Virology & Mycology
Open Access

Enzyme biomass combustion by shared oxidation and hydrolysis mechanisms

International Conference on Mycology & Mushrooms

September 12-14, 2016 San Antonio, USA

Rolf Alexander Prade

Oklahoma State University, USA

Posters & Accepted Abstracts: Virol Mycol

Abstract :

Biomass is abundant and renewable, useful in biochemical commodity production systems if polymers may perhaps be extracted. Myceliophthora thermophila secretes in addition to the classic hydrolytic enzymes an array of oxidoreductases, some of whose functions remain unknown. The objective of this work was to determine the nature of polysaccharide decomposition mechanisms used by M. thermophila. Liquid chromatography-tandem mass spectrometry was employed in quantitative evaluation of secretome compositions. A molecular genetics manipulated protein overproduction and secretion system combined with high-resolution chromatography purification was employed to obtain pure proteins. Advanced spectroscopic electron-transfer enzymology (dye-coupled reduction/oxidation of heme and flavin domains) was used to determine how electrons flow in the system. To determine enzymatic products and intermediates (oxidized sugars, H2O2, OH-, etc.) HPLC, HPAEC, LC-MS/MS, MALDI-TOF and liquid chromatography was used. Three-dimensional protein structure and protein intermediate folding states were deduced from X-ray crystallography and SAXs experiments. The most abundant enzyme in M. thermophila secretomes grown on natural cellulosic substrates was cellobiose dehydrogenase followed by three cellobiohydrolases, a beta glucosidase, an aryl-alcohol oxidase, an aldose epimerase and a glyoxal oxidase. Cellobiose dehydrogenase, a hemoflavoenzyme oxidized cellobiose to cellobiolactone in the flavin domain, which interacted with high redox potential aryl-alcohol and glyoxal oxidase as well as at least three low abundant polysaccharide mono oxygenases producing excessive amounts of hydrogen peroxide and oxygen radicals that resulted in non-selective Fenton like oxidation of glycosidic bonds. Our findings show that M. thermophila preferably oxidizes biomass glycosidic linkages rather than hydrolyzing them.

Biography :

Email: prade@okstate.edu