Home About us MoEF Contact us Sitemap Tamil Website  
About Envis
Whats New
Microorganisms
Research on Microbes
Database
Bibliography
Publications
Library
E-Resources
Microbiology Experts
Events
Online Submission
Access Statistics

Site Visitors

blog tracking


 
Food and Bioproducts Processing
Volume 124, 2020, Pages 82-96

Preparation and assessment of cross-linked enzyme aggregates (CLEAs) of -galactosidase from Lactobacillus leichmannii 313

Min Xu, DaweiJi, Yongjin Deng, Dominic Agyei

Department of Food Science, University of Otago, Dunedin 9054, New Zealand.

Abstract

β-galactosidases from Lactobacillus leichmannii 313 (LL 313) were immobilized for the first time by cross-linked enzyme aggregates (CLEA) technology. By using three precipitants (saturated ammonium sulfate (ASF), acetone (ACT), and isopropanol (IPA) in CLEA preparation and assessing performance in comparison with crude enzyme, recovered activities of 23% (ASF-CLEA), 18% (ACT-CLEA), 13.6% (IPA-CLEA) were obtained. Immobilization did not change the optimal pH (7.0) and temperature (55 °C), except for ACT-CLEA (60°C). CLEA retained activity (∼90% for ASF-CLEA) after 2 weeks storage at 4°C in buffer; and for ACT-CLEA and IPA-CLEA, ∼ 50% of initial activity was retained after 10 cycles of use. Plackett–Burman (PB) and Response Surface Methodology (RSM) optimization with ASF as precipitant gave 23.5 mM of glutaraldehyde, reaction pH 6.9 and reaction time of 3.4 h as the optimum conditions giving highest recovered activity of 37.7%. The kinetics (Vmax and Km) were 0.06 mmol g-1 min-1 and 4.95 mM respectively for ASF-CLEA, compared with 0.07 mmol g-1 min-1 and 4.08 mM for crude enzyme. All CLEA types exhibited the capability to hydrolyze lactose and generate GOS. This study shows that CLEA is a suitable technique to immobilize β-galactosidase from LL313, and the resulting enzyme system has promising applications in the food industry.

Keywords: -galactosidase, Lactobacillus leichmannii 313 (LL 313), Immobilization, Cross-linked enzyme aggregates, Response surface methodology.

Copyright © 2005 ENVIS Centre ! All rights reserved
This site is optimized for 1024 x 768 screen resolution