HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Wierzbicki, L. E. Articles by Kosikowski, F. V. Search for Related Content PubMed Articles by Wierzbicki, L. E. Articles by Kosikowski, F. V.

Lactase Potential of Various Microorganisms Grown in Whey

Department of Food Science, Cornell University, Ithaca, New York 14850

ABSTRACT

Microbial cell preparations from selected microorganisms were evaluated for their ability to hydrolyze lactose to monosugars in a pH adjusted whey medium. Optimal pH and temperature for such activity were established.

Freeze-dried crude cell preparations of lactase from mold, yeast, and bacteria, depending on species and strain, hy-drolyzed 5 to 80% lactose in nutrient whey during 5-hour incubation under optimal conditions. Molds had the lowest lactase activity but the highest cell yields, and bacteria produced the highest lactase activity and lowest cell yields. Activity was increased up to 34% with freeze-dried yeast and bacteria cell preparations given individual physical and chemical treatments. Washing with toulene proved most effective. Mold preparations gave lower activity after similar treatments.

Crude cell preparations showing highest lactase activity in deproteinized whey medium among molds were Neurospora crassa; the yeast, Saccharomyces fragilis; and the bacterium, Lactobacillus hel-veticus.

¹ Present address - Department Chemical Engineering, Cornell University, Ithaca, New York.