PCR and Omics Based Techniques to Study the Diversity, Ecology and Biology of Anaerobic FungiInsights, Challenges, and Opportunities

Authors Organisations
  • Joan Elizabeth Edwards(Author)
    Wageningen University and Research Centre
  • Robert J. Forster(Author)
    Agriculture and Agri-Food Canada
  • Tony Callaghan(Author)
    Bavarian State Research Center for Agriculture
  • Veronika Dollhofer(Author)
    Bavarian State Research Center for Agriculture
  • Sumit Dagar(Author)
    Agharkar Research Institute
  • Yanfen Cheng(Author)
    Nanjing Agricultural University
  • Jongsoo Chang(Author)
    Korea National Open University
  • Sandra Kittelmann(Author)
    AgResearch
  • Katerina Fliegerova(Author)
    Czech Academy of Sciences
  • Anil Puniya(Author)
    Guru Angad Dev Veterinary and Animal Sciences University
  • John Henske(Author)
    University of California, Santa Barbara
  • Sean Gilmore(Author)
    University of California, Santa Barbara
  • Michelle O'Malley(Author)
    University of California, Santa Barbara
  • Gareth Griffith(Author)
  • Hauke Smidt(Author)
    Wageningen University and Research Centre
Type Article
Original languageEnglish
Article number1657
JournalFrontiers in Microbiology
Volume8
DOI
Publication statusPublished - 25 Sep 2017
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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 generalisation 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

Keywords

  • anaerobic fungi, Neocallimastigomycota, rumen, phylogeny, genomics, (meta) transcriptomics, proteomics, metabolomics