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United States Department of Agriculture

Agricultural Research Service

Title: Plant Cell Wall Degrading Enzymes Produced by the White-Rot Fungus

Authors
item Sethuraman, Anand - UGA BIOCHEM & MOL BIOLOGY
item Akin, Danny
item Erkisson, Karl-Erik - UGA BIOCHEM & MOL BIOLOGY

Submitted to: Applied Biochemistry and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 2, 1997
Publication Date: N/A

Interpretive Summary: Various groups of fungi produce different enzymes that give them considerably different abilities in nature. Many of these microorganisms produce enzymes and other products that can add value to agricultural commodities, but other groups of fungi exist which appear to have a similar potential but have not been investigated for enzymes and activities that could enhance the quality of crops and residues. Researchers at the University of Georgia and ARS engaged in collaborative research to determine the full enzymatic profile of heretofore unexplored fungi that could upgrade lignocellulosic residues. Results showed a wide range of enzymes useful to degrade recalcitrant compounds in agricultural crops leaving cellulose as a potential value-added by-product for subsequent use. Data provide a body of knowledge on these fungi for future reference concerning methods and enzymes to add value to lignin-containing agricultural crops and residues.

Technical Abstract: The production of various plant cell wall degrading enzymes by the white-rot fungus Ceriporiopsis subvermispora was monitored in shake flask cultures. Analyses included various cellulolytic (i.e., endo-1,4-beta-glucanase, exo-1,4-beta-glucanase, 1,4-beta-glucosidase), hemicellulolytic (i.e., xylanases, 1,4-beta-xylosidases, mannanases, 1,4-beta-mannosidases), and lignolytic (i.e., laccase and manganese peroxidase) enzymes. Other enzymes studied were pectinases, proteases, amylases, phenolic acid esterases, and lipases. Glucose, cellobiose, avicel, and Whatman cellulose were the primary carbon sources used. Flax and kenaf flour generally induced more enzyme production over xylan, mannan, and pectin. Laccase and manganese peroxidase were the two lignolytic enzymes produced. Pectin, xylan, and mannan induced more pectinases than other substrates. Proteases and amylases were also produced, but no lipase activity was detected. C. subvermispora also produced phenolic acid esterases in the avicel and xylan cultures. Preference for a more amorphous cellulose, avicel, and hemicelluloses over a more crystalline Whatman cellulose as substrates for active growth is most likely the reason for the lignin specificity of C. subvermispora. Enzyme profiles suggest that C. subvermispora shows a potential for various industrial applications where removal of the lignin components, while maintaining cellulosic fiber strength property, is important.

Last Modified: 9/23/2014
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