SciELO - Scientific Electronic Library Online

 
vol.30 issue4Some enzymatic properties of cholesterol oxidase produced by Brevibacterium spProduction of bacteriocin-like inhibitory substances (BLIS) by Streptococcus salivarius strains isolated from the tongue and throat of children with and without sore throat author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Revista de Microbiologia

Print version ISSN 0001-3714

Abstract

SILVA, Maria Estela da  and  FRANCO, Telma Teixeira. Purification of microbial b-galactosidase from Kluyveromyces fragilis by bioaffinity partitioning. Rev. Microbiol. [online]. 1999, vol.30, n.4, pp. 324-331. ISSN 0001-3714.  http://dx.doi.org/10.1590/S0001-37141999000400006.

This work investigated the partitioning of b-galactosidase from Kluyveromyces fragilis in aqueous two-phase systems (ATPS) by bioaffinity. PEG 4000 was chemically activated with thresyl chloride, and the biospecific ligand p-aminophenyl 1-thio-b-D-galactopyranoside (APGP) was attached to the activated PEG 4000. A new two-step method for extraction and purification of the enzyme b-galactosidase from Kluyveromyces fragilis was developed. In the first step, a system composed of 6% PEG 4000-APGP and 8% dextran 505 was used, where b-galactosidase was strongly partitioned to the top phase (K = 2,330). In the second step, a system formed of 13% PEG-APGP and 9% phosphate salt was used to revert the value of the partition coefficient of b-galactosidase (K = 2 x 10-5) in order to provide the purification and recovery of 39% of the enzyme in the bottom salt-rich phase.

Keywords : b-galactosidase; aqueous two-phase systems; protein purification; downstream-processing; affinity.

        · abstract in Portuguese     · text in English     · pdf in English