Thermoanaerobic bacteria are of considerable interest as producers of thermostable amylolytic enzymes. The soluble amylolytic enzyme system of Thermoanaerobacterium thermosaccharolyticum DSM 571 was fractionated into a pullulanase, a glucoamylase, and an alpha-glucosidase. The enzymes were purified to homogeneity and their physical and catalytic properties were studied. The pullulanase, which c...

Glucoamylase mutations to reduce isomaltose formation from glucose condensation and thus increase glucose yield from starch hydrolysis were designed to produce minor changes in the active site at positions not totally conserved. Tyr175-->Phe and Ser411-->Gly glucoamylases had catalytic efficiencies on DP 2-7 maltooligosaccharides like those of wild-type glucoamylase, while the catalytic efficie...

Background: A major challenge in downstream processing is the separation and purification of a target biomolecule from the fermentation broth which is a cocktail of various biomolecules as impurities. Aqueous two phase system (ATPS) can address this issue to a great extent so that the separation and partial purification of a target biomolecule can be integrated into a single step. In the food i...

BACKGROUND Fungal amylase, mainly constitute of fungal α-amylase and glucoamylase, are utilized in a broad range of industries, such as starch hydrolysis, food and brewing. Although various amylases have been found in fungi, the amylases from Aspergillus dominate the commercial application. One of main problems exist with regard to these commercial use of amylases is relatively low thermal and ...

Maltase activity (EC 3.2.1.20) was solubilized from rabbit kidney brush-border membrane by using 1.0% Triton X-100 and purified 230-fold with an overall recovery of 30%. The purification procedure makes use of heat precipitation, chromatography on DE-52 DEAE-cellulose and gel filtration on Sephacryl S-300. Rabbit kidney brush border exhibited glucoamylase activity with a maltase/glucoamylase ra...

Glucoamylase was covalently immobilized through the spacer-arm of the poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) spheres by using a glutaraldehyde as a coupling agent. The influence of the enzyme load, applied to the support on immobilization, yield and specific activity, has been determined. Obtained specific activity was 700 U/g with immobilization yield of 35 %. The Km val...

Mutations Asn20-->Cys/Ala27-->Cys (SS), Ala27-->Pro, Ser30-->Pro, Lys108-->Arg, Gly137-->Ala, Tyr312-->Trp and Ser436-->Pro in Aspergillus awamori glucoamylase, along with a mutation inserting a seven-residue loop between Tyr311 and Gly314 (311-314 Loop), were made to increase glucose yield from maltodextrin hydrolysis. No active Lys108-->Met glucoamylase was found in the supernatant after bein...

A glucoamylase-immobilized system based on cross-linked gelatin nanoparticles (CLGNs) was prepared by coacervation method. This system exhibited characteristics of temperature-triggered phase transition, which could be used for enzyme immobilization and release. Their morphology and size distribution were examined by transmission electron microscopy and dynamic light scattering particle size an...

To understand the differences in production and secretion patterns between plasmid-harboring and chromosome-integrated recombinant yeasts, the two recombinant Saccharomyces cerevisiae yeasts, containing the structural glucoamylase STA gene and the SUC2 promoter, were investigated. Both systems were regulated by glucose concentration in the culture broth. First, the glucoamylase activity per gen...