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Kanokratana P, Wongwilaiwalin S, Mhuantong W, Tangphatsornruang S, Eurwilaichitr L, Champreda V. Characterization of cellulolytic microbial consortium enriched on Napier grass using metagenomic approaches. J Biosci Bioeng 2017; 125:439-447. [PMID: 29169786 DOI: 10.1016/j.jbiosc.2017.10.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 09/11/2017] [Accepted: 10/25/2017] [Indexed: 11/17/2022]
Abstract
Energy grass is a promising substrate for production of biogas by anaerobic digestion. However, the conversion efficiency is limited by the enzymatically recalcitrant nature of cellulosic wastes. In this study, an active, structurally stable mesophilic lignocellulolytic degrading microbial consortium (Np-LMC) was constructed from forest compost soil microbiota by successive subcultivation on Napier grass under facultative anoxic conditions. According to tagged 16S rRNA gene amplicon sequencing, increasing abundance of facultative Proteobacteria was found in the middle of batch cycle which was then subsequently replaced by the cellulose degraders Firmicutes and Bacteroidetes along with decreasing CMCase, xylanase, and β-glucanase activity profiles in the supernatant after 5 days of incubation. Anaerobic/facultative bacteria Dysgonomonas and Sedimentibacter and aerobic bacteria Comamonas were the major genera found in Np-LMC. The consortium was active on degradation of the native and delignified grass. Direct shotgun sequencing of the consortium metagenome revealed relatively high abundance of genes encoding for various lignocellulose degrading enzymes in 23 glycosyl hydrolase (GH) families compared to previously reported cellulolytic microbial communities in mammalian digestive tracts. Enzymes attacking cellulose and hemicellulose were dominated by GH2, 3, 5, 9, 10, 26, 28 and 43 in addition to a variety of carbohydrate esterases (CE) and auxiliary activities (AA), reflecting adaptation of the enzyme systems to the native herbaceous substrate. The consortium identified here represents the microcosm specifically bred on energy grass, with potential for enhancing degradation of fibrous substrates in bioenergy industry.
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Affiliation(s)
- Pattanop Kanokratana
- Enzyme Technology Laboratory, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Pahonyothin Road, Klong Luang, Pathum Thani 12120, Thailand.
| | - Sarunyou Wongwilaiwalin
- Enzyme Technology Laboratory, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Pahonyothin Road, Klong Luang, Pathum Thani 12120, Thailand
| | - Wuttichai Mhuantong
- Enzyme Technology Laboratory, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Pahonyothin Road, Klong Luang, Pathum Thani 12120, Thailand
| | - Sithichoke Tangphatsornruang
- Genomic Research Laboratory, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Pahonyothin Road, Klong Luang, Pathum Thani 12120, Thailand
| | - Lily Eurwilaichitr
- Enzyme Technology Laboratory, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Pahonyothin Road, Klong Luang, Pathum Thani 12120, Thailand
| | - Verawat Champreda
- Enzyme Technology Laboratory, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Pahonyothin Road, Klong Luang, Pathum Thani 12120, Thailand
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Jain A, Pelle HS, Baughman WH, Henson JM. Conversion of ammonia-pretreated switchgrass to biofuel precursors by bacterial-fungal consortia under solid-state and submerged-state cultivation. J Appl Microbiol 2017; 122:953-963. [PMID: 27626760 DOI: 10.1111/jam.13295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 08/22/2016] [Accepted: 08/25/2016] [Indexed: 11/27/2022]
Abstract
AIM The aim of this study was to develop and evaluate bacterial-fungal communities to deconstruct switchgrass to biofuel precursors. METHODS AND RESULTS Bacterial-fungal consortia, mesophilic (25°C) and thermophilic (50°C), were enriched from switchgrass bales from which enzyme mixtures were used to deconstruct delignified switchgrass (DSG). The bacterial-fungal consortia were able to produce enzymes including endoglucanase, exoglucanase, β-glucosidase, xylanase, xylosidase and pectinase to convert DSG to soluble carbohydrates. 454 pyrosequencing revealed that Paenibacillus and Streptomyces were the dominant bacteria in the mesophilic and thermophilic consortia respectively. Penicillium and Acremonium were the dominant fungi in the mesophilic consortia, whereas Aspergillus and Penicillium were the dominant fungi present in the thermophilic consortia. CONCLUSIONS The results show that the state of cultivation, solid-state or submerged-state, affects the community structure as well as enzyme activities produced by these bacterial-fungal consortia. The enzyme mixture produced by the bacterial-fungal consortia released a higher amount of xylose than glucose during saccharification of DSG. SIGNIFICANCE AND IMPACT OF THE STUDY The study provides a novel approach to produce enzymes for conversion of lignocellulolytic feedstocks to soluble sugars which can be used to produce biofuel precursors.
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Affiliation(s)
- A Jain
- Biotechnology Institute, University of Minnesota, Twin Cities, Falcon Heights, MN, USA
| | - H S Pelle
- Department of Biology, Sacred Heart University, Fairfield, CT, USA
| | - W H Baughman
- University of South Carolina School of Law, Columbia, SC, USA
| | - J M Henson
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
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Mello BL, Alessi AM, McQueen-Mason S, Bruce NC, Polikarpov I. Nutrient availability shapes the microbial community structure in sugarcane bagasse compost-derived consortia. Sci Rep 2016; 6:38781. [PMID: 27941835 PMCID: PMC5150498 DOI: 10.1038/srep38781] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 11/14/2016] [Indexed: 01/09/2023] Open
Abstract
Microbial communities (MCs) create complex metabolic networks in natural habitats and respond to environmental changes by shifts in the community structure. Although members of MCs are often not amenable for cultivation in pure culture, it is possible to obtain a greater diversity of species in the laboratory setting when microorganisms are grown as mixed cultures. In order to mimic the environmental conditions, an appropriate growth medium must be applied. Here, we examined the hypothesis that a greater diversity of microorganisms can be sustained under nutrient-limited conditions. Using a 16 S rRNA amplicon metagenomic approach, we explored the structure of a compost-derived MC. During a five-week time course the MC grown in minimal medium with sugarcane bagasse (SCB) as a sole carbon source showed greater diversity and enrichment in lignocellulose-degrading microorganisms. In contrast, a MC grown in nutrient rich medium with addition of SCB had a lower microbial diversity and limited number of lignocellulolytic species. Our approach provides evidence that factors such as nutrient availability has a significant selective pressure on the biodiversity of microorganisms in MCs. Consequently, nutrient-limited medium may displace bacterial generalist species, leading to an enriched source for mining novel enzymes for biotechnology applications.
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Affiliation(s)
- Bruno L Mello
- Instituto de Física de São Carlos, Universidade de São Paulo, Av. Trabalhador São-carlense 400, São Carlos, SP, 13560-970, Brazil
| | - Anna M Alessi
- Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Simon McQueen-Mason
- Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Neil C Bruce
- Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Igor Polikarpov
- Instituto de Física de São Carlos, Universidade de São Paulo, Av. Trabalhador São-carlense 400, São Carlos, SP, 13560-970, Brazil
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High-throughput pyrosequencing used for the discovery of a novel cellulase from a thermophilic cellulose-degrading microbial consortium. Biotechnol Lett 2016; 39:123-131. [DOI: 10.1007/s10529-016-2224-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 09/15/2016] [Indexed: 10/20/2022]
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Zhu N, Yang J, Ji L, Liu J, Yang Y, Yuan H. Metagenomic and metaproteomic analyses of a corn stover-adapted microbial consortium EMSD5 reveal its taxonomic and enzymatic basis for degrading lignocellulose. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:243. [PMID: 27833656 PMCID: PMC5103373 DOI: 10.1186/s13068-016-0658-z] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 10/28/2016] [Indexed: 05/08/2023]
Abstract
BACKGROUND Microbial consortia represent promising candidates for aiding in the development of plant biomass conversion strategies for biofuel production. However, the interaction between different community members and the dynamics of enzyme complements during the lignocellulose deconstruction process remain poorly understood. We present here a comprehensive study on the community structure and enzyme systems of a lignocellulolytic microbial consortium EMSD5 during growth on corn stover, using metagenome sequencing in combination with quantitative metaproteomics. RESULTS The taxonomic affiliation of the metagenomic data showed that EMSD5 was primarily composed of members from the phyla Proteobacteria, Firmicutes and Bacteroidetes. The carbohydrate-active enzyme (CAZyme) annotation revealed that representatives of Firmicutes encoded a broad array of enzymes responsible for hemicellulose and cellulose deconstruction. Extracellular metaproteome analysis further pinpointed the specific role and synergistic interaction of Firmicutes populations in plant polysaccharide breakdown. In particular, a wide range of xylan degradation-related enzymes, including xylanases, β-xylosidases, α-l-arabinofuranosidases, α-glucuronidases and acetyl xylan esterases, were secreted by diverse members from Firmicutes during growth on corn stover. Using label-free quantitative proteomics, we identified the differential secretion pattern of a core subset of enzymes, including xylanases and cellulases with multiple carbohydrate-binding modules (CBMs). In addition, analysis of the coordinate expression patterns indicated that transport proteins and hypothetical proteins may play a role in bacteria processing lignocellulose. Moreover, enzyme preparation from EMSD5 demonstrated synergistic activities in the hydrolysis of pretreated corn stover by commercial cellulases from Trichoderma reesei. CONCLUSIONS These results demonstrate that the corn stover-adapted microbial consortium EMSD5 harbors a variety of lignocellulolytic anaerobic bacteria and degradative enzymes, especially those implicated in hemicellulose decomposition. The data in this study highlight the pivotal role and cooperative relationship of Firmicutes members in the biodegradation of plant lignocellulose by EMSD5. The differential expression patterns of enzymes reveal the strategy of sequential lignocellulose deconstruction by EMSD5. Our findings provide insights into the mechanism by which consortium members orchestrate their array of enzymes to degrade complex lignocellulosic biomass.
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Affiliation(s)
- Ning Zhu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Beijing, China
| | - Jinshui Yang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Beijing, China
| | - Lei Ji
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Beijing, China
| | - Jiawen Liu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Beijing, China
| | - Yi Yang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Beijing, China
| | - Hongli Yuan
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Beijing, China
- National Energy R & D Center for Non-food Biomass, China Agricultural University, Beijing, 100193 China
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Biodegradation of cellulosic and lignocellulosic waste by Pseudoxanthomonas sp R-28. Carbohydr Polym 2015; 134:761-6. [DOI: 10.1016/j.carbpol.2015.08.072] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/19/2015] [Accepted: 08/22/2015] [Indexed: 11/22/2022]
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Du R, Yan J, Li S, Zhang L, Zhang S, Li J, Zhao G, Qi P. Cellulosic ethanol production by natural bacterial consortia is enhanced by Pseudoxanthomonas taiwanensis. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:10. [PMID: 25648981 PMCID: PMC4308921 DOI: 10.1186/s13068-014-0186-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 12/15/2014] [Indexed: 05/11/2023]
Abstract
BACKGROUND Natural bacterial consortia are considered a promising solution for one-step production of ethanol from lignocellulose because of their adaptation to a wide range of natural lignocellulosic substrates and their capacity for efficient cellulose degradation. However, their low ethanol conversion efficiency has greatly limited the development and application of natural bacterial consortia. RESULTS In the present study, we analyzed 16 different natural bacterial consortia from a variety of habitats in China and found that the HP consortium exhibited relatively high ethanol production (2.06 g/L ethanol titer from 7 g/L α-cellulose at 55°C in 6 days). Further studies showed that Pseudoxanthomonas taiwanensis played an important role in the high ethanol productivity of HP and that this strain effectively boosted the ethanol production of various other natural bacterial consortia. Finally, we developed a new consortium, termed HPP, by optimizing the proportion of P. taiwanensis in the HP consortium to achieve the highest ethanol production reported for natural consortia. The ethanol conversion ratio reached 78%, with ethanol titers up to 2.5 g/L. CONCLUSIONS In the present study, we found a natural bacterial consortium with outstanding ethanol production performance, and revealed an efficient method with potentially broad applicability for further improving the ethanol production of natural bacterial consortia.
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Affiliation(s)
- Ran Du
- />Institute of New Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 China
- />Beijing Engineering Research Center for Biofuels, Tsinghua University, Beijing, 100084 China
| | - Jianbin Yan
- />The Tsinghua University-Peking University Center for Life Sciences, MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Shizhong Li
- />Institute of New Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 China
- />Beijing Engineering Research Center for Biofuels, Tsinghua University, Beijing, 100084 China
| | - Lei Zhang
- />Institute of New Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 China
- />Beijing Engineering Research Center for Biofuels, Tsinghua University, Beijing, 100084 China
| | - Sandra Zhang
- />Institute of New Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 China
- />Beijing Engineering Research Center for Biofuels, Tsinghua University, Beijing, 100084 China
| | - Jihong Li
- />Institute of New Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 China
- />Beijing Engineering Research Center for Biofuels, Tsinghua University, Beijing, 100084 China
| | - Gang Zhao
- />Institute of New Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 China
| | - Panlu Qi
- />Research Institute of Petroleum Processing, Beijing, 100000 China
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Vieira MGA, Almeida Neto AFD, Silva MGCD, Carneiro CN, Melo Filho AA. Adsorption of lead and copper ions from aqueous effluents on rice husk ash in a dynamic system. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2014. [DOI: 10.1590/0104-6632.20140312s00002103] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Yan P, Su L, Chen J, Wu J. Heterologous expression and biochemical characterization of an endo-β-1,4-glucanase fromThermobifida fusca. Biotechnol Appl Biochem 2013; 60:348-55. [DOI: 10.1002/bab.1097] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 01/08/2013] [Indexed: 11/10/2022]
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Gao ZM, Xu X, Ruan LW. Enrichment and characterization of an anaerobic cellulolytic microbial consortium SQD-1.1 from mangrove soil. Appl Microbiol Biotechnol 2013; 98:465-74. [PMID: 23529681 DOI: 10.1007/s00253-013-4857-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 03/09/2013] [Accepted: 03/12/2013] [Indexed: 11/29/2022]
Abstract
Enrichment of microbial consortia provides an approach to simulate and investigate microbial communities in natural environments. In this study, a cellulolytic microbial consortium SQD-1.1 was enriched from mangrove soil of Qinglan port (Hainan, China) by 27 times continuous subcultivation under anaerobic static conditions. The consortium could completely degrade 0.2% (w/v) filter paper within 3 days and utilized it as the sole carbon source. PCR-denaturing gradient gel electrophoresis analysis revealed a stable microbial community structure in the incubation process of 10 days and in the procedure of subcultivation. Twenty-four operational taxonomic units belonging to seven phyla were obtained from the full-length 16S rRNA gene library. Five clones, closest related to the genera Alkaliflexus, Clostridium, Alistipes, Spirochaeta, and Trichococcus, were the predominant ones. Among them, M117, phylogeneticly showing high similarity (16S rRNA gene identity, 95.3%) with the cellulolytic anaerobic bacterium Clostridium straminisolvens CSK1(T), was the potential key cellulolytic bacterium. Using the plate cultivation method, 12 strains, including one potential new species and four potential new species of new genera, were isolated. The strain P2, corresponding to the most frequently detected clone (M05) in the 16S rRNA gene library, showed both CMCase and xylanase activity and may be another important cellulolytic bacterium. The findings of cellulase activity in cell pellet and cohesion and dockerin domains in metagenome data further suggested the potential of utilization of cellulosomes by the consortium to degrade cellulose. Consortium SQD-1.1 provides a candidate for investigating the mechanism of cellulose degradation under anoxic conditions in natural environments.
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Affiliation(s)
- Zhao-Ming Gao
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration (SOA), Xiamen, 361005, People's Republic of China
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Quantitative proteomic analysis of secretome of microbial consortium during saw dust utilization. J Proteomics 2012; 75:5590-603. [DOI: 10.1016/j.jprot.2012.08.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Revised: 07/28/2012] [Accepted: 08/13/2012] [Indexed: 11/23/2022]
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Wen B, Yuan X, Cao Y, Liu Y, Wang X, Cui Z. Optimization of liquid fermentation of microbial consortium WSD-5 followed by saccharification and acidification of wheat straw. BIORESOURCE TECHNOLOGY 2012; 118:141-149. [PMID: 22705517 DOI: 10.1016/j.biortech.2012.05.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 05/06/2012] [Accepted: 05/08/2012] [Indexed: 06/01/2023]
Abstract
The microbial consortium WSD-5 is composed of bacteria and fungi, and the cooperation and symbiosis of the contained microbes enhance the degradation ability of WSD-5. Experiment results showed that the highest cellulase and hemicellulase were obtained when ventilation volume was 4 L/min, stirring rate was 0 rpm, and substrate loading rate was 3%. After 6 days of cultivation, a 67.60% loss in wheat straw dry weight was observed. The crude enzyme secreted from WSD-5 after optimization was evaluated by experiments of saccharification and acidification. The maximum concentration of reducing sugars was 3254 mg/L after 48 h saccharification. The concentration of sCOD peaked on day 2 with a value of 4345 mg/L during acidification, and the biogas yield and methane yield were 22.3% and 32.3% higher than un-acidified samples. This study is the first attempt to explore both the saccharification and the acidification ability of crude enzymes secreted by microbial consortium.
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Affiliation(s)
- Boting Wen
- College of Agronomy and Biotechnology/Center of Biomass Engineering, China Agricultural University, Beijing 100193, PR China
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Yuan X, Cao Y, Li J, Wen B, Zhu W, Wang X, Cui Z. Effect of pretreatment by a microbial consortium on methane production of waste paper and cardboard. BIORESOURCE TECHNOLOGY 2012; 118:281-288. [PMID: 22705535 DOI: 10.1016/j.biortech.2012.05.058] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2012] [Revised: 05/12/2012] [Accepted: 05/14/2012] [Indexed: 06/01/2023]
Abstract
A microbial consortium MC1 was used to pretreat filter paper, office paper, newspaper, and cardboard to enhance methane production. The results of pretreatment indicated that sCOD of hydrolysates of the four substrates increased significantly in the early stage, and peaked on day 7. During pretreatment, ethanol, acetic acid, propionic acid, butyric acid, and glycerol were the predominant volatile organic products in hydrolysates. MC1 had strong degradation ability on the four substrates, and the weight loss of filter paper, office paper, newspaper, and cardboard reached 78.3%, 80.5%, 39.7%, and 49.7%, respectively. The results of anaerobic digestion showed that methane production yields and rates of the four substrates significantly increased after pretreatment. This study is the first attempt to explore the microbial pretreatment method for anaerobic digestion of waste paper and cardboard. Microbial consortium pretreatment could be an effective method for enhancing methane production of waste paper and cardboard into bioenergy.
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Affiliation(s)
- Xufeng Yuan
- College of Agronomy and Biotechnology/Center of Biomass Engineering, China Agricultural University, Beijing 100193, China
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Lü Y, Li N, Gong D, Wang X, Cui Z. The Effect of Temperature on the Structure and Function of a Cellulose-Degrading Microbial Community. Appl Biochem Biotechnol 2012; 168:219-33. [DOI: 10.1007/s12010-012-9731-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 05/08/2012] [Indexed: 11/30/2022]
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Biodegradation of Leonardite by an alkali-producing bacterial community and characterization of the degraded products. Appl Microbiol Biotechnol 2011; 93:2581-90. [PMID: 22075634 DOI: 10.1007/s00253-011-3669-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 10/02/2011] [Accepted: 10/23/2011] [Indexed: 10/15/2022]
Abstract
In this study, three bacterial communities were obtained from 12 Leonardite samples with the aim of identifying a clean, effective, and economic technique for the dissolution of Leonardite, a type of low-grade coal, in the production of humic acid (HA). The biodegradation ability and characteristics of the degraded products of the most effective bacterial community (MCSL-2), which degraded 50% of the Leonardite within 21 days, were further investigated. Analyses of elemental composition, (13)C NMR, and Fourier transform infrared revealed that the contents of C, O, and aliphatic carbon were similar in biodegraded humic acid (bHA) and chemically (alkali) extracted humic acid (cHA). However, the N and carboxyl carbon contents of bHA was higher than that of cHA. Furthermore, a positive correlation was identified between the degradation efficiency and the increasing pH of the culture medium, while increases of manganese peroxidase and esterase activities were also observed. These data demonstrated that both alkali production and enzyme reactions were involved in Leonardite solubilization by MCSL-2, although the former mechanism predominated. No fungus was observed by microscopy. Only four bacterial phylotypes were recognized, and Bacillus licheniformis-related bacteria were identified as the main group in MCSL-2 by analysis of amplified 16S rRNA genes, thus demonstrating that Leonardite degradation ability has a limited distribution in bacteria. Hormone-like bioactivities of bHA were also detected. In this study, a bacterial community capable of Leonardite degradation was identified and the products characterized. These data implicate the use of such bacteria for the exploitation of Leonardite as a biofertilizer.
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Wang W, Yan L, Cui Z, Gao Y, Wang Y, Jing R. Characterization of a microbial consortium capable of degrading lignocellulose. BIORESOURCE TECHNOLOGY 2011; 102:9321-4. [PMID: 21831630 DOI: 10.1016/j.biortech.2011.07.065] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 07/13/2011] [Accepted: 07/19/2011] [Indexed: 05/10/2023]
Abstract
A microbial consortium, designated WCS-6, was established by successive subcultivation in the presence of rice straw under static conditions. The degradation efficiencies of WSC-6 for 0.5 g filter paper, cotton and rice straw after 3 days of cultivation were 99.0±0.7%, 76.9±1.5% and 81.3±0.8%, respectively as determined by gravimetrical methods. Nine bacterial isolates were obtained from WCS-6 plated under aerobic conditions, and sequencing of their 16S rDNA indicated that these bacteria were related to Bacillus thermoamylovorans BTa, Paenibacillus barengoltzii SAFN-016, Proteobacterium S072, Pseudoxanthomonas taiwanensis CB-226, Rhizobiaceae str. M100, Bacillus sp. E53-10, Beta proteobacterium HMD444, Petrobacter succinimandens 4BON, and Tepidiphilus margaritifer N2-214. DGGE (denaturing gradient gel electrophoresis) and sequencing of 16S rDNA sequences amplified from total consortium DNA revealed the presence of sequences related to those of Ureibacillus thermosphaericus, uncultured bacterium clone GC3, uncultured Clostridium sp. clone A1-3, Clostridium thermobutyricum, and Clostridium thermosuccinogenes in addition to the sequences identified from the cultured bacteria. The microbial community identified herein is a potential candidate consortium for the degradation of waste lignocellulosic biomass.
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Affiliation(s)
- Weidong Wang
- College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319, PR China.
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Herculano PN, Lima DMM, Fernandes MJS, Neves RP, Souza-Motta CM, Porto ALF. Isolation of cellulolytic fungi from waste of castor (Ricinus communis L.). Curr Microbiol 2011; 62:1416-22. [PMID: 21279512 DOI: 10.1007/s00284-011-9879-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 01/12/2011] [Indexed: 11/26/2022]
Abstract
This is the first report of isolation of fungi present in fatty and defatted castor bean meal as well as the first of crop's selection to test the cellulolytic potential, in order to verify the diversity and potential of cellulolytic fungi in castor bean waste (Ricinus communis L.). For the screening on solid medium, it was used carboxymethylcellulose (CMC) as the sole carbon source. The microcrystalline cellulose (Avicel) was used as a substrate for submerged fermentation for production of cellobiohydrolase (FPase) and the CMC to produce endoglucanases (CMCase) and β-glycosidases (BG). 189 cultures of fungi were isolated, including 40 species of filamentous fungi and three yeasts. The Aspergillus was the most frequent found genus. Regarding the distribution of isolated species from defatted castor bean meal, the A. niger was the most frequent one; and within the fatty castor bean meal, the Emericela variecolor prevailed among other species. Among the 67 fungal cultures tested in the initial screening on solid media to assess the cellulolytic potential, 54 disclosed Cellulolytic Index (CI) ranging from 1.04 to 6.00 mm. The isolates were selected for enzyme production in liquid medium with values above 2.0 CI. They were obtained with A. japonicus URM5620 FPase activity (4.99 U/ml) and BG (0.05 U/ml), and Rhodotorula glutinis URM5724 activity of CMCase 3.58 U/ml. These cases occurred after 168 h of submersion for both species of fungi. In our study, we could conclude that the castor bean is a promising source of fungi capable of producing cellulolytic enzymes.
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Affiliation(s)
- Polyanna N Herculano
- Mycology Department, Federal University of Pernambuco, Cidade Universitária, CEP, Recife, PE 50670-420, Brazil
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Wongwilaiwalin S, Rattanachomsri U, Laothanachareon T, Eurwilaichitr L, Igarashi Y, Champreda V. Analysis of a thermophilic lignocellulose degrading microbial consortium and multi-species lignocellulolytic enzyme system. Enzyme Microb Technol 2010. [DOI: 10.1016/j.enzmictec.2010.07.013] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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