Continuous Production of Isomalto-oligosaccharides by Thermo-inactivated Cells of Aspergillus niger J2 with Coarse Perlite as an Immobilizing Material

Abstract

The coarse perlite 40-80 mesh was selected as an immobilizing material and put into a packed bed reactor (PBR) to continuously convert maltose to isomalto-oligosaccharides (IMOs). The PBR was prepared by mixing the thermo-inactivated cells (TIC) from Aspergillus niger J2 strain with the coarse perlite, then the mixture was put into an overpressure-resistant column. Compared with diatomite 40-80 mesh and thin perlite 80-120 mesh in PBR, coarse perlite was chosen as the best filtration aid, when the ratio of coarse perlite versus TIC was 1:1. The thermal and pH stability of the free and immobilized TIC and the optimum conditions for the transglycosylation reactions were determined. The results show that approximately 75 and 82% and 87 and 91% of α-glucosidase activity were reserved for free and immobilized TIC at temperatures from 30 to 60 °C and pH from 3.00 to 7.00 for 12 h, respectively. With 30% malt syrup under the conditions of 50 °C and pH 4.00, a mini-scale packed bed reactor (Mi-PBR) and medium-scale packed bed reactor (Me-PBR) could continuously produce IMO over 25 and 34 days with the yield of effective IMO (eIMO) ≥ 35% and total IMO (tIMO) ≥ 50%, respectively. The strategy of mixing the coarse perlite with TIC in PBR is a novel approach to continuously produce IMO and has great application potential in industry.

Heterologous Expression of Thermotolerant α-Glucosidase in Bacillus subtilis 168 and Improving Its Thermal Stability by Constructing Cyclized Proteins

“…Isomaltooligosaccharides (IMOs) are functional oligosaccharides consisting of 2 to 10 glucosyl saccharide units linked by α-1, 6-glycosidic bonds [1]. The prebiotic component of IMOs mainly include isomaltose, panose and isomaltotriose [2].…”

“…IMOs are industrially produced mainly by α-glucosidase catalyzed maltose. The method consists of three main steps: (1) Starch is liquefied by heat-resistant α-amylase to produce oligosaccharides and dextrins. (2) Further saccharification of oligosaccharides and dextrins by glycosylases occurs, such as β-amylase and pullulanase.…”

Molecular dynamics reveals insight into how N226P and H227Y mutations affect maltose binding in the active site of α-glucosidase II from European honeybee, Apis mellifera

“…Potential applications of HBGase II include production of isomalto-oligosaccharides (IMOs) [5]. Due to their functions in mammalian metabolic processes and its low calories, IMOs are widely used as prebiotics, food additives and feed ingredients [6,7]. Moreover, HBGase II could potentially be used in brewing industry, where α-glucosidase is used for malt hydrolysis [8,9].…”

Heterologous Expression of a Thermostable α-Glucosidase from Geobacillus sp. Strain HTA-462 by Escherichia coli and Its Potential Application for Isomaltose–Oligosaccharide Synthesis

“…Isomalto–oligosaccharides (IMOs) are a group of functional oligosaccharides with a degree of polymerization (DP) ranging 2–10, which consist of glucosyl saccharide units linked by α-1, 6-glycosidic linkages [1]. Isomaltose, panose, isomaltotriose and tetrasaccharides are defined as the main functional components of IMOs [2].…”