Starch hydrolysis by derepressed mutants of Schwanniomyces castellii

Dhawale, Motiram R.; Ingledew, W. M.

doi:10.1007/bf00131900

Cited by 47 publications

(10 citation statements)

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“…The attempt to isolate derepressed mutants of fusion hybrid IX)-148 by the NTG method described previously (Dhawale and Ingledew, 1983) was successful, however most of such mutants were not stable upon repeated streaking for purification. Two stable strains eventually found displayed a cell size the same as the original parent (PD-511 or JW-4048).…”

Section: Results and Disct~sionmentioning

confidence: 99%

“…castellii appears to be superior to Schw. alluvius in amylolytic enzyme activities (Dhawale and Ingledew, 1983). This may be due to an additional starch hydrolyzing glucoamylase species present in this yeast.…”

Section: Introductionmentioning

confidence: 98%

“…The amylolytic enzyme system of a second Schwanniomyces yeast, Schw. castellii, is also under intensive investigation in several laboratories (Oteng-Gyang, et al, 1981; Wilson and Ingledew, 1982;Sills and Stewart, 1982;and Dhawale and Ingledew, 1983). Table 1 is compiled to demonstrate the differences in the amylolytic systems of these two yeast species.…”

Section: Introductionmentioning

confidence: 98%

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Interspecific protoplast Fusion of Schwanniomyces yeasts

Dhawale

Ingledew

1983

Biotechnol Lett

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SUMMARYInterspecific protoplast fusion of multiple auxotrophic mutants of Schwannic~ces castellii and Schwannicmyces alluvius resulted in fusion products displaying good stability and increased ploidy as a consequence of increased DNA content and cell-volume.Following mitotic segregation analysis, recombinants were observed suggesting that protoplast fusion resulted in nuclear fusion.Attempts to isolate NTG -induced derepressed mutants of one fusion product were successful, however such mutants were similar in cell-size and amylolytic activities to the auxotrophic strains from which they were initially derived.

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Section: Results and Disct~sionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 98%

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Interspecific protoplast Fusion of Schwanniomyces yeasts

Dhawale

Ingledew

1983

Biotechnol Lett

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“…This analog has been used with various regimens of mutagenesis to select carbon catabolite-derepressed mutants that produce amylolytic activity during growth on glucose (32). A few mutants of this type have been isolated from different Schwanniomyces species (6,20,30,39). To determine whether 2-deoxyglucose affects glucoamylase expression in the same way as glucose, cells adapted to minimal medium with 1% glucose were shifted to minimal medium containing 1% (wt/vol) 2-deoxyglucose, harvested at 30, 60, and 90 min, and analyzed for glucoamylase expression as described earlier (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…We and others are interested in developing the genetics of members of the budding yeast Schwanniomyces (7,24), particularly in view of their ability to hydrolyze starch (3,5,6,10,15,19,21,23,26,28,29,31,39,40). The 146-kilodalton (kDa) extracellular glucoamylase of Schwanniomyces castellii that we have characterized is of particular interest because it has both a-1,4 and ot-1,6 activity and is thermally labile (29,30).…”

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confidence: 99%

Expression and regulation of glucoamylase from the yeast Schwanniomyces castellii

Dowhanick¹,

Russell²,

Scherer³

et al. 1990

J Bacteriol

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Expression of the 146-kilodalton (kDa) extracellular glucoamylase by the budding yeast Schwanniomyces castellii is induced by maltose and starch. By use of antiglucoamylase antisera, we found that this expression was regulated at the level of the mRNA, taking place within 30 min after exposure of yeast cells to the respective sugars. Polyacrylamide gel electrophoresis analysis of the in vitro-translated products of total RNA from maltose-treated cells established that the glucoamylase precursor was approximately 120 kDa in size. Stable glucoamylase transcript was not produced in cells exposed to glucose, 2-deoxyglucose, and heat shock. Cells exposed to these two sugars also degraded intracellular and extracellular glucoamylase. In the presence of sugars such as cellobiose, galactose, lactose, and xylose or in the absence of any carbohydrate, a low-level, constitutive-like expression of this preglucoamylase occurred. The nascent glucoamylase underwent at least two posttranslational modifications, resulting in a 138-kDa cell-associated form and the 146-kDa active form that was found free in the medium. These results suggest that glucoamylase expression is tightly regulated similarly to expression of the enzymes responsible for maltose metabolism in Saccharomyces yeasts.

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Glucose oxidase biosynthesis in relation to biochemical mutations in Aspergillus niger

Fiedurek

Szczodrak

1995

Acta Biotechnologica

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The production of extracellular glucose oxidase in a submerged culture by a number of auxotrophic, 2-deoxy-D-glucose resistant and protease-less mutants of Aspergillus niger was evaluated. Among the auxotrophic strains, no evident dependence was found between the kind of the nutritional requirements and the level of the glucose oxidase activity. However, the majority of auxotrophs. requiring serine or niacin, showed a higher enzyme activity (from 16 to 680%) than the parent strain. The dynamics of the glucose oxidase synthesis by the free and immobiliied mycelium of the most active niacin-mutant of A. niger was also investigated.

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Starch hydrolysis by derepressed mutants of Schwanniomyces castellii

Cited by 47 publications

References 8 publications

Interspecific protoplast Fusion of Schwanniomyces yeasts

Interspecific protoplast Fusion of Schwanniomyces yeasts

Expression and regulation of glucoamylase from the yeast Schwanniomyces castellii

Glucose oxidase biosynthesis in relation to biochemical mutations in Aspergillus niger

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