title: Presence and transcriptional activity of anaerobic fungi in agricultural biogas plants.
abstract: Bioaugmentation with anaerobic fungi (AF) is promising for improved biogas generation from lignocelluloses-rich substrates. However, before implementing AF into biogas processes it is necessary to investigate their natural occurrence, community structure and transcriptional activity in agricultural biogas plants. Thus, AF were detected with three specific PCR based methods: (i) Copies of their 18S genes were found in 7 of 10 biogas plants. (ii) Transcripts of a GH5 endoglucanase gene were present at low level in two digesters, indicating transcriptional cellulolytic activity of AF. (iii) Phylogeny of the AF-community was inferred with the 28S gene. A new Piromyces species was isolated from a PCR-positive digester. Evidence for AF was only found in biogas plants operated with high proportions of animal feces. Thus, AF were most likely transferred into digesters with animal derived substrates. Additionally, high process temperatures in combination with long retention times seemed to impede AF survival and activity.
authors.affiliation: Department for Quality Assurance and Analytics, Bavarian State Research Center for Agriculture, Lange Point 6, 85354 Freising, Germany(1). Electronic address: veronika.dollhofer@lfl.bayern.de.
authors.forename: Veronika
authors.initials: V
authors.lastname: Dollhofer
authors.affiliation: Institute of Biological Sciences, University of Wales, Aberystwyth, UK. Electronic address: neocallimastix@gmail.com.
authors.forename: Tony M
authors.initials: TM
authors.lastname: Callaghan
authors.affiliation: Institute of Biological Sciences, University of Wales, Aberystwyth, UK. Electronic address: gwg@aber.ac.uk.
authors.forename: Gareth W
authors.initials: GW
authors.lastname: Griffith
authors.affiliation: Department for Quality Assurance and Analytics, Bavarian State Research Center for Agriculture, Lange Point 6, 85354 Freising, Germany(1). Electronic address: michael.lebuhn@lfl.bayern.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Lebuhn
authors.affiliation: Chair of Animal Hygiene, WZW, TUM, Weihenstephaner Berg 3, 85354 Freising, Germany. Electronic address: johann.m.bauer@t-online.de.
authors.forename: Johann
authors.initials: J
authors.lastname: Bauer
mesh_terms: D000383:Agriculture; D000693:Anaerobiosis; D056804:Biofuels / Q000382:microbiology*; D019149:Bioreactors / Q000382:microbiology*; D005658:Fungi; D010802:Phylogeny
chemical_list: D056804:Biofuels
keywords: Anaerobic fungi; Biogas; Lignocellulose utilization; Strain isolation; Transcriptional activity