Development and Evaluation of Whole‐Cell Yeast Lactase for Use in Dairy Processing

Abstract

A low-cost industrial grade lactase was developed for one-time use in dairy products. The preparation contained the entire biomass of a selected hyperproducing strain of the yeast Kluyveromyces fmgi/is. Intracellular lactase .was made freely accessible to its substrate by permeabilization of the cell membrane with food compatible reagents. In 0. IM phosphate plus 0.4% methyl paraben, permeabilization was complete in 0.5-l hr at 5O"C, with 90% activity recovery from 180 g/L of cells. Whole-cell lactase contained no viable cells and was free of proteolytic activity. Its pH optimum of 5.6-6.0 proved suitable for lactose hydrolysis concurrent with cottage cheese fermentation. Hydrolyzed whey was used in ice cream and bakers' yeast production.

Produção de B-1, 3-glucanase de Cellulosimicrobium cellulans 191 para lise enzimatica da levedura Kluyveromyces marxianus var. bulgaricus e obtenção de B-galactosidade

“…Alíquotas de 100 L da preparação enzimática foram adicionados em tubos de ensaio contendo 700 L do tampão fosfato 0,2M pH 7,0. Os tubos foram submetidos a diferentes temperaturas(5,15,20,25,30,35,40, 45 e 50ºC) durante 1 hora.A atividade de β-galactosidase foi medida na mistura de reação conforme descrito no item3.2.3.2 utilizando o substrato ONPG. 3.11 Produção e purificação da β β β β-galactosidase de Kluyveromyces marxianus var.…”