Increase in Beta-galactosidase activity in a non-isothermal bioreactor utilizing immobilized cells of Kluyveromyces fragilis: fundamentals and applications.

The β-galactosidaseactivity of Kluyveromyces fragiliscellsimmobilized in a kappa carrageenan gel was studied in abioreactor functioning under isothermal and non-isothermal conditions. We observed an increase in enzyme activity which was found to be proportional to the intensity of the temperature gradient applied across the biocatalytic membrane, as well as to the average temperature of the bioreactor. The efficiency of such anon-isothermalbioreactor was calculated with respect to the yield of abioreactor working under comparable isothermal conditions and was evaluated in terms of reduction of processing times in industrial applications. The possibility that enzyme activity in living cells is affected by non-isothermal conditions naturally existing owing to metabolic heat production is also discussed.