THERMOSTABLE L-RIBOSE ISOMERASE, PROCESS FOR PRODUCING THE SAME AND USE THEREOF

摘要

Object: To provide a thermostable L-ribose isomerase. Means for Resolution: The thermostable L-ribose isomerase with MW. 32,000 (by SDS-PAGE), optimal temperature of 45°C, optimal pH of pH 9. 0 (glycine-NaOH buffer), and stable physicochemical properties such as temperature stability up to 45°C during thermal treatment at pH 9.0 for 10 minutes, and with an action to isomerize L-ribose to generate L-ribulose or of inversely to isomerize L-ribulose to generate L-ribose. A conversion method between an aldose and a ketose comprising allowing the thermostable L-ribose isomerase as an enzyme derived from (1) Raoultella ornithinolytica strain MB426 (NITE BP-277) to interact with an aldose selected from L-ribose, D-lyxose, D-tallose, D-mannose, L-allose and L-gulose to isomerize the aldose to generate a ketose selected from the individually corresponding L-ribulose, D-xylulose, D-tagatose, D-fructose, L-psicose and L-sorbose or to interact with a ketose selected from L-ribulose, D-xylulose, D-tagatose, D-fructose, L-psicose and L-sorbose to isomerize the ketose to generate an aldose selected from the individually corresponding L-ribose, D-lyxose, D-tallose, D-mannose, L-allose and L-gulose.