Thermostable extracellular ?-amylase and ?-glucosidase ofLipomyces starkeyi

A novel extracellular carbohydrase produced by Lipomyces tetrasporus

“…Similar values of 4.5-5.0 were reported for Saccharomyces logos a-glucosidase (Chiba et al i973a) and 4.5 for the a-glucosidase of L. starkeyi (Kelly et al 1985), but these are lower than the general pH optimum range of 6.5-7.0, reported for yeast a-glucosidases (Needleman et al 1978). In general, yeast a-glucosidases have temperature optima between 35-45°C (Chiba et al 1973a) while amyloglucosidases are in the range 40-60°C (Fogarty and Kelly 1979).…”

“…Values range from 35 000 for L. starkeyi (Kelly et al 1985) to 270000 for S. lo9os (Chiba et al 1973a), while the molecular weight value for this enzyme was estimated to range from 150000 (SDS-PAGE) to 183000 (FPLC Superose 12 gel filtration). The enzyme was found to be a glycoprotein with a carbohydrate content of 9.0-15.8%.…”

“…Considerable interest exists in obtaining enzymes with new or unusual properties or applications. Quite a number of yeasts are now known to be amylolytic with numerous reports of aamylases (EC 3.2.1.1), amyloglucosidases (EC 3.2.1.3) and a-glucosidases (EC 3.2.1.20) (De Mot and Verachtert 1987;Kelly et al 1985;McCann and Barnett 1986). On the other hand, degradation of dextran, an a-l,6-linked polymeric substrate, has not yet been widely investigated in yeasts.…”

Similarities and differences in the biochemical and enzymological properties of the four isomaltases from Saccharomyces cerevisiae

“…Strong discrepancies were noticed in published data, i.e . substrates specificities and kinetic parameters of the isomaltase from the yeast S. cerevisiae [8–12] and from closely related yeast species [8,16,17], probably because enzymological properties have been determined from different isoenzymes or purified fractions that contained a mix of these isoenzymes. Current facilities for gene expression and protein purification allowed us to carry out a detailed biochemical and enzymological characterization of the four isomaltases encoded by the yeast S. cerevisiae [6,15], including a revision of the biochemical properties of the protein encoded by IMA1 [5,13,14].…”

Application of maltitol to improve production of raw starch digesting glucoamylase by Aspergillus niger F-08

“…Much work has been done to enhance the activities of raw starch degrading enzymes, such as searching for potential producers, optimization of the medium composition and culture conditions (Mamo and Gessesse 1999;Marlida et al 2000a;Sun et al 2007) and molecular cloning (Hostinová et al 2003). It was reported that raw starch digesting enzymes are produced constitutively at a relatively low level and can be induced by inducers, such as starch, maltose and dextrin (Kelly et al 1985;Gašperik et al 1985;De et al 1984;Moulin et al 1982;Moulin and Galzy 1978a and b). Maltose was found to be an efficient inducer for the production of raw starch digesting glucoamylase (RSDG) by Aspergillus niger (Rajoka and Yasmeen 2005).…”