Fermentation of starch by Klebsiella oxytoca p2, containing plasmids with α-amylase and pullulanase genes
✍ Scribed by Vera Lúcia dos Santos; Elza Fernandes Araújo; Everaldo Gonçalves de Barros; Walter Vieira Guimarães
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 61 KB
- Volume
- 65
- Category
- Article
- ISSN
- 0006-3592
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✦ Synopsis
Klebsiella oxytoca P2(pC46)
, an ethanolproducing recombinant, has been evaluated in fermentation of maltose and starch. The maximum ethanol produced by P2(pC46) was 0.34 g ethanol/g maltose and 0.38, 0.40, or 0.36 g ethanol/g starch in fermentation of 1, 2, or 4% starch, representing 68, 71, and 64% the theoretical yield. The pC46 plasmid transformed to cells of K. oxytoca P2 reduced the ethanol production from maltose and starch. In fermentation of starch after its digestion at 60°C for 24 h, in two-step fermentation, the time for maximum ethanol production was reduced to 12-24 h and the theoretical yield was around 90%. The increase in starch concentration resulted in lower ␣-amylase activity but in higher pullulanase activity. The high activity and thermostability of the amylolytic enzymes from this transformant suggest that it has a potential for amylolytic enzymes source.