ENZYMES AND PROCESSES UTILISING ENZYMES

摘要

A novel .beta.-galactosidase comprises an enzyme having a thermal stability such that when in purified form it has an active half life of at least 1 1/2 hours at 55.degree., at least 1 hour at 60.degree.C and at least 10 minutes at 65.degree.C, as measured using ONPG as substrate, said enzyme being derived from a bacterium of species Bacillus stearothermophilus. There is also provided a process for the production of the novel .beta.-galactosidase, comprising culturing in a medium containing appropriate nutrients a micro-organism of species B. stearothermophilus having characteristics similar to or the same as the strains identified as NCIB 11407-11413, and which contains the .beta.-galactosidase of the invention. Additionally there is provided a process for the hydrolysis of lactose to a product comprising glucose and galactose which comprises contacting lactose with the .beta.-galactosidase of the invention e.g. at a temperature of at least 55.degree.C preferably at least 60.degree.C or especially about 65.degree.C.