Screening for distinct xylan degrading enzymes in complex shake flask fermentation supernatants

• Published in: Bioresource technology Vol. 102; no. 10; pp. 6039 - 6047
• Main Authors: Van Gool, M.P., Vancsó, I., Schols, H.A., Toth, K., Szakacs, G., Gruppen, H.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2011; Elsevier
• Subjects: Accessory enzymes; alpha-l-arabinofuranosidases; arabinofuranohydrolase; aspergillus; Biological and medical sciences; Biotechnology; Chromatography, High Pressure Liquid; Degradation; Enzyme screening; Enzymes; Esterases; eucalyptus-globulus labill; Fermentation; Fundamental and applied biological sciences. Psychology; Fungi; Hemicellulases; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; mode; oligosaccharides; purification; Screening; Soil fungi; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Straw; Triticum aestivum; wheat-flour arabinoxylan; Xylanase; xylanolytic enzymes; Xylosidases - metabolism; Accessory enzymes; Hemicellulases; Xylanase; Soil fungi; Enzyme screening; Enzyme; Supernatant; Fermentation; Hemicellulase; Xylanolytic enzyme; Fungi; Screening; Soils; Hydrolases
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2011.02.105

The efficient degradation of complex xylans needs collaboration of many xylan degrading enzymes. Assays for xylan degrading activities based on reducing sugars or PNP substrates are not indicative for the presence of enzymes able to degrade complex xylans: They do not provide insight into the possible presence of xylanase-accessory enzymes within enzyme mixtures. A new screening method is described, by which specific xylan modifying enzymes can be detected. Fermentation supernatants of 78 different fungal soil isolates grown on wheat straw were analyzed by HPLC and MS. This strategy is powerful in recognizing xylanases, arabinoxylan hydrolases, acetyl xylan esterases and glucuronidases. No fungus produced all enzymes necessary to totally degrade the substrates tested. Some fungi produce high levels of xylanase active against linear xylan, but are unable to degrade complex xylans. Other fungi producing relative low levels of xylanase secrete many useful accessory enzyme component(s).