1 Action of a GH115 α-glucuronidase from Amphibacillus xylanus at alkaline condition promotes release of 4-O-methylglucopyranosyluronic acid from glucuronoxylan and arabinoglucuronoxylan Ruoyu Yan, Thu V. Vuong, Weijun Wang, Emma R. Master* Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5, Canada *Corresponding author: Emma R. Master Telephone: 416-946-7891 Fax: 416-978-8605 Email: emma.master@utoronto.ca Email addresses: yanruoyu2005@gmail.com (R. Y.), thu.vuong@utoronto.ca (T. V.), wce.wang@utoronto.ca (W. W.)