To overcome the problem of enzyme extraction and poor permeability of cell membrane to lactose, experimentation was carried to
permeabilize Kluyveromyces marxianus NCIM 3465 cells for their subsequent use for the production of lactose-hydrolyzed milk. Different
process parameters, such as biomass load, temperature, agitation and treatment time, were optimized for maximum lactose hydrolysis
in skim milk using these cells. The ethanol-permeabilized yeast cells gave 89% hydrolysis of milk lactose under optimized conditions.