Efficient production of isomalto-oligosaccharides by cell associated transglucosidase of isolated strain Debaryomyces hansenii using microfiltration membrane

Abstract

An efficient recycling method of microfiltration membrane was used to develop the continuous production of isomalto-oligosacharides (IMOs) by cell associated transglucosidase(TG) of a novel strain, D.hansenii from maltose. Transglucosidase synthesized seventy types of microbial strains were screened,isolated and investigated the efficiency of IMOs production. The most potent transglucosidase producer was identified as Debaryomyces hansenii using 18s rRNA sequencing. Media optimization preliminary studies were performed to maximize the synthesize of transglucosidase and biomass yield (54 g L-1). Parameters optimization studies were investigated using whole cells of D.hansenii (~4023 units L-1 α-glucosidase activity) from 10 L fermenter to increase the transglucosidase activity through biotransformation. IMOs was continuously synthesised by reusing the cell biomass (6%, w/v) in a 3L bioreactor using microfiltration membrane system with 30% (w/v) maltose concentration under controlled temperature of 34°C in9 to 18h for 5 cycles. The isolated yeast strain, D.hansenii was found to utilize more than 98% maltose with higher conversion efficiency for production of IMOs with 65% purity, 85% yield and productivity of 48.8 g L-1.h which confirmed by HPLC.