RESUMO
OBJECTIVE: To produce an alcoholic beverage containing anthocyanins that can act as antioxidants and have anticarcinogenic activities and antihypertensive effects. RESULTS: High starch-assimilating sake yeast strain of Saccharomyces cerevisiae co-expressing the glucoamylase and α-amylase genes from Debaryomyces occidentalis using the double rDNA-integration system was developed. The new strain grew substantially using 5 % (w/v) purple sweet potato flour as the sole carbon source. Its cell yield reached 14.5 mg ml(-1) after 3 days. This value was 2.4-fold higher than that of the parental wild-type strain. It produced 12 % (v/v) ethanol from 20 % (w/v) purple sweet potato flour and consumed 98 % of the starch content in purple sweet potato flour after 5 days of fermentation. CONCLUSION: We have produced a health-promoting alcoholic beverage abundant in anthocyanins from purple sweet potato.
Assuntos
Bebidas Alcoólicas/análise , Antocianinas/metabolismo , Ipomoea batatas/metabolismo , Saccharomyces cerevisiae/metabolismo , Antocianinas/análise , Debaryomyces/enzimologia , Debaryomyces/genética , Fermentação , Glucana 1,4-alfa-Glucosidase/genética , Glucana 1,4-alfa-Glucosidase/metabolismo , Saccharomyces cerevisiae/genética , Amido/metabolismo , alfa-Amilases/genética , alfa-Amilases/metabolismoRESUMO
Industrial strains of a polyploid, distiller's Saccharomyces cerevisiae that produces glucoamylase and α-amylase was used for the direct fermentation of raw starch to ethanol. Strains contained either Aspergillus awamori glucoamylase gene (GA1), Debaryomyces occidentalis glucoamylase gene (GAM1) or D. occidentalis α-amylase gene (AMY), singly or in combination, integrated into their chromosomes. The strain expressing both GA1 and AMY generated 10.3% (v/v) ethanol (80.9 g l(-1)) from 20% (w/v) raw corn starch after 6 days of fermentation, and decreased the raw starch content to 21% of the initial concentration.
Assuntos
Etanol/metabolismo , Glucana 1,4-alfa-Glucosidase/metabolismo , Saccharomyces cerevisiae/metabolismo , Amido/metabolismo , alfa-Amilases/metabolismo , Clonagem Molecular , Debaryomyces/enzimologia , Debaryomyces/genética , Etanol/análise , Fermentação , Proteínas Fúngicas/metabolismo , Glucana 1,4-alfa-Glucosidase/biossíntese , Glucana 1,4-alfa-Glucosidase/genética , Microbiologia Industrial/métodos , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/genética , Amido/análise , alfa-Amilases/biossíntese , alfa-Amilases/genéticaRESUMO
Three series of 5-day submerged cultures with Pediococcus pentosaceus MITJ-10 and Lactobacillus acidophilus Hansen 1748 were carried out in starch-based media, and the effect of cultural factors on the changes of starch, diacetyl and amylase activity determined. In axenic cultures, Ped. pentosaceus MITJ-10 produced more diacetyl (63.27 mg l(-1)) by adding glucose, yeast extract and CaCO3 (P < 0.01), at 28 degrees C (P < 0.05); but more starch was consumed (18.4 g l(-1)) in the absence of glucose (P < 0.01). Lact. acidophilus Hansen 1748 consumed more starch (26.56 g l(-1)) at 28 degrees C, with CaCO3, glucose (P < 0.01) and yeast extract (P < 0.05); however, the amylolytic activity (10077U l(-1)) was favoured at 35 degrees C (P < 0.01). Little starch was consumed in mixed cultures due to the low pH; nevertheless, diacetyl content rose to 135.76 mg l(-1) at 32 degrees C (P < 0.01). Therefore, both studied strains might be useful to produce aromatic extensors from starchy substrates. These natural aromatic extensors are of interest to the food industry.