l -Ribulose production from l -arabinose by an l -arabinose isomerase mutant from Geobacillus thermodenitrificans

摘要

Geobacillus thermodenitrificans, with a double-site mutation in l-arabinose isomerase, produced 95 g l-ribulose l−1 from 500 g l-arabinose l−1 under optimum conditions of pH 8, 70°C, and 10 units enzyme ml−1 with a conversion yield of 19% over 2 h. The half-lives of the mutated enzyme at 70 and 75°C were 35 and 4.5 h, respectively.