1
|
Undiandeye J, Gallegos D, Bonatelli ML, Kleinsteuber S, Bin-Hudari MS, Abdulkadir N, Stinner W, Sträuber H. Medium-chain carboxylates production from plant waste: kinetic study and effect of an enriched microbiome. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:79. [PMID: 38867271 PMCID: PMC11167882 DOI: 10.1186/s13068-024-02528-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 06/04/2024] [Indexed: 06/14/2024]
Abstract
BACKGROUND The need for addition of external electron donors such as ethanol or lactate impairs the economic viability of chain elongation (CE) processes for the production of medium-chain carboxylates (MCC). However, using feedstocks with inherent electron donors such as silages of waste biomass can improve the economics. Moreover, the use of an appropriate inoculum is critical to the overall efficiency of the CE process, as the production of a desired MCC can significantly be influenced by the presence or absence of specific microorganisms and their metabolic interactions. Beyond, it is necessary to generate data that can be used for reactor design, simulation and optimization of a given CE process. Such data can be obtained using appropriate mathematical models to predict the dynamics of the CE process. RESULTS In batch experiments using silages of sugar beet leaves, cassava leaves, and Elodea/wheat straw as substrates, caproate was the only MCC produced with maximum yields of 1.97, 3.48, and 0.88 g/kgVS, respectively. The MCC concentrations were accurately predicted with the modified Gompertz model. In a semi-continuous fermentation with ensiled sugar beet leaves as substrate and digestate from a biogas reactor as the sole inoculum, a prolonged lag phase of 7 days was observed for the production of MCC (C6-C8). The lag phase was significantly shortened by at least 4 days when an enriched inoculum was added to the system. With the enriched inoculum, an MCC yield of 93.67 g/kgVS and a productivity of 2.05 gMCC/L/d were achieved. Without the enriched inoculum, MCC yield and productivity were 43.30 g/kgVS and 0.95 gMCC/L/d, respectively. The higher MCC production was accompanied by higher relative abundances of Lachnospiraceae and Eubacteriaceae. CONCLUSIONS Ensiled waste biomass is a suitable substrate for MCC production using CE. For an enhanced production of MCC from ensiled sugar beet leaves, the use of an enriched inoculum is recommended for a fast process start and high production performance.
Collapse
Affiliation(s)
- Jerome Undiandeye
- Department of Biochemical Conversion, DBFZ Deutsches Biomasseforschungszentrum Gemeinnützige GmbH, 04347, Leipzig, Germany.
- Department of Chemical Engineering, University of Port Harcourt, PMB 5323, Port Harcourt, Nigeria.
| | - Daniela Gallegos
- Department of Biochemical Conversion, DBFZ Deutsches Biomasseforschungszentrum Gemeinnützige GmbH, 04347, Leipzig, Germany
| | - Maria L Bonatelli
- Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research - UFZ, 04318, Leipzig, Germany
| | - Sabine Kleinsteuber
- Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research - UFZ, 04318, Leipzig, Germany
| | - Mohammad Sufian Bin-Hudari
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, 04318, Leipzig, Germany
| | - Nafi'u Abdulkadir
- Research Unit for Comparative Microbiome Analysis, Helmholtz Munich, German Research Center for Environmental Health, 85764, Neuherberg, Germany
- Department of Microbiology, Sokoto State University, Sokoto, 852101, Nigeria
| | - Walter Stinner
- Department of Biochemical Conversion, DBFZ Deutsches Biomasseforschungszentrum Gemeinnützige GmbH, 04347, Leipzig, Germany
| | - Heike Sträuber
- Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research - UFZ, 04318, Leipzig, Germany
| |
Collapse
|
2
|
Wang Z, Fernández-Blanco C, Chen J, Veiga MC, Kennes C. Effect of electron acceptors on product selectivity and carbon flux in carbon chain elongation with Megasphaera hexanoica. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169509. [PMID: 38141983 DOI: 10.1016/j.scitotenv.2023.169509] [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: 11/06/2023] [Revised: 12/14/2023] [Accepted: 12/17/2023] [Indexed: 12/25/2023]
Abstract
Megasphaera hexanoica is a bacterial strain following the reverse β-oxidation pathway to synthesize caproate (CA) using lactate (LA) as an electron donor (ED) and acetate (AA) or butyrate (BA) as electron acceptors (EA). Differences in the type and concentration of EA lead to distinctions in product distribution and energy bifurcation of carbon fluxes in ED pathways, thereby affecting CA production. In this study, the effect of various ratios of AA, BA, and AA+BA as EA on carbon flux and CA specific titer during the carbon chain elongation in M. hexanoica was explored. The results indicated that the maximum levels of CA were 18.81 mM and 31.48 mM when the molar ratios of LA/AA and LA/BA were 10:1 and 3:1, respectively. Meanwhile, when AA and BA were used as combined EA (LA, AA, and BA molar amounts of 100, 23, and 77 mM), a maximum CA production of 39.45 mM was obtained. Further analysis revealed that the combined EA exhibited a CA production carbon flux of 49 % (4.3 % and 19.5 % higher compared to AA or BA, respectively) and a CA production specific titer of 45.24 mol (80.89 % and 58.51 % higher compared to AA or BA, respectively), indicating that the effective carbon utilization rate and CA production efficiency were greatly improved. Finally, a scaled-up experiment was conducted in a 1.2 L (working volume) automated bioreactor, implying high biomass (optical density at 600 nm or OD600 = 1.809) and a slight decrease in CA production (28.45 mM). A decrease in H2 production (4.11 g/m3) and an increase in CO2 production (0.632 g/m3) demonstrated the appropriate metabolic adaptation of M. hexanoica to environmental changes such as stirring shear.
Collapse
Affiliation(s)
- Zeyu Wang
- Chemical Engineering Laboratory, Faculty of Sciences and Interdisciplinary Centre of Chemistry and Biology - Centro Interdisciplinar de Química y Biología (CICA), BIOENGIN group, University of La Coruña (UDC), E-15008 La Coruña, Spain; Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou 310015, China
| | - Carla Fernández-Blanco
- Chemical Engineering Laboratory, Faculty of Sciences and Interdisciplinary Centre of Chemistry and Biology - Centro Interdisciplinar de Química y Biología (CICA), BIOENGIN group, University of La Coruña (UDC), E-15008 La Coruña, Spain
| | - Jun Chen
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou 310015, China
| | - María C Veiga
- Chemical Engineering Laboratory, Faculty of Sciences and Interdisciplinary Centre of Chemistry and Biology - Centro Interdisciplinar de Química y Biología (CICA), BIOENGIN group, University of La Coruña (UDC), E-15008 La Coruña, Spain
| | - Christian Kennes
- Chemical Engineering Laboratory, Faculty of Sciences and Interdisciplinary Centre of Chemistry and Biology - Centro Interdisciplinar de Química y Biología (CICA), BIOENGIN group, University of La Coruña (UDC), E-15008 La Coruña, Spain.
| |
Collapse
|
3
|
Candry P, Chadwick GL, Caravajal-Arroyo JM, Lacoere T, Winkler MKH, Ganigué R, Orphan VJ, Rabaey K. Trophic interactions shape the spatial organization of medium-chain carboxylic acid producing granular biofilm communities. THE ISME JOURNAL 2023; 17:2014-2022. [PMID: 37715042 PMCID: PMC10579388 DOI: 10.1038/s41396-023-01508-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/17/2023]
Abstract
Granular biofilms producing medium-chain carboxylic acids (MCCA) from carbohydrate-rich industrial feedstocks harbor highly streamlined communities converting sugars to MCCA either directly or via lactic acid as intermediate. We investigated the spatial organization and growth activity patterns of MCCA producing granular biofilms grown on an industrial side stream to test (i) whether key functional guilds (lactic acid producing Olsenella and MCCA producing Oscillospiraceae) stratified in the biofilm based on substrate usage, and (ii) whether spatial patterns of growth activity shaped the unique, lenticular morphology of these biofilms. First, three novel isolates (one Olsenella and two Oscillospiraceae species) representing over half of the granular biofilm community were obtained and used to develop FISH probes, revealing that key functional guilds were not stratified. Instead, the outer 150-500 µm of the granular biofilm consisted of a well-mixed community of Olsenella and Oscillospiraceae, while deeper layers were made up of other bacteria with lower activities. Second, nanoSIMS analysis of 15N incorporation in biofilms grown in normal and lactic acid amended conditions suggested Oscillospiraceae switched from sugars to lactic acid as substrate. This suggests competitive-cooperative interactions may govern the spatial organization of these biofilms, and suggests that optimizing biofilm size may be a suitable process engineering strategy. Third, growth activities were similar in the polar and equatorial biofilm peripheries, leaving the mechanism behind the lenticular biofilm morphology unexplained. Physical processes (e.g., shear hydrodynamics, biofilm life cycles) may have contributed to lenticular biofilm development. Together, this study develops an ecological framework of MCCA-producing granular biofilms that informs bioprocess development.
Collapse
Affiliation(s)
- Pieter Candry
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Ghent, Belgium
- Civil and Environmental Engineering, University of Washington, 201 More Hall, Box 352700, Seattle, WA, 98195-2700, USA
| | - Grayson L Chadwick
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - José Maria Caravajal-Arroyo
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Tim Lacoere
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | | | - Ramon Ganigué
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Ghent, Belgium
- Center for Advanced Processes and Technology for Urban Resource Recovery (CAPTURE), Frieda Saeysstraat 1, 9000, Ghent, Belgium
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Korneel Rabaey
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
- Center for Advanced Processes and Technology for Urban Resource Recovery (CAPTURE), Frieda Saeysstraat 1, 9000, Ghent, Belgium.
| |
Collapse
|
4
|
Logan M, Zhu F, Lens PNL, Cetecioglu Z. Influence of pH, Heat Treatment of Inoculum, and Selenium Oxyanions on Concomitant Selenium Bioremediation and Volatile Fatty Acid Production from Food Waste. ACS OMEGA 2023; 8:34397-34409. [PMID: 37779932 PMCID: PMC10535259 DOI: 10.1021/acsomega.2c06459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/24/2023] [Indexed: 10/03/2023]
Abstract
Developing novel strategies to enhance volatile fatty acid (VFA) yield from abundant waste resources is imperative to improve the competitiveness of biobased VFAs over petrochemical-based VFAs. This study hypothesized to improve the VFA yield from food waste via three strategies, viz., pH adjustment (5 and 10), supplementation of selenium (Se) oxyanions, and heat treatment of the inoculum (at 85 °C for 1 h). The highest VFA yield of 0.516 g COD/g VS was achieved at alkaline pH, which was 45% higher than the maximum VFA production at acidic pH. Heat treatment resulted in VFA accumulation after day 10 upon alkaline pretreatment. Se oxyanions acted as chemical inhibitors to improve the VFA yield at pH 10 with non-heat-treated inoculum (NHT). Acetic and propionic acid production was dominant at alkaline pH (NHT); however, the VFA composition diversified under the other tested conditions. More than 95% Se removal was achieved on day 1 under all the conditions tested. However, the heat treatment was detrimental for selenate reduction, with less than 15% Se removal after 20 days. Biosynthesized Se nanoparticles were confirmed by transmission and scanning electron microscopy and and energy dispersive X-ray analyses. The heat treatment inhibited the presence of nonsporulating bacteria and methanogenic archaea (Methanobacteriaceae). High-throughput sequencing also revealed higher relative abundances of the bacterial families (such as Clostridiaceae, Bacteroidaceae, and Prevotellaceae) that are capable of VFA production and/or selenium reduction.
Collapse
Affiliation(s)
- Mohanakrishnan Logan
- Department
of Chemical Engineering, School of Engineering Sciences in Chemistry,
Biotechnology and Health, KTH Royal Institute
of Technology, Stockholm SE 100 44, Sweden
- Department
of Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland, University Road, Galway H91 TK33, Ireland
| | - Fengyi Zhu
- Department
of Industrial Biotechnology, School of Engineering Sciences in Chemistry,
Biotechnology and Health, KTH Royal Institute
of Technology, Stockholm SE 106 91, Sweden
| | - Piet N. L. Lens
- Department
of Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland, University Road, Galway H91 TK33, Ireland
| | - Zeynep Cetecioglu
- Department
of Chemical Engineering, School of Engineering Sciences in Chemistry,
Biotechnology and Health, KTH Royal Institute
of Technology, Stockholm SE 100 44, Sweden
- Department
of Industrial Biotechnology, School of Engineering Sciences in Chemistry,
Biotechnology and Health, KTH Royal Institute
of Technology, Stockholm SE 106 91, Sweden
| |
Collapse
|
5
|
Dahiya S, Mohan SV. Co-fermenting lactic acid and glucose towards caproic acid production. CHEMOSPHERE 2023; 328:138491. [PMID: 36963586 DOI: 10.1016/j.chemosphere.2023.138491] [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: 08/25/2022] [Revised: 02/20/2023] [Accepted: 03/21/2023] [Indexed: 06/18/2023]
Abstract
The functional role of lactate (HLac), as a co-substrate along with glucose (Glu) as well as an electron donor for the synthesis of caproic acid (HCa), a medium chain fatty acid (MCFAs) was studied. A varied HLac and Glu ratios were thus investigated in fed-batch anaerobic reactors (R1-R5) operated at pH 6 with a heat-treated anaerobic consortium. R1 and R5 were noted as controls and operated with sole Glu and HLac, respectively. Strategically, ethanol (HEth) was additionally supplemented as co-electron donor after the production of short chain carboxylic acids (SCCAs) for chain elongation in all the reactors. The reactor operated with HLac and Glu in a ratio of 0.25:0.75 (1.25 g/L (HLac) and 3.75 g/L (Glu)) showed the highest HCa production of 1.86 g/L. R5 operated with solely HLac yielded propionic acid (HPr) as the major product which further led to the higher valeric acid (HVa) production of 1.1 g/L within the reactor. Butyric acid (HBu) was observed in R1, which used Glu as carbon source alone indicating the importance of HLac as electron co-donor. Clostridium observed as the most dominant genera in shotgun metagenome sequencing in R2 and R3, the reactors that produced the highest HCa in comparison to other studied reactors. The study thus provided insight into the importance of substrate and electron donor and their supplementation strategies during the production of MCFAs.
Collapse
Affiliation(s)
- Shikha Dahiya
- Bioengineering and Environmental Science Lab, Department of Energy and Environmental Engineering, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, 500 007, India; Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - S Venkata Mohan
- Bioengineering and Environmental Science Lab, Department of Energy and Environmental Engineering, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, 500 007, India; Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, 201002, India.
| |
Collapse
|
6
|
Ho Ahn J, Hwan Jung K, Seok Lim E, Min Kim S, Ok Han S, Um Y. Recent advances in microbial production of medium chain fatty acid from renewable carbon resources: a comprehensive review. BIORESOURCE TECHNOLOGY 2023; 381:129147. [PMID: 37169199 DOI: 10.1016/j.biortech.2023.129147] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 04/29/2023] [Accepted: 05/04/2023] [Indexed: 05/13/2023]
Abstract
Microbial production of medium chain length fatty acids (MCFAs) from renewable resources is becoming increasingly important in establishing a sustainable and clean chemical industry. This review comprehensively summarizes current advances in microbial MCFA production from renewable resources. Detailed information is provided on two major MCFA production pathways using various renewable resources and other auxiliary pathways supporting MCFA production to help understand the fundamentals of bio-based MCFA production. In addition, conventional and well-studied MCFA producers are classified into two categories, natural and synthetic producers, and their characteristics on MCFA production are outlined. Moreover, various engineering strategies employed to achieve the highest MCFAs production up to date are showcased together with key enzymes suggested for MCFA overproduction. Finally, future challenges and perspectives are discussed towards more efficient production of bio-based MCFA production.
Collapse
Affiliation(s)
- Jung Ho Ahn
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; Division of Energy and Environment Technology, KIST School, University of Science and Technology (UST), Daejeon 34113, Republic of Korea
| | - Kweon Hwan Jung
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; Department of Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Eui Seok Lim
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; Department of Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Sang Min Kim
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; Department of Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Sung Ok Han
- Department of Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Youngsoon Um
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; Division of Energy and Environment Technology, KIST School, University of Science and Technology (UST), Daejeon 34113, Republic of Korea.
| |
Collapse
|
7
|
Jin X, Yin X, Ling L, Mao H, Dong X, Chang X, Chen M, Fang S. Adding glucose delays the conversion of ethanol and acetic acid to caproic acid in Lacrimispora celerecrescens JSJ-1. Appl Microbiol Biotechnol 2023; 107:1453-1463. [PMID: 36703009 DOI: 10.1007/s00253-023-12378-7] [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: 08/03/2022] [Revised: 01/07/2023] [Accepted: 01/10/2023] [Indexed: 01/28/2023]
Abstract
Caproic acid is an important fatty acid with diverse applications. In this study, the biomass growth and metabolites of Lacrimispora celerecrescens JSJ-1 were investigated under different carbon sources (ethanol, starch, sucrose, and glucose), with a focus on the effect of the coexistence of glucose and ethanol on the synthesis of caproic acid. The results showed that starch, glucose, and sucrose all contributed to the biomass of L. celerecrescens JSJ-1. Under the three carbon sources, L. celerecrescens JSJ-1 produced acetic acid, butyric acid, lactic acid, ethanol, and butanol, but caproic acid was not produced. Ethanol was the optimal substrate for the production of caproic acid. When glucose and ethanol coexisted, the generation time of caproic acid was delayed compared with that in ethanol sodium acetate medium (ES medium). This was because glucose was preferentially consumed over ethanol. Lactic acid was generated as a result of glucose consumption, which led to a significant decrease in pH from 6.45 to 4.68. The low pH (< 5) inhibited the synthesis of caproic acid. Then, the strain's usage of lactic acid and the reaction between CaCO3 and lactic acid caused the pH to increase. L. celerecrescens JSJ-1 did not start producing caproic acid using ethanol and acetic acid until the pH increased to 5.8. This research enriches the knowledge regarding the metabolism of L. celerecrescens JSJ-1 and provides guidelines for the industrial production of caproic acid by using L. celerecrescences JSJ-1. KEY POINTS: • Ethanol is the optimal substrate for the synthesis of caproic acid by Lacrimispora celerecrescens JSJ-1. • Lacrimispora celerecrescens JSJ-1 produced lactic acid rapidly when it used glucose, causing a sharp drop in pH. • pH is a crucial factor affecting the synthesis of caproic acid from ethanol by Lacrimispora celerecrescens JSJ-1.
Collapse
Affiliation(s)
- Xiangyi Jin
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, Wuhan, 430068, China
| | - Xiangxiang Yin
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, Wuhan, 430068, China
| | - Li Ling
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, Wuhan, 430068, China
| | - Hao Mao
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, Wuhan, 430068, China
| | | | - Xu Chang
- Angel Yeast Co. Ltd, Yichang, 443200, China
| | - Maobin Chen
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, Wuhan, 430068, China
| | - Shangling Fang
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, Wuhan, 430068, China.
| |
Collapse
|
8
|
Van Nguyen T, Viver T, Mortier J, Liu B, Smets I, Bernaerts K, Faust K, Lavigne R, Poughon L, Dussap CG, Springael D. Isolation and characterization of a thermophilic chain elongating bacterium that produces the high commodity chemical n-caproate from polymeric carbohydrates. BIORESOURCE TECHNOLOGY 2023; 367:128170. [PMID: 36283667 DOI: 10.1016/j.biortech.2022.128170] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/15/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
A thermophilic chain elongating bacterium, strain MDTJ8, was isolated from a thermophilic acidogenic anaerobic digestor producing n-caproate from human waste, growing optimally at 50-55 °C and pH 6.5. 16S rRNA gene analysis suggests that MDTJ8 represents a new species/genus within a group currently composed of mesophilic chain elongators of the Oscillospiraceae family. Genome analysis showed that strain MDTJ8 contains homologues of genes encoding for chain elongation and energy conservation but also indicated n-caproate production from carbohydrates including polymeric substances. This was confirmed by culturing experiments in which MDTJ8 converted, at pH 6.5 and 55 °C, mono-, di- and polymeric carbohydrates (starch and hemicellulose) to n-caproate reaching concentrations up to 283 mg/L and accounting for up to 10 % of the measured fermentation products. MDTJ8 is the first axenic organism that thermophilically performs chain elongation, opening doors to understand and intensify thermophilic bioprocesses targeting anaerobic digestion towards the production of the value-added chemical n-caproate.
Collapse
Affiliation(s)
- Tinh Van Nguyen
- Division of Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium; Institut Pascal, Université Clermont Auvergne, Avenue Blaise Pascal 4, F-63178 Aubiére cedex, France
| | - Tomeu Viver
- Marine Microbiology Group, Mediterranean Institute of Advanced Studies (CSIC-UIB), C/Miquel Marqués 21, 07190 Esporles, Spain
| | - Jonah Mortier
- Division of Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium
| | - Bin Liu
- Laboratory of Molecular Bacteriology (Rega Institute), KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Ilse Smets
- Chemical Reactor Engineering and Safety, KU Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium
| | - Kristel Bernaerts
- Chemical Reactor Engineering and Safety, KU Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium
| | - Karoline Faust
- Laboratory of Molecular Bacteriology (Rega Institute), KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Rob Lavigne
- Laboratory of Gene Technology, KU Leuven, Kasteelpark Arenberg 21, B-3001 Heverlee, Belgium
| | - Laurent Poughon
- Institut Pascal, Université Clermont Auvergne, Avenue Blaise Pascal 4, F-63178 Aubiére cedex, France
| | - Claude-Gilles Dussap
- Institut Pascal, Université Clermont Auvergne, Avenue Blaise Pascal 4, F-63178 Aubiére cedex, France
| | - Dirk Springael
- Division of Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium.
| |
Collapse
|
9
|
Zhu X, Huang H, He Y, Wang X, Jia J, Feng X, Li D, Li H. A preliminary study on the feasibility of industrialization for n-caproic acid recovery from food wastewater: From lab to pilot. BIORESOURCE TECHNOLOGY 2022; 366:128154. [PMID: 36270389 DOI: 10.1016/j.biortech.2022.128154] [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: 09/07/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
Food wastewater is associated with greenhouse gas emission and has a significant water footprint. Here, the platform chemical n-caproate was recovered from liquor brewing wastewater at maximum and mean concentrations of 26.4 g/L and 17.0 ± 4.3 g/L, respectively, after 377 d operation. Laboratory-scale lactate-driven chain elongation (CE) process was implemented first. Taxonomic composition and metagenomic data analyses revealed that Caproiciproducens (e.g., Ruminococcaceae bacterium CPB6) and bacteria affiliated with Lachnospiraceae transformed lactate to n-caproate by reverse β-oxidation and/or fatty acid biosynthesis. The lactate-driven CE process was then scaled up from 2.5 L to 500 L and achieved a n-caproate production of 14.5 ± 0.6 g/L within 96 h. n-Caproic acid was extracted at a concentration and purity of 815.9 ± 8.3 g/L and 88.6 ± 8.9 %, respectively. The present study demonstrated a commercially viable strategy for resource recovery and carbon fixation from food waste streams.
Collapse
Affiliation(s)
- Xiaoyu Zhu
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China; University of Chinese Academy of Sciences, Beijing 100864, PR China.
| | - Huanhuan Huang
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China; University of Chinese Academy of Sciences, Beijing 100864, PR China
| | - Yong He
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China; University of Chinese Academy of Sciences, Beijing 100864, PR China
| | - Xinyu Wang
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China; University of Chinese Academy of Sciences, Beijing 100864, PR China; Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, PR China
| | - Jia Jia
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China; University of Chinese Academy of Sciences, Beijing 100864, PR China
| | - Xin Feng
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China; University of Chinese Academy of Sciences, Beijing 100864, PR China
| | - Dong Li
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China; University of Chinese Academy of Sciences, Beijing 100864, PR China
| | - Haixiang Li
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, PR China
| |
Collapse
|
10
|
Revealing the Characteristics of Glucose- and Lactate-Based Chain Elongation for Caproate Production by Caproicibacterium lactatifermentans through Transcriptomic, Bioenergetic, and Regulatory Analyses. mSystems 2022; 7:e0053422. [PMID: 36073803 PMCID: PMC9600882 DOI: 10.1128/msystems.00534-22] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Caproate, an important medium-chain fatty acid, can only be synthesized by limited bacterial species by using ethanol, lactate, or certain saccharides. Caproicibacterium lactatifermentans is a promising caproate producer due to its glucose and lactate utilization capabilities. However, the global cellular responses of this bacterium to different carbon sources were not well understood. Here, C. lactatifermentans showed robust growth on glucose but more active caproate synthesis on lactate. Comparative transcriptome revealed that the genes involved in reverse β-oxidation for caproate synthesis and V-type ATPase-dependent ATP generation were upregulated under lactate condition, while several genes responsible for biomass synthesis were upregulated under glucose condition. Based on metabolic pathway reconstructions and bioenergetics analysis, the biomass accumulation on glucose condition may be supported by sufficient supplies of ATP and metabolite intermediates via glycolysis. In contrast, the ATP yield per glucose equivalent from lactate conversion into caproate was only 20% of that from glucose. Thus, the upregulation of the reverse β-oxidation genes may be essential for cell survival under lactate conditions. Furthermore, the remarkably decreased lactate utilization was observed after glucose acclimatization, indicating the negative modulation of lactate utilization by glucose metabolism. Based on the cotranscription of the lactate utilization repressor gene lldR with sugar-specific PTS genes and the opposite expression patterns of lldR and lactate utilization genes, a novel regulatory mechanism of glucose-repressed lactate utilization mediated via lldR was proposed. The results of this study suggested the molecular mechanism underlying differential physiologic and metabolic characteristics of C. lactatifermentans grown on glucose and lactate. IMPORTANCE Caproicibacterium lactatifermentans is a unique and robust caproate-producing bacterium in the family Oscillospiraceae due to its lactate utilization capability, whereas its close relatives such as Caproicibacterium amylolyticum, Caproiciproducens galactitolivorans, and Caproicibacter fermentans cannot utilize lactate but produce lactate as the main fermentation end product. Moreover, C. lactatifermentans can also utilize several saccharides such as glucose and maltose. Although the metabolic versatility of the bacterium makes it to be a promising industrial caproate producer, the cellular responses of C. lactatifermentans to different carbon sources were unknown. Here, the molecular mechanisms of biomass synthesis supported by glucose utilization and the cell survival supported by lactate utilization were revealed. A novel insight into the regulatory machinery in which glucose negatively regulates lactate utilization was proposed. This study provides a valuable basis to control and optimize caproate production, which will contribute to achieving a circular economy and environmental sustainability.
Collapse
|
11
|
Feng S, Meng C, Hao Z, Liu H. Bacillus licheniformis Reshapes the Gut Microbiota to Alleviate the Subhealth. Nutrients 2022; 14:1642. [PMID: 35458204 PMCID: PMC9025434 DOI: 10.3390/nu14081642] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 02/05/2023] Open
Abstract
Subhealth is a condition between health and disease that has become a common public health risk. Therefore, it is necessary to find more scientific therapies that can alleviate the symptoms of subhealth effectively. The gut microbiota is closely associated with subhealth. As a mature probiotic preparation, Bacillus licheniformis (B. licheniformis) can regulate gut microbiota balance, which indicates that B. licheniformis has the potential in regulating subhealth. This study produced the subhealthy rats by using chronic stress for 4 weeks to simulate psychological stress, with excessive antibiotics for 1 week to simulate bad living habits. Then, they were treated for 4 weeks with B. licheniformis. The results showed that B. licheniformis could recover the gut microbiota balance that had been destroyed by subhealth. The serum corticosterone and the proinflammatory cytokine tumor necrosis factor-α decreased after being treated by B. licheniformis. B. licheniformis also reduced glutamic acid and norepinephrine levels while increasing γ-aminobutyric acid and 5-hydroxytryptamine levels in the brain. In addition to the physiological changes, B. licheniformis decreased the anxiety-like behaviors of rats. Therefore B. licheniformis could alleviate the subhealth state, mainly by remodeling the gut microbiota, reducing inflammation, inhibiting the hypothalamic-pituitary-adrenal axis hyperactivity, regulating neurotransmitter levels, and easing a negative mood.
Collapse
Affiliation(s)
- Siyuan Feng
- Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100083, China; (S.F.); (C.M.)
- Institute of Environmental Biology and Life Support Technology, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China
| | - Chen Meng
- Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100083, China; (S.F.); (C.M.)
- Institute of Environmental Biology and Life Support Technology, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China
| | - Zikai Hao
- Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100083, China; (S.F.); (C.M.)
- Institute of Environmental Biology and Life Support Technology, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China
- State Key Laboratory of Software Development Environment, School of Computer Science and Engineering, Beihang University, Beijing 100083, China
| | - Hong Liu
- Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100083, China; (S.F.); (C.M.)
- Institute of Environmental Biology and Life Support Technology, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China
- International Joint Research Center of Aerospace Biotechnology & Medical Engineering, Beihang University, Beijing 100083, China
| |
Collapse
|
12
|
Kim H, Kang S, Sang BI. Metabolic cascade of complex organic wastes to medium-chain carboxylic acids: A review on the state-of-the-art multi-omics analysis for anaerobic chain elongation pathways. BIORESOURCE TECHNOLOGY 2022; 344:126211. [PMID: 34710599 DOI: 10.1016/j.biortech.2021.126211] [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: 08/31/2021] [Revised: 10/18/2021] [Accepted: 10/20/2021] [Indexed: 06/13/2023]
Abstract
Medium-chain carboxylic acid (MCCA) production from organic wastes has attracted much attention because of their higher energy contents and diverse applications. Anaerobic reactor microbiomes are stable and resilient and have resulted in efficient performance during many years of operation for thousands of full-scale anaerobic digesters worldwide. The method underlying how the relevant microbial pathways contribute to elongate carbon chains in reactor microbiomes is important. In particular, the reverse β-oxidation pathway genes are critical to upgrading short-chain fermentation products to MCCAs via a chain elongation (CE) process. Diverse genomics and metagenomics studies have been conducted in various fields, ranging from intracellular metabolic pathways to metabolic cascades between different strains. This review covers taxonomic approach to culture processes depending on types of organic wastes and the deeper understanding of genome and metagenome-scale CE pathway construction, and the co-culture and multi-omics technology that should be addressed in future research.
Collapse
Affiliation(s)
- Hyunjin Kim
- Department of Chemical Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
| | - Seongcheol Kang
- Department of Chemical Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
| | - Byoung-In Sang
- Department of Chemical Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
| |
Collapse
|
13
|
Lu S, Jin H, Wang Y, Tao Y. Genome-Wide Transcriptomic Analysis of n-Caproic Acid Production in Ruminococcaceae Bacterium CPB6 with Lactate Supplementation. J Microbiol Biotechnol 2021; 31:1533-1544. [PMID: 34489376 PMCID: PMC9705837 DOI: 10.4014/jmb.2107.07009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/25/2021] [Accepted: 08/25/2021] [Indexed: 12/15/2022]
Abstract
n-Caproic acid (CA) is gaining increased attention due to its high value as a chemical feedstock. Ruminococcaceae bacterium strain CPB6 is an anaerobic mesophilic bacterium that is highly prolific in its ability to perform chain elongation of lactate to CA. However, little is known about the genome-wide transcriptional analysis of strain CPB6 for CA production triggered by the supplementation of exogenous lactate. In this study, cultivation of strain CPB6 was carried out in the absence and presence of lactate. Transcriptional profiles were analyzed using RNA-seq, and differentially expressed genes (DEGs) between the lactate-supplemented cells and control cells without lactate were analyzed. The results showed that lactate supplementation led to earlier CA p,roduction, and higher final CA titer and productivity. 295 genes were substrate and/or growth dependent, and these genes cover crucial functional categories. Specifically, 5 genes responsible for the reverse β-oxidation pathway, 11 genes encoding ATP-binding cassette (ABC) transporters, 6 genes encoding substrate-binding protein (SBP), and 4 genes encoding phosphotransferase system (PTS) transporters were strikingly upregulated in response to the addition of lactate. These genes would be candidates for future studies aiming at understanding the regulatory mechanism of lactate conversion into CA, as well as for the improvement of CA production in strain CPB6. The findings presented herein reveal unique insights into the biomolecular effect of lactate on CA production at the transcriptional level.
Collapse
Affiliation(s)
- Shaowen Lu
- CAS Key Laboratory of Environmental and Applied Microbiology and Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, P.R. China
| | - Hong Jin
- School of Basic Medical Science, Chengdu Medical College, Chengdu 610083, P.R. China
| | - Yi Wang
- Department of Biosystems Engineering, Auburn University, Auburn, Alabama, Alabama 36849, USA
| | - Yong Tao
- CAS Key Laboratory of Environmental and Applied Microbiology and Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, P.R. China,Faculty of Bioengineering, Sichuan University of Science and Engineering, Xueyuan Street 180#, Huixing Rd. Zigong 643000, P.R. China,Corresponding author Phone: 86-028-82890211 Fax: 86-028-82890211 E-mail:
| |
Collapse
|
14
|
Butyryl/Caproyl-CoA:Acetate CoA-transferase: cloning, expression and characterization of the key enzyme involved in medium-chain fatty acid biosynthesis. Biosci Rep 2021; 41:229427. [PMID: 34338280 PMCID: PMC8360832 DOI: 10.1042/bsr20211135] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 07/07/2021] [Accepted: 07/30/2021] [Indexed: 12/12/2022] Open
Abstract
Coenzyme A transferases (CoATs) are important enzymes involved in carbon chain elongation, contributing to medium-chain fatty acid (MCFA) biosynthesis. For example, butyryl-CoA:acetate CoA transferase (BCoAT) is responsible for the final step of butyrate synthesis from butyryl-CoA. However, little is known about caproyl-CoA:acetate CoA-transferase (CCoAT), which is responsible for the final step of caproate synthesis from caproyl-CoA. In the present study, two CoAT genes from Ruminococcaceae bacterium CPB6 and Clostridium tyrobutyricum BEY8 were identified by gene cloning and expression analysis. Enzyme assays and kinetic studies were carried out using butyryl-CoA or caproyl-CoA as the substrate. CPB6-CoAT can catalyze the conversion of both butyryl-CoA into butyrate and caproyl-CoA into caproate, but its catalytic efficiency with caproyl-CoA as the substrate was 3.8-times higher than that with butyryl-CoA. In contrast, BEY8-CoAT had only BCoAT activity, not CCoAT activity. This demonstrated the existence of a specific CCoAT involved in chain elongation via the reverse β-oxidation pathway. Comparative bioinformatics analysis showed the presence of a highly conserved motif (GGQXDFXXGAXX) in CoATs, which is predicted to be the active center. Single point mutations in the conserved motif of CPB6-CoAT (Asp346 and Ala351) led to marked decreases in the activity for butyryl-CoA and caproyl-CoA, indicating that the conserved motif is the active center of CPB6-CoAT and that Asp346 and Ala351 have a significant impact on the enzymatic activity. This work provides insight into the function of CCoAT in caproic acid biosynthesis and improves understanding of the chain elongation pathway for MCFA production.
Collapse
|
15
|
Microbial Ecological Mechanism for Long-Term Production of High Concentrations of n-Caproate via Lactate-Driven Chain Elongation. Appl Environ Microbiol 2021; 87:AEM.03075-20. [PMID: 33741616 DOI: 10.1128/aem.03075-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/10/2021] [Indexed: 12/11/2022] Open
Abstract
Lactate-driven chain elongation (LCE) has emerged as a new biotechnology to upgrade organic waste streams into a valuable biochemical and fuel precursor, medium-chain carboxylate, n-caproate. Considering that a low cost of downstream extraction is critical for biorefinery technology, a high concentration of n-caproate production is very important to improve the scale-up of the LCE process. We report here that in a nonsterile open environment, the n-caproate concentration was increased from the previous record of 25.7 g·liter-1 to a new high level of 33.7 g·liter-1 (76.8 g chemical oxygen demand [COD]·liter - 1), with the highest production rate being 11.5 g·liter-1·day-1 (26.2 g COD·liter - 1·day-1). In addition, the LCE process remained stable, with an average concentration of n-caproate production of 20.2 ± 5.62 g·liter-1 (46.1 ± 12.8 g COD·liter - 1) for 780 days. Dynamic changes in taxonomic composition integrated with metagenomic data reveal the microbial ecology for long-term production of high concentrations of n-caproate: (i) the core microbiome is related to efficient functional groups, such as Ruminococcaceae (with functional strain CPB6); (ii) the core bacteria can maintain stability for long-term operation; (iii) the microbial network has relatively low microbe-microbe interaction strength; and (iv) low relative abundance and variety of competitors. The network structure could be shaped by hydraulic retention time (HRT) over time, and long-term operation at an HRT of 8 days displayed higher efficacy.IMPORTANCE Our research revealed the microbial network of the LCE reactor microbiome for n-caproate production at high concentrations, which will provide a foundation for designing or engineering the LCE reactor microbiome to recover n-caproate from organic waste streams in the future. In addition, the hypothetical model of the reactor microbiome that we proposed may offer guidance for researchers to find the underlying microbial mechanism when they encounter low-efficiency n-caproate production from the LCE process. We anticipate that our research will rapidly advance LCE biotechnology with the goal of promoting the sustainable development of human society.
Collapse
|
16
|
Gu Y, Zhu X, Lin F, Shen C, Li Y, Ao L, Fan W, Ren C, Xu Y. Caproicibacterium amylolyticum gen. nov., sp. nov., a novel member of the family Oscillospiraceae isolated from pit clay used for making Chinese strong aroma-type liquor. Int J Syst Evol Microbiol 2021; 71. [PMID: 33906707 DOI: 10.1099/ijsem.0.004789] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An anaerobic, Gram-stain-positive, rod-shaped, motile and spore-forming bacterium, designated strain LBM18003T, was isolated from pit clay used for making Chinese strong aroma-type liquor. Growth occurred at 20-40 °C (optimum, 30-37 °C), pH 4.5-9.5 (optimum, pH 6.5-7.0) and in the presence of 0.0-1.0 % (w/v) sodium chloride (optimum, 0 %). The predominant fatty acids were C16:0, C14:0, C14:0 DMA and C16:0 3-OH, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, two unidentified phospholipids and nine unidentified glycolipids. Phylogenetic analysis revealed that strain LBM18003T is a novel member of the family Oscillospiraceae. The 16S rRNA gene sequence similarities of strain LBM18003T to its two most closely related species were less than 94.5 % for distinguishing genera, i.e. closely related to Caproiciproducens galactitolivorans JCM 30532T (94.1 %) and Caproicibacter fermentans DSM 107079T (93.2 %). The genome size of strain LBM18003T was 2 996 201 bp and its DNA G+C content was 48.48 mol%. Strain LBM18003T exhibited 67.8 and 68.1% pairwise-determined whole-genome average nucleotide identity values to Caproiciproducens galactitolivorans JCM 30532T and Caproicibacter fermentans DSM 107079T, respectively; and showed 62.2 and 61.0 % the average amino acid identity values to Caproiciproducens galactitolivorans JCM 30532T and Caproicibacter fermentans DSM 107079T, respectively; and demonstrated 46.1 and 41.5 % conserved genes to Caproiciproducens galactitolivorans JCM 30532T and Caproicibacter fermentans DSM 107079T, respectively. The comparisons of 16S rRNA gene and genome sequences confirmed that strain LBM18003T represented a novel genus of the family Oscillospiraceae. Based on morphological, physiological, biochemical, chemotaxonomic, genotypic and phylogenetic results, strain LBM18003T represents a novel species of a novel genus of the family Oscillospiraceae, for which the name Caproicibacterium amylolyticum gen. nov., sp. nov. is proposed. The type strain is LBM18003T (=GDMCC 1.1626T=JCM 33783T).
Collapse
Affiliation(s)
- Yang Gu
- Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, PR China
| | - Xiaojun Zhu
- Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, PR China
| | - Feng Lin
- National Engineering Research Center of Solid-state Brewing, Luzhou 646000, PR China
| | - Caihong Shen
- National Engineering Research Center of Solid-state Brewing, Luzhou 646000, PR China
| | - Yong Li
- National Engineering Research Center of Solid-state Brewing, Luzhou 646000, PR China
| | - Ling Ao
- National Engineering Research Center of Solid-state Brewing, Luzhou 646000, PR China
| | - Wenlai Fan
- Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, PR China
| | - Cong Ren
- Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, PR China
| | - Yan Xu
- Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, PR China
| |
Collapse
|
17
|
Lactate Metabolism and Microbiome Composition Are Affected by Nitrogen Gas Supply in Continuous Lactate-Based Chain Elongation. FERMENTATION 2021. [DOI: 10.3390/fermentation7010041] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Chain elongation reactor microbiomes produce valuable medium-chain carboxylates (MCC) from non-sterile residual substrates where lactate is a relevant intermediate. Gas supply has been shown to impact chain elongation performance. In the present study, the effect of nitrogen gas (N2) supply on lactate metabolism, conversion rates, biomass growth, and microbiome composition was evaluated in a lactate-fed upflow anaerobic reactor with continuous or intermittent N2 gas supply. Successful MCC production was achieved with continuous N2 gas supply at low superficial gas velocities (SGV) of 0.22 m∙h−1. Supplying N2 at high SGV (>2 m∙h−1) either continuously (2.2 m∙h−1) or intermittently (3.6 m∙h−1) disrupted chain elongation, resulting in production of short-chain carboxylates (SCC), i.e., acetate, propionate, and n-butyrate. Caproiciproducens-dominated chain-elongating microbiomes enriched at low SGV were washed out at high SGV where Clostridium tyrobutyricum-dominated microbiomes thrived, by displaying higher lactate consumption rates. Suspended growth seemed to be dominant regardless of SGV and gas supply regime applied with no measurable sludge bed formed. The highest MCC production from lactate of 10 g COD∙L−1∙d−1 with electron selectivities of 72 ± 5%was obtained without N2 gas supply at a hydraulic retention time (HRT) of 1 day. The addition of 5 g∙L−1 of propionate did not inhibit chain elongation, but rather boosted lactate conversion rates towards MCC with n-heptylate reaching 1.8 g COD∙L−1∙d−1. N2 gas supply can be used for mixing purposes and to steer lactate metabolism to MCC or SCC production.
Collapse
|
18
|
Candry P, Ganigué R. Chain elongators, friends, and foes. Curr Opin Biotechnol 2021; 67:99-110. [PMID: 33529974 DOI: 10.1016/j.copbio.2021.01.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 01/02/2021] [Accepted: 01/07/2021] [Indexed: 12/14/2022]
Abstract
Bioproduction of medium chain carboxylic acids has recently emerged as an alternative strategy to valorize low-value organic waste and side-streams. Key to this route is chain elongation, an anaerobic microbial process driven by ethanol, lactic acid, or carbohydrates. Because these technologies use wastes as feedstocks, mixed microbial communities are often considered as biocatalysts. Understanding and steering these microbiomes is key to optimize bioprocess performance. From a meta-analysis of publicly available sequencing data, we (i) explore how the current collection of isolated chain elongators compares to microbiome members, (ii) discuss the main beneficial and antagonistic interactions with community partners, and (iii) identify the key research gaps and needs to help understand chain elongation microbiomes, and design/steer these novel bioproduction processes.
Collapse
Affiliation(s)
- Pieter Candry
- Civil and Environmental Engineering, University of Washington, 201 More Hall, Box 352700, Seattle, WA 98195-2700, USA
| | - Ramon Ganigué
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
| |
Collapse
|
19
|
Esquivel-Elizondo S, Bağcı C, Temovska M, Jeon BS, Bessarab I, Williams RBH, Huson DH, Angenent LT. The Isolate Caproiciproducens sp. 7D4C2 Produces n-Caproate at Mildly Acidic Conditions From Hexoses: Genome and rBOX Comparison With Related Strains and Chain-Elongating Bacteria. Front Microbiol 2021; 11:594524. [PMID: 33584563 PMCID: PMC7873966 DOI: 10.3389/fmicb.2020.594524] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 12/03/2020] [Indexed: 12/13/2022] Open
Abstract
Bulk production of medium-chain carboxylates (MCCs) with 6-12 carbon atoms is of great interest to biotechnology. Open cultures (e.g., reactor microbiomes) have been utilized to generate MCCs in bioreactors. When in-line MCC extraction and prevention of product inhibition is required, the bioreactors have been operated at mildly acidic pH (5.0-5.5). However, model chain-elongating bacteria grow optimally at neutral pH values. Here, we isolated a chain-elongating bacterium (strain 7D4C2) that grows at mildly acidic pH. We studied its metabolism and compared its whole genome and the reverse β-oxidation (rBOX) genes to other bacteria. Strain 7D4C2 produces lactate, acetate, n-butyrate, n-caproate, biomass, and H2/CO2 from hexoses. With only fructose as substrate (pH 5.5), the maximum n-caproate specificity (i.e., products per other carboxylates produced) was 60.9 ± 1.5%. However, this was considerably higher at 83.1 ± 0.44% when both fructose and n-butyrate (electron acceptor) were combined as a substrate. A comparison of 7D4C2 cultures with fructose and n-butyrate with an increasing pH value from 4.5 to 9.0 showed a decreasing n-caproate specificity from ∼92% at mildly acidic pH (pH 4.5-5.0) to ∼24% at alkaline pH (pH 9.0). Moreover, when carboxylates were extracted from the broth (undissociated n-caproic acid was ∼0.3 mM), the n-caproate selectivity (i.e., product per substrate fed) was 42.6 ± 19.0% higher compared to 7D4C2 cultures without extraction. Based on the 16S rRNA gene sequence, strain 7D4C2 is most closely related to the isolates Caproicibacter fermentans (99.5%) and Caproiciproducens galactitolivorans (94.7%), which are chain-elongating bacteria that are also capable of lactate production. Whole-genome analyses indicate that strain 7D4C2, C. fermentans, and C. galactitolivorans belong to the same genus of Caproiciproducens. Their rBOX genes are conserved and located next to each other, forming a gene cluster, which is different than for other chain-elongating bacteria such as Megasphaera spp. In conclusion, Caproiciproducens spp., comprising strain 7D4C2, C. fermentans, C. galactitolivorans, and several unclassified strains, are chain-elongating bacteria that encode a highly conserved rBOX gene cluster. Caproiciproducens sp. 7D4C2 (DSM 110548) was studied here to understand n-caproate production better at mildly acidic pH within microbiomes and has the additional potential as a pure-culture production strain to convert sugars into n-caproate.
Collapse
Affiliation(s)
- Sofia Esquivel-Elizondo
- AG Angenent, Max Planck Institute for Developmental Biology, Max Planck Society (MPG), Tübingen, Germany
| | - Caner Bağcı
- Algorithms in Bioinformatics, Department of Computer Science, University of Tübingen, Tübingen, Germany
- International Max Planck Research School “From Molecules to Organisms”, Max Planck Institute for Developmental Biology, University of Tübingen, Tübingen, Germany
| | - Monika Temovska
- Environmental Biotechnology Group, Center for Applied Geosciences, University of Tübingen, Tübingen, Germany
| | - Byoung Seung Jeon
- Environmental Biotechnology Group, Center for Applied Geosciences, University of Tübingen, Tübingen, Germany
| | - Irina Bessarab
- Integrative Analysis Unit, Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore, Singapore
| | - Rohan B. H. Williams
- Integrative Analysis Unit, Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore, Singapore
| | - Daniel H. Huson
- Algorithms in Bioinformatics, Department of Computer Science, University of Tübingen, Tübingen, Germany
- Integrative Analysis Unit, Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore, Singapore
| | - Largus T. Angenent
- AG Angenent, Max Planck Institute for Developmental Biology, Max Planck Society (MPG), Tübingen, Germany
- Environmental Biotechnology Group, Center for Applied Geosciences, University of Tübingen, Tübingen, Germany
| |
Collapse
|
20
|
Cloning and characterization of a L-lactate dehydrogenase gene from Ruminococcaceae bacterium CPB6. World J Microbiol Biotechnol 2020; 36:182. [PMID: 33170386 DOI: 10.1007/s11274-020-02958-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 11/03/2020] [Indexed: 10/23/2022]
Abstract
Lactate are proved to be attractive electron donor for the production of n-caproic acid (CA) that is a high value-added fuel precursor and chemical feedstock, but little is known about molecular mechanism of lactate transformation. In the present study, the gene for L-lactate dehydrogenase (LDH, EC.1.1.1.27) from a Ruminococcaceae strain CPB6 was cloned and expressed in Escherichia coli BL21 (DE3) with plasmid pET28a. The recombinant LDH exhibited molecular weight of 36-38 kDa in SDS-PAGE. The purified LDH was found to have the maximal oxidation activity of 29.6 U/mg from lactate to pyruvate at pH 6.5, and the maximal reduction activity of 10.4 U/mg from pyruvate to lactate at pH 8.5, respectively. Strikingly, its oxidative activity predominates over reductive activity, leading to a 17-fold increase for the utilization of lactate in E. coli/pET28a-LDH than E. coli/pET28a. The CPB6 LDH gene encodes a 315 amino acid protein sharing 42.19% similarity with Clostridium beijerinckii LDH, and lower similarity with LDHs of other organisms. Significant difference were observed between the CPB6 LDH and C. beijerinckii and C. acetobutylicum LDH in the predicted tertiary structure and active center. Further, X-ray crystal structure analysis need to be performed to verify the specific active center of the CPB6 LDH and its role in the conversion of lactate into CA.
Collapse
|
21
|
Braundmeier-Fleming AG, Skenandore CS, Gil L, Jacobsen V, Cregger M, Badger T, Karr M, Wu G, Smith SB, Newell-Fugate AE. Dietary substitution of soybean oil with coconut oil in the absence of dietary antibiotics supports growth performance and immune function in nursery and grower pigs. J Anim Sci Biotechnol 2020; 11:27. [PMID: 32190298 PMCID: PMC7075000 DOI: 10.1186/s40104-020-0428-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 01/15/2020] [Indexed: 12/31/2022] Open
Abstract
Background We hypothesized that supplementation of nursery and grower pig diets with coconut oil in the absence of antibiotics would yield maintenance of glucose homeostasis, growth performance, and immune function similar to what is achieved with nursery and grower pig diets containing antibiotics. Pigs received the same base treatment diets from d24 (weaning) to d71 of age and had blood and fecal samples collected on d24, d31, d45 and d71 for measurement of whole blood glucose, serum insulin, cortisol and cytokines, and fecal microbiome. Pigs had weekly weights and daily feed consumption measured throughout the study. Animals were euthanized at d71 and subcutaneous fat and ileal contents were collected for assessment for fatty acids and microbiome, respectively. Diet treatments consisted of 2% soybean oil plus antibiotics (ABX; n = 22), 2% soybean oil without antibiotics (NABX; n = 22), and 2% coconut oil without antibiotics (COC; n = 22). Statistical analysis examined the effect of diet within each timepoint using a repeated measures ANOVA. Results Pigs fed COC diet had decreased serum insulin levels, maintained feed intake, feed conversion and weight gain, and, based on serum cytokines and fecal microbiome, were immunologically similar to ABX-fed pigs. However, NABX-fed pigs performed similarly to the ABX-fed pigs in all parameters except for serum cytokines. Additionally, there was no difference in the incidence of diarrhea between any of the diet treatments. Conclusions This study demonstrates that dietary antibiotics are not necessary to maintain growth performance in nursery and grower pigs. However, dietary antibiotics appear to modulate circulating cytokine levels. Dietary coconut oil is neither harmful nor helpful to growth performance or immune function in nursery and grower pigs but does modulate serum insulin levels. Therefore, while coconut oil fed at 2% by weight is a suitable substitute for dietary antibiotics, this study suggests that no substitute for dietary antibiotics is needed at all.
Collapse
Affiliation(s)
- Andrea G Braundmeier-Fleming
- 1Department of Medical Microbiology, Immunology and Cell Biology, School of Medicine, Southern Illinois University, Springfield, IL 62702 USA
| | - Cassandra S Skenandore
- 2Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, 4466 TAMU, College Station, TX 77843 USA
| | - Lesly Gil
- 2Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, 4466 TAMU, College Station, TX 77843 USA
| | - Victoria Jacobsen
- 2Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, 4466 TAMU, College Station, TX 77843 USA
| | - Melissa Cregger
- 1Department of Medical Microbiology, Immunology and Cell Biology, School of Medicine, Southern Illinois University, Springfield, IL 62702 USA
| | - Taylor Badger
- 1Department of Medical Microbiology, Immunology and Cell Biology, School of Medicine, Southern Illinois University, Springfield, IL 62702 USA
| | - Mallory Karr
- 1Department of Medical Microbiology, Immunology and Cell Biology, School of Medicine, Southern Illinois University, Springfield, IL 62702 USA
| | - Guoyao Wu
- 3Department of Animal Science, Texas A&M University, 2471 TAMU, College Station, TX 77843 USA
| | - Stephen B Smith
- 3Department of Animal Science, Texas A&M University, 2471 TAMU, College Station, TX 77843 USA
| | - Annie E Newell-Fugate
- 2Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, 4466 TAMU, College Station, TX 77843 USA
| |
Collapse
|
22
|
Syngas-aided anaerobic fermentation for medium-chain carboxylate and alcohol production: the case for microbial communities. Appl Microbiol Biotechnol 2019; 103:8689-8709. [PMID: 31612269 DOI: 10.1007/s00253-019-10086-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/06/2019] [Accepted: 08/07/2019] [Indexed: 01/01/2023]
Abstract
Syngas fermentation has been successfully implemented in commercial-scale plants and can enable the biochemical conversion of the driest fractions of biomass through synthesis gas (H2, CO2, and CO). The process relies on optimized acetogenic strains able to reach and maintain high productivity of ethanol and acetate. In parallel, microbial communities have shown to be the best choice for the production of valuable medium-chain carboxylates through anaerobic fermentation of biomass, demanding low technical complexity and being able to realize simultaneous hydrolysis of the substrate. Each of the two technologies benefits from different strong points and has different challenges to overcome. This review discusses the rationales for merging these two seemingly disparate technologies by analyzing previous studies and drawing opinions based on the lessons learned from such studies. For keeping the technical demands of the resulting process low, a case is built for using microbial communities instead of pure strains. For that to occur, a shift from conventional syngas-based to "syngas-aided" anaerobic fermentation is suggested. Strategies for tackling the intricacies of working simultaneously with communities and syngas, such as competing pathways, and thermodynamic aspects are discussed as well as the stoichiometry and economic feasibility of the concept. Overall, syngas-aided anaerobic fermentation seems to be a promising concept for the biorefinery of the future. However, the effects of process parameters on microbial interactions have to be understood in greater detail, in order to achieve and sustain feasible medium-chain carboxylate and alcohol productivity.
Collapse
|