title: Characterization of four endophytic fungi as potential consolidated bioprocessing hosts for conversion of lignocellulose into advanced biofuels.
abstract: Recently, several endophytic fungi have been demonstrated to produce volatile organic compounds (VOCs) with properties similar to fossil fuels, called "mycodiesel," while growing on lignocellulosic plant and agricultural residues. The fact that endophytes are plant symbionts suggests that some may be able to produce lignocellulolytic enzymes, making them capable of both deconstructing lignocellulose and converting it into mycodiesel, two properties that indicate that these strains may be useful consolidated bioprocessing (CBP) hosts for the biofuel production. In this study, four endophytes Hypoxylon sp. CI4A, Hypoxylon sp. EC38, Hypoxylon sp. CO27, and Daldinia eschscholzii EC12 were selected and evaluated for their CBP potential. Analysis of their genomes indicates that these endophytes have a rich reservoir of biomass-deconstructing carbohydrate-active enzymes (CAZys), which includes enzymes active on both polysaccharides and lignin, as well as terpene synthases (TPSs), enzymes that may produce fuel-like molecules, suggesting that they do indeed have CBP potential. GC-MS analyses of their VOCs when grown on four representative lignocellulosic feedstocks revealed that these endophytes produce a wide spectrum of hydrocarbons, the majority of which are monoterpenes and sesquiterpenes, including some known biofuel candidates. Analysis of their cellulase activity when grown under the same conditions revealed that these endophytes actively produce endoglucanases, exoglucanases, and β-glucosidases. The richness of CAZymes as well as terpene synthases identified in these four endophytic fungi suggests that they are great candidates to pursue for development into platform CBP organisms.
authors.affiliation: Biomass Science and Conversion Technologies, Sandia National Laboratories, 7011 East Avenue, Livermore, CA, 94551, USA. whwu@ucdavis.edu.
authors.forename: Weihua
authors.initials: W
authors.lastname: Wu
authors.affiliation: Biomass Science and Conversion Technologies, Sandia National Laboratories, 7011 East Avenue, Livermore, CA, 94551, USA.
authors.forename: Ryan W
authors.initials: RW
authors.lastname: Davis
authors.affiliation: Biomass Science and Conversion Technologies, Sandia National Laboratories, 7011 East Avenue, Livermore, CA, 94551, USA.
authors.forename: Mary Bao
authors.initials: MB
authors.lastname: Tran-Gyamfi
authors.affiliation: Department of Energy Joint Genome Institute, Walnut Creek, CA, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Kuo
authors.affiliation: Department of Energy Joint Genome Institute, Walnut Creek, CA, USA.
authors.forename: Kurt
authors.initials: K
authors.lastname: LaButti
authors.affiliation: Department of Energy Joint Genome Institute, Walnut Creek, CA, USA.
authors.forename: Sirma
authors.initials: S
authors.lastname: Mihaltcheva
authors.affiliation: Department of Energy Joint Genome Institute, Walnut Creek, CA, USA.
authors.forename: Hope
authors.initials: H
authors.lastname: Hundley
authors.affiliation: Department of Energy Joint Genome Institute, Walnut Creek, CA, USA.
authors.forename: Mansi
authors.initials: M
authors.lastname: Chovatia
authors.affiliation: Department of Energy Joint Genome Institute, Walnut Creek, CA, USA.
authors.forename: Erika
authors.initials: E
authors.lastname: Lindquist
authors.affiliation: Department of Energy Joint Genome Institute, Walnut Creek, CA, USA.
authors.forename: Kerrie
authors.initials: K
authors.lastname: Barry
authors.affiliation: Department of Energy Joint Genome Institute, Walnut Creek, CA, USA.
authors.forename: Igor V
authors.initials: IV
authors.lastname: Grigoriev
authors.affiliation: CNRS, Aix-Marseille University, AFMB, Marseille, France.|Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Bernard
authors.initials: B
authors.lastname: Henrissat
authors.affiliation: Biomass Science and Conversion Technologies, Sandia National Laboratories, 7011 East Avenue, Livermore, CA, 94551, USA. jmgladden@lbl.gov.|Joint BioEnergy Institute, Emeryville, CA, USA. jmgladden@lbl.gov.
authors.forename: John M
authors.initials: JM
authors.lastname: Gladden
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism; D056804:Biofuels; D002480:Cellulase / Q000235:genetics / Q000378:metabolism; D044602:Cellulases / Q000235:genetics / Q000378:metabolism; D060026:Endophytes / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D016681:Genome, Fungal; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism; D008031:Lignin / Q000378:metabolism*; D039821:Monoterpenes / Q000378:metabolism; D010802:Phylogeny; D011134:Polysaccharides / Q000378:metabolism; D012717:Sesquiterpenes / Q000378:metabolism; D055549:Volatile Organic Compounds / Q000378:metabolism; D013098:Xylariales / Q000145:classification / Q000201:enzymology* / Q000235:genetics
chemical_list: D056804:Biofuels; D005656:Fungal Proteins; D039821:Monoterpenes; D011134:Polysaccharides; D012717:Sesquiterpenes; D055549:Volatile Organic Compounds; C036909:lignocellulose; D008031:Lignin; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase; D044602:Cellulases; D006026:Glycoside Hydrolases; D002480:Cellulase
keywords: CAZy; Consolidated bioprocessing; Endophyte; Ligninolytic enzymes; Terpene; Volatile organic compound