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Ozsefil IC, Miraloglu IH, Ozbayram EG, Ince B, Ince O. Bioaugmentation of anaerobic digesters with the enriched lignin-degrading microbial consortia through a metagenomic approach. CHEMOSPHERE 2024; 355:141831. [PMID: 38561162 DOI: 10.1016/j.chemosphere.2024.141831] [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: 12/16/2023] [Revised: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 04/04/2024]
Abstract
The recalcitrance of lignin impedes the efficient utilization of lignocellulosic biomass, hindering the efficient production of biogas and value-added materials. Despite the emergence of anaerobic digestion as a superior alternative to the aerobic method for lignin processing, achieving its feasibility requires thorough characterization of lignin-degrading anaerobic microorganisms, assessment of their biomethane production potential, and a comprehensive understanding of the degradation pathway. This study aimed to address the aforementioned necessities by bioaugmenting seed sludge with three distinct enriched lignin-degrading microbial consortia at both 25 °C and 37 °C. Enhanced biomethane yields was detected in the bioaugmented digesters, while the highest production was observed as 188 mLN CH4 gVS-1 in digesters operated at 37 °C. Moreover, methane yield showed a significant improvement in the samples at 37 °C ranging from 110% to 141% compared to the control, demonstrating the efficiency of the enriched lignin-degrading microbial community. Temperature and substrate were identified as key factors influencing microbial community dynamics. The observation that microbial communities tended to revert to the initial state after lignin depletion, indicating the stability of the overall microbiota composition in the digesters, is a promising finding for large-scale studies. Noteworthy candidates for lignin degradation, including Sporosarcina psychrophila, Comamonas aquatica, Shewanella baltica, Pseudomonas sp. C27, and Brevefilum fermentans were identified in the bioaugmented samples. PICRUSt2 predictions suggest that the pathway and specific proteins involved in anaerobic lignin degradation might share similarities with those engaged in the degradation of aromatic compounds.
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Affiliation(s)
- Ibrahim Cem Ozsefil
- Bogazici University, Institute of Environmental Sciences, Bebek, 34342, Istanbul, Turkey
| | | | - E Gozde Ozbayram
- Istanbul University, Faculty of Aquatic Sciences, Department of Marine and Freshwater Resources Management, Fatih, 34134, Istanbul, Turkey
| | - Bahar Ince
- Bogazici University, Institute of Environmental Sciences, Bebek, 34342, Istanbul, Turkey
| | - Orhan Ince
- Department of Environmental Engineering, Faculty of Civil Engineering, Istanbul Technical University, Maslak, 34396, Istanbul, Turkey
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2
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Ahmad A, Ghufran R. Microbial granules on reactors performance during organic butyrate digestion: clean production. Crit Rev Biotechnol 2023; 43:1236-1256. [PMID: 36130802 DOI: 10.1080/07388551.2022.2103641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 06/09/2022] [Indexed: 11/03/2022]
Abstract
This critical review for anaerobic degradation of complex organic compounds like butyrate using reactors has been enormously applied for biogas production. Biogas production rate has a great impact on: reactor granulation methanogenesis, nutrient content, shear velocity, organic loading and loss of nutrients taking place in the reactor continuously. Various technologies have been applied to closed anaerobic reactors to improve biogas production and treatment efficiency. Recent reviews showed that the application of closed anaerobic reactors can accelerate the degradation of organics like volatile fatty acid-butyrate and affect microbial biofilm formation by increasing the number of methanogens and increase methane production 16.5 L-1 CH4 L-1 POME-1. The closed anaerobic reactors with stable microbial biofilm and established organic load were responsible for the improvement of the reactor and methane production. The technology mentioned in this review can be used to monitor biogas concentration, which directly correlates to organic concentrations. This review attempts to evaluate interactions among the: degradation of organics, closed anaerobic reactors system, and microbial granules. This article provides a useful picture for the improvement of the degradation of organic butyrate for COD removal, biogas and methane production in an anaerobic closed reactor.
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Affiliation(s)
- Anwar Ahmad
- Civil and Environmental Engineering Department, College of Engineering and Architecture, University of Nizwa, Nizwa, Sultanate of Oman
| | - Roomana Ghufran
- Faculty of Civil Engineering and Earth Resources, University Malaysia Pahang (UMP) Lebuhraya Tun Razak, Gambang, Malaysia
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3
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Gállego-Bravo AK, García-Mena J, Piña-Escobedo A, López-Jiménez G, Gutiérrez-Castillo ME, Tovar-Gálvez LR. Monitoring of a microbial community during bioaugmentation with hydrogenotrophic methanogens to improve methane yield of an anaerobic digestion process. Biotechnol Lett 2023; 45:1339-1353. [PMID: 37535136 PMCID: PMC10460350 DOI: 10.1007/s10529-023-03414-7] [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: 12/14/2022] [Revised: 06/12/2023] [Accepted: 06/26/2023] [Indexed: 08/04/2023]
Abstract
Methane production by microbial fermentation of municipal waste is a challenge for better yield processes. This work describes the characterization of a hydrogenotrophic methanogen microbial community used in a bioaugmentation procedure to improve the methane yield in a thermophilic anaerobic process, digesting the organic fraction of municipal solid waste. The performance of the bioaugmentation was assessed in terms of methane production and changes in the microbial community structure. The results showed that bioaugmentation slightly improved the cumulative methane yield (+ 4%) in comparison to the control, and its use led to an acceleration of the methanogenesis stage. We observed associated significant changes in the relative abundance of taxa and their interactions, using high throughput DNA sequencing of V3-16S rRNA gene libraries, where the abundance of the archaeal hydrogenotrophic genus Methanoculleus (class Methanomicrobia, phylum Euryarchaeota) and the bacterial order MBA08 (class Clostridia, phylum Firmicutes) were dominant. The relevant predicted metabolic pathways agreed with substrate degradation and the anaerobic methanogenic process. The purpose of the study was to evaluate the effect of the addition of hydrogenotrophic methanogens in the generation of methane, while treating organic waste through anaerobic digestion.
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Affiliation(s)
- Aixa Kari Gállego-Bravo
- Instituto Politécnico Nacional, Centro Mexicano Para la Producción más Limpia, Av. Acueducto s/n, 07340 Ciudad de Mexico, Mexico
| | - Jaime García-Mena
- Departamento de Genética y Biología Molecular, Cinvestav, Av. Instituto Politécnico Nacional 2508, 07360 Ciudad de México, Mexico
| | - Alberto Piña-Escobedo
- Departamento de Genética y Biología Molecular, Cinvestav, Av. Instituto Politécnico Nacional 2508, 07360 Ciudad de México, Mexico
| | - Gloria López-Jiménez
- Departamento de Ciencias Básicas, Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto s/n, 07340 Ciudad de Mexico, Mexico
| | - María Eugenia Gutiérrez-Castillo
- Instituto Politécnico Nacional, Centro Interdisciplinario de Investigaciones y Estudios Sobre Medio Ambiente y Desarrollo, Calle 30 de Junio de 1520 s/n, 07340 Ciudad de Mexico, Mexico
| | - Luis Raúl Tovar-Gálvez
- Instituto Politécnico Nacional, Centro Interdisciplinario de Investigaciones y Estudios Sobre Medio Ambiente y Desarrollo, Calle 30 de Junio de 1520 s/n, 07340 Ciudad de Mexico, Mexico
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Obi LU, Roopnarain A, Tekere M, Adeleke RA. Bioaugmentation potential of inoculum derived from anaerobic digestion feedstock for enhanced methane production using water hyacinth. World J Microbiol Biotechnol 2023; 39:153. [PMID: 37032393 PMCID: PMC10083160 DOI: 10.1007/s11274-023-03600-9] [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: 04/19/2022] [Accepted: 04/02/2023] [Indexed: 04/11/2023]
Abstract
The utilisation of water hyacinth for production of biogas is considered to be a solution to both its control and the global renewable energy challenge. In this instance, an investigation was conducted to evaluate the potential of water hyacinth inoculum to enhance methane production during anaerobic digestion (AD). Chopped whole water hyacinth (10% (w/v)) was digested to prepare an inoculum consisting mainly of water hyacinth indigenous microbes. The inoculum was incorporated in the AD of freshly chopped whole water hyacinth to set up different ratios of water hyacinth inoculum and water hyacinth mixture with appropriate controls. The results of batch tests with water hyacinth inoculum showed a maximal cumulative volume of 211.67 ml of methane after 29 days of AD as opposed to 88.6 ml of methane generated from the control treatment without inoculum. In addition to improving methane production, inclusion of water hyacinth inoculum reduced the electrical conductivity (EC) values of the resultant digestate, and, amplification of nifH and phoD genes in the digestate accentuates it as a potential soil ameliorant. This study provides an insight into the potential of water hyacinth inoculum to enhance methane production and contribute to the feasibility of the digestate as a soil fertility enhancer.
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Affiliation(s)
- Linda U Obi
- Department of Environmental Sciences, University of South Africa, Johannesburg, South Africa.
- Microbiology and Environmental Biotechnology Research Group, Institute for Soil, Climate and Water, Agricultural Research Council, Arcadia, Pretoria, 0083, South Africa.
- Department of Biological Sciences, Godfrey Okoye University, Jideofor St, Thinkers Corner, Enugu, 400001, Enugu State, Nigeria.
| | - Ashira Roopnarain
- Microbiology and Environmental Biotechnology Research Group, Institute for Soil, Climate and Water, Agricultural Research Council, Arcadia, Pretoria, 0083, South Africa
| | - Memory Tekere
- Department of Environmental Sciences, University of South Africa, Johannesburg, South Africa
| | - Rasheed A Adeleke
- Microbiology and Environmental Biotechnology Research Group, Institute for Soil, Climate and Water, Agricultural Research Council, Arcadia, Pretoria, 0083, South Africa
- Unit for Environment Science and Management, North-West University (Potchefstroom Campus), Potchefstroom, South Africa
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Ma L, Wang X, Zhou J, Lü X. Degradation of switchgrass by Bacillus subtilis 1AJ3 and expression of a beta-glycoside hydrolase. Front Microbiol 2022; 13:922371. [PMID: 35966659 PMCID: PMC9374367 DOI: 10.3389/fmicb.2022.922371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
Increasing demand for carbon neutrality has led to the development of new techniques and modes of low carbon production. The utilization of microbiology to convert low-cost renewable resources into more valuable chemicals is particularly important. Here, we investigated the ability of a cellulolytic bacterium, Bacillus subtilis 1AJ3, in switchgrass lignocellulose degradation. After 5 days of culture with the strain under 37°C, cellulose, xylan, and acid-insoluble lignin degradation rates were 16.13, 14.24, and 13.91%, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis and field emission scanning electron microscopy (FE-SEM) indicated that the lignin and surface of switchgrass were degraded after incubation with the bacterial strain. Strain 1AJ3 can grow well below 60°C, which satisfies the optimum temperature (50°C) condition of most cellulases; subsequent results emphasize that acid-heat incubation conditions increase the reducing sugar content in a wide range of cellulosic biomass degraded by B. subtilis 1AJ3. To obtain more reducing sugars, we focused on β-glycoside hydrolase, which plays an important role in last steps of cellulose degradation to oligosaccharides. A β-glycoside hydrolase (Bgl-16A) was characterized by cloning and expression in Escherichia coli BL21 and further determined to belong to glycoside hydrolase (GH) 16 family. The Bgl-16A had an enzymatic activity of 365.29 ± 10.43 U/mg, and the enzyme's mode of action was explained by molecular docking. Moreover, the critical influence on temperature (50°C) of Bgl-16A also explained the high-efficiency degradation of biomass by strain under acid-heat conditions. In terms of potential applications, both the strain and the recombinant enzyme showed that coffee grounds would be a suitable and valuable substrate. This study provides a new understanding of cellulose degradation by B. subtilis 1AJ3 that both the enzyme action mode and optimum temperature limitation by cellulases could impact the degradation. It also gave new sight to unique advantage utilization in the industrial production of green manufacturing.
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Affiliation(s)
- Lingling Ma
- Science Center for Future Foods, Jiangnan University, Wuxi, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, Wuxi, China
- Laboratory of Bioresources, College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Xin Wang
- Laboratory of Bioresources, College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Jingwen Zhou
- Science Center for Future Foods, Jiangnan University, Wuxi, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, Wuxi, China
| | - Xin Lü
- Laboratory of Bioresources, College of Food Science and Engineering, Northwest A&F University, Xianyang, China
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Mohd Johari SA, Mahad Nasir MM, Ali S, Hamza A, Aleem W, Ameen M, Aqsha A. Recent Technology Developments in Biogas Production from Waste Materials in Malaysia. CHEMBIOENG REVIEWS 2021. [DOI: 10.1002/cben.202100016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Siti Aminah Mohd Johari
- Universiti Teknologi PETRONAS Higher Institution Centre of Excellence (HiCoE) Centre for Biofuel and Biochemical Research (CBBR) Institute of Sustainable Living (ISB) 32610 Seri Iskandar Malaysia
- Universiti Teknologi PETRONAS Department of Chemical Engineering 32610 Seri Iskandar Malaysia
| | | | - Sundas Ali
- University of Punjab Institute of Chemical Engineering and Technology 54590 Lahore Pakistan
| | - Ameer Hamza
- University of Punjab Institute of Chemical Engineering and Technology 54590 Lahore Pakistan
| | - Waqas Aleem
- Mir Chakar Khan Rind University of Technology Department of Chemical Engineering & Technology Dera Ghazi Khan Pakistan
| | - Mariam Ameen
- Universiti Teknologi PETRONAS Higher Institution Centre of Excellence (HiCoE) Centre for Biofuel and Biochemical Research (CBBR) Institute of Sustainable Living (ISB) 32610 Seri Iskandar Malaysia
- Universiti Teknologi PETRONAS Department of Chemical Engineering 32610 Seri Iskandar Malaysia
| | - Aqsha Aqsha
- Institut Teknologi Bandung Department of Bioenergy and Chemurgy Engineering, Faculty of Technology Industry 45363 Bandung Indonesia
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Olatunji KO, Ahmed NA, Ogunkunle O. Optimization of biogas yield from lignocellulosic materials with different pretreatment methods: a review. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:159. [PMID: 34281615 PMCID: PMC8287798 DOI: 10.1186/s13068-021-02012-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 07/09/2021] [Indexed: 05/10/2023]
Abstract
Population increase and industrialization has resulted in high energy demand and consumptions, and presently, fossil fuels are the major source of staple energy, supplying 80% of the entire consumption. This has contributed immensely to the greenhouse gas emission and leading to global warming, and as a result of this, there is a tremendous urgency to investigate and improve fresh and renewable energy sources worldwide. One of such renewable energy sources is biogas that is generated by anaerobic fermentation that uses different wastes such as agricultural residues, animal manure, and other organic wastes. During anaerobic digestion, hydrolysis of substrates is regarded as the most crucial stage in the process of biogas generation. However, this process is not always efficient because of the domineering stableness of substrates to enzymatic or bacteria assaults, but substrates' pretreatment before biogas production will enhance biogas production. The principal objective of pretreatments is to ease the accessibility of the enzymes to the lignin, cellulose, and hemicellulose which leads to degradation of the substrates. Hence, the use of pretreatment for catalysis of lignocellulose substrates is beneficial for the production of cost-efficient and eco-friendly process. In this review, we discussed different pretreatment technologies of hydrolysis and their restrictions. The review has shown that different pretreatments have varying effects on lignin, cellulose, and hemicellulose degradation and biogas yield of different substrate and the choice of pretreatment technique will devolve on the intending final products of the process.
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Affiliation(s)
- Kehinde Oladoke Olatunji
- Department of Mechanical Engineering Science, Faculty of Engineering and Built Environment, University of Johannesburg, Johannesburg, South Africa.
| | - Noor A Ahmed
- Department of Mechanical Engineering Science, Faculty of Engineering and Built Environment, University of Johannesburg, Johannesburg, South Africa
| | - Oyetola Ogunkunle
- Department of Mechanical Engineering Science, Faculty of Engineering and Built Environment, University of Johannesburg, Johannesburg, South Africa
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8
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Cayetano RDA, Park J, Kim GB, Jung JH, Kim SH. Enhanced anaerobic digestion of waste-activated sludge via bioaugmentation strategy-Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt2) analysis through hydrolytic enzymes and possible linkage to system performance. BIORESOURCE TECHNOLOGY 2021; 332:125014. [PMID: 33839513 DOI: 10.1016/j.biortech.2021.125014] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/13/2021] [Accepted: 03/13/2021] [Indexed: 06/12/2023]
Abstract
In this study, anaerobic digestion of waste-activated sludge was bioaugmented with hydrolytic bacteria, Bacteroidetes uniformis (Bacteroidetes, B) and Clostridium sp. (Firmicutes, F) at various dosages. Bioaugmentation resulted in enhanced methane conversion of waste-activated sludge. The highest methane yield of 298.1 mL CH4/g-COD, 85.2% COD conversion efficiency was obtained when Bacteroidetes uniformis and Clostridium sp. were augmented at 100 and 900 CFU/mL, respectively. The microbial community analysis demonstrated that bioaugmentation increased the proportion of Bacteroidetes, Firmicutes, and Proteobacteria. Furthermore, at the highest methane yield, the principal methanogenic pathway was altered from acetoclastic to a mixture of hydrogenotrophic and acetoclastic; the major species shifted from Methanosaeta concilii to Methanobacterium subterraneum. Predicted gene analysis revealed that increased expression of hydrolases resulted in enhanced methane conversion through bioaugmentation.
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Affiliation(s)
- Roent Dune A Cayetano
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Jungsu Park
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Gi-Beom Kim
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Ju-Hyeong Jung
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Sang-Hyoun Kim
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea.
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Murali N, Srinivas K, Ahring BK. Increasing the Production of Volatile Fatty Acids from Corn Stover Using Bioaugmentation of a Mixed Rumen Culture with Homoacetogenic Bacteria. Microorganisms 2021; 9:337. [PMID: 33567655 PMCID: PMC7914532 DOI: 10.3390/microorganisms9020337] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 01/29/2021] [Accepted: 02/04/2021] [Indexed: 12/03/2022] Open
Abstract
Volatile fatty acids (VFA) are industrially versatile chemicals and have a major market. Although currently produced from petrochemicals, chemical industries are moving towards more bio-based VFA produced from abundant, cheap and renewable sources such as lignocellulosic biomass. In this study, we examined the effect of bioaugmentation with homoacetogenic bacteria for increasing VFA production in lignocellulose fermentation process. The central hypothesis of this study was that inhibition of methanogenesis in an in vitro rumen bioreactor fed with lignocellulosic biomass hydrolysate increases the hydrogen partial pressure, which can be redirected towards increased VFA production, particularly acetic acid, through targeted bioaugmentation with known homoacetogenic bacteria. In this study, methanogenesis during ruminal fermentation of wet exploded corn stover was initially inhibited with 10 mM of 2-bromoethanesulfonate (BES), followed by bioaugmentation with either Acetitomaculum ruminis and Acetobacterium woodii in two separate bioreactors. During the inhibition phase, we found that addition of BES decreased the acetic acid yield by 24%, while increasing headspace hydrogen from 1% to 60%. After bioaugmentation, the headspace hydrogen was consumed in both bioreactors and the concentration of acetic acids increased 45% when A. ruminis was added and 70% with A. woodii added. This paper demonstrates that mixed microbial fermentation can be manipulated to increase VFA production through bioaugmentation.
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Affiliation(s)
- Nanditha Murali
- Department of Chemical Engineering, Voiland College of Engineering and Architecture, Washington State University, Pullman, WA 99163, USA; (N.M.); (K.S.)
- Bio-Products, Sciences and Engineering Laboratory, Washington State University, Richland, WA 99354, USA
| | - Keerthi Srinivas
- Department of Chemical Engineering, Voiland College of Engineering and Architecture, Washington State University, Pullman, WA 99163, USA; (N.M.); (K.S.)
- Bio-Products, Sciences and Engineering Laboratory, Washington State University, Richland, WA 99354, USA
| | - Birgitte K. Ahring
- Department of Chemical Engineering, Voiland College of Engineering and Architecture, Washington State University, Pullman, WA 99163, USA; (N.M.); (K.S.)
- Bio-Products, Sciences and Engineering Laboratory, Washington State University, Richland, WA 99354, USA
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99163, USA
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Obi LU, Tekere M, Roopnarain A, Sanko T, Maguvu TE, Bezuidenhout CC, Adeleke RA. Whole genome sequence of Serratia marcescens 39_H1, a potential hydrolytic and acidogenic strain. ACTA ACUST UNITED AC 2020; 28:e00542. [PMID: 33102161 PMCID: PMC7569290 DOI: 10.1016/j.btre.2020.e00542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/27/2020] [Accepted: 10/09/2020] [Indexed: 11/28/2022]
Abstract
Serratia marcescens 39_H1 could enhance the hydrolysis of lignocellulosic biomass. Serratia marcescens 39_H1 is a plant growth promoting organism. Genome analysis showed diverse potential biotechnological application of organism. This is an original report on the hydrolytic and acidogenic attributes ofSerratia marcescens 39_H1 for biogas production.
Here, we report a high quality annotated draft genome of Serratia marcescens 39_H1, a Gram-negative facultative anaerobe that was isolated from an anaerobic digester. The strain exhibited hydrolytic/acidogenic properties by significantly improving methane production when used as a single isolate inoculum during anaerobic digestion of water hyacinth and cow dung. The total genome size of the isolate was 5,106,712 bp which corresponds to an N50 of 267,528 and G + C content of 59.7 %. Genome annotation with the NCBI Prokaryotic Genome Annotation Pipeline (PGAP) predicted a total of 4,908 genes of which 4,755 were protein coding genes; there were no plasmids detected. A number of genes associated with hydrolytic/acidogenic activities as well as other metabolic activities were identified and discussed.
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Affiliation(s)
- Linda U Obi
- Department of Environmental Sciences, University of South Africa, Johannesburg, South Africa.,Microbiology and Environmental Biotechnology Research Group, Institute for Soil, Climate and Water, Agricultural Research Council, Arcadia, 0083, Pretoria, South Africa
| | - Memory Tekere
- Department of Environmental Sciences, University of South Africa, Johannesburg, South Africa
| | - Ashira Roopnarain
- Microbiology and Environmental Biotechnology Research Group, Institute for Soil, Climate and Water, Agricultural Research Council, Arcadia, 0083, Pretoria, South Africa
| | - Tomasz Sanko
- Unit for Environment Sciences and Management, North-West University (Potchefstroom Campus), Potchefstroom, South Africa
| | - Tawanda E Maguvu
- Unit for Environment Sciences and Management, North-West University (Potchefstroom Campus), Potchefstroom, South Africa
| | - Cornelius C Bezuidenhout
- Unit for Environment Sciences and Management, North-West University (Potchefstroom Campus), Potchefstroom, South Africa
| | - Rasheed A Adeleke
- Microbiology and Environmental Biotechnology Research Group, Institute for Soil, Climate and Water, Agricultural Research Council, Arcadia, 0083, Pretoria, South Africa.,Unit for Environment Sciences and Management, North-West University (Potchefstroom Campus), Potchefstroom, South Africa
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Mahmod SS, Azahar AM, Luthfi AAI, Abdul PM, Mastar MS, Anuar N, Takriff MS, Jahim JMD. Potential Utilisation of Dark-Fermented Palm Oil Mill Effluent in Continuous Production of Biomethane by Self-Granulated Mixed Culture. Sci Rep 2020; 10:9167. [PMID: 32514030 PMCID: PMC7280187 DOI: 10.1038/s41598-020-65702-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 04/22/2020] [Indexed: 01/03/2023] Open
Abstract
Two-stage anaerobic digestion of palm oil mill effluent (POME) is a promising method for converting the waste from the largest agricultural industry in Southeast Asia into a clean and sustainable energy. This study investigates the degradation of acid-rich effluent from the dark fermentation stage for the production of biomethane (BioCH4) in a 30-L continuous stirred-tank reactor (CSTR). The continuous methanogenic process was operated with varied HRTs (10 - 1 day) and OLRs (4.6-40.6 gCOD/L.d-1) under thermophilic conditions. Methanothermobacter sp. was the dominant thermophilic archaea that was responsible for the production rate of 4.3 LCH4/LPOME.d-1 and methane yield of 256.77 LCH4kgCOD at HRT of 2 d, which is the lowest HRT reported in the literature. The process was able to digest 85% and 64% of the initial POME's COD and TSS, respectively. The formation of methane producing granules (MPG) played a pivotal role in sustaining the efficient and productive anaerobic system. We report herein that the anaerobic digestion was not only beneficial in reducing the contaminants in the liquid effluent, but generating BioCH4 gas with a positive net energy gain of 7.6 kJ/gCOD.
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Affiliation(s)
- Safa Senan Mahmod
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
| | - Azratul Madihah Azahar
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
| | - Abdullah Amru Indera Luthfi
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
| | - Peer Mohamed Abdul
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
- Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Mohd Shahbudin Mastar
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
- Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Nurina Anuar
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
- Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Mohd Sobri Takriff
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
- Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Jamaliah M D Jahim
- Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia.
- Chemical Engineering Programme, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia.
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David A, Tripathi AK, Sani RK. Acetate Production from Cafeteria Wastes and Corn Stover Using a Thermophilic Anaerobic Consortium: A Prelude Study for the Use of Acetate for the Production of Value-Added Products. Microorganisms 2020; 8:E353. [PMID: 32131386 PMCID: PMC7143096 DOI: 10.3390/microorganisms8030353] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 02/25/2020] [Accepted: 02/28/2020] [Indexed: 11/16/2022] Open
Abstract
Efficient and sustainable biochemical production using low-cost waste assumes considerable industrial and ecological importance. Solid organic wastes (SOWs) are inexpensive, abundantly available resources and their bioconversion to volatile fatty acids, especially acetate, aids in relieving the requirements of pure sugars for microbial biochemical productions in industries. Acetate production from SOW that utilizes the organic carbon of these wastes is used as an efficient solid waste reduction strategy if the environmental factors are optimized. This study screens and optimizes influential factors (physical and chemical) for acetate production by a thermophilic acetogenic consortium using two SOWs-cafeteria wastes and corn stover. The screening experiment revealed significant effects of temperature, bromoethane sulfonate, and shaking on acetate production. Temperature, medium pH, and C:N ratio were further optimized using statistical optimization with response surface methodology. The maximum acetate concentration of 8061 mg L-1 (>200% improvement) was achieved at temperature, pH, and C:N ratio of 60 °C, 6, 25, respectively, and acetate accounted for more than 85% of metabolites. This study also demonstrated the feasibility of using acetate-rich fermentate (obtained from SOWs) as a substrate for the growth of industrially relevant yeast Yarrowia lipolytica, which can convert acetate into higher-value biochemicals.
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Affiliation(s)
- Aditi David
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA; (A.D.); (A.K.T.)
| | - Abhilash Kumar Tripathi
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA; (A.D.); (A.K.T.)
| | - Rajesh Kumar Sani
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA; (A.D.); (A.K.T.)
- BuG ReMeDEE Consortium, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
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Ma L, Zhao Y, Meng L, Wang X, Yi Y, Shan Y, Liu B, Zhou Y, Lü X. Isolation of Thermostable Lignocellulosic Bacteria From Chicken Manure Compost and a M42 Family Endocellulase Cloning From Geobacillus thermodenitrificans Y7. Front Microbiol 2020; 11:281. [PMID: 32174898 PMCID: PMC7054444 DOI: 10.3389/fmicb.2020.00281] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 02/07/2020] [Indexed: 01/01/2023] Open
Abstract
The composting ecosystem provides a potential resource for finding new microorganisms with the capability for cellulose degradation. In the present study, Congo red method was used for the isolating of thermostable lignocellulose-degrading bacteria from chicken manure compost. A thermophilic strain named as Geobacillus thermodenitrificans Y7 with acid-resident property was successfully isolated and employed to degrade raw switchgrass at 60°C for 5 days, which resulted in the final degradation rates of cellulose, xylan, and acid-insoluble lignin as 18.64, 12.96, and 17.21%, respectively. In addition, GC-MS analysis about aromatic degradation affirm the degradation of lignin by G. thermodenitrificans Y7. Moreover, an endocellulase gene belong to M42 family was successfully cloned from G. thermodenitrificans Y7 and expressed in Escherichia coli BL21. Recombinant enzyme Cel-9 was purified by Ni-NTA column based the His-tag, and the molecular weight determined as 40.4 kDa by SDA-PAGE. The characterization of the enzyme Cel-9 indicated that the maximum enzyme activity was realized at 50°C and pH 8.6 and, Mn2+ could greatly improve the CMCase enzyme activity of Cel-9 at 10 mM, which was followed by Fe2+ and Co2+. Besides, it also found that the β-1,3-1,4, β-1,3, β-1,4, and β-1,6 glucan linkages all could be hydrolyzed by enzyme Cel-9. Finally, during the application of enzyme Cel-9 to switchgrass, the saccharification rates achieved to 1.81 ± 0.04% and 2.65 ± 0.03% for 50 and 100% crude enzyme, respectively. All these results indicated that both the strain G. thermodenitrificans Y7 and the recombinant endocellulase Cel-9 have the potential to be applied to the biomass industry.
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Affiliation(s)
- Lingling Ma
- Laboratory of Bioresources, College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Yuchun Zhao
- Laboratory of Bioresources, College of Food Science and Engineering, Northwest A&F University, Yangling, China
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Limin Meng
- Laboratory of Bioresources, College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Xin Wang
- Laboratory of Bioresources, College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Yanglei Yi
- Laboratory of Bioresources, College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Yuanyuan Shan
- Laboratory of Bioresources, College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Bianfang Liu
- Laboratory of Bioresources, College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Yuan Zhou
- Laboratory of Bioresources, College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Xin Lü
- Laboratory of Bioresources, College of Food Science and Engineering, Northwest A&F University, Yangling, China
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Mahdy A, Wandera SM, Aka B, Qiao W, Dong R. Biostimulation of sewage sludge solubilization and methanization by hyper-thermophilic pre-hydrolysis stage and the shifts of microbial structure profiles. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 699:134373. [PMID: 31677470 DOI: 10.1016/j.scitotenv.2019.134373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 09/04/2019] [Accepted: 09/08/2019] [Indexed: 06/10/2023]
Abstract
This study evaluated the influence of hyper-thermophilic pre-hydrolysis stage (70 °C) on methane recovery of sewage sludge at 35 °C. In this configuration, the process performance in both temperatures were estimated and the microbial communities were characterized by full-length16S rRNA genes and/or microbial activities. In addition, the appropriate solubilization reaction time was assessed. The results revealed that the higher hydrolysis and acidogenesis activities were achieved with longer reaction time of pretreatment (5 days) and thus higher organic nitrogen conversion and alkalinity were attained. Under appropriate pretreatment reaction time, pretreated sludge was characterized by 65% higher organic matters solubilization and 1.4-fold higher volatile fatty acids (VFAs) concentration compared to raw sludge. The overall methane yield produced under this scenario was 179 L CH4. KgVSin, with 15% of the absolute yield was produced in hydrolysis reactor. 50% reduction in bacteria belong to Firmicurtes was observed at mesophilic reactor and meanwhile the relative abundance of Bacteroidetes and Cloacimonetes were enhanced. The predominant methanogens in both stages did not change implying adaptation of Methanothermobacter (>62%) to mesophilic condition. However, increasing acetoclastic methanogens up to 30% in mesophilic reactor indicating methane was produced from pretreated sludge mainly through H2- mediated CO2 reduction and partially from acetate cleavage. The results highlight the key role of hyper-thermophilic pre-hydrolysis stage for better stabilization of sewage sludge without further investments in current biogas plants.
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Affiliation(s)
- Ahmed Mahdy
- College of Engineering, China Agricultural University, Beijing 100083, China; Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, 44511 Zagazig, Egypt
| | - Simon M Wandera
- College of Engineering, China Agricultural University, Beijing 100083, China
| | - Behairy Aka
- Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, 44511 Zagazig, Egypt
| | - Wei Qiao
- College of Engineering, China Agricultural University, Beijing 100083, China; State R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development, and Reform Committee, Beijing 100083, China.
| | - Renjie Dong
- College of Engineering, China Agricultural University, Beijing 100083, China; State R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development, and Reform Committee, Beijing 100083, China
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15
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Suksong W, Kongjan P, Prasertsan P, O-Thong S. Thermotolerant cellulolytic Clostridiaceae and Lachnospiraceae rich consortium enhanced biogas production from oil palm empty fruit bunches by solid-state anaerobic digestion. BIORESOURCE TECHNOLOGY 2019; 291:121851. [PMID: 31374416 DOI: 10.1016/j.biortech.2019.121851] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 07/17/2019] [Accepted: 07/18/2019] [Indexed: 06/10/2023]
Abstract
Thermotolerant cellulolytic consortium for improvement biogas production from oil palm empty fruit bunches (EFB) by prehydrolysis and bioaugmentation strategies was investigated via solid-state anaerobic digestion (SS-AD). The prehydrolysis EFB with Clostridiaceae and Lachnospiraceae rich consortium have maximum methane yield of 252 and 349 ml CH4 g-1 VS with total EFB degradation efficiency of 62% and 86%, respectively. Clostridiaceae and Lachnospiraceae rich consortium augmentation in biogas reactor have maximum methane yield of 217 and 85.2 ml CH4 g-1 VS with degradation efficiency of 42% and 16%, respectively. The best improvement of biogas production was achieved by prehydrolysis EFB with Lachnospiraceae rich consortium with maximum methane production of 113 m3 CH4 tonne-1 EFB. While, Clostridiaceae rich consortium was suitable for augmentation in biogas reactor with maximum methane production of 70.6 m3 CH4 tonne-1 EFB. Application of thermotolerant cellulolytic consortium into the SS-AD systems could enhance biogas production of 3-11 times.
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Affiliation(s)
- Wantanasak Suksong
- Biotechnology Program, Faculty of Science, Thaksin University, Phatthalung, Thailand
| | - Prawit Kongjan
- Department of Science, Faculty of Science and Technology, Prince of Songkla University, Pattani, Thailand
| | - Poonsuk Prasertsan
- Department of Industrial Biotechnology, Faculty of Agro-Industry, Prince of Songkla University, Songkhla 90112, Thailand
| | - Sompong O-Thong
- Biotechnology Program, Faculty of Science, Thaksin University, Phatthalung, Thailand; Research Center in Energy and Environment, Faculty of Science, Thaksin University, Phatthalung, Thailand.
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Microbial Profile of the Leachate from Mexico City’s Bordo Poniente Composting Plant: An Inoculum to Digest Organic Waste. ENERGIES 2019. [DOI: 10.3390/en12122343] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In recent years, municipal solid waste (MSW) management has become a complex problem worldwide. Similarly, Mexico City is facing such a situation for the management and treatment of organic fraction of municipal solid waste (OFMSW). Therefore, in this work, we investigated whether leachate from the composting plant, Bordo Poniente, located in Mexico City can be used as an inoculum for the treatment of OFMSW using thermophilic anaerobic digestion (AD) with a hydraulic retention time of 30 days. We analyzed the physicochemical properties of the leachate and performed a biochemical methane potential test. Archaeal and bacterial diversity was also identified using high throughput DNA sequencing of 16S rDNA libraries. Methane yield was 0.29 m3 CH4/kg VSadded in the positive control and 0.16 m3 CH4/kg VSadded in the treatment group. The phylum, Bacteroidetes, and genus, Methanosarcina, prevailed in the leachate. However, in thermophilic conditions, the microbial communities changed, and the phylum, Firmicutes, genera, Methanoculleus, and candidate genus, vadinCA11, were dominant in the treatment group. We concluded that the leachate contains a suitable initial charge of many active bacteria and methanogenic archaea which contribute to the AD process, hence it can be used as an inoculum for the treatment of OFMSW.
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Anaerobic treatment of opaque beer wastewater with enhanced biogas recovery through Acti-zyme bio augmentation. SOUTH AFRICAN JOURNAL OF CHEMICAL ENGINEERING 2018. [DOI: 10.1016/j.sajce.2018.10.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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18
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Atasoy M, Owusu-Agyeman I, Plaza E, Cetecioglu Z. Bio-based volatile fatty acid production and recovery from waste streams: Current status and future challenges. BIORESOURCE TECHNOLOGY 2018; 268:773-786. [PMID: 30030049 DOI: 10.1016/j.biortech.2018.07.042] [Citation(s) in RCA: 205] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 07/06/2018] [Accepted: 07/08/2018] [Indexed: 05/28/2023]
Abstract
Bio-based volatile fatty acid (VFA) production from waste-stream is getting attention due to increasing market demand and wide range usage area as well as its cost-effective and environmentally friendly approach. The aim of this paper is to give a comprehensive review of bio-based VFA production and recovery methods and to give an opinion on future research outlook. Effects of operation conditions including pH, temperature, retention time, type of substrate and mixed microbial cultures on VFA production and composition were reviewed. The recovery methods in terms of gas stripping with absorption, adsorption, solvent extraction, electrodialysis, reverse osmosis, nanofiltration, and membrane contractor of VFA were evaluated. Furthermore, strategies to enhance bio-based VFA production and recovery from waste streams, specifically, in-line VFA recovery and bioaugmentation, which are currently not used in common practice, are seen as some of the approaches to enhance bio-based VFA production.
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Affiliation(s)
- Merve Atasoy
- Department of Chemical Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - Isaac Owusu-Agyeman
- Department of Chemical Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - Elzbieta Plaza
- Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - Zeynep Cetecioglu
- Department of Chemical Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
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Multidisciplinary involvement and potential of thermophiles. Folia Microbiol (Praha) 2018; 64:389-406. [PMID: 30386965 DOI: 10.1007/s12223-018-0662-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 10/25/2018] [Indexed: 12/15/2022]
Abstract
The full biotechnological exploitation of thermostable enzymes in industrial processes is necessary for their commercial interest and industrious value. The heat-tolerant and heat-resistant enzymes are a key for efficient and cost-effective translation of substrates into useful products for commercial applications. The thermophilic, hyperthermophilic, and microorganisms adapted to extreme temperatures (i.e., low-temperature lovers or psychrophiles) are a rich source of thermostable enzymes with broad-ranging thermal properties, which have structural and functional stability to underpin a variety of technologies. These enzymes are under scrutiny for their great biotechnological potential. Temperature is one of the most critical parameters that shape microorganisms and their biomolecules for stability under harsh environmental conditions. This review describes in detail the sources of thermophiles and thermostable enzymes from prokaryotes and eukaryotes (microbial cell factories). Furthermore, the review critically examines perspectives to improve modern biocatalysts, its production and performance aiming to increase their value for biotechnology through higher standards, specificity, resistance, lowing costs, etc. These thermostable and thermally adapted extremophilic enzymes have been used in a wide range of industries that span all six enzyme classes. Thus, in particular, target of this review paper is to show the possibility of both high-value-low-volume (e.g., fine-chemical synthesis) and low-value-high-volume by-products (e.g., fuels) by minimizing changes to current industrial processes.
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20
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Ozbayram EG, Kleinsteuber S, Nikolausz M, Ince B, Ince O. Bioaugmentation of anaerobic digesters treating lignocellulosic feedstock by enriched microbial consortia. Eng Life Sci 2018; 18:440-446. [PMID: 32624925 DOI: 10.1002/elsc.201700199] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/16/2018] [Accepted: 04/05/2018] [Indexed: 11/07/2022] Open
Abstract
Three different bioaugmentation cultures enriched from natural and engineered cellulolytic environments (cow and goat rumen, a biogas reactor digesting sorghum biomass) were compared for their enhancement potential on the anaerobic digestion of wheat straw. Methane yields were determined in batch tests using the Automatic Methane Potential Test System operated for 30 days under mesophilic conditions. All cultures had positive effects on substrate degradation, and higher methane yields were observed in the bioaugmented reactors compared to control reactors set up with standard inoculum. However, the level of enhancement differed according to the type of the enrichment culture. Methane yield in batch reactors augmented with 2% cow rumen derived enrichment culture was increased by only 6%. In contrast, reactors amended with 2% goat rumen derived enrichment culture or with the bioaugmentation culture obtained from the biogas reactor digesting sorghum biomass produced 27 and 20% more methane, respectively. The highest methane yield was recorded in reactors amended with 6% goat rumen derived enrichment culture, which represented an increase by 36%. The microbial communities were quite similar at the end of the batch tests independently of the bioaugmentation sources, indicating that the introduced microbial communities of the enrichment cultures did not dominate the reactors.
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Affiliation(s)
- Emine Gozde Ozbayram
- Department of Environmental Engineering Faculty of Civil Engineering Istanbul Technical University Istanbul Turkey
| | - Sabine Kleinsteuber
- Department of Environmental Microbiology Helmholtz Centre for Environmental Research - UFZ Leipzig Germany
| | - Marcell Nikolausz
- Department of Environmental Microbiology Helmholtz Centre for Environmental Research - UFZ Leipzig Germany
| | - Bahar Ince
- Institute of Environmental Sciences Boğaziçi University Istanbul Turkey
| | - Orhan Ince
- Department of Environmental Engineering Faculty of Civil Engineering Istanbul Technical University Istanbul Turkey
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Mulat DG, Huerta SG, Kalyani D, Horn SJ. Enhancing methane production from lignocellulosic biomass by combined steam-explosion pretreatment and bioaugmentation with cellulolytic bacterium Caldicellulosiruptor bescii. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:19. [PMID: 29422947 PMCID: PMC5787918 DOI: 10.1186/s13068-018-1025-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 01/13/2018] [Indexed: 05/07/2023]
Abstract
BACKGROUND Biogas production from lignocellulosic biomass is generally considered to be challenging due to the recalcitrant nature of this biomass. In this study, the recalcitrance of birch was reduced by applying steam-explosion (SE) pretreatment (210 °C and 10 min). Moreover, bioaugmentation with the cellulolytic bacterium Caldicellulosiruptor bescii was applied to possibly enhance the methane production from steam-exploded birch in an anaerobic digestion (AD) process under thermophilic conditions (62 °C). RESULTS Overall, the combined SE and bioaugmentation enhanced the methane yield up to 140% compared to untreated birch, while SE alone contributed to the major share of methane enhancement by 118%. The best methane improvement of 140% on day 50 was observed in bottles fed with pretreated birch and bioaugmentation with lower dosages of C. bescii (2 and 5% of inoculum volume). The maximum methane production rate also increased from 4-mL CH4/g VS (volatile solids)/day for untreated birch to 9-14-mL CH4/g VS/day for steam-exploded birch with applied bioaugmentation. Bioaugmentation was particularly effective for increasing the initial methane production rate of the pretreated birch yielding 21-44% more methane than the pretreated birch without applied bioaugmentation. The extent of solubilization of the organic matter was increased by more than twofold when combined SE pretreatment and bioaugmentation was used in comparison with the methane production from untreated birch. The beneficial effects of SE and bioaugmentation on methane yield indicated that biomass recalcitrance and hydrolysis step are the limiting factors for efficient AD of lignocellulosic biomass. Microbial community analysis by 16S rRNA amplicon sequencing showed that the microbial community composition was altered by the pretreatment and bioaugmentation processes. Notably, the enhanced methane production by pretreatment and bioaugmentation was well correlated with the increase in abundance of key bacterial and archaeal communities, particularly the hydrolytic bacterium Caldicoprobacter, several members of syntrophic acetate oxidizing bacteria and the hydrogenotrophic Methanothermobacter. CONCLUSION Our findings demonstrate the potential of combined SE and bioaugmentation for enhancing methane production from lignocellulosic biomass.
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Affiliation(s)
- Daniel Girma Mulat
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O.Box 5003, 1432 Ås, Norway
| | - Silvia Greses Huerta
- Department of Chemical Engineering, University of Valencia, P.O.Box 46100, Valencia, Spain
| | - Dayanand Kalyani
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O.Box 5003, 1432 Ås, Norway
| | - Svein Jarle Horn
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O.Box 5003, 1432 Ås, Norway
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Kovacs KL. Biogas Science 2016. Anaerobe 2017; 46:1-2. [PMID: 28890221 DOI: 10.1016/j.anaerobe.2017.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kornel L Kovacs
- Department of Biotechnology, University of Szeged, Közép fasor 52, Szeged 6726, Hungary.
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