Genome sequencing and functional characterization of a Dictyopanus pusillus fungal enzymatic extract offers a promising alternative for lignocellulose pretreatment of oil palm residues

PLoS One. 2020 Jul 30;15(7):e0227529. doi: 10.1371/journal.pone.0227529. eCollection 2020.

Abstract

The pretreatment of biomass remains a critical requirement for bio-renewable fuel production from lignocellulose. Although current processes primarily involve chemical and physical approaches, the biological breakdown of lignin using enzymes and microorganisms is quickly becoming an interesting eco-friendly alternative to classical processes. As a result, bioprospection of wild fungi from naturally occurring lignin-rich sources remains a suitable method to uncover and isolate new species exhibiting ligninolytic activity. In this study, wild species of white rot fungi were collected from Colombian forests based on their natural wood decay ability and high capacity to secrete oxidoreductases with high affinity for phenolic polymers such as lignin. Based on high activity obtained from solid-state fermentation using a lignocellulose source from oil palm as matrix, we describe the isolation and whole-genome sequencing of Dictyopanus pusillus, a wild basidiomycete fungus exhibiting ABTS oxidation as an indication of laccase activity. Functional characterization of a crude enzymatic extract identified laccase activity as the main enzymatic contributor to fungal extracts, an observation supported by the identification of 13 putative genes encoding for homologous laccases in the genome. To the best of our knowledge, this represents the first report of an enzymatic extract exhibiting laccase activity in the Dictyopanus genera, offering means to exploit this species and its enzymes for the delignification process of lignocellulosic by-products from oil palm.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agaricales / classification
  • Agaricales / enzymology
  • Agaricales / genetics*
  • Biomass
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • Genome, Fungal*
  • Hydrogen-Ion Concentration
  • Laccase / genetics
  • Laccase / metabolism
  • Lignin / metabolism*
  • Oxidation-Reduction
  • Palm Oil / metabolism*
  • Phylogeny
  • Temperature
  • Whole Genome Sequencing

Substances

  • Fungal Proteins
  • lignocellulose
  • Palm Oil
  • Lignin
  • Laccase

Grants and funding

This work was partially supported by a grant from Universidad Industrial de Santander, Vicerrectoria de Investigación y Extension (Grant number 5199) (to C.I.S. and D.M.V.), Industrias Acuña INAL LTDA (Grant number 8712) (to C.I.S.), and a Natural Sciences and Engineering Research Council of Canada (NSERC), via Discovery Grant RGPIN-2016-05557 (to N.D.). A.T.V. received a Postdoctoral Fellowship from NSERC. A.M.R. was supported by a doctoral scholarship from the Colombian Departamento Administrativo de Ciencia, Tecnología e Innovación (Colciencias) (PhD scholarship 567, 2012), and was the recipient of a scholarship from the Emerging Leaders in the Americas Program (ELAP) from the Government of Canada. F.V. and N.D. hold Fonds de Recherche Québec-Santé (FRQS) Research Scholar Junior 1 and Senior Career Awards, respectively (numbers 35038 and 281993). There was no additional external funding received for this study.