%0 Journal Article %J Bioresource Technology %D 2013 %T Carrier free co-immobilization of alpha amylase, glucoamylase and pullulanase as combined cross-linked enzyme aggregates (combi-CLEAs): a tri-enzyme biocatalyst with one pot starch hydrolytic activity %A Talekar, Sachin %A Pandharbale, Amol %A Ladole, Mayur %A Nadar, Shamraja %A Mulla, Mosin %A Japhalekar, Kshitija %A Pattankude, Kishori %A Arage, Devika %K Alpha amylase %K Combined cross-linked enzyme aggregates (combi-CLEAs) %K Glucoamylase %K One pot starch hydrolysis %K Pullulanase %X

A tri-enzyme biocatalyst ``combi-CLEAs'' with starch hydrolytic activity was prepared from commercially available alpha amylase, glucoamylase and pullulanase preparations by aggregating enzymes with ammonium sulphate followed by cross-linking formed aggregates for 4.5 h with 40 mM glutaraldehyde. The effects of precipitant type and cross-linking were studied and the biocatalyst was characterized. Scanning electron microscopy analysis showed that tri-enzyme biocatalyst was of spherical structure. For one pot starch hydrolytic activity, shift in optimum pH from 6 to 7 and temperature from 65 to 75 degrees C were observed after co-immobilization of enzymes. After one pot starch hydrolysis reaction in batch mode, 100%, 60% and 40% conversions were obtained with combi-CLEAs, separate CLEAs mixture and free enzyme mixture, respectively. Co-immobilization also enhanced the thermal stability of enzymes. Finally, the catalytic activity of enzymes in combi-CLEAs during one pot starch hydrolysis was well maintained up to five cycles without performance changes. (C) 2013 Elsevier Ltd. All rights reserved.

%B Bioresource Technology %I ELSEVIER SCI LTD %C THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND %V 147 %P 269-275 %8 NOV %G eng %3 Foreign %4 5.039 %R 10.1016/j.biortech.2013.08.035