EJPAU 2010. Eliwa . , El-Hofi M. β-GALACTOSIDASE (β-GAL) FROM THE YEAST <I>RHODOTORULA INGENIOSA</I> AND ITS UTILIZATION IN ICE MILK PRODUCTION

Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.

2010
Volume 13
Issue 1

Topic:

Biotechnology

ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES

Eliwa . , El-Hofi M. 2010. β-GALACTOSIDASE (β-GAL) FROM THE YEAST RHODOTORULA INGENIOSA AND ITS UTILIZATION IN ICE MILK PRODUCTION, EJPAU 13(1), #02.
Available Online: http://www.ejpau.media.pl/volume13/issue1/abs-02.html

β-GALACTOSIDASE (β-GAL) FROM THE YEAST RHODOTORULA INGENIOSA AND ITS UTILIZATION IN ICE MILK PRODUCTION

EL-Sayed Eliwa¹, Mahmoud El-Hofi²
¹ Microbial Chemistry Department, National Research Centre, Dokki, Cairo, Egypt
² Dairy Science Department, National Research Centre, Dokki, Cairo, Egypt

ABSTRACT

Among of 100 of yeast isolated from Egyptian soils and tested for their β;-galactosidase
(β-gal) activity, the highest producer was characterized and identified as Rhodotorula ingeniosa .This enzyme
was found to be intracellulary produced, therefore permealization treatments
to release the enzyme in a good yield was noticed when homogenization with sterile
sea sand under cooling was employed as compared with chemical treatment. The
enzyme was maximally produced when cellobiose at 1% final concentration and ammonium
suphate at 1.5% final concentration were employed. The enzyme was partially
purified with ammonium sulphate followed by Sephadex G-100 column chromatography.
Some properties of the purified enzyme including the Effect of pHs, Effect of
temperature Effect of reaction periods, and Effect of metal ions on the activity
were estimated. On the other hand the use of this enzyme in ice milk production
was studied. Different concentration of the enzyme was added to fresh pasteurized
milk. Results clear indicate that the addition of the enzyme to ice milk mixes
increased the sweetness although the organoletic properties of the resultant
ice milk was slightly decreased.

Key words: β-galactosidase, Rhodotorula ingeniosa, isolation, purification, ice milk production.

EL-Sayed Eliwa
Microbial Chemistry Department,
National Research Centre, Dokki, Cairo, Egypt

Mahmoud El-Hofi
Dairy Science Department,
National Research Centre, Dokki, Cairo, Egypt

email: mahmoudhofi@yahoo.com

Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed 'Discussions' and hyperlinked to the article.