BioChem - DOS

Characterization of the Cross-Linked Enzyme Aggregates of a Novel β-Galactosidase, a Potential Catalyst for the Synthesis of Galacto-Oligosaccharides

Journal of agricultural and food chemistry

Li, Liang; Li, Gang; Cao, Li-chuang; Ren, Guang-hui; Kong, Wei; Wang, Si-di; Guo, Geng-shan; Liu, Yu-Huan

<P>A novel &beta;-galactosidase (Bgal1-3) was isolated from a marine metagenomic library and then its cross-linked enzyme aggregates (CLEAs) were prepared. The enzymatic properties of Bgal1-3-CLEAs were studied and compared with that of the free enzyme. The thermostability and storage stability of Bgal1-3 were significantly improved after it was immobilized as CLEAs. The galactose-tolerance of the enzyme was also enhanced after the immobilization, which could relieve the inhibitory effect and then tends to be beneficial for the galacto-oligosaccharides (GOS) synthesis. Moreover, higher GOS yield was achieved (59.4 &plusmn; 1.5%) by Bgal1-3-CLEAs compared to the free counterpart (57.1 &plusmn; 1.7%) in an organic&ndash;aqueous biphasic system. The GOS content and composition of the syrups synthesized by the free enzyme and Bgal1-3-CLEAs were similar and they both contained at least seven different oligosaccharides with the degree of polymerization (DP) ranging between 3 and 9. Furthermore, Bgal1-3-CLEAs maintained 82.1 &plusmn; 2.1% activity after ten cycles of reuse; the GOS yield of the tenth batch was 52.3 &plusmn; 0.3%, which was still higher than that of the most former reports. To the best of our knowledge, this is the first report on the GOS synthesis using CLEAs of &beta;-galactosidase in an organic&ndash;aqueous biphasic system. The study not only further expands the application scope of CLEA, but also provides a potential catalyst for the synthesis of GOS with low cost.</P><P><B>Graphic Abstract</B><BR><IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jafcau/2015/jafcau.2015.63.issue-3/jf504473k/production/images/medium/jf-2014-04473k_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jf504473k'>ACS Electronic Supporting Info</A></P>

2015

American Chemical Society

0021-8561

1520-5118

63

3

pp.894-901

10.1021/jf504473k

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART71360665

β-Galactosidase; immobilization; cross-linked enzyme aggregates; galacto-oligosaccharides