Title: Myceliophthora thermophila M77 utilizes hydrolytic and oxidative mechanisms to deconstruct biomass

Abstract

Biomass is abundant, renewable and useful for biofuel production as well as chemical priming for plastics and composites. Deconstruction of biomass by enzymes is perceived as recalcitrant while an inclusive breakdown mechanism remains to be discovered. Fungi such as Myceliophthora thermophila M77 appear to decompose natural biomass sources quite well. This work reports on this fungus fermentation property while producing cellulolytic enzymes using natural biomass substrates. Little hydrolytic activity was detected, insufficient to explain the large amount of biomass depleted in the process. Furthermore, this work makes a comprehensive account of extracellular proteins and describes how secretomes redirect their qualitative protein content based on the nature and chemistry of the nutritional source. Fungus grown on purified cellulose or on natural biomass produced secretomes constituted by: cellobiohydrolases, cellobiose dehydrogenase, β-1,3 glucanase, β-glucosidases, aldose epimerase, glyoxal oxidase, GH74 xyloglucanase, galactosidase, aldolactonase and polysaccharide monooxygenases. Fungus grown on a mixture of purified hemicellulose fractions (xylans, arabinans and arabinoxylans) produced many enzymes, some of which are listed here: xylosidase, mixed β-1,3(4) glucanase, β-1,3 glucanases, β-glucosidases, β-mannosidase, β-glucosidases, galactosidase, chitinases, polysaccharide lyase, endo β-1,6 galactanase and aldose epimerase. Secretomes produced on natural biomass displayed a comprehensive set of enzymes involved in hydrolysis and oxidation ofmore » cellulose, hemicellulose-pectin and lignin. Furthermore, the participation of oxidation reactions coupled to lignin decomposition in the breakdown of natural biomass may explain the discrepancy observed for cellulose decomposition in relation to natural biomass fermentation experiments.« less

Authors:

dos Santos, Hévila Brognaro; Bezerra, Thaís Milena Souza; Pradella, José G. C.; Delabona, Priscila; Lima, Deise; Gomes, Eleni; Hartson, Steve D.; Rogers, Janet; Couger, Brian; Prade, Rolf

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Publication Date:

Wed Nov 02 00:00:00 EDT 2016

Research Org.:

Oklahoma State Univ., Stillwater, OK (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1330731

Alternate Identifier(s):

OSTI ID: 1375956

Grant/Contract Number:  

06103-OKL; ZDJ-7-77608-01; 403090/2012-1

Resource Type:

Journal Article: Published Article

Journal Name:

AMB Express

Additional Journal Information:

Journal Name: AMB Express Journal Volume: 6 Journal Issue: 1; Journal ID: ISSN 2191-0855

Publisher:

Springer Science + Business Media

Country of Publication:

Germany

Language:

English

Subject:

09 BIOMASS FUELS; Myceliophthora thermophila; Biomass; Cellulose degradation; Secretome composition; Cellulose hydrolysis; Cellulose oxidation