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 Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Macris, B. J. Search for Related Content PubMed PubMed Citation Articles by Macris, B. J. Agricola Articles by Macris, B. J.

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1982 November; 44(5): 1035-1038
Copyright © 1982, American Society for Microbiology. All Rights Reserved.

Production of a Thermostable ß-D-Galactosidase by Alternaria alternata Grown in Whey

Department of Biology, Nuclear Research Center "Demokritos," Aghia Paraskevi, Attiki, Greece

ABSTRACT

In the course of exploring new microbial sources of extracellular ß-D-galactosidase (EC. 3.2.1.23), Alternaria alternata was found to excrete elevated quantities of a thermostable form of the enzyme when cultivated in whey growth medium. Optimum cultural conditions for maximum enzyme production were a whey lactose concentration of 6%, supplementation of the medium with 0.050 M (NH₄)₂SO₄, an inoculum size of 10³ conidia per ml, and a cultivation time at 28 to 30°C of 5 days. The fungus utilized whey lactose for the production of the enzyme most efficiently, and the observed maximum yield, 280 nanokatals of hydrolyzed o-nitrophenyl-ß-D-galactopyranoside per g of whey lactose, was comparable to maximum yields reported for certain commercial fungi. The optimum pH and temperature of the enzymatic reaction were 4.5 to 5.5 and 60 to 70°C, respectively, and the enzyme lost half of its activity when heated at 65°C for 84 min. These properties make the enzyme particularly suitable for processing acid and less-acid (pH 5 to 6) dairy products and by-products.

This article has been cited by other articles:

• Somkutl, G.A., Holsinger, V.H. (1997). Microbial technologies in the production of low-lactose dairy foods / Tecnologias microbiologicas para la elaboracion de productos lacteos con bajo contenido en lactosa. Food Science and Technology International 3: 163-169 [Abstract]