|
Accession number;01A0622446
|
| Title;Effect of Yeast Acid Phosphatase on Inositol Liberation in Sake Mash. |
| Author;
FURUKAWA KEIJI
(Kikumasamuneshuzo Soken)
MIZOGUCHI HARUHIKO
(Kikumasamuneshuzo Soken)
HARA SHODO
(Kikumasamuneshuzo Soken)
|
Journal Title;Seibutsu Kogakkaishi
|
Journal Code:G0440B
|
ISSN:0919-3758
|
|
VOL.79;NO.5;PAGE.133-141(2001)
|
| Figure&Table&Reference;FIG.7, TBL.2, REF.20 |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;Although the yeast strain K901 could grow in a low-phosphate culture supplemented with phytate, it could not grow when the amount of phosphate was high, suggesting that yeast repressible acid phosphatase(AP) liberates inositol from phytate. PHO5-3(a PHO5-PHO3 fusion gene) and PHO11 from K901, and PHO5 from X2180-1A, were constitutively expressed in UT-1. The expression of PHO11 markedly influenced the effect of phytate on growth. Additionally, crude AP originating from PHO11 liberated inositol from phytate more than from the other PHO genes. These results revealed that the expression of PHO11 enables yeast to hydrolyze phytate and subsequently to utilize it for growth. Yeast could grow sufficiently even when a commercial enzyme was used instead of koji in sake mash, whereas it grew to a lesser extent when phosphate was added exogeneously. These findings suggest that in sake mash, yeast AP also liberates inositol from phytate in steamed rice. Phytate in steamed rice was not solubilized in the liquid phase and remained in the residue even if starch was degraded. However the degradation of protein led to the solubilization of phytate. Phytate solubilization through the degradation of protein by koji or a commercial enzyme made it possible for yeast AP to liberate inositol from phytate in sake mash. Although the phytate-hydrolyzing activity of yeast AP in the supernatant of sake mash is about 1/3 of that of koji in the initial stage, yeast AP contributes to yeast growth as much as koji-enzyme because cell-bound yeast AP activity is greater than the extracellar activity and is effective in liberating inositol from solubilized phytate. (author abst.) |
|
|
|
Related Articles;
|
