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Porter R, Černoša A, Fernández-Sanmartín P, Cortizas AM, Aranda E, Luo Y, Zalar P, Podlogar M, Gunde-Cimerman N, Gostinčar C. Degradation of polypropylene by fungi Coniochaeta hoffmannii and Pleurostoma richardsiae. Microbiol Res 2023; 277:127507. [PMID: 37793281 DOI: 10.1016/j.micres.2023.127507] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/11/2023] [Accepted: 09/21/2023] [Indexed: 10/06/2023]
Abstract
The urgent need for better disposal and recycling of plastics has motivated a search for microbes with the ability to degrade synthetic polymers. While microbes capable of metabolizing polyurethane and polyethylene terephthalate have been discovered and even leveraged in enzymatic recycling approaches, microbial degradation of additive-free polypropylene (PP) remains elusive. Here we report the isolation and characterization of two fungal strains with the potential to degrade pure PP. Twenty-seven fungal strains, many isolated from hydrocarbon contaminated sites, were screened for degradation of commercially used textile plastic. Of the candidate strains, two identified as Coniochaeta hoffmannii and Pleurostoma richardsiae were found to colonize the plastic fibers using scanning electron microscopy (SEM). Further experiments probing degradation of pure PP films were performed using C. hoffmannii and P. richardsiae and analyzed using SEM, Raman spectroscopy and Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR). The results showed that the selected fungi were active against pure PP, with distinct differences in the bonds targeted and the degree to which each was altered. Whole genome and transcriptome sequencing was conducted for both strains and the abundance of carbohydrate active enzymes, GC content, and codon usage bias were analyzed in predicted proteomes for each. Enzymatic assays were conducted to assess each strain's ability to degrade naturally occurring compounds as well as synthetic polymers. These investigations revealed potential adaptations to hydrocarbon-rich environments and provide a foundation for further investigation of PP degrading activity in C. hoffmannii and P. richardsiae.
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Affiliation(s)
- Rachel Porter
- Biophysics Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Anja Černoša
- University of Ljubljana, Biotechnical Faculty, Department of Biology, Jamnikarjeva 101, Ljubljana, Slovenia
| | - Paola Fernández-Sanmartín
- CRETUS, EcoPast Research Group (GI-1553), Departamento de Edafoloxía e Química Agrícola, Faculty of Biology, Universidade de Santiago de Compostela, Campus Vida, 15782 Santiago de Compostela, Spain
| | - Antonio Martínez Cortizas
- CRETUS, EcoPast Research Group (GI-1553), Departamento de Edafoloxía e Química Agrícola, Faculty of Biology, Universidade de Santiago de Compostela, Campus Vida, 15782 Santiago de Compostela, Spain
| | - Elisabet Aranda
- University of Granada, Institute of Water Research, Environmental Microbiology Group, Ramón y Cajal n4, 18071 Granada, Spain
| | - Yonglun Luo
- Lars Bolund Institute of Regenerative Medicine, Qingdao-Europe Advanced Institute for Life Sciences, BGI-Qingdao, Qingdao 266555, China
| | - Polona Zalar
- University of Ljubljana, Biotechnical Faculty, Department of Biology, Jamnikarjeva 101, Ljubljana, Slovenia
| | - Matejka Podlogar
- Department for Nanostructured Materials, Jožef Stefan Institute, Jamova cesta 39, Ljubljana, Slovenia
| | - Nina Gunde-Cimerman
- University of Ljubljana, Biotechnical Faculty, Department of Biology, Jamnikarjeva 101, Ljubljana, Slovenia
| | - Cene Gostinčar
- University of Ljubljana, Biotechnical Faculty, Department of Biology, Jamnikarjeva 101, Ljubljana, Slovenia.
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Riley R, Bowers RM, Camargo AP, Campbell A, Egan R, Eloe-Fadrosh EA, Foster B, Hofmeyr S, Huntemann M, Kellom M, Kimbrel JA, Oliker L, Yelick K, Pett-Ridge J, Salamov A, Varghese NJ, Clum A. Terabase-Scale Coassembly of a Tropical Soil Microbiome. Microbiol Spectr 2023; 11:e0020023. [PMID: 37310219 PMCID: PMC10434106 DOI: 10.1128/spectrum.00200-23] [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: 01/12/2023] [Accepted: 05/24/2023] [Indexed: 06/14/2023] Open
Abstract
Petabases of environmental metagenomic data are publicly available, presenting an opportunity to characterize complex environments and discover novel lineages of life. Metagenome coassembly, in which many metagenomic samples from an environment are simultaneously analyzed to infer the underlying genomes' sequences, is an essential tool for achieving this goal. We applied MetaHipMer2, a distributed metagenome assembler that runs on supercomputing clusters, to coassemble 3.4 terabases (Tbp) of metagenome data from a tropical soil in the Luquillo Experimental Forest (LEF), Puerto Rico. The resulting coassembly yielded 39 high-quality (>90% complete, <5% contaminated, with predicted 23S, 16S, and 5S rRNA genes and ≥18 tRNAs) metagenome-assembled genomes (MAGs), including two from the candidate phylum Eremiobacterota. Another 268 medium-quality (≥50% complete, <10% contaminated) MAGs were extracted, including the candidate phyla Dependentiae, Dormibacterota, and Methylomirabilota. In total, 307 medium- or higher-quality MAGs were assigned to 23 phyla, compared to 294 MAGs assigned to nine phyla in the same samples individually assembled. The low-quality (<50% complete, <10% contaminated) MAGs from the coassembly revealed a 49% complete rare biosphere microbe from the candidate phylum FCPU426 among other low-abundance microbes, an 81% complete fungal genome from the phylum Ascomycota, and 30 partial eukaryotic MAGs with ≥10% completeness, possibly representing protist lineages. A total of 22,254 viruses, many of them low abundance, were identified. Estimation of metagenome coverage and diversity indicates that we may have characterized ≥87.5% of the sequence diversity in this humid tropical soil and indicates the value of future terabase-scale sequencing and coassembly of complex environments. IMPORTANCE Petabases of reads are being produced by environmental metagenome sequencing. An essential step in analyzing these data is metagenome assembly, the computational reconstruction of genome sequences from microbial communities. "Coassembly" of metagenomic sequence data, in which multiple samples are assembled together, enables more complete detection of microbial genomes in an environment than "multiassembly," in which samples are assembled individually. To demonstrate the potential for coassembling terabases of metagenome data to drive biological discovery, we applied MetaHipMer2, a distributed metagenome assembler that runs on supercomputing clusters, to coassemble 3.4 Tbp of reads from a humid tropical soil environment. The resulting coassembly, its functional annotation, and analysis are presented here. The coassembly yielded more, and phylogenetically more diverse, microbial, eukaryotic, and viral genomes than the multiassembly of the same data. Our resource may facilitate the discovery of novel microbial biology in tropical soils and demonstrates the value of terabase-scale metagenome sequencing.
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Affiliation(s)
- Robert Riley
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley California, USA
| | - Robert M. Bowers
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley California, USA
| | - Antonio Pedro Camargo
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley California, USA
| | - Ashley Campbell
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Rob Egan
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley California, USA
| | | | - Brian Foster
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley California, USA
| | - Steven Hofmeyr
- Applied Math and Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Marcel Huntemann
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley California, USA
| | - Matthew Kellom
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley California, USA
| | - Jeffrey A. Kimbrel
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Leonid Oliker
- Applied Math and Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Katherine Yelick
- Applied Math and Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California, USA
| | - Jennifer Pett-Ridge
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
- Life & Environmental Sciences Department, University of California Merced, Merced, California, USA
| | - Asaf Salamov
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley California, USA
| | - Neha J. Varghese
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley California, USA
| | - Alicia Clum
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley California, USA
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Campos-Quiroz C, Castro JF, Santelices C, Carrasco-Fernández J, Guerra M, Cares-Gatica D, Ortiz-Campos J, Ocares Y, Barra-Bucarei L, Theelen B. Description of Two Fungal Endophytes Isolated from Fragaria chiloensis subsp. chiloensis f. patagonica: Coniochaeta fragariicola sp. nov. and a New Record of Coniochaeta hansenii. TAXONOMY 2023. [DOI: 10.3390/taxonomy3020014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Prospection of the endosphere of the native plant Fragaria chiloensis subsp. chiloensis f. patagonica from the foothills of the Chilean Andes led to the isolation of two strains of the genus Coniochaeta. We addressed the taxonomic placement of these strains based on DNA sequencing data using the ITS and LSU genetic markers, morphological features, and biochemical traits. One of these strains was identified as Coniochaeta hansenii, for which the anamorph and teleomorph states were described. The second strain did not seem to match any of the currently described species of this genus; therefore, we propose the name Coniochaeta fragariicola sp. nov.
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Affiliation(s)
- Carolina Campos-Quiroz
- Instituto de Investigaciones Agropecuarias, INIA Quilamapu. Av. Vicente Méndez 515, Chillán 3800062, Ñuble, Chile
| | - Jean Franco Castro
- Instituto de Investigaciones Agropecuarias, INIA Quilamapu. Av. Vicente Méndez 515, Chillán 3800062, Ñuble, Chile
| | - Cecilia Santelices
- Instituto de Investigaciones Agropecuarias, INIA Quilamapu. Av. Vicente Méndez 515, Chillán 3800062, Ñuble, Chile
| | - Jorge Carrasco-Fernández
- Instituto de Investigaciones Agropecuarias, INIA Quilamapu. Av. Vicente Méndez 515, Chillán 3800062, Ñuble, Chile
| | - Matías Guerra
- Instituto de Investigaciones Agropecuarias, INIA Quilamapu. Av. Vicente Méndez 515, Chillán 3800062, Ñuble, Chile
| | - Diego Cares-Gatica
- Instituto de Investigaciones Agropecuarias, INIA Quilamapu. Av. Vicente Méndez 515, Chillán 3800062, Ñuble, Chile
| | - Javiera Ortiz-Campos
- Instituto de Investigaciones Agropecuarias, INIA Quilamapu. Av. Vicente Méndez 515, Chillán 3800062, Ñuble, Chile
| | - Yocelyn Ocares
- Instituto de Investigaciones Agropecuarias, INIA Quilamapu. Av. Vicente Méndez 515, Chillán 3800062, Ñuble, Chile
| | - Lorena Barra-Bucarei
- Instituto de Investigaciones Agropecuarias, INIA Quilamapu. Av. Vicente Méndez 515, Chillán 3800062, Ñuble, Chile
| | - Bart Theelen
- Westerdijk Fungal Biodiversity Institute, 3584 CT Utrecht, The Netherlands
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4
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Hage H, Rosso MN, Tarrago L. Distribution of methionine sulfoxide reductases in fungi and conservation of the free-methionine-R-sulfoxide reductase in multicellular eukaryotes. Free Radic Biol Med 2021; 169:187-215. [PMID: 33865960 DOI: 10.1016/j.freeradbiomed.2021.04.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 12/17/2022]
Abstract
Methionine, either as a free amino acid or included in proteins, can be oxidized into methionine sulfoxide (MetO), which exists as R and S diastereomers. Almost all characterized organisms possess thiol-oxidoreductases named methionine sulfoxide reductase (Msr) enzymes to reduce MetO back to Met. MsrA and MsrB reduce the S and R diastereomers of MetO, respectively, with strict stereospecificity and are found in almost all organisms. Another type of thiol-oxidoreductase, the free-methionine-R-sulfoxide reductase (fRMsr), identified so far in prokaryotes and a few unicellular eukaryotes, reduces the R MetO diastereomer of the free amino acid. Moreover, some bacteria possess molybdenum-containing enzymes that reduce MetO, either in the free or protein-bound forms. All these Msrs play important roles in the protection of organisms against oxidative stress. Fungi are heterotrophic eukaryotes that colonize all niches on Earth and play fundamental functions, in organic matter recycling, as symbionts, or as pathogens of numerous organisms. However, our knowledge on fungal Msrs is still limited. Here, we performed a survey of msr genes in almost 700 genomes across the fungal kingdom. We show that most fungi possess one gene coding for each type of methionine sulfoxide reductase: MsrA, MsrB, and fRMsr. However, several fungi living in anaerobic environments or as obligate intracellular parasites were devoid of msr genes. Sequence inspection and phylogenetic analyses allowed us to identify non-canonical sequences with potentially novel enzymatic properties. Finaly, we identified several ocurences of msr horizontal gene transfer from bacteria to fungi.
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Affiliation(s)
- Hayat Hage
- Biodiversité et Biotechnologie Fongiques, UMR1163, INRAE, Aix Marseille Université, Marseille, France
| | - Marie-Noëlle Rosso
- Biodiversité et Biotechnologie Fongiques, UMR1163, INRAE, Aix Marseille Université, Marseille, France
| | - Lionel Tarrago
- Biodiversité et Biotechnologie Fongiques, UMR1163, INRAE, Aix Marseille Université, Marseille, France.
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5
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Roots, Tissues, Cells and Fragments—How to Characterize Peat from Drained and Rewetted Fens. SOIL SYSTEMS 2020. [DOI: 10.3390/soilsystems4010012] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We present analyses of macroscopic and microscopic remains as a tool to characterise sedge fen peats. We use it to describe peat composition and stages of peat decomposition, to assess the success of rewetting of a formerly drained fen, and to understand the workings of these novel ecosystems. We studied two percolation fen sites, one drained and one drained and rewetted 20 years ago. Years of deep drainage have resulted in a layer of strongly decomposed peat which lacks recognizable macro-remains. We could associate micro-remains with macro-remains, and thus still characterise the peat and the plants that once formed it. We show that the strongly decomposed peat is of the same origin as the slightly decomposed peat below, and that is was ploughed. We present descriptions of eight types of the main constituent of sedge peat: plant roots, including Carex rostrata type, C. lasiocarpa/rostrata type, C. limosa type, C. acutiformis type, C. echinata type, Phragmites australis type, Cladium type, Equisetum type. We describe three new non-pollen palynomorph types (microscopic remains) and five new subtypes. The rewetted fen provides insights into plant succession after rewetting and the formation of peat that predominantly consists of roots. Results indicate that leaf sheaths may be a consistent component of the peat.
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Gebbie L, Dam TT, Ainscough R, Palfreyman R, Cao L, Harrison M, O'Hara I, Speight R. A snapshot of microbial diversity and function in an undisturbed sugarcane bagasse pile. BMC Biotechnol 2020; 20:12. [PMID: 32111201 PMCID: PMC7049217 DOI: 10.1186/s12896-020-00609-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/24/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Sugarcane bagasse is a major source of lignocellulosic biomass, yet its economic potential is not fully realised. To add value to bagasse, processing is needed to gain access to the embodied recalcitrant biomaterials. When bagasse is stored in piles in the open for long periods it is colonised by microbes originating from the sugarcane, the soil nearby or spores in the environment. For these microorganisms to proliferate they must digest the bagasse to access carbon for growth. The microbial community in bagasse piles is thus a potential resource for the discovery of useful and novel microbes and industrial enzymes. We used culturing and metabarcoding to understand the diversity of microorganisms found in a uniquely undisturbed bagasse storage pile and screened the cultured organisms for fibre-degrading enzymes. RESULTS Samples collected from 60 to 80 cm deep in the bagasse pile showed hemicellulose and partial lignin degradation. One hundred and four microbes were cultured from different layers and included a high proportion of oleaginous yeast and biomass-degrading fungi. Overall, 70, 67, 70 and 57% of the microbes showed carboxy-methyl cellulase, xylanase, laccase and peroxidase activity, respectively. These percentages were higher in microbes selectively cultured from deep layers, with all four activities found for 44% of these organisms. Culturing and amplicon sequencing showed that there was less diversity and therefore more selection in the deeper layers, which were dominated by thermophiles and acid tolerant organisms, compared with the top of pile. Amplicon sequencing indicated that novel fungi were present in the pile. CONCLUSIONS A combination of culture-dependent and independent methods was successful in exploring the diversity in the bagasse pile. The variety of species that was found and that are known for biomass degradation shows that the bagasse pile was a valuable selective environment for the identification of new microbes and enzymes with biotechnological potential. In particular, lignin-modifying activities have not been reported previously for many of the species that were identified, suggesting future studies are warranted.
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Affiliation(s)
- Leigh Gebbie
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia
| | - Tuan Tu Dam
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia
| | - Rebecca Ainscough
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia
| | - Robin Palfreyman
- Metabolomics Australia, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Li Cao
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia
| | - Mark Harrison
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia
| | - Ian O'Hara
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia
| | - Robert Speight
- Queensland University of Technology, 2 George St, Brisbane, QLD, 4000, Australia.
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7
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Mondo SJ, Jiménez DJ, Hector RE, Lipzen A, Yan M, LaButti K, Barry K, van Elsas JD, Grigoriev IV, Nichols NN. Genome expansion by allopolyploidization in the fungal strain Coniochaeta 2T2.1 and its exceptional lignocellulolytic machinery. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:229. [PMID: 31572496 PMCID: PMC6757388 DOI: 10.1186/s13068-019-1569-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 09/13/2019] [Indexed: 05/03/2023]
Abstract
BACKGROUND Particular species of the genus Coniochaeta (Sordariomycetes) exhibit great potential for bioabatement of furanic compounds and have been identified as an underexplored source of novel lignocellulolytic enzymes, especially Coniochaeta ligniaria. However, there is a lack of information about their genomic features and metabolic capabilities. Here, we report the first in-depth genome/transcriptome survey of a Coniochaeta species (strain 2T2.1). RESULTS The genome of Coniochaeta sp. strain 2T2.1 has a size of 74.53 Mbp and contains 24,735 protein-encoding genes. Interestingly, we detected a genome expansion event, resulting ~ 98% of the assembly being duplicated with 91.9% average nucleotide identity between the duplicated regions. The lack of gene loss, as well as the high divergence and strong genome-wide signatures of purifying selection between copies indicates that this is likely a recent duplication, which arose through hybridization between two related Coniochaeta-like species (allopolyploidization). Phylogenomic analysis revealed that 2T2.1 is related Coniochaeta sp. PMI546 and Lecythophora sp. AK0013, which both occur endophytically. Based on carbohydrate-active enzyme (CAZy) annotation, we observed that even after in silico removal of its duplicated content, the 2T2.1 genome contains exceptional lignocellulolytic machinery. Moreover, transcriptomic data reveal the overexpression of proteins affiliated to CAZy families GH11, GH10 (endoxylanases), CE5, CE1 (xylan esterases), GH62, GH51 (α-l-arabinofuranosidases), GH12, GH7 (cellulases), and AA9 (lytic polysaccharide monoxygenases) when the fungus was grown on wheat straw compared with glucose as the sole carbon source. CONCLUSIONS We provide data that suggest that a recent hybridization between the genomes of related species may have given rise to Coniochaeta sp. 2T2.1. Moreover, our results reveal that the degradation of arabinoxylan, xyloglucan and cellulose are key metabolic processes in strain 2T2.1 growing on wheat straw. Different genes for key lignocellulolytic enzymes were identified, which can be starting points for production, characterization and/or supplementation of enzyme cocktails used in saccharification of agricultural residues. Our findings represent first steps that enable a better understanding of the reticulate evolution and "eco-enzymology" of lignocellulolytic Coniochaeta species.
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Affiliation(s)
- Stephen J. Mondo
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
- Bioagricultural Science and Pest Management Department, Colorado State University, Fort Collins, CO 80521 USA
| | - Diego Javier Jiménez
- Microbiomes and Bioenergy Research Group, Department of Biological Sciences, Universidad de los Andes, Carrera 1 No 18A-12, Bogotá, Colombia
| | - Ronald E. Hector
- Bioenergy Research Unit, National Center for Agricultural Utilization Research, USDA-ARS, Peoria, IL 61604 USA
| | - Anna Lipzen
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Mi Yan
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Kurt LaButti
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Kerrie Barry
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Jan Dirk van Elsas
- Cluster of Microbial Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Igor V. Grigoriev
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720-3102 USA
| | - Nancy N. Nichols
- Bioenergy Research Unit, National Center for Agricultural Utilization Research, USDA-ARS, Peoria, IL 61604 USA
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Atanasova L, Dubey M, Grujić M, Gudmundsson M, Lorenz C, Sandgren M, Kubicek CP, Jensen DF, Karlsson M. Evolution and functional characterization of pectate lyase PEL12, a member of a highly expanded Clonostachys rosea polysaccharide lyase 1 family. BMC Microbiol 2018; 18:178. [PMID: 30404596 PMCID: PMC6223089 DOI: 10.1186/s12866-018-1310-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 10/10/2018] [Indexed: 11/29/2022] Open
Abstract
Background Pectin is one of the major and most complex plant cell wall components that needs to be overcome by microorganisms as part of their strategies for plant invasion or nutrition. Microbial pectinolytic enzymes therefore play a significant role for plant-associated microorganisms and for the decomposition and recycling of plant organic matter. Recently, comparative studies revealed significant gene copy number expansion of the polysaccharide lyase 1 (PL1) pectin/pectate lyase gene family in the Clonostachys rosea genome, while only low numbers were found in Trichoderma species. Both of these fungal genera are widely known for their ability to parasitize and kill other fungi (mycoparasitism) and certain species are thus used for biocontrol of plant pathogenic fungi. Results In order to understand the role of the high number of pectin degrading enzymes in Clonostachys, we studied diversity and evolution of the PL1 gene family in C. rosea compared with other Sordariomycetes with varying nutritional life styles. Out of 17 members of C. rosea PL1, we could only detect two to be secreted at acidic pH. One of them, the pectate lyase pel12 gene was found to be strongly induced by pectin and, to a lower degree, by polygalacturonic acid. Heterologous expression of the PEL12 in a PL1-free background of T. reesei revealed direct enzymatic involvement of this protein in utilization of pectin at pH 5 without a requirement for Ca2+. The mutants showed increased utilization of pectin compounds, but did not increase biocontrol ability in detached leaf assay against the plant pathogen Botrytis cinerea compared to the wild type. Conclusions In this study, we aimed to gain insight into diversity and evolution of the PL1 gene family in C. rosea and other Sordariomycete species in relation to their nutritional modes. We show that C. rosea PL1 expansion does not correlate with its mycoparasitic nutritional mode and resembles those of strong plant pathogenic fungi. We further investigated regulation, specificity and function of the C. rosea PEL12 and show that this enzyme is directly involved in degradation of pectin and pectin-related compounds, but not in C. rosea biocontrol. Electronic supplementary material The online version of this article (10.1186/s12866-018-1310-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lea Atanasova
- Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, P.O. Box 7026, SE-75007, Uppsala, Sweden. .,Research division of Biochemical Technology, Institute of Chemical, Environmental and Biological Engineering, Vienna University of Technology, Gumpendorferstrasse 1a, 1060, Vienna, Austria. .,Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 11, 1190, Vienna, Austria.
| | - Mukesh Dubey
- Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, P.O. Box 7026, SE-75007, Uppsala, Sweden
| | - Marica Grujić
- Research division of Biochemical Technology, Institute of Chemical, Environmental and Biological Engineering, Vienna University of Technology, Gumpendorferstrasse 1a, 1060, Vienna, Austria
| | - Mikael Gudmundsson
- Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-75007, Uppsala, Sweden
| | - Cindy Lorenz
- Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 11, 1190, Vienna, Austria
| | - Mats Sandgren
- Molecular Sciences, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-75007, Uppsala, Sweden
| | - Christian P Kubicek
- Research division of Biochemical Technology, Institute of Chemical, Environmental and Biological Engineering, Vienna University of Technology, Gumpendorferstrasse 1a, 1060, Vienna, Austria.,, Present address: Steinschötelgasse 7, 1100, Vienna, Austria
| | - Dan Funck Jensen
- Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, P.O. Box 7026, SE-75007, Uppsala, Sweden
| | - Magnus Karlsson
- Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, P.O. Box 7026, SE-75007, Uppsala, Sweden
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9
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Draft Genome Sequence of the Sordariomycete Lecythophora ( Coniochaeta) hoffmannii CBS 245.38. GENOME ANNOUNCEMENTS 2018; 6:6/7/e01510-17. [PMID: 29449401 PMCID: PMC5814504 DOI: 10.1128/genomea.01510-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Lecythophora (Coniochaeta) hoffmannii, a soil- and lignocellulose-inhabiting sordariomycete (Ascomycota) that can also live as a facultative tree pathogen causing soft rot, belongs to the family Coniochaetaceae. The strain CBS 245.38 sequenced here was assembled into 869 contigs, has a size of 30.8 Mb, and comprises 10,596 predicted protein-coding genes.
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Physico-Chemical Conversion of Lignocellulose: Inhibitor Effects and Detoxification Strategies: A Mini Review. Molecules 2018; 23:molecules23020309. [PMID: 29389875 PMCID: PMC6017906 DOI: 10.3390/molecules23020309] [Citation(s) in RCA: 164] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 01/18/2018] [Accepted: 01/30/2018] [Indexed: 11/20/2022] Open
Abstract
A pretreatment of lignocellulosic biomass to produce biofuels, polymers, and other chemicals plays a vital role in the biochemical conversion process toward disrupting the closely associated structures of the cellulose-hemicellulose-lignin molecules. Various pretreatment steps alter the chemical/physical structure of lignocellulosic materials by solubilizing hemicellulose and/or lignin, decreasing the particle sizes of substrate and the crystalline portions of cellulose, and increasing the surface area of biomass. These modifications enhance the hydrolysis of cellulose by increasing accessibilities of acids or enzymes onto the surface of cellulose. However, lignocellulose-derived byproducts, which can inhibit and/or deactivate enzyme and microbial biocatalysts, are formed, including furan derivatives, lignin-derived phenolics, and carboxylic acids. These generation of compounds during pretreatment with inhibitory effects can lead to negative effects on subsequent steps in sugar flat-form processes. A number of physico-chemical pretreatment methods such as steam explosion, ammonia fiber explosion (AFEX), and liquid hot water (LHW) have been suggested and developed for minimizing formation of inhibitory compounds and alleviating their effects on ethanol production processes. This work reviews the physico-chemical pretreatment methods used for various biomass sources, formation of lignocellulose-derived inhibitors, and their contributions to enzymatic hydrolysis and microbial activities. Furthermore, we provide an overview of the current strategies to alleviate inhibitory compounds present in the hydrolysates or slurries.
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