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Dai M, Xu Y, Zhao L, Wu M, Ma H, Zhu L, Li W, Li X, Sun B. Caproicibacter sp. BJN0012, a potential new species isolated from cellar mud for caproic acid production from glucose. J Biotechnol 2024; 388:11-23. [PMID: 38614441 DOI: 10.1016/j.jbiotec.2024.04.005] [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: 12/29/2023] [Revised: 04/08/2024] [Accepted: 04/09/2024] [Indexed: 04/15/2024]
Abstract
Acids play a crucial role in enhancing the flavor of strong-aroma Baijiu, and among them, caproic acid holds significant importance in determining the flavor of the final product. However, the metabolic synthesis of caproic acid during the production process of Baijiu has received limited attention, resulting in fluctuations in caproic acid content among fermentation batches and generating production instability. Acid-producing bacteria found in the cellar mud are the primary microorganisms responsible for caproic acid synthesis, but there is a lack of research on the related microbial resources and their metabolic properties. Therefore, it is essential to identify and investigate these acid-producing microorganisms from cellar mud to ensure stable caproic acid synthesis. In this study, a unique strain was isolated from the cellar mud, exhibiting a 98.12 % similarity in its 16 S rRNA sequence and an average nucleotide identity of 79.57 % with the reference specie, together with the DNA-DNA hybridization of 23.20 % similarity, confirming the distinct species boundaries. The strain was able to produce 1.22 ± 0.55 g/L caproic acid from glucose. Through genome sequencing, annotation, and bioinformatics analysis, the complete pathway of caproic acid synthesis from glucose was elucidated, and the catalytic mechanism of the key thiolase for caproic acid synthesis was investigated. These findings provide useful fundamental data for revealing the metabolic properties of caproic acid-producing bacteria found in cellar mud.
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Affiliation(s)
- Mengqi Dai
- School of Food and Health, Beijing Technology and Businmmess University, Beijing 100048, China
| | - Youqiang Xu
- School of Food and Health, Beijing Technology and Businmmess University, Beijing 100048, China; Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing 100048, China.
| | - Lei Zhao
- School of Food and Health, Beijing Technology and Businmmess University, Beijing 100048, China
| | - Mengqin Wu
- School of Food and Health, Beijing Technology and Businmmess University, Beijing 100048, China
| | - Huifeng Ma
- Hebei Fenglaiyi Wine Industry Co., Ltd, Xingtai, Hebei province 055550, China
| | - Lining Zhu
- Hebei Fenglaiyi Wine Industry Co., Ltd, Xingtai, Hebei province 055550, China
| | - Weiwei Li
- School of Food and Health, Beijing Technology and Businmmess University, Beijing 100048, China; Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing 100048, China
| | - Xiuting Li
- Key Laboratory of Brewing Microbiome and Enzymatic Molecular Engineering, China General Chamber of Commerce, Beijing 102401, China.
| | - Baoguo Sun
- Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing Technology and Business University, Beijing 100048, China; Key Laboratory of Geriatric Nutrition and Health (Beijing Technology and Business University), Ministry of Education, Beijing 100048, China
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Ulčar B, Regueira A, Podojsteršek M, Boon N, Ganigué R. Why do lactic acid bacteria thrive in chain elongation microbiomes? Front Bioeng Biotechnol 2024; 11:1291007. [PMID: 38274012 PMCID: PMC10809155 DOI: 10.3389/fbioe.2023.1291007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 12/11/2023] [Indexed: 01/27/2024] Open
Abstract
Efficient waste management is necessary to transition towards a more sustainable society. An emerging trend is to use mixed culture biotechnology to produce chemicals from organic waste. Insights into the metabolic interactions between community members and their growth characterization are needed to mediate knowledge-driven bioprocess development and optimization. Here, a granular sludge bioprocess for the production of caproic acid through sugar-based chain elongation metabolism was established. Lactic acid and chain-elongating bacteria were identified as the two main functional guilds in the granular community. The growth features of the main community representatives (isolate Limosilactobacillus musocae G03 for lactic acid bacteria and type strain Caproiciproducens lactatifermentans for chain-elongating bacteria) were characterized. The measured growth rates of lactic acid bacteria (0.051 ± 0.005 h-1) were two times higher than those of chain-elongating bacteria (0.026 ± 0.004 h-1), while the biomass yields of lactic acid bacteria (0.120 ± 0.005 g biomass/g glucose) were two times lower than that of chain-elongating bacteria (0.239 ± 0.007 g biomass/g glucose). This points towards differential growth strategies, with lactic acid bacteria resembling that of a r-strategist and chain-elongating bacteria resembling that of a K-strategist. Furthermore, the half-saturation constant of glucose for L. mucosae was determined to be 0.35 ± 0.05 g/L of glucose. A linear trend of caproic acid inhibition on the growth of L. mucosae was observed, and the growth inhibitory caproic acid concentration was predicted to be 13.6 ± 0.5 g/L, which is the highest reported so far. The pre-adjustment of L. mucosae to 4 g/L of caproic acid did not improve the overall resistance to it, but did restore the growth rates at low caproic acid concentrations (1-4 g/L) to the baseline values (i.e., growth rate at 0 g/L of caproic acid). High resistance to caproic acid enables lactic acid bacteria to persist and thrive in the systems intended for caproic acid production. Here, insights into the growth of two main functional guilds of sugar-based chain elongation systems are provided which allows for a better understanding of their interactions and promotes future bioprocess design and optimization.
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Affiliation(s)
- Barbara Ulčar
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Ghent University, Gent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Gent, Belgium
| | - Alberte Regueira
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Ghent University, Gent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Gent, Belgium
- Department of Chemical Engineering, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Maja Podojsteršek
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Ghent University, Gent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Gent, Belgium
| | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Ghent University, Gent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Gent, Belgium
| | - Ramon Ganigué
- Center for Microbial Ecology and Technology (CMET), Department of Biotechnology, Ghent University, Gent, Belgium
- Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Gent, Belgium
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Zeng C, Zeng X, Xia S, Ye G. Caproicibacterium argilliputei sp. nov., a novel caproic acid producing anaerobic bacterium isolated from pit clay. Int J Syst Evol Microbiol 2024; 74. [PMID: 38265435 DOI: 10.1099/ijsem.0.006246] [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] [Indexed: 01/25/2024] Open
Abstract
An anaerobic, Gram-positive, rod-shaped, motile and spore-forming bacterium, designated strain ZCY20-5T, was isolated from pit clay of Chinese strong-aroma type Baijiu (Chinese liquor). Phylogenetic analyses based on 16S rRNA gene and genome sequences showed that strain ZCY20-5T belonged to the genus Caproicibacterium, family Oscillospiracheae, but it showed low similarity to the type species Caproicibacterium amylolyticum LBM18003T (98.00 %) and Caproicibacterium lactatifermentans LBM19010T (95.67 %). In anaerobic yeast extract medium, growth was observed at 20-45 °C (optimum, 35-40 °C), at pH 4.0-9.0 (optimum, pH 6.5-7.0) and with 0.0-2.0 % NaCl (w/v). The predominant fatty acids were C16 : 0, C14 : 0, C13 3-OH and C16 3-OH, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, three phospholipids of unknown structure containing glucosamine and two unidentified phospholipids. Strain ZCY20-5T exhibited an 81.32 % pairwise average nucleotide identity value, a 78.98 % average amino acid identity value and a 22.30 % digital DNA-DNA hybridization value compared to its closest relative C. amylolyticum LBM18003T. Based on morphological, physiological, biochemical, chemotaxonomic, genotypic and phylogenetic results, strain ZCY20-5T represents a novel species of Caproicibacterium, and the type strain is ZCY20-5T (=MCCC 1A19399T=KCTC 25590T).
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Affiliation(s)
- Caiyu Zeng
- College of Bioengineering, Sichuan University of Science & Engineering, Yibin644000,Sichuan, PR China
- Liquormaking Biotechnology and Application of Key Laboratory of Sichuan Province, Sichuan University of Science & Engineering, Yibin 644000, Sichuan, PR China
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, Fujian, PR China
| | - Xiang Zeng
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, Fujian, PR China
- Faculty of Marine Biology, Xiamen Ocean Vocational College, Xiamen 361100, Fujian, PR China
| | - Shangcao Xia
- College of Bioengineering, Sichuan University of Science & Engineering, Yibin644000,Sichuan, PR China
- Liquormaking Biotechnology and Application of Key Laboratory of Sichuan Province, Sichuan University of Science & Engineering, Yibin 644000, Sichuan, PR China
| | - Guangbin Ye
- College of Bioengineering, Sichuan University of Science & Engineering, Yibin644000,Sichuan, PR China
- Liquormaking Biotechnology and Application of Key Laboratory of Sichuan Province, Sichuan University of Science & Engineering, Yibin 644000, Sichuan, PR China
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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.
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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.
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Wu M, Xu Y, Dai M, Li W, Zhang C, Li X, Sun B. Butyriproducens baijiuensis BJN0003: a potential new member of the family Oscillospiraceae isolated from Chinese Baijiu. 3 Biotech 2023; 13:205. [PMID: 37223001 PMCID: PMC10200727 DOI: 10.1007/s13205-023-03624-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 05/10/2023] [Indexed: 05/25/2023] Open
Abstract
Acid-producing bacteria are one kind of crucial species for Baijiu fermentation. The strain BJN0003 with the ability of producing butyric acid was isolated from the cellar mud of Baijiu, and the 16S rRNA gene sequence similarity was 94.2% to its most closely related type species Caproicibacterium lactiferaments JNU-WLY1368T, less than the threshold value of 94.5% for distinguishing genera. Furthermore, the genome of BJN0003 showed a length of 2,458,513 bp and a DNA G + C content of 43.3% through high throughput sequence. BJN0003 exhibited whole-genome average nucleotide identity value of 68.9% to the most closely related species, while the whole-genome digital DNA-DNA hybridization value was only 23.1%, which were both below the delineation thresholds of species. These results indicated BJN0003 could represent a potential novel species of a new genus of the family Oscillospiraceae, and was proposed the name as Butyriproducens baijiuensis. In addition, gene annotation and metabolic analysis showed that BJN0003 harbored the metabolic pathway of converting glucose to butyric acid. The discovery of the new species provided bacterial resource for Baijiu production and the revealing of genetic characteristics would promote the investigation of acid synthesis during Baijiu manufacturing process. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-023-03624-w.
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Affiliation(s)
- Mengqin Wu
- Key Laboratory of Brewing Microbiology and Enzymatic Molecular Engineering of China General Chamber of Commerce, Beijing Technology and Business University, No. 33, Fucheng Road, Haidian District, Beijing, 100048 China
| | - Youqiang Xu
- Key Laboratory of Brewing Microbiology and Enzymatic Molecular Engineering of China General Chamber of Commerce, Beijing Technology and Business University, No. 33, Fucheng Road, Haidian District, Beijing, 100048 China
| | - Mengqi Dai
- Key Laboratory of Brewing Microbiology and Enzymatic Molecular Engineering of China General Chamber of Commerce, Beijing Technology and Business University, No. 33, Fucheng Road, Haidian District, Beijing, 100048 China
| | - Weiwei Li
- Key Laboratory of Brewing Microbiology and Enzymatic Molecular Engineering of China General Chamber of Commerce, Beijing Technology and Business University, No. 33, Fucheng Road, Haidian District, Beijing, 100048 China
| | - Chengnan Zhang
- Key Laboratory of Brewing Microbiology and Enzymatic Molecular Engineering of China General Chamber of Commerce, Beijing Technology and Business University, No. 33, Fucheng Road, Haidian District, Beijing, 100048 China
| | - Xiuting Li
- Key Laboratory of Brewing Microbiology and Enzymatic Molecular Engineering of China General Chamber of Commerce, Beijing Technology and Business University, No. 33, Fucheng Road, Haidian District, Beijing, 100048 China
- Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing Technology and Business University, No. 33, Fucheng Road, Haidian District, Beijing, 100048 China
| | - Baoguo Sun
- Key Laboratory of Brewing Microbiology and Enzymatic Molecular Engineering of China General Chamber of Commerce, Beijing Technology and Business University, No. 33, Fucheng Road, Haidian District, Beijing, 100048 China
- Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing Technology and Business University, No. 33, Fucheng Road, Haidian District, Beijing, 100048 China
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Zhou Z, Liu Z, Wen S, Ouyang G, Shen Y, Yang Q, Ren C, Xu Y. Rare short- and medium-chain fatty acid-producing anaerobes from raw soil play vital roles in formation of diverse flavour compounds of Jiangxiangxing Baijiu. Food Microbiol 2023; 112:104247. [PMID: 36906311 DOI: 10.1016/j.fm.2023.104247] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/17/2023] [Accepted: 02/23/2023] [Indexed: 02/27/2023]
Abstract
Pit mud is an essential habitat for diverse anaerobes, however, how pit mud of Jiangxiangxing Baijiu contributes to flavour is still unclear. The correlation between pit mud anaerobes and flavour compounds formation was investigated by analyzing flavour compounds and prokaryotic community of pit mud as well as fermented grains. Then scaling-down fermentation and culture-dependent approach were used to verify the effects of pit mud anaerobes on flavour compound formation. We found that short- and medium-chain fatty acids and alcohols, e.g., propionate, butyrate, caproate, 1-butanol, 1-hexanol, and 1-heptanol, were the vital flavour compounds produced by pit mud anaerobes. Pit mud anaerobes hardly migrated into fermented grains because of the low pH and low moisture of fermented grains. Therefore, the flavour compounds produced by pit mud anaerobes might enter fermented grains via volatilization. Moreover, enrichment culturing proved that raw soil was one of the sources for pit mud anaerobes, e.g., Clostridiumtyrobutyricum, Ruminococcaceae bacterium BL-4 and Caproicibacteriumamylolyticum. These rare short- and medium-chain fatty acid-producing anaerobes in raw soil can be enriched during Jiangxiangxing Baijiu fermentation. These findings clarified the role of pit mud during Jiangxiangxing Baijiu fermentation and revealed the key species involved in short- and medium-chain fatty acid-producing production.
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Affiliation(s)
- Zihan Zhou
- Laboratory of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Ave., Wuxi, 214122, Jiangsu, China
| | - Zhihao Liu
- Laboratory of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Ave., Wuxi, 214122, Jiangsu, China
| | - Shangyu Wen
- Jingpai Maotai Town Liquor Co., Ltd., Zunyi, 564501, Guizhou, China
| | - Gaowei Ouyang
- Jingpai Maotai Town Liquor Co., Ltd., Zunyi, 564501, Guizhou, China
| | - Yongxiang Shen
- Jingpai Maotai Town Liquor Co., Ltd., Zunyi, 564501, Guizhou, China
| | - Qiang Yang
- Jing Brand Research Institute, Jing Brand Co., Ltd., Daye, 435100, Hubei, China
| | - Cong Ren
- Laboratory of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Ave., Wuxi, 214122, Jiangsu, China.
| | - Yan Xu
- Laboratory of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Ave., Wuxi, 214122, Jiangsu, China.
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Nguyen TV, Viver T, Smets I, Bernaerts K, Faust K, Lavigne R, Poughon L, Dussap CG, Springael D. Thermocaproicibacter melissae gen. nov., sp. nov., a thermophilic chain-elongating bacterium, producing n-caproate from polymeric carbohydrates. Int J Syst Evol Microbiol 2023; 73. [PMID: 37200213 DOI: 10.1099/ijsem.0.005893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023] Open
Abstract
Strain MDTJ8T is a chain-elongating thermophilic bacterium isolated from a thermophilic acidogenic anaerobic digestor treating human waste while producing the high commodity chemical n-caproate. The strain grows and produces formate, acetate, n-butyrate, n-caproate and lactate from mono-, di- and polymeric saccharides at 37-60 °C (optimum, 50-55 °C) and at pH 5.0-7.0 (optimum, pH 6.5). The organism is an obligate anaerobe, is motile and its cells form rods (0.3-0.5×1.0-3.0 µm) that stain Gram-positive and occur primarily as chains. Phylogenetic analysis of both the 16S rRNA gene and full genome sequence shows that strain MDTJ8T belongs to a group that consists of mesophylic chain-elongating bacteria within the family Oscillospiraceae, being nearest to Caproicibacter fermentans EA1T (94.8 %) and Caproiciproducens galactitolivorans BS-1T (93.7 %). Its genome (1.96 Mbp) with a G+C content of 49.6 mol% is remarkably smaller than those of other chain-elongating bacteria of the family Oscillospiraceae. Pairwise average nucleotide identity and DNA-DNA hybridization values between strain MDJT8T and its mesophilic family members are less than 70 and 35 %, respectively, while pairwise average amino acid identity values are less than 68 %. In addition, strain MDJT8T uses far less carbohydrate and non-carbohydrate substrates compared to its nearest family members. The predominant cellular fatty acids of strain MDTJ8T are C14 : 0, C14 : 0 DMA (dimethyl acetal) and C16 : 0, while its polar lipid profile shows three unidentified glycophospholipids, 11 glycolipids, 13 phospholipids and six unidentified lipids. No respiratory quinones and polyamines are detected. Based on its phylogenetic, genotypic, morphological, physiological, biochemical and chemotaxonomic characteristics, strain MDTJ8T represents a novel species and novel genus of the family Oscillospiraceae and Thermocaproicibacter melissae gen. nov., sp. nov. is proposed as its name. The type strain is MDTJ8T (=DSM 114174T=LMG 32615T=NCCB 100883T).
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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 Marquès 21, 07190 Esporles, Spain
| | - 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
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Li D, Ye G, Zong X, Zou W. Effect of Multiple Rounds of Enrichment on Metabolite Accumulation and Microbiota Composition of Pit Mud for Baijiu Fermentation. Foods 2023; 12:foods12081594. [PMID: 37107389 PMCID: PMC10137600 DOI: 10.3390/foods12081594] [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: 03/10/2023] [Revised: 04/06/2023] [Accepted: 04/07/2023] [Indexed: 04/29/2023] Open
Abstract
Pit mud (PM) is the main component of Baijiu (traditional Chinese liquor), and its microorganisms are the primary sources of the aroma of Chinese strong-flavor Baijiu (SFB). Enrichment plays an important role in the selection of functional microorganisms in PM. Herein, the PM of SFB was submitted to six rounds of enrichment using clostridial growth medium (CGM), and changes in the metabolite accumulation and microbiota composition were evaluated. Based on the metabolite production and microbiota composition, the enrichment rounds were classified as the acclimation stage (round 2), main fermentation stage (rounds 3 and 4), and late fermentation stage (rounds 5 and 6). Species within the genus Clostridium dominated in the acclimation stage (65.84-74.51%). In the main fermentation stage, the dominant microbial groups were producers of butyric acid, acetic acid, and caproic acid, which included Clostridium (45.99-74.80%), Caproicibacter (1.45-17.02%), and potential new species within the order of Oscillataceae (14.26-29.10%). In the late stage of enrichment, Pediococcus dominated (45.96-79.44%). Thus, the main fermentation stage can be considered optimal for the isolation of acid-producing bacteria from PM. The findings discussed herein support the development and application of functional bacteria by bioaugmentation, and contribute to improving the quality of PM and SFB production.
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Affiliation(s)
- Dong Li
- School of Life Science, Sichuan University of Science & Engineering, Yibin 644000, China
| | - Guangbin Ye
- School of Life Science, Sichuan University of Science & Engineering, Yibin 644000, China
- Liquor-Making Biotechnology and Application of Key Laboratory of Sichuan Province, Sichuan University of Science & Engineering, Yibin 644000, China
| | - Xuyan Zong
- School of Life Science, Sichuan University of Science & Engineering, Yibin 644000, China
- Liquor-Making Biotechnology and Application of Key Laboratory of Sichuan Province, Sichuan University of Science & Engineering, Yibin 644000, China
| | - Wei Zou
- School of Life Science, Sichuan University of Science & Engineering, Yibin 644000, China
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Xu Y, Wu M, Zhao D, Zheng J, Dai M, Li X, Li W, Zhang C, Sun B. Simulated Fermentation of Strong-Flavor Baijiu through Functional Microbial Combination to Realize the Stable Synthesis of Important Flavor Chemicals. Foods 2023; 12:foods12030644. [PMID: 36766173 PMCID: PMC9913964 DOI: 10.3390/foods12030644] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 01/19/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
The solid-state fermentation of Baijiu is complicated by the co-fermentation of many microorganisms. The instability of the composition and abundance of the microorganisms in the fermentation process leads to fluctuations of product quality, which is one of the bottleneck problems faced by the Strong-flavor Baijiu industry. In this study, we established a combination of functional microorganisms for the stable fermentation of the main flavor compounds of Baijiu, including medium and long-chain fatty acid ethyl esters such as hexanoic acid, ethyl ester; butanoic acid, ethyl ester; octanoic acid, ethyl ester; acetic acid, ethyl ester; 9,12-octadecadienoic acid, ethyl ester; and decanoic acid, ethyl ester in the fermented grains. Our study investigated the effects of microbial combinations on the fermentation from three aspects: microbial composition, microbial interactions, and microbial association with flavor compounds. The results showed that the added functional microorganisms (Lactobacillus, Clostridium, Caproiciproducens, Saccharomyces, and Aspergillus) became the dominant species in the fermentation system and formed positive interactions with other microorganisms, while the negative interactions between microorganisms were significantly reduced in the fermentation systems that contained both Daqu and functional microorganisms. The redundancy analysis showed that the functional microorganisms (Lactobacillus, Saccharomyces, Clostridium, Cloacibacterium, Chaenothecopsis, Anaerosporobacter, and Sporolactobacillus) showed strong positive correlations with the main flavor compounds (hexanoic acid, ethyl ester; lactic acid, ethyl ester; butanoic acid, ethyl ester; acetic acid, ethyl ester; and octanoic acid, ethyl ester). These results indicated that it was feasible to produce Baijiu with a functional microbial combination, and that this could promote stable Baijiu production.
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Affiliation(s)
- Youqiang Xu
- School of Food and Health, Beijing Technology and Business University (BTBU), Beijing 100048, China
- Correspondence: (Y.X.); (X.L.)
| | - Mengqin Wu
- School of Food and Health, Beijing Technology and Business University (BTBU), Beijing 100048, China
| | - Dong Zhao
- Wuliangye Yibin Co., Ltd., Yibin 644000, China
| | - Jia Zheng
- Wuliangye Yibin Co., Ltd., Yibin 644000, China
| | - Mengqi Dai
- School of Food and Health, Beijing Technology and Business University (BTBU), Beijing 100048, China
| | - Xiuting Li
- Key Laboratory of Brewing Microbiome and Enzymatic Molecular Engineering, China General Chamber of Commerce, Beijing 102401, China
- Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing Technology and Business University (BTBU), Beijing 100048, China
- Correspondence: (Y.X.); (X.L.)
| | - Weiwei Li
- School of Food and Health, Beijing Technology and Business University (BTBU), Beijing 100048, China
| | - Chengnan Zhang
- School of Food and Health, Beijing Technology and Business University (BTBU), Beijing 100048, China
| | - Baoguo Sun
- Key Laboratory of Brewing Microbiome and Enzymatic Molecular Engineering, China General Chamber of Commerce, Beijing 102401, China
- Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing Technology and Business University (BTBU), Beijing 100048, China
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10
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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.
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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.
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11
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Miao Z, Hao H, Yan R, Wang X, Wang B, Sun J, Li Z, Zhang Y, Sun B. Individualization of Chinese alcoholic beverages: Feasibility towards a regulation of organic acids. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2022.114168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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12
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Liu Q, Zheng H, Wang H, Zhou W, Zhao D, Qiao Z, Zheng J, Ren C, Xu Y. Proteiniphilum propionicum sp. nov., a novel member of the phylum Bacteroidota isolated from pit clay used to produce Chinese liquor. Int J Syst Evol Microbiol 2022; 72. [PMID: 36748686 DOI: 10.1099/ijsem.0.005612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
A novel, Gram-stain-negative, rod-shaped, strictly anaerobic bacterium of genus Proteiniphilum of the phylum Bacteroidota, named strain JNU-WLY501T, was isolated from pit clay used to produce strong aroma-type liquor in PR China. The genomic DNA G+C content and genome size of JNU-WLY501T were 41.4 % and 3.9 Mbp, respectively. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that JNU-WLY501T was closely related to Proteiniphilum acetatigenes DSM 18083T (95.7 %) and Proteiniphilum saccharofermentans M3/6T (94.9 %). The pairwise average nucleotide identity based on blast and average amino acid identity values of JNU-WLY501T compared with Proteiniphilum saccharofermentans M3/6T were 73.6 and 77.3 %, respectively, which both were lower than the threshold values for bacterial species delineation. The strain grew at 20-40 °C, with optimum growth at 37 °C. The pH range for growth was 5.4-9.1, with optimum growth at pH 7.5. The sodium chloride range for growth was 0.0-4.0 %, with optimum growth at 0 %. The strain did not use glucose, maltose, fructose or starch. Yeast extract, tryptone and peptone supported the growth of JNU-WLY501T, and the main fermentation products were acetate and propionate. The predominant cellular fatty acids (>5 %) of JNU-WLY501T were anteiso-C15 : 0 (30.6 %), anteiso-C17 : 0 (26.1 %), C16 : 0 (7.7 %), iso-C16 : 0 (5.0 %) and iso-C17 : 0 (5.0 %). The respiratory quinone of JNU-WLY501T was MK-5. On the basis of the morphological, physiological, biochemical, chemotaxonomic, genotypic and phylogenetic results, JNU-WLY501T represents a novel species of the genus Proteiniphilum, for which the name Proteiniphilum propionicum sp. nov. is proposed. The type strain is JNU-WLY501T (=GDMCC 1.2686T=JCM 34753T).
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Affiliation(s)
- Qiuju Liu
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Huizhen Zheng
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Huilin Wang
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Weicheng Zhou
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Dong Zhao
- Wuliangye Yibin Co., Ltd., No.150 Minjiang West Road, Yibin 644007, PR China.,Key Laboratory of Wuliangye-flavor Liquor Solid-state Fermentation, China National Light Industry, Yibin 644007, PR China.,JNU-WLY Collaborative Innovation Laboratory of Microbiome and Ecological Fermentation Technology, Jiangnan University, Wuxi 214122, PR China
| | - Zongwei Qiao
- Wuliangye Yibin Co., Ltd., No.150 Minjiang West Road, Yibin 644007, PR China.,Key Laboratory of Wuliangye-flavor Liquor Solid-state Fermentation, China National Light Industry, Yibin 644007, PR China.,JNU-WLY Collaborative Innovation Laboratory of Microbiome and Ecological Fermentation Technology, Jiangnan University, Wuxi 214122, PR China
| | - Jia Zheng
- Wuliangye Yibin Co., Ltd., No.150 Minjiang West Road, Yibin 644007, PR China.,Key Laboratory of Wuliangye-flavor Liquor Solid-state Fermentation, China National Light Industry, Yibin 644007, PR China.,JNU-WLY Collaborative Innovation Laboratory of Microbiome and Ecological Fermentation Technology, Jiangnan University, Wuxi 214122, PR China
| | - Cong Ren
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, PR China.,JNU-WLY Collaborative Innovation Laboratory of Microbiome and Ecological Fermentation Technology, Jiangnan University, Wuxi 214122, PR China
| | - Yan Xu
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, PR China.,JNU-WLY Collaborative Innovation Laboratory of Microbiome and Ecological Fermentation Technology, Jiangnan University, Wuxi 214122, PR China
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13
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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.
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14
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Mariën Q, Ulčar B, Verleyen J, Vanthuyne B, Ganigué R. High-rate conversion of lactic acid-rich streams to caproic acid in a fermentative granular system. BIORESOURCE TECHNOLOGY 2022; 355:127250. [PMID: 35562021 DOI: 10.1016/j.biortech.2022.127250] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/26/2022] [Accepted: 04/27/2022] [Indexed: 06/15/2023]
Abstract
Lactic acid-driven chain elongation enables upgrading low-value organic streams into caproic acid. Recently, volumetric production rates over 0.5 g L-1 h-1have been reported for carbohydrate-rich streams in expanded granular sludge bed (EGSB) reactors. However, many target streams contain mixtures of carbohydrates and lactic acid, and little is known about their impact on product profile and microbial ecology, or the importance of carbohydrates as substrate to achieve high rates. This manuscript investigated varying glucose-to-lactate ratios and observed that decreasing glucose-content eliminated odd-chain by-products, while glucose omission required acetic acid addition to support lactic acid conversion. Decreasing the glucose-content fed resulted in decreasing amounts of granular biomass, with the disappearance of granules when no glucose was fed. Lowering the HRT to 0.3 days while feeding only lactic and acetic acid likely triggered re-granulation, enabling the highest lactic acid-driven caproic acid production rates reported thus far at 16.4 ± 1.7 g L-1 d-1.
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Affiliation(s)
- Quinten Mariën
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium; Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Frieda Saeysstraat 1, 9000 Ghent, Belgium
| | - Barbara Ulčar
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium; Center for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Frieda Saeysstraat 1, 9000 Ghent, Belgium
| | - Jesper Verleyen
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Benjamin Vanthuyne
- 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 Process Technology for Urban Resource Recovery (CAPTURE), Frieda Saeysstraat 1, 9000 Ghent, Belgium.
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15
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Wang H, Gu Y, Zhao D, Qiao Z, Zheng J, Gao J, Ren C, Xu Y. Caproicibacterium lactatifermentans sp. nov., isolated from pit clay used for the production of Chinese strong aroma-type liquor. Int J Syst Evol Microbiol 2022; 72. [PMID: 35085065 DOI: 10.1099/ijsem.0.005206] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two recently reported bacterial strains that were identified as the dominant caproate-producing bacteria in pit clay, were further characterized to determine their phylogeny and taxonomy. The two strains, designated as LBM19010T and JNU-WLY1368, were short rod-shaped, Gram-stain-positive, non-motile and strictly anaerobic. Analysis of the 16S rRNA gene sequences revealed that strains LBM19010T and JNU-WLY1368 shared a 16S rRNA gene sequence similarity of 99.93 % and belonged to a recent proposed genus Caproicibacterium in the family Oscillospiraceae. The proposed type strain, LBM19010T, showed the highest 16S rRNA gene sequence similarity to Caproicibacterium amylolyticum LBM18003T (96.34%), followed by Caproiciproducens galactitolivorans JCM 30532T (94.14 %). The pairwise average nucleotide identity and average amino acid identity values between strains LBM19010T and LBM18003T were 74.84 and 76.18 %, respectively. Growth of strain LBM19010T occurred at pH 4.5-7.5 (optimum, pH 5.0-5.5), 20-40 °C (optimum, 35 °C) and with 0-1 % (w/v) NaCl (optimum, 0 %). Strains LBM19010T and JNU-WLY1368 were both able to ferment several hexoses, disaccharides, starch and lactate but not pentoses. Caproate and butyrate were the major end-products from glucose. The predominant cellular fatty acids (>10 %) of strain LBM19010T were C16 : 0 (56.3 %), C14 : 0 DMA (19.5 %) and C14 : 0 (14.9 %). The identified polar lipids of strain LBM19010T were diphosphatidylglycerol, phosphatidylglycerol, three unidentified phospholipids and nine unidentified glycolipids. Based on phylogenetic, phenotypic and chemotaxonomic evidence, strains LBM19010T and JNU-WLY1368 belong to a novel species of the genus Caproicibacterium, for which the name Caproicibacterium lactatifermentans sp. nov. is proposed. The type strain is LBM19010T (=GDMCC 1.1627T=JCM 33782T).
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Affiliation(s)
- Huilin Wang
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Yang Gu
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Dong Zhao
- China Light Industry Key Laboratory of Solid-state Fermentation for Strong Aroma-type Liquor, Yibin 644007, PR China
| | - Zongwei Qiao
- China Light Industry Key Laboratory of Solid-state Fermentation for Strong Aroma-type Liquor, Yibin 644007, PR China
| | - Jia Zheng
- China Light Industry Key Laboratory of Solid-state Fermentation for Strong Aroma-type Liquor, Yibin 644007, PR China
| | - Jiangjing Gao
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Cong Ren
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Yan Xu
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, PR China
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16
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Adaptability of a caproate-producing bacterium contributes to its dominance in an anaerobic fermentation system. Appl Environ Microbiol 2021; 87:e0120321. [PMID: 34378978 DOI: 10.1128/aem.01203-21] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The transformation of diverse feedstocks into medium-chain fatty acids (MCFAs) by mixed cultures is a promising biorefinery route because of the high value of MCFAs. A particular concern is how to maintain the microbial consortia in mixed cultures to achieve stable MCFA production. Chinese strong aroma-type liquor (Baijiu) fermentation system continually produces caproic acid for decades through a spontaneous inoculation of anaerobes from pit mud into fermented grains. Therefore, illuminating the dominant caproate-producing bacterium (CPB) in pit mud and how the CPB sustains in the spontaneous fermentation system will benefit to reveal the microbiological mechanisms of the stable caproate production. Here, we examined pit mud samples across four Chinese strong aroma-type Baijiu producing areas and found that a caproate-producing Caproicibacterium sp. was widely distributed in these distilleries with relative abundance ranging from 1.4% to 35.5% and an average abundance of 11.4%. Through controlling carbon source availability, we achieved different simplified caproate-producing consortia and found that the growth advantage of Caproicibacterium sp. was highly dependent on glucose. Then two strains, named Caproicibacterium sp. LBM19010 and Caproicibacterium sp. JNU-WLY1368, were isolated from pit mud of two regions. The metabolic versatility of this bacterium utilizing starch, maltose, glucose and lactate reflected its adaptability to the fermentation environment where these carbon sources coexist. The simultaneous utilization of glucose and lactate contributed to the balance between cell growth and pH homeostasis. This study reveals that multiple adaptation strategies employed by the predominant CPB promotes its stability and dominance in a saccharide- and lactate-rich anaerobic habitat. IMPORTANCE Chinese strong aroma-type liquor (Baijiu) fermentation environment is a typical medium-chain fatty acid producing system with complex nutrients. Although several studies have revealed the correlation between microbial community composition and abiotic factors, the adaptation mechanisms of dominant species to abiotic environment are still unknown in this special anaerobic habitat. This study identified the predominant CPB in Chinese strong aroma-type Baijiu fermentation system. Metabolic versatility and flexibility of the dominant CPB with a small-size genome indicated that this bacterium can effectively exploit available carbon and nitrogen sources, which could be a key factor to promote its ecological success in a multi-species environment. The understanding of growth and metabolic features of CPB responsible for its dominance in microbial community will not only contribute to the improvement of Chinese strong aroma-type Baijiu production but also expand its potential industrial applications in caproate production.
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