Title: Brown Rot-Type Fungal Decomposition of Sorghum Bagasse: Variable Success and Mechanistic Implications

Abstract

Sweet sorghum is a promising crop for a warming, drying African climate, and basic information is lacking on conversion pathways for its lignocellulosic residues (bagasse). Brown rot wood-decomposer fungi use carbohydrate-selective pathways that, when assessed on sorghum, a grass substrate, can yield information relevant to both plant biomass conversion and fungal biology. In testing sorghum decomposition by brown rot fungi ( Gloeophyllum trabeum , Serpula lacrymans ), we found that G. trabeum readily degraded sorghum, removing xylan prior to removing glucan. Serpula lacrymans , conversely, caused little decomposition. Ergosterol (fungal biomarker) and protein levels were similar for both fungi, but S. lacrymans produced nearly 4x lower polysaccharide-degrading enzyme specific activity on sorghum than G. trabeum , perhaps a symptom of starvation. Linking this information to genome comparisons including other brown rot fungi known to have a similar issue regarding decomposing grasses (Postia placenta, Fomitopsis pinicola) suggested that a lack of CE 1 feruloyl esterases as well as low xylanase activity in S. lacrymans (3x lower than in G. trabeum ) may hinder S. lacrymans , P. placenta, and F. pinicola when degrading grass substrates. These results indicate variability in brown rot mechanisms, which may stem from a differing ability tomore » degrade certain lignin-carbohydrate complexes.« less

Authors:

Presley, Gerald N.  ^[1];

• Search DOE PAGES for author "Presley, Gerald N."
• Search DOE PAGES for ORCID "0000-0002-5506-7419"

Ndimba, Bongani K. ^[2]; Schilling, Jonathan S.  ^[3]

• Search DOE PAGES for author "Schilling, Jonathan S."
• Search DOE PAGES for ORCID "0000-0003-0810-3007"

---

+ Show Author Affiliations

1. Department of Bioproducts and Biosystems Engineering, University of Minnesota, 2004 Folwell Ave. St. Paul, MN 55108, USA
2. Agricultural Research Council of South Africa (ARC-Infruitec/Nietvoorbij), Private Bag X5026, Stellenbosch 7599, South Africa, Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
3. Department of Bioproducts and Biosystems Engineering, University of Minnesota, 2004 Folwell Ave. St. Paul, MN 55108, USA, Department of Plant and Microbial Biology, University of Minnesota, 1500 Gortner Ave. St. Paul, MN 55108, USA

Publication Date:

Mon Jan 01 00:00:00 EST 2018

Research Org.:

Univ. of Minnesota, St. Paul, MN (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER). Biological Systems Science Division

OSTI Identifier:

1431388

Alternate Identifier(s):

OSTI ID: 1629671

Grant/Contract Number:  

SC0004012; SC0012742

Resource Type:

Published Article

Journal Name:

International Journal of Microbiology

Additional Journal Information:

Journal Name: International Journal of Microbiology Journal Volume: 2018; Journal ID: ISSN 1687-918X

Publisher:

Hindawi Publishing Corporation

Country of Publication:

United Kingdom

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES