [Indexed: 11/09/2022]
Abstract
The fate of carbon sequestered in permafrost is a key concern for future global warming as this large carbon stock is rapidly becoming a net methane source due to widespread thaw. Methane release from permafrost is moderated by methanotrophs, which oxidise 20-60% of this methane before emission to the atmosphere. Despite the importance of methanotrophs to carbon cycling, these microorganisms are under-characterised and have not been studied across a natural permafrost thaw gradient. Here, we examine methanotroph communities from the active layer of a permafrost thaw gradient in Stordalen Mire (Abisko, Sweden) spanning three years, analysing 188 metagenomes and 24 metatranscriptomes paired with in situ biogeochemical data. Methanotroph community composition and activity varied significantly as thaw progressed from intact permafrost palsa, to partially thawed bog and fully thawed fen. Thirteen methanotroph population genomes were recovered, including two novel genomes belonging to the uncultivated upland soil cluster alpha (USCα) group and a novel potentially methanotrophic Hyphomicrobiaceae. Combined analysis of porewater δ13C-CH4 isotopes and methanotroph abundances showed methane oxidation was greatest below the oxic-anoxic interface in the bog. These results detail the direct effect of thaw on autochthonous methanotroph communities, and their consequent changes in population structure, activity and methane moderation potential.
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Guo W, Li D, He R, Wu M, Chen W, Gao F, Zhang Z, Yao Y, Yu L, Chen S. Synthesizing value-added products from methane by a new Methylomonas. J Appl Microbiol 2018; 123:1214-1227. [PMID: 28888065 DOI: 10.1111/jam.13581] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 07/23/2017] [Accepted: 08/11/2017] [Indexed: 01/08/2023]
Abstract
AIMS Methane and methanol are potential carbon sources of industrial micro-organisms in addition to crop-derived bio-carbon sources. Methanotrophs that can utilize these simple, stable and large amounts chemicals are expected to be developed into 'cell factories' for the production of specific chemicals. In this study, a methanotroph that can synthesize lycopene, C30 carotenoid and exopolysaccharides (EPS) with relative better performances from C1 substrates was isolated, and its performances were evaluated. METHODS AND RESULTS The isolated strain was identified as Methylomonas sp. ZR1 based on 16S rRNA sequence analysis. Its maximum specific growth rate achieved 0·200 h-1 under flask culture conditions, and 0·386 h-1 in bubble column reactors. ZR1 was able to utilize 35 g l-1 of methanol and even exhibited slight growth in the presence of 40 g l-1 of methanol. Furthermore, ZR1 was proved to synthesize lycopene (C40 carotenoids) besides the C30 carotenoids through HPLC-DAD and HPLC-MS/MS analysis methods. Its carotenoid extracts exhibited excellent antioxidative activities measured by the ABTS+ method. Plenty of polysaccharides were also synthesized by ZR1, the components of the polysaccharides were identified as glucose, mannose and galactose with a proportion of 1 : 2 : 1 by GC-MS, and its yield achieved 0·13 g g-1 cell dry weight. CONCLUSIONS The isolated strain has great potential for the production of value-added bioproducts from C1 compounds because of its excellent C1 substrate utilizing abilities and its abilities to naturally synthesize lycopene, C30 carotenoids and EPS. SIGNIFICANCE AND IMPACT OF THE STUDY In this study, we isolated a fast-growing methanotroph, its C1 carbon substrate utilizing ability is excellent in comparison with reported methanotrophs. Furthermore, besides polysaccharides and C30 carotenoids which were commonly synthesized by methanotrophs, our findings suggested that C40 lycopene could also be naturally synthesized from methane by methanotrophs.
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Affiliation(s)
- W Guo
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Science, Tianjin, China
| | - D Li
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Science, Tianjin, China
| | - R He
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Science, Tianjin, China
| | - M Wu
- Food and Environmental Department, Dalian University of Technology, Panjin, China
| | - W Chen
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Science, Tianjin, China
| | - F Gao
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Science, Tianjin, China
| | - Z Zhang
- Technology Support Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Science, Tianjin, China
| | - Y Yao
- Technology Support Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Science, Tianjin, China
| | - L Yu
- Department of Biological Systems Engineering, Washington State University, Pullman, WA, USA
| | - S Chen
- Tianjin Key Laboratory for Industrial Biological Systems and Bioprocessing Engineering, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Science, Tianjin, China
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Sheets JP, Lawson K, Ge X, Wang L, Yu Z, Li Y. Development and evaluation of a trickle bed bioreactor for enhanced mass transfer and methanol production from biogas. Biochem Eng J 2017. [DOI: 10.1016/j.bej.2017.03.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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50
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Chidambarampadmavathy K, Karthikeyan OP, Huerlimann R, Maes GE, Heimann K. Response of mixed methanotrophic consortia to different methane to oxygen ratios. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 61:220-228. [PMID: 27876290 DOI: 10.1016/j.wasman.2016.11.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 08/31/2016] [Accepted: 11/04/2016] [Indexed: 05/22/2023]
Abstract
Methane (CH4) and oxygen (air) concentrations affect the CH4 oxidation capacity (MOC) and mixed methanotrophic community structures in compost (fresh) and landfill (age old) top cover soils. A change in the mixed methanotrophic community structure in response has implications for landfill CH4 bio-filter remediation and possible bio-product outcomes (i.e., fatty acid methyl esters (FAME) content and profiles and polyhydroxybutyrate (PHB) contents). Therefore the study aimed to evaluate the effect of variable CH4 to oxygen ratios (10-50% CH4 in air) on mixed methanotrophic community structures enriched from landfill top cover (LB) and compost soils (CB) and to quantify flow on impacts on MOC, total FAME contents and profiles, and PHB accumulation. A stable consortium developed achieving average MOCs of 3.0±0.12, 4.1±0.26, 6.9±0.7, 7.6±1.3 and 9.2±1.2mgCH4g-1DWbiomassh-1 in LB and 2.9±0.04, 5.05±0.32, 6.7±0.31, 7.9±0.61 and 8.6±0.48mgCH4g-1DWbiomassh-1 in CB for a 20day cultivation period at 10, 20, 30, 40 and 50% CH4, respectively. CB at 10% CH4 had a maximal FAME content of 40.5±0.8mgFAMEg-1DWbiomass, while maximal PHB contents (25mgg-1DWbiomass) was observed at 40% CH4 in LB. Despite variable CH4/O2 ratios, the mixed methanotrophic community structures in both LB and CB were relatively stable, dominated by Methylosarcina sp., and Chryseobacterium, suggesting that a resilient consortium had formed which can now be tested in bio-filter operations for CH4 mitigations in landfills.
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Affiliation(s)
- K Chidambarampadmavathy
- College of Science and Engineering, James Cook University, Townsville 4811, Queensland, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville 4811, Queensland, Australia
| | - O P Karthikeyan
- College of Science and Engineering, James Cook University, Townsville 4811, Queensland, Australia; Comparative Genomics Centre, James Cook University, Townsville 4811, Queensland, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville 4811, Queensland, Australia; Sino-Forest Applied Research Centre for Pearl River Delta Environment (ARCPE), Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region
| | - R Huerlimann
- College of Science and Engineering, James Cook University, Townsville 4811, Queensland, Australia; Comparative Genomics Centre, James Cook University, Townsville 4811, Queensland, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville 4811, Queensland, Australia
| | - G E Maes
- College of Science and Engineering, James Cook University, Townsville 4811, Queensland, Australia; Comparative Genomics Centre, James Cook University, Townsville 4811, Queensland, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville 4811, Queensland, Australia; Center for Human Genetics, Genomics Core, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - K Heimann
- College of Science and Engineering, James Cook University, Townsville 4811, Queensland, Australia; Comparative Genomics Centre, James Cook University, Townsville 4811, Queensland, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville 4811, Queensland, Australia; Centre for Bio-discovery and Molecular Development of Therapeutics, James Cook University, Townsville 4811, Queensland, Australia.
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