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Heom KA, Wangsanuwat C, Butkovich LV, Tam SC, Rowe AR, O'Malley MA, Dey SS. Targeted rRNA depletion enables efficient mRNA sequencing in diverse bacterial species and complex co-cultures. mSystems 2023; 8:e0028123. [PMID: 37855606 PMCID: PMC10734481 DOI: 10.1128/msystems.00281-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 09/12/2023] [Indexed: 10/20/2023] Open
Abstract
IMPORTANCE Microbes present one of the most diverse sources of biochemistry in nature, and mRNA sequencing provides a comprehensive view of this biological activity by quantitatively measuring microbial transcriptomes. However, efficient mRNA capture for sequencing presents significant challenges in prokaryotes as mRNAs are not poly-adenylated and typically make up less than 5% of total RNA compared with rRNAs that exceed 80%. Recently developed methods for sequencing bacterial mRNA typically rely on depleting rRNA by tiling large probe sets against rRNAs; however, such approaches are expensive, time-consuming, and challenging to scale to varied bacterial species and complex microbial communities. Therefore, we developed EMBR-seq+, a method that requires fewer than 10 short oligonucleotides per rRNA to achieve up to 99% rRNA depletion in diverse bacterial species. Finally, EMBR-seq+ resulted in a deeper view of the transcriptome, enabling systematic quantification of how microbial interactions result in altering the transcriptional state of bacteria within co-cultures.
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Affiliation(s)
- Kellie A. Heom
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California, USA
- Biological Engineering Program, University of California Santa Barbara, Santa Barbara, California, USA
| | - Chatarin Wangsanuwat
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California, USA
- Biological Engineering Program, University of California Santa Barbara, Santa Barbara, California, USA
| | - Lazarina V. Butkovich
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California, USA
| | - Scott C. Tam
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California, USA
| | - Annette R. Rowe
- Biological Sciences, University of Cincinnati, Cincinnati, Ohio, USA
| | - Michelle A. O'Malley
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California, USA
- Biological Engineering Program, University of California Santa Barbara, Santa Barbara, California, USA
| | - Siddharth S. Dey
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California, USA
- Biological Engineering Program, University of California Santa Barbara, Santa Barbara, California, USA
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, USA
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2
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Lange L, Barrett K, Meyer AS. New Method for Identifying Fungal Kingdom Enzyme Hotspots from Genome Sequences. J Fungi (Basel) 2021; 7:jof7030207. [PMID: 33799907 PMCID: PMC8000046 DOI: 10.3390/jof7030207] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/05/2021] [Accepted: 03/07/2021] [Indexed: 11/23/2022] Open
Abstract
Fungal genome sequencing data represent an enormous pool of information for enzyme discovery. Here, we report a new approach to identify and quantitatively compare biomass-degrading capacity and diversity of fungal genomes via integrated function-family annotation of carbohydrate-active enzymes (CAZymes) encoded by the genomes. Based on analyses of 1932 fungal genomes the most potent hotspots of fungal biomass processing CAZymes are identified and ranked according to substrate degradation capacity. The analysis is achieved by a new bioinformatics approach, Conserved Unique Peptide Patterns (CUPP), providing for CAZyme-family annotation and robust prediction of molecular function followed by conversion of the CUPP output to lists of integrated “Function;Family” (e.g., EC 3.2.1.4;GH5) enzyme observations. An EC-function found in several protein families counts as different observations. Summing up such observations allows for ranking of all analyzed genome sequenced fungal species according to richness in CAZyme function diversity and degrading capacity. Identifying fungal CAZyme hotspots provides for identification of fungal species richest in cellulolytic, xylanolytic, pectinolytic, and lignin modifying enzymes. The fungal enzyme hotspots are found in fungi having very different lifestyle, ecology, physiology and substrate/host affinity. Surprisingly, most CAZyme hotspots are found in enzymatically understudied and unexploited species. In contrast, the most well-known fungal enzyme producers, from where many industrially exploited enzymes are derived, are ranking unexpectedly low. The results contribute to elucidating the evolution of fungal substrate-digestive CAZyme profiles, ecophysiology, and habitat adaptations, and expand the knowledge base for novel and improved biomass resource utilization.
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Affiliation(s)
- Lene Lange
- BioEconomy, Research & Advisory, Copenhagen, 2500 Valby, Denmark;
| | - Kristian Barrett
- Section for Protein Chemistry and Enzyme Technology, Department of Biotechnology and Biomedicine, Building 221, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark;
| | - Anne S. Meyer
- Section for Protein Chemistry and Enzyme Technology, Department of Biotechnology and Biomedicine, Building 221, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark;
- Correspondence: ; Tel.: +45-4525-2600
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3
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Hanafy RA, Johnson B, Youssef NH, Elshahed MS. Assessing anaerobic gut fungal diversity in herbivores using D1/D2 large ribosomal subunit sequencing and multi-year isolation. Environ Microbiol 2020; 22:3883-3908. [PMID: 32656919 DOI: 10.1111/1462-2920.15164] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/22/2020] [Accepted: 07/10/2020] [Indexed: 11/30/2022]
Abstract
The anaerobic gut fungi (AGF, Neocallimastigomycota) reside in the alimentary tracts of herbivores where they play a central role in the breakdown of plant material. Here, we report on the development of the hypervariable domains D1/D2 of the large ribosomal subunit (D1/D2 LSU) as a barcoding marker for the AGF. We generated a reference D1/D2 LSU database for all cultured AGF genera, as well as the majority of candidate genera encountered in prior internal transcribed spacer 1 (ITS1)-based surveys. Subsequently, a D1/D2 LSU-based diversity survey using long read PacBio SMRT sequencing was conducted on faecal samples from 21 wild and domesticated herbivores. Twenty-eight genera and candidate genera were identified, including multiple novel lineages that were predominantly, but not exclusively, identified in wild herbivores. Association between certain AGF genera and animal lifestyles, or animal host family was observed. Finally, to address the current paucity of AGF isolates, concurrent isolation efforts utilizing multiple approaches to maximize recovery yielded 216 isolates belonging to 12 different genera, several of which have no prior cultured-representatives. Our results establish the utility of D1/D2 LSU and PacBio sequencing for AGF diversity surveys, the culturability of multiple AGF taxa, and demonstrate that wild herbivores represent a yet-untapped reservoir of AGF diversity.
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Affiliation(s)
- Radwa A Hanafy
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Britny Johnson
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Noha H Youssef
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Mostafa S Elshahed
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
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4
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Wilken SE, Seppälä S, Lankiewicz TS, Saxena M, Henske JK, Salamov AA, Grigoriev IV, O’Malley MA. Genomic and proteomic biases inform metabolic engineering strategies for anaerobic fungi. Metab Eng Commun 2020; 10:e00107. [PMID: 31799118 PMCID: PMC6883316 DOI: 10.1016/j.mec.2019.e00107] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 10/24/2019] [Accepted: 11/04/2019] [Indexed: 12/22/2022] Open
Abstract
Anaerobic fungi (Neocallimastigomycota) are emerging non-model hosts for biotechnology due to their wealth of biomass-degrading enzymes, yet tools to engineer these fungi have not yet been established. Here, we show that the anaerobic gut fungi have the most GC depleted genomes among 443 sequenced organisms in the fungal kingdom, which has ramifications for heterologous expression of genes as well as for emerging CRISPR-based genome engineering approaches. Comparative genomic analyses suggest that anaerobic fungi may contain cellular machinery to aid in sexual reproduction, yet a complete mating pathway was not identified. Predicted proteomes of the anaerobic fungi also contain an unusually large fraction of proteins with homopolymeric amino acid runs consisting of five or more identical consecutive amino acids. In particular, threonine runs are especially enriched in anaerobic fungal carbohydrate active enzymes (CAZymes) and this, together with a high abundance of predicted N-glycosylation motifs, suggests that gut fungal CAZymes are heavily glycosylated, which may impact heterologous production of these biotechnologically useful enzymes. Finally, we present a codon optimization strategy to aid in the development of genetic engineering tools tailored to these early-branching anaerobic fungi.
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Affiliation(s)
- St. Elmo Wilken
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Susanna Seppälä
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Thomas S. Lankiewicz
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
- Department of Evolution Ecology and Marine Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Mohan Saxena
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - John K. Henske
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Asaf A. Salamov
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Igor V. Grigoriev
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Michelle A. O’Malley
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
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5
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Leveraging anaerobic fungi for biotechnology. Curr Opin Biotechnol 2019; 59:103-110. [DOI: 10.1016/j.copbio.2019.03.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 02/19/2019] [Accepted: 03/12/2019] [Indexed: 12/30/2022]
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6
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Seppälä S, Yoo JI, Yur D, O'Malley MA. Heterologous transporters from anaerobic fungi bolster fluoride tolerance in Saccharomyces cerevisiae. Metab Eng Commun 2019; 9:e00091. [PMID: 31016136 PMCID: PMC6475669 DOI: 10.1016/j.mec.2019.e00091] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 03/22/2019] [Accepted: 04/09/2019] [Indexed: 12/21/2022] Open
Abstract
Membrane-embedded transporters are crucial for the stability and performance of microbial production strains. Apart from engineering known transporters derived from model systems, it is equally important to identify transporters from nonconventional organisms that confer advantageous traits for biotechnological applications. Here, we transferred genes encoding fluoride exporter (FEX) proteins from three strains of early-branching anaerobic fungi (Neocallimastigomycota) to Saccharomyces cerevisiae. The heterologous transporters are localized to the plasma membrane and complement a fluoride-sensitive yeast strain that is lacking endogenous fluoride transporters up to 10.24 mM fluoride. Furthermore, we show that fusing an amino-terminal leader sequence to FEX proteins in yeast elevates protein yields, yet inadvertently causes a loss of transporter function. Adaptive laboratory evolution of FEX proteins restores fluoride tolerance of these strains, in one case exceeding the solute tolerance observed in wild type S. cerevisiae; however, the underlying molecular mechanisms and cause for the increased tolerance in the evolved strains remain elusive. Our results suggest that microbial cultures can achieve solvent tolerance through different adaptive trajectories, and the study is a promising step towards the identification, production, and biotechnological application of membrane proteins from nonconventional fungi. First report describing the heterologous production of functional ion transport proteins sourced from anaerobic gut fungi. Codon-optimization enables production of functional, gut fungal membrane proteins in S. cerevisiae but not in E. coli. Addition of an N-terminal leader peptide elevates membrane protein yields yet diminishes cellular activity. Adaptive laboratory evolution restores cellular fluoride export activity in yeast to levels exceeding native tolerance.
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Affiliation(s)
- Susanna Seppälä
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Justin I. Yoo
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Daniel Yur
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Michelle A. O'Malley
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
- Corresponding author.
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7
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Lian J, Liu J, Yue Y, Li F, Chen X, Zhang Z, Ping Y, Qin G, Li L, Zhang K, Liu S, Zhang L, Qiao S, Liu N, Zheng Y, Wu J, Zeng Q, Zhang Y. The repertoire features of T cell receptor β-chain of different age and gender groups in healthy Chinese individuals. Immunol Lett 2019; 208:44-51. [DOI: 10.1016/j.imlet.2019.03.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 02/24/2019] [Accepted: 03/13/2019] [Indexed: 01/15/2023]
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8
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Podolsky IA, Seppälä S, Lankiewicz TS, Brown JL, Swift CL, O'Malley MA. Harnessing Nature's Anaerobes for Biotechnology and Bioprocessing. Annu Rev Chem Biomol Eng 2019; 10:105-128. [PMID: 30883214 DOI: 10.1146/annurev-chembioeng-060718-030340] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Industrial biotechnology has the potential to decrease our reliance on petroleum for fuel and bio-based chemical production and also enable valorization of waste streams. Anaerobic microorganisms thrive in resource-limited environments and offer an array of novel bioactivities in this regard that could revolutionize biomanufacturing. However, they have not been adopted for widespread industrial use owing to their strict growth requirements, limited number of available strains, difficulty in scale-up, and genetic intractability. This review provides an overview of current and future uses for anaerobes in biotechnology and bioprocessing in the postgenomic era. We focus on the recently characterized anaerobic fungi (Neocallimastigomycota) native to the digestive tract of large herbivores, which possess a trove of enzymes, pathways, transporters, and other biomolecules that can be harnessed for numerous biotechnological applications. Resolving current genetic intractability, scale-up, and cultivation challenges will unlock the potential of these lignocellulolytic fungi and other nonmodel micro-organisms to accelerate bio-based production.
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Affiliation(s)
- Igor A Podolsky
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Susanna Seppälä
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Thomas S Lankiewicz
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Jennifer L Brown
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Candice L Swift
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Michelle A O'Malley
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
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9
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Hydrogenosomes of Anaerobic Fungi: An Alternative Way to Adapt to Anaerobic Environments. HYDROGENOSOMES AND MITOSOMES: MITOCHONDRIA OF ANAEROBIC EUKARYOTES 2019. [DOI: 10.1007/978-3-030-17941-0_7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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10
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Hooker CA, Hillman ET, Overton JC, Ortiz-Velez A, Schacht M, Hunnicutt A, Mosier NS, Solomon KV. Hydrolysis of untreated lignocellulosic feedstock is independent of S-lignin composition in newly classified anaerobic fungal isolate, Piromyces sp. UH3-1. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:293. [PMID: 30386430 PMCID: PMC6203967 DOI: 10.1186/s13068-018-1292-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 10/15/2018] [Indexed: 05/26/2023]
Abstract
BACKGROUND Plant biomass is an abundant but underused feedstock for bioenergy production due to its complex and variable composition, which resists breakdown into fermentable sugars. These feedstocks, however, are routinely degraded by many uncommercialized microbes such as anaerobic gut fungi. These gut fungi express a broad range of carbohydrate active enzymes and are native to the digestive tracts of ruminants and hindgut fermenters. In this study, we examine gut fungal performance on these substrates as a function of composition, and the ability of this isolate to degrade inhibitory high syringyl lignin-containing forestry residues. RESULTS We isolated a novel fungal specimen from a donkey in Independence, Indiana, United States. Phylogenetic analysis of the Internal Transcribed Spacer 1 sequence classified the isolate as a member of the genus Piromyces within the phylum Neocallimastigomycota (Piromyces sp. UH3-1, strain UH3-1). The isolate penetrates the substrate with an extensive rhizomycelial network and secretes many cellulose-binding enzymes, which are active on various components of lignocellulose. These activities enable the fungus to hydrolyze at least 58% of the glucan and 28% of the available xylan in untreated corn stover within 168 h and support growth on crude agricultural residues, food waste, and energy crops. Importantly, UH3-1 hydrolyzes high syringyl lignin-containing poplar that is inhibitory to many fungi with efficiencies equal to that of low syringyl lignin-containing poplar with no reduction in fungal growth. This behavior is correlated with slight remodeling of the fungal secretome whose composition adapts with substrate to express an enzyme cocktail optimized to degrade the available biomass. CONCLUSIONS Piromyces sp. UH3-1, a newly isolated anaerobic gut fungus, grows on diverse untreated substrates through production of a broad range of carbohydrate active enzymes that are robust to variations in substrate composition. Additionally, UH3-1 and potentially other anaerobic fungi are resistant to inhibitory lignin composition possibly due to changes in enzyme secretion with substrate. Thus, anaerobic fungi are an attractive platform for the production of enzymes that efficiently use mixed feedstocks of variable composition for second generation biofuels. More importantly, our work suggests that the study of anaerobic fungi may reveal naturally evolved strategies to circumvent common hydrolytic inhibitors that hinder biomass usage.
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Affiliation(s)
- Casey A. Hooker
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, IN 47907-2093 USA
- Laboratory of Renewable Resources Engineering (LORRE), Purdue University, 500 Central Drive, West Lafayette, IN 47907-2022 USA
| | - Ethan T. Hillman
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, IN 47907-2093 USA
- Purdue University Interdisciplinary Life Sciences (PULSe) Program, Purdue University, 155 South Grant Street, West Lafayette, IN 47907-2114 USA
| | - Jonathan C. Overton
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, IN 47907-2093 USA
- Laboratory of Renewable Resources Engineering (LORRE), Purdue University, 500 Central Drive, West Lafayette, IN 47907-2022 USA
| | - Adrian Ortiz-Velez
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, IN 47907-2093 USA
| | - Makayla Schacht
- Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054 USA
| | - Abigail Hunnicutt
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, IN 47907-2093 USA
| | - Nathan S. Mosier
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, IN 47907-2093 USA
- Laboratory of Renewable Resources Engineering (LORRE), Purdue University, 500 Central Drive, West Lafayette, IN 47907-2022 USA
| | - Kevin V. Solomon
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, IN 47907-2093 USA
- Laboratory of Renewable Resources Engineering (LORRE), Purdue University, 500 Central Drive, West Lafayette, IN 47907-2022 USA
- Purdue University Interdisciplinary Life Sciences (PULSe) Program, Purdue University, 155 South Grant Street, West Lafayette, IN 47907-2114 USA
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11
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Henske JK, Gilmore SP, Haitjema CH, Solomon KV, O'Malley MA. Biomass‐degrading enzymes are catabolite repressed in anaerobic gut fungi. AIChE J 2018. [DOI: 10.1002/aic.16395] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- John K. Henske
- Dept. of Chemical Engineering University of California Santa Barbara CA, 93106
| | - Sean P. Gilmore
- Dept. of Chemical Engineering University of California Santa Barbara CA, 93106
| | - Charles H. Haitjema
- Dept. of Chemical Engineering University of California Santa Barbara CA, 93106
| | - Kevin V. Solomon
- Dept. of Chemical Engineering University of California Santa Barbara CA, 93106
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12
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Henske JK, Wilken SE, Solomon KV, Smallwood CR, Shutthanandan V, Evans JE, Theodorou MK, O'Malley MA. Metabolic characterization of anaerobic fungi provides a path forward for bioprocessing of crude lignocellulose. Biotechnol Bioeng 2018; 115:874-884. [DOI: 10.1002/bit.26515] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 11/15/2017] [Accepted: 12/08/2017] [Indexed: 12/14/2022]
Affiliation(s)
- John K. Henske
- Department of Chemical EngineeringUniversity of CaliforniaSanta BarbaraCalifornia
| | - St. Elmo Wilken
- Department of Chemical EngineeringUniversity of CaliforniaSanta BarbaraCalifornia
| | - Kevin V. Solomon
- Department of Chemical EngineeringUniversity of CaliforniaSanta BarbaraCalifornia
- Agriculture and Biological EngineeringPurdue UniversityW. LafayetteIndiana
| | - Chuck R. Smallwood
- Environmental Molecular Sciences LaboratoryPacific Northwest National LaboratoryRichlandWashington
| | | | - James E. Evans
- Environmental Molecular Sciences LaboratoryPacific Northwest National LaboratoryRichlandWashington
| | - Michael K. Theodorou
- Animal ProductionWelfare and Veterinary SciencesHarper Adams UniversityNewportShropshireUK
| | - Michelle A. O'Malley
- Department of Chemical EngineeringUniversity of CaliforniaSanta BarbaraCalifornia
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13
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Seppälä S, Wilken SE, Knop D, Solomon KV, O’Malley MA. The importance of sourcing enzymes from non-conventional fungi for metabolic engineering and biomass breakdown. Metab Eng 2017; 44:45-59. [DOI: 10.1016/j.ymben.2017.09.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/16/2017] [Accepted: 09/16/2017] [Indexed: 10/18/2022]
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14
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Edwards JE, Forster RJ, Callaghan TM, Dollhofer V, Dagar SS, Cheng Y, Chang J, Kittelmann S, Fliegerova K, Puniya AK, Henske JK, Gilmore SP, O'Malley MA, Griffith GW, Smidt H. PCR and Omics Based Techniques to Study the Diversity, Ecology and Biology of Anaerobic Fungi: Insights, Challenges and Opportunities. Front Microbiol 2017; 8:1657. [PMID: 28993761 PMCID: PMC5622200 DOI: 10.3389/fmicb.2017.01657] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/15/2017] [Indexed: 11/25/2022] Open
Abstract
Anaerobic fungi (phylum Neocallimastigomycota) are common inhabitants of the digestive tract of mammalian herbivores, and in the rumen, can account for up to 20% of the microbial biomass. Anaerobic fungi play a primary role in the degradation of lignocellulosic plant material. They also have a syntrophic interaction with methanogenic archaea, which increases their fiber degradation activity. To date, nine anaerobic fungal genera have been described, with further novel taxonomic groupings known to exist based on culture-independent molecular surveys. However, the true extent of their diversity may be even more extensively underestimated as anaerobic fungi continue being discovered in yet unexplored gut and non-gut environments. Additionally many studies are now known to have used primers that provide incomplete coverage of the Neocallimastigomycota. For ecological studies the internal transcribed spacer 1 region (ITS1) has been the taxonomic marker of choice, but due to various limitations the large subunit rRNA (LSU) is now being increasingly used. How the continued expansion of our knowledge regarding anaerobic fungal diversity will impact on our understanding of their biology and ecological role remains unclear; particularly as it is becoming apparent that anaerobic fungi display niche differentiation. As a consequence, there is a need to move beyond the broad generalization of anaerobic fungi as fiber-degraders, and explore the fundamental differences that underpin their ability to exist in distinct ecological niches. Application of genomics, transcriptomics, proteomics and metabolomics to their study in pure/mixed cultures and environmental samples will be invaluable in this process. To date the genomes and transcriptomes of several characterized anaerobic fungal isolates have been successfully generated. In contrast, the application of proteomics and metabolomics to anaerobic fungal analysis is still in its infancy. A central problem for all analyses, however, is the limited functional annotation of anaerobic fungal sequence data. There is therefore an urgent need to expand information held within publicly available reference databases. Once this challenge is overcome, along with improved sample collection and extraction, the application of these techniques will be key in furthering our understanding of the ecological role and impact of anaerobic fungi in the wide range of environments they inhabit.
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Affiliation(s)
- Joan E. Edwards
- Laboratory of Microbiology, Wageningen University & ResearchWageningen, Netherlands
| | - Robert J. Forster
- Lethbridge Research and Development Centre, Agriculture and Agri-Food CanadaLethbridge, AB, Canada
| | - Tony M. Callaghan
- Department for Quality Assurance and Analytics, Bavarian State Research Center for AgricultureFreising, Germany
| | - Veronika Dollhofer
- Department for Quality Assurance and Analytics, Bavarian State Research Center for AgricultureFreising, Germany
| | | | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural UniversityNanjing, China
| | - Jongsoo Chang
- Department of Agricultural Science, Korea National Open UniversitySeoul, South Korea
| | - Sandra Kittelmann
- Grasslands Research Centre, AgResearch Ltd.Palmerston North, New Zealand
| | - Katerina Fliegerova
- Institute of Animal Physiology and Genetics, Czech Academy of SciencesPrague, Czechia
| | - Anil K. Puniya
- College of Dairy Science and Technology, Guru Angad Dev Veterinary and Animal Sciences UniversityLudhiana, India
- Dairy Microbiology Division, ICAR-National Dairy Research InstituteKarnal, India
| | - John K. Henske
- Department of Chemical Engineering, University of California, Santa BarbaraSanta Barbara, CA, United States
| | - Sean P. Gilmore
- Department of Chemical Engineering, University of California, Santa BarbaraSanta Barbara, CA, United States
| | - Michelle A. O'Malley
- Department of Chemical Engineering, University of California, Santa BarbaraSanta Barbara, CA, United States
| | - Gareth W. Griffith
- Institute of Biological Environmental and Rural Sciences, Aberystwyth UniversityAberystwyth, United Kingdom
| | - Hauke Smidt
- Laboratory of Microbiology, Wageningen University & ResearchWageningen, Netherlands
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15
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da Silva RR, Pedezzi R, Souto TB. Exploring the bioprospecting and biotechnological potential of white-rot and anaerobic Neocallimastigomycota fungi: peptidases, esterases, and lignocellulolytic enzymes. Appl Microbiol Biotechnol 2017; 101:3089-3101. [PMID: 28314873 DOI: 10.1007/s00253-017-8225-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 02/26/2017] [Accepted: 03/04/2017] [Indexed: 11/28/2022]
Abstract
Fungi constitute an invaluable natural resource for scientific research, owing to their diversity; they offer a promising alternative for bioprospecting, thus contributing to biotechnological advances. For a long time, extensive information has been exploited and fungal products have been tested as a source of natural compounds. In this context, enzyme production remains a field of interest, since it offers an efficient alternative to the hazardous processes of chemical transformations. Owing to their vast biodiversity and peculiar biochemical characteristics, two fungal categories, white-rot and anaerobic Neocallimastigomycota, have gathered considerable attention for biotechnological applications. These fungi are known for their ability to depolymerize complex molecular structures and are used in degradation of lignocellulosic biomass, improvement of animal feed digestibility, biogas and bioethanol production, and various other applications. However, there are only limited reports that describe proteolytic enzymes and esterases in these fungi and their synergistic action with lignocellulolytic enzymes on degradation of complex polymers. Thus, in this minireview, we focus on the importance of these organisms in enzyme technology, their bioprospecting, possibility of integration of their enzyme repertoire, and their prospects for future biotechnological innovation.
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Affiliation(s)
- Ronivaldo Rodrigues da Silva
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, s/n Campus Universitário da USP, Ribeirão Preto, São Paulo, 14040-903, Brazil.
| | - Rafael Pedezzi
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, s/n Campus Universitário da USP, Ribeirão Preto, São Paulo, 14040-903, Brazil
| | - Tatiane Beltramini Souto
- Instituto Federal de Educação, Ciência e Tecnologia do Espírito Santo (IFES), Nova Venécia, ES, Brazil
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16
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Henske JK, Gilmore SP, Knop D, Cunningham FJ, Sexton JA, Smallwood CR, Shutthanandan V, Evans JE, Theodorou MK, O’Malley MA. Transcriptomic characterization of Caecomyces churrovis: a novel, non-rhizoid-forming lignocellulolytic anaerobic fungus. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:305. [PMID: 29270219 PMCID: PMC5737911 DOI: 10.1186/s13068-017-0997-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 12/12/2017] [Indexed: 05/19/2023]
Abstract
Anaerobic gut fungi are the primary colonizers of plant material in the rumen microbiome, but are poorly studied due to a lack of characterized isolates. While most genera of gut fungi form extensive rhizoidal networks, which likely participate in mechanical disruption of plant cell walls, fungi within the Caecomyces genus do not possess these rhizoids. Here, we describe a novel fungal isolate, Caecomyces churrovis, which forms spherical sporangia with a limited rhizoidal network yet secretes a diverse set of carbohydrate active enzymes (CAZymes) for plant cell wall hydrolysis. Despite lacking an extensive rhizoidal system, C. churrovis is capable of growth on fibrous substrates like switchgrass, reed canary grass, and corn stover, although faster growth is observed on soluble sugars. Gut fungi have been shown to use enzyme complexes (fungal cellulosomes) in which CAZymes bind to non-catalytic scaffoldins to improve biomass degradation efficiency. However, transcriptomic analysis and enzyme activity assays reveal that C. churrovis relies more on free enzymes compared to other gut fungal isolates. Only 15% of CAZyme transcripts contain non-catalytic dockerin domains in C. churrovis, compared to 30% in rhizoid-forming fungi. Furthermore, C. churrovis is enriched in GH43 enzymes that provide complementary hemicellulose degrading activities, suggesting that a wider variety of these activities are required to degrade plant biomass in the absence of an extensive fungal rhizoid network. Overall, molecular characterization of a non-rhizoid-forming anaerobic fungus fills a gap in understanding the roles of CAZyme abundance and associated degradation mechanisms during lignocellulose breakdown within the rumen microbiome.
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Affiliation(s)
- John K. Henske
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106 USA
| | - Sean P. Gilmore
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106 USA
| | - Doriv Knop
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106 USA
| | - Francis J. Cunningham
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106 USA
| | - Jessica A. Sexton
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106 USA
| | - Chuck R. Smallwood
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354 USA
| | | | - James E. Evans
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354 USA
| | - Michael K. Theodorou
- Agriculture Centre for Sustainable Energy Systems (ACSES), Animal Production, Welfare and Veterinary Sciences, Harper Adams University, Newport, Shropshire TF10 8NB UK
| | - Michelle A. O’Malley
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106 USA
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17
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Dollhofer V, Callaghan TM, Dorn-In S, Bauer J, Lebuhn M. Development of three specific PCR-based tools to determine quantity, cellulolytic transcriptional activity and phylogeny of anaerobic fungi. J Microbiol Methods 2016; 127:28-40. [PMID: 27220661 DOI: 10.1016/j.mimet.2016.05.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 05/20/2016] [Accepted: 05/20/2016] [Indexed: 11/27/2022]
Abstract
Anaerobic fungi (AF) decompose plant material with their rhizoid and multiple cellulolytic enzymes. They disintegrate the complex structure of lignocellulosic substrates, making them more accessible and suitable for further microbial degradation. There is also much interest in their use as biocatalysts for biotechnological applications. Here, three novel polymerase chain reaction (PCR)-based methods for detecting AF and their transcriptional activity in in vitro cultures and environmental samples were developed. Two real-time quantitative PCR (qPCR)-based methods targeting AF were developed: AF-SSU, was designed to quantify the 18S rRNA genes of AF. AF-Endo, measuring transcripts of an endoglucanase gene from the glycoside hydrolase family 5 (GH5), was developed to quantify their transcriptional cellulolytic activity. The third PCR based approach was designed for phylogenetical analysis. It targets the 28S rRNA gene (LSU) of AF revealing their phylogenetic affiliation. The in silico-designed primer/probe combinations were successfully tested for the specific amplification of AF from animal and biogas plant derived samples. In combination, these three methods represent useful tools for the analysis of AF transcriptional cellulolytic activity, their abundance and their phylogenetic placement.
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Affiliation(s)
- Veronika Dollhofer
- Department for Quality Assurance and Analytics, Bavarian State Research Center for Agriculture, Lange Point 6, 85354 Freising, Germany.
| | - Tony Martin Callaghan
- Department for Quality Assurance and Analytics, Bavarian State Research Center for Agriculture, Lange Point 6, 85354 Freising, Germany.
| | - Samart Dorn-In
- Chair of Animal Hygiene, WZW, TUM, Weihenstephaner Berg 3, 85354 Freising, Germany.
| | - Johann Bauer
- Chair of Animal Hygiene, WZW, TUM, Weihenstephaner Berg 3, 85354 Freising, Germany.
| | - Michael Lebuhn
- Department for Quality Assurance and Analytics, Bavarian State Research Center for Agriculture, Lange Point 6, 85354 Freising, Germany.
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18
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Solomon KV, Haitjema CH, Henske JK, Gilmore SP, Borges-Rivera D, Lipzen A, Brewer HM, Purvine SO, Wright AT, Theodorou MK, Grigoriev IV, Regev A, Thompson DA, O'Malley MA. Early-branching gut fungi possess a large, comprehensive array of biomass-degrading enzymes. Science 2016; 351:1192-5. [PMID: 26912365 PMCID: PMC5098331 DOI: 10.1126/science.aad1431] [Citation(s) in RCA: 186] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 02/09/2016] [Indexed: 01/22/2023]
Abstract
The fungal kingdom is the source of almost all industrial enzymes in use for lignocellulose bioprocessing. We developed a systems-level approach that integrates transcriptomic sequencing, proteomics, phenotype, and biochemical studies of relatively unexplored basal fungi. Anaerobic gut fungi isolated from herbivores produce a large array of biomass-degrading enzymes that synergistically degrade crude, untreated plant biomass and are competitive with optimized commercial preparations from Aspergillus and Trichoderma. Compared to these model platforms, gut fungal enzymes are unbiased in substrate preference due to a wealth of xylan-degrading enzymes. These enzymes are universally catabolite-repressed and are further regulated by a rich landscape of noncoding regulatory RNAs. Additionally, we identified several promising sequence-divergent enzyme candidates for lignocellulosic bioprocessing.
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Affiliation(s)
- Kevin V Solomon
- Department of Chemical Engineering, University of California, Santa Barbara (UCSB), Santa Barbara, CA 93106, USA
| | - Charles H Haitjema
- Department of Chemical Engineering, University of California, Santa Barbara (UCSB), Santa Barbara, CA 93106, USA
| | - John K Henske
- Department of Chemical Engineering, University of California, Santa Barbara (UCSB), Santa Barbara, CA 93106, USA
| | - Sean P Gilmore
- Department of Chemical Engineering, University of California, Santa Barbara (UCSB), Santa Barbara, CA 93106, USA
| | | | - Anna Lipzen
- U.S. Department of Energy (DOE) Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Heather M Brewer
- Earth and Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA. Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Samuel O Purvine
- Earth and Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA. Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Aaron T Wright
- Earth and Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Michael K Theodorou
- Animal Production, Welfare and Veterinary Sciences, Harper Adams University, Newport, Shropshire TF10 8NB, UK
| | - Igor V Grigoriev
- U.S. Department of Energy (DOE) Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Aviv Regev
- Broad Institute of MIT and Harvard, Cambridge, MA 02143, USA
| | - Dawn A Thompson
- Broad Institute of MIT and Harvard, Cambridge, MA 02143, USA
| | - Michelle A O'Malley
- Department of Chemical Engineering, University of California, Santa Barbara (UCSB), Santa Barbara, CA 93106, USA.
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19
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Chen YC, Chen WT, Liu JC, Tsai LC, Cheng HL. A highly active beta-glucanase from a new strain of rumen fungus Orpinomyces sp.Y102 exhibits cellobiohydrolase and cellotriohydrolase activities. BIORESOURCE TECHNOLOGY 2014; 170:513-521. [PMID: 25164344 DOI: 10.1016/j.biortech.2014.08.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/31/2014] [Accepted: 08/01/2014] [Indexed: 06/03/2023]
Abstract
A new strain of rumen fungus was isolated from Bos taurus, identified and designated Orpinomyces sp.Y102. A clone, celC7, isolated from the cDNA library of Orpinomyces sp.Y102, was predicted to encode a protein containing a signal peptide (Residues 1-17), an N-terminal dockerin-containing domain, and a C-terminal cellobiohydrolase catalytic domain of glycoside hydrolase family 6. CelC7 was insoluble when expressed in Escherichia coli. Deletion of 17 or 105 residues from the N-terminus significantly improved its solubility. The resulting enzymes, CelC7(-17) and CelC7(-105), were highly active to β-glucan substrates and were stable between pH 5.0 and 11.0. CelC7(-105) worked as an exocellulase releasing cellobiose and cellotriose from acid-swollen Avicel and cellooligosaccharides, and displayed a Vmax of 6321.64μmole/min/mg and a Km of 2.18mg/ml to barley β-glucan. Further, the crude extract of CelC7(-105) facilitated ethanol fermentation from cellulose. Thus, CelC7(-105) is a good candidate for industrial applications such as biofuel production.
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Affiliation(s)
- Yo-Chia Chen
- Department of Biological Science and Technology, National Pingtung University of Science and Technology, 1, Shuehfu Rd., Neipu, Pingtung 91201, Taiwan, ROC
| | - Wan-Ting Chen
- Department of Biological Science and Technology, National Pingtung University of Science and Technology, 1, Shuehfu Rd., Neipu, Pingtung 91201, Taiwan, ROC
| | - Jeng-Chen Liu
- Graduate Institute of Bioresources, National Pingtung University of Science and Technology, 1, Shuehfu Rd., Neipu, Pingtung 91201, Taiwan, ROC
| | - Li-Chu Tsai
- Institute of Organic and Polymeric Materials, National Taipei University of Technology, 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 10608, Taiwan, ROC
| | - Hsueh-Ling Cheng
- Department of Biological Science and Technology, National Pingtung University of Science and Technology, 1, Shuehfu Rd., Neipu, Pingtung 91201, Taiwan, ROC.
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20
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Gruninger RJ, Puniya AK, Callaghan TM, Edwards JE, Youssef N, Dagar SS, Fliegerova K, Griffith GW, Forster R, Tsang A, McAllister T, Elshahed MS. Anaerobic fungi (phylum Neocallimastigomycota): advances in understanding their taxonomy, life cycle, ecology, role and biotechnological potential. FEMS Microbiol Ecol 2014; 90:1-17. [PMID: 25046344 DOI: 10.1111/1574-6941.12383] [Citation(s) in RCA: 202] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 07/03/2014] [Accepted: 07/07/2014] [Indexed: 02/05/2023] Open
Abstract
Anaerobic fungi (phylum Neocallimastigomycota) inhabit the gastrointestinal tract of mammalian herbivores, where they play an important role in the degradation of plant material. The Neocallimastigomycota represent the earliest diverging lineage of the zoosporic fungi; however, understanding of the relationships of the different taxa (both genera and species) within this phylum is in need of revision. Issues exist with the current approaches used for their identification and classification, and recent evidence suggests the presence of several novel taxa (potential candidate genera) that remain to be characterised. The life cycle and role of anaerobic fungi has been well characterised in the rumen, but not elsewhere in the ruminant alimentary tract. Greater understanding of the 'resistant' phase(s) of their life cycle is needed, as is study of their role and significance in other herbivores. Biotechnological application of anaerobic fungi, and their highly active cellulolytic and hemi-cellulolytic enzymes, has been a rapidly increasing area of research and development in the last decade. The move towards understanding of anaerobic fungi using -omics based (genomic, transcriptomic and proteomic) approaches is starting to yield valuable insights into the unique cellular processes, evolutionary history, metabolic capabilities and adaptations that exist within the Neocallimastigomycota.
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21
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Haitjema CH, Solomon KV, Henske JK, Theodorou MK, O'Malley MA. Anaerobic gut fungi: Advances in isolation, culture, and cellulolytic enzyme discovery for biofuel production. Biotechnol Bioeng 2014; 111:1471-82. [PMID: 24788404 DOI: 10.1002/bit.25264] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 04/09/2014] [Accepted: 04/10/2014] [Indexed: 12/12/2022]
Abstract
Anaerobic gut fungi are an early branching family of fungi that are commonly found in the digestive tract of ruminants and monogastric herbivores. It is becoming increasingly clear that they are the primary colonizers of ingested plant biomass, and that they significantly contribute to the decomposition of plant biomass into fermentable sugars. As such, anaerobic fungi harbor a rich reservoir of undiscovered cellulolytic enzymes and enzyme complexes that can potentially transform the conversion of lignocellulose into bioenergy products. Despite their unique evolutionary history and cellulolytic activity, few species have been isolated and studied in great detail. As a result, their life cycle, cellular physiology, genetics, and cellulolytic metabolism remain poorly understood compared to aerobic fungi. To help address this limitation, this review briefly summarizes the current body of knowledge pertaining to anaerobic fungal biology, and describes progress made in the isolation, cultivation, molecular characterization, and long-term preservation of these microbes. We also discuss recent cellulase- and cellulosome-discovery efforts from gut fungi, and how these interesting, non-model microbes could be further adapted for biotechnology applications.
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Affiliation(s)
- Charles H Haitjema
- Department of Chemical Engineering, University of California, Santa Barbara, California, 93106
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22
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Leis S, Dresch P, Peintner U, Fliegerová K, Sandbichler AM, Insam H, Podmirseg SM. Finding a robust strain for biomethanation: anaerobic fungi (Neocallimastigomycota) from the Alpine ibex (Capra ibex) and their associated methanogens. Anaerobe 2013; 29:34-43. [PMID: 24384307 DOI: 10.1016/j.anaerobe.2013.12.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 12/04/2013] [Accepted: 12/19/2013] [Indexed: 10/25/2022]
Abstract
Anaerobic fungi occupy the rumen and digestive tract of herbivores, where they play an important role in enzymatic digestion of lignocellulosic and cellulosic substrates, i.e. organic material that their hosts are unable to decompose on their own. In this study we isolated anaerobic fungi from a typical alpine herbivore, the Alpine ibex (C. ibex). Three fungal strains, either as pure culture (ST2) or syntrophic co-culture with methanogens (ST3, ST4) were successfully obtained and morphologically characterised by different microscopy- and staining-techniques and by rDNA ITS gene sequencing. The isolated fungi were identified as Neocallimastix frontalis (ST2) and Caecomyces communis (ST3 and ST4). We introduce a novel field of application for lactofuchsin-staining, combined with confocal laser scanning microscopy. This approach proved as an effective method to visualize fungal structures, especially in the presence of plant biomass, generally exhibiting high autofluorescence. Moreover, we could demonstrate that fungal morphology is subject to changes depending on the carbon source used for cultivation. Oxygen tolerance was confirmed for both, C. communis-cultures for up to three, and for the N. frontalis-isolate for up to 12 h, respectively. With PCR, FISH and an oligonucleotide microarray we found associated methanogens (mainly Methanobacteriales) for C. communis, but not for N. frontalis.
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Affiliation(s)
- Stefanie Leis
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, A-6020 Innsbruck, Austria
| | - Philipp Dresch
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, A-6020 Innsbruck, Austria
| | - Ursula Peintner
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, A-6020 Innsbruck, Austria
| | - Katerina Fliegerová
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Videnska 1083, Prague, Czech Republic
| | | | - Heribert Insam
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, A-6020 Innsbruck, Austria
| | - Sabine Marie Podmirseg
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, A-6020 Innsbruck, Austria.
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23
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The genome of the anaerobic fungus Orpinomyces sp. strain C1A reveals the unique evolutionary history of a remarkable plant biomass degrader. Appl Environ Microbiol 2013; 79:4620-34. [PMID: 23709508 DOI: 10.1128/aem.00821-13] [Citation(s) in RCA: 156] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Anaerobic gut fungi represent a distinct early-branching fungal phylum (Neocallimastigomycota) and reside in the rumen, hindgut, and feces of ruminant and nonruminant herbivores. The genome of an anaerobic fungal isolate, Orpinomyces sp. strain C1A, was sequenced using a combination of Illumina and PacBio single-molecule real-time (SMRT) technologies. The large genome (100.95 Mb, 16,347 genes) displayed extremely low G+C content (17.0%), large noncoding intergenic regions (73.1%), proliferation of microsatellite repeats (4.9%), and multiple gene duplications. Comparative genomic analysis identified multiple genes and pathways that are absent in Dikarya genomes but present in early-branching fungal lineages and/or nonfungal Opisthokonta. These included genes for posttranslational fucosylation, the production of specific intramembrane proteases and extracellular protease inhibitors, the formation of a complete axoneme and intraflagellar trafficking machinery, and a near-complete focal adhesion machinery. Analysis of the lignocellulolytic machinery in the C1A genome revealed an extremely rich repertoire, with evidence of horizontal gene acquisition from multiple bacterial lineages. Experimental analysis indicated that strain C1A is a remarkable biomass degrader, capable of simultaneous saccharification and fermentation of the cellulosic and hemicellulosic fractions in multiple untreated grasses and crop residues examined, with the process significantly enhanced by mild pretreatments. This capability, acquired during its separate evolutionary trajectory in the rumen, along with its resilience and invasiveness compared to prokaryotic anaerobes, renders anaerobic fungi promising agents for consolidated bioprocessing schemes in biofuels production.
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Sirohi SK, Singh N, Dagar SS, Puniya AK. Molecular tools for deciphering the microbial community structure and diversity in rumen ecosystem. Appl Microbiol Biotechnol 2012; 95:1135-54. [PMID: 22782251 DOI: 10.1007/s00253-012-4262-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 06/20/2012] [Accepted: 06/22/2012] [Indexed: 12/30/2022]
Abstract
Rumen microbial community comprising of bacteria, archaea, fungi, and protozoa is characterized not only by the high population density but also by the remarkable diversity and the most complex microecological interactions existing in the biological world. This unprecedented biodiversity is quite far from full elucidation as only about 15-20 % of the rumen microbes are identified and characterized till date using conventional culturing and microscopy. However, the last two decades have witnessed a paradigm shift from cumbersome and time-consuming classical methods to nucleic acid-based molecular approaches for deciphering the rumen microbial community. These techniques are rapid, reproducible and allow both the qualitative and quantitative assessment of microbial diversity. This review describes the different molecular methods and their applications in elucidating the rumen microbial community.
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Affiliation(s)
- Sunil Kumar Sirohi
- Nutrition Biotechnology Laboratory, Dairy Cattle Nutrition Division, National Dairy Research Institute, Karnal, 132001, Haryana, India.
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25
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Qi M, Wang P, O'Toole N, Barboza PS, Ungerfeld E, Leigh MB, Selinger LB, Butler G, Tsang A, McAllister TA, Forster RJ. Snapshot of the eukaryotic gene expression in muskoxen rumen--a metatranscriptomic approach. PLoS One 2011; 6:e20521. [PMID: 21655220 PMCID: PMC3105075 DOI: 10.1371/journal.pone.0020521] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 05/01/2011] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Herbivores rely on digestive tract lignocellulolytic microorganisms, including bacteria, fungi and protozoa, to derive energy and carbon from plant cell wall polysaccharides. Culture independent metagenomic studies have been used to reveal the genetic content of the bacterial species within gut microbiomes. However, the nature of the genes encoded by eukaryotic protozoa and fungi within these environments has not been explored using metagenomic or metatranscriptomic approaches. METHODOLOGY/PRINCIPAL FINDINGS In this study, a metatranscriptomic approach was used to investigate the functional diversity of the eukaryotic microorganisms within the rumen of muskoxen (Ovibos moschatus), with a focus on plant cell wall degrading enzymes. Polyadenylated RNA (mRNA) was sequenced on the Illumina Genome Analyzer II system and 2.8 gigabases of sequences were obtained and 59129 contigs assembled. Plant cell wall degrading enzyme modules including glycoside hydrolases, carbohydrate esterases and polysaccharide lyases were identified from over 2500 contigs. These included a number of glycoside hydrolase family 6 (GH6), GH48 and swollenin modules, which have rarely been described in previous gut metagenomic studies. CONCLUSIONS/SIGNIFICANCE The muskoxen rumen metatranscriptome demonstrates a much higher percentage of cellulase enzyme discovery and an 8.7x higher rate of total carbohydrate active enzyme discovery per gigabase of sequence than previous rumen metagenomes. This study provides a snapshot of eukaryotic gene expression in the muskoxen rumen, and identifies a number of candidate genes coding for potentially valuable lignocellulolytic enzymes.
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Affiliation(s)
- Meng Qi
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
| | - Pan Wang
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Nicholas O'Toole
- Centre for Structural and Functional Genomics, Concordia University, Montreal, Quebec, Canada
| | - Perry S. Barboza
- Department of Biology and Wildlife, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Emilio Ungerfeld
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
| | - Mary Beth Leigh
- Department of Biology and Wildlife, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - L. Brent Selinger
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Greg Butler
- Centre for Structural and Functional Genomics, Concordia University, Montreal, Quebec, Canada
| | - Adrian Tsang
- Centre for Structural and Functional Genomics, Concordia University, Montreal, Quebec, Canada
| | - Tim A. McAllister
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
| | - Robert J. Forster
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
- * E-mail:
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26
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Heterologous expression of an endo-β-1,4-glucanase gene from the anaerobic fungus Orpinomyces PC-2 in Trichoderma reesei. World J Microbiol Biotechnol 2011. [DOI: 10.1007/s11274-011-0774-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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27
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Tamaru Y, Miyake H, Kuroda K, Ueda M, Doi RH. Comparative genomics of the mesophilic cellulosome-producing Clostridium cellulovorans and its application to biofuel production via consolidated bioprocessing. ENVIRONMENTAL TECHNOLOGY 2010; 31:889-903. [PMID: 20662379 DOI: 10.1080/09593330.2010.490856] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Clostridium cellulovorans is an anaerobic, mesophilic bacterium that efficiently degrades native substrates in soft biomass such as corn fibre and rice straw by producing an extracellular enzyme complex called the cellulosomes. By examining genome sequences from multiple Clostridium species, comparative genomics offers new insight into genome evolution and the way natural selection moulds functional DNA sequence evolution. Recently, we reported the whole genome sequence of C. cellulovorans. A total of 57 cellulosomal genes were found in the C. cellulovorans genome and coded for not only carbohydrate-active enzymes but also lipase, peptidase and proteinase inhibitors, in addition to two novel genes encoding scaffolding proteins CbpB and CbpC. Interestingly, the genome size of C. cellulovorans was about 1 Mbp larger than that of other cellulosome-producing clostridia: mesophilic C. cellulolyticum and thermophilic C. thermocellum. Since the C. cellulovorans genome included not only cellulosomal genes but also a large number of genes encoding non-cellulosomal enzymes, the genome expansion of C. cellulovorans included genes more related to degradation of polysaccharides, such as hemicelluloses and pectins, than to cellulose. In this review, we propose a strategy for industrial applications such as biofuel production using enhanced mesophilic cellulosome- and solvent-producing clostridia.
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Affiliation(s)
- Yutaka Tamaru
- Department of Life Science, Mie University Graduate School of Bioresourses, 1577 Kurimamachiya, Tsu, Mie 514-8507, Japan.
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Nicholson MJ, McSweeney CS, Mackie RI, Brookman JL, Theodorou MK. Diversity of anaerobic gut fungal populations analysed using ribosomal ITS1 sequences in faeces of wild and domesticated herbivores. Anaerobe 2009; 16:66-73. [PMID: 19465140 DOI: 10.1016/j.anaerobe.2009.05.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Accepted: 05/11/2009] [Indexed: 10/20/2022]
Abstract
Gut fungal-specific PCR primers have been used to selectively amplify the ITS1 region of gut fungal rDNA recovered from faeces of domestic and wild animals to investigate population diversity. Two different gel-based methods are described for separating populations of gut fungal rDNA amplicons, namely (1) denaturing gradient gel electrophoresis (DGGE) and (2) separation according to small size differences using Spreadex, a proprietary matrix for electrophoresis. Gut fungal populations were characterised by analysis of rDNA in faeces of seventeen domesticated and ten wild herbivores. Sequences derived from these gel-based characterisations were analysed and classified using a hidden Markov model-based fingerprint matching algorithm. Faecal samples contained a broad spectrum of fungi and sequences from five of the six recognised genera were identified, including Cyllamyces, the most recently described gut fungal genus, which was found to be widely distributed in the samples. Furthermore, four other novel groupings of gut fungal sequences were identified that did not cluster with sequences from any of the previously described genera. Both gel- and sequence- based profiles for gut fungal populations suggested a lack of geographical restriction on occurrence of any individual fungal type.
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Affiliation(s)
- Matthew J Nicholson
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Plas Gogerddan, Aberystywth, Ceredigion SY23 3EB, UK
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Denman SE, Nicholson MJ, Brookman JL, Theodorou MK, McSweeney CS. Detection and monitoring of anaerobic rumen fungi using an ARISA method. Lett Appl Microbiol 2009; 47:492-9. [PMID: 19120916 DOI: 10.1111/j.1472-765x.2008.02449.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIM To develop an automated ribosomal intergenic spacer region analysis (ARISA) method for the detection of anaerobic rumen fungi and also to demonstrate utility of the technique to monitor colonization and persistence of fungi, and diet-induced changes in community structure. METHODS AND RESULTS The method could discriminate between three genera of anaerobic rumen fungal isolates, representing Orpinomyces, Piromyces and Neocallimastix species. Changes in anaerobic fungal composition were observed between animals fed a high-fibre diet compared with a grain-based diet. ARISA analysis of rumen samples from animals on grain showed a decrease in fungal diversity with a dominance of Orpinomyces and Piromyces spp. Clustering analysis of ARISA profile patterns grouped animals based on diet. A single strain of Orpinomyces was dosed into a cow and was detectable within the rumen fungal population for several weeks afterwards. CONCLUSIONS The ARISA technique was capable of discriminating between pure cultures at the genus level. Diet composition has a significant influence on the diversity of anaerobic fungi in the rumen and the method can be used to monitor introduced strains. SIGNIFICANCE AND IMPACT OF THE STUDY Through the use of ARISA analysis, a better understanding of the effect of diets on rumen anaerobic fungi populations is provided.
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Affiliation(s)
- S E Denman
- CSIRO Livestock Industries, Queensland Bioscience Precinct, Brisbane, Queensland, Australia
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Comparison of morphological and enzyme characteristics of anaerobic fungi isolated from Cervus dama. Open Life Sci 2008. [DOI: 10.2478/s11535-007-0046-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractSeven anaerobic fungal isolates from Cervus dama (domesticated and free living) were grown on carboxymethyl cellulose (CMC) and avicel, and monitored over a five day period for substrate utilization and cellulase activities. All fungal isolates showed monocentric growth patterns; four of them had polyflagellated zoospores and morphologically resembled members of the genus Neocallimastix; the other three had monoflagellated zoospores and resembled members of the genus Piromyces. All of the isolates degraded CMC and avicel, and exhibited cellulolytic activities (carboxymethyl cellulase-(CMC-ase) and avicelase).
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Doi RH. Cellulases of mesophilic microorganisms: cellulosome and noncellulosome producers. Ann N Y Acad Sci 2007; 1125:267-79. [PMID: 18096849 DOI: 10.1196/annals.1419.002] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The cellulolytic activity of mesophilic bacteria and fungi is described, with special emphasis on the large extracellular enzyme complex called the cellulosome. The cellulosome is composed of a scaffolding protein, which is attached to various cellulolytic and hemicellulolytic enzymes, and this complex allows the organisms to degrade plant cell walls very efficently. The enzymes include a variety of cellulases, hemicellulases, and pectinases that work synergistically to degrade complex cell-wall molecules.
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Affiliation(s)
- Roy H Doi
- Section of Molecular and Cellular Biology, University of California, One Shields Avenue, Davis, CA 95616, USA.
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Expression of an AT-rich xylanase gene from the anaerobic fungus Orpinomyces sp. strain PC-2 in and secretion of the heterologous enzyme by Hypocrea jecorina. Appl Microbiol Biotechnol 2007. [DOI: 10.1007/s00253-006-0787-6 72] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
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Koch M, Strobel E, Tebbe CC, Heritage J, Breves G, Huber K. Transgenic maize in the presence of ampicillin modifies the metabolic profile and microbial population structure of bovine rumen fluidin vitro. Br J Nutr 2007; 96:820-9. [PMID: 17092369 DOI: 10.1017/bjn20061889] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Recently, transgenic crops have been considered as possible donors of transgenes that could be taken up by micro-organisms under appropriate conditions. In anin vitrorumen simulation system, effects of ampicillin on microbial communities growing either on rumen contents with transgenic maize carrying a gene that confers resistance to ampicillin or its isogenic counterpart as substrates were examined continuously over 13 d. Rate of production of SCFA was measured to determine functional changes in the rumen model and single-strand conformational polymorphism was used to detect alterations in structure of the microbial community. Rumen contents treated with ampicillin displayed a marked decrease in the rate of production of SCFA and diversity of the microbial community was reduced severely. In the presence of transgenic maize, however, the patterns of change of rumen micro-organisms and their metabolic profiles were different from that of rumen fluid incorporating maize bred conventionally. Recovery of propionate production was observed both in the rumen fluid fed transgenic and conventional maize after a delay of several days but recovery occurred earlier in fermenters fed transgenic maize. Alterations in the microbial population structures resulting from the ampicillin challenge were not reversed during the experimental run although there was evidence of adaptation of the microbial communities over time in the presence of the antibiotic, showing that populations with different microbial structures could resume a pre-challenge metabolic profile following the introduction of ampicillin, irrespective of the source of the plant material in the growth medium.
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Affiliation(s)
- Melanie Koch
- Department of Physiology, School of Veterinary Medicine, Bischofsholer Damm 15/102, 30273 Hannover, Germany
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Li XL, Skory CD, Ximenes EA, Jordan DB, Dien BS, Hughes SR, Cotta MA. Expression of an AT-rich xylanase gene from the anaerobic fungus Orpinomyces sp. strain PC-2 in and secretion of the heterologous enzyme by Hypocrea jecorina. Appl Microbiol Biotechnol 2007; 74:1264-75. [PMID: 17225100 DOI: 10.1007/s00253-006-0787-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Revised: 11/28/2006] [Accepted: 11/30/2006] [Indexed: 12/01/2022]
Abstract
The catalytic domain encoded by an adenine-thymine (AT)-rich xylanase gene (xynA) of the anaerobic fungus Orpinomyces was expressed in Hypocrea jecorina under the control of the cel7A promoter and terminator. No XynA protein was detected in H. jecorina culture supernatants when the original sequence was fused to the H. jecorina cel5A region coding for its signal peptide, carbohydrate-binding module, and hinge. Replacing the xynA (56% AT content) with a synthetic sequence containing lower AT content (39%) supported the extracellular production (150 mg l(-1)) of the fusion xylanase by H. jecorina. Northern analysis revealed that successful production after the decrease in AT content was related to higher levels of the xylanase-specific mRNA. Another construct with an RDKR-coding sequence inserted between the cel5A linker and the xynA catalytic domain allowed production of the fully processed active xylanase catalytic domain. Both the fusion (40 kDa) and the fully processed (28 kDa) forms displayed enzymatic properties of family 11 xylanases. Both the R and the Kex2-like KR sites were recognized during secretion, resulting in a mixture of two amino termini for the 28-kDa xylanase. The work demonstrated for the first time that glycoside hydrolases derived from anaerobic fungi can be produced by H. jecorina.
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MESH Headings
- AT Rich Sequence/genetics
- Amino Acid Sequence
- Base Sequence
- Blotting, Northern
- Blotting, Southern
- Blotting, Western
- Cloning, Molecular
- Electrophoresis, Polyacrylamide Gel
- Endo-1,4-beta Xylanases/genetics
- Endo-1,4-beta Xylanases/metabolism
- Fungal Proteins/genetics
- Fungal Proteins/metabolism
- Gene Expression Regulation, Enzymologic
- Hypocrea/genetics
- Molecular Sequence Data
- Neocallimastigales/enzymology
- Neocallimastigales/genetics
- Plasmids/chemistry
- Plasmids/genetics
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
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Affiliation(s)
- Xin-Liang Li
- Fermentation Biotechnology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture-Agricultural Research Service, 1815 N. University Street, Peoria, IL, USA.
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