Disruption of phospholipase B gene, PLB1, increases the survival of baker's yeast Torulaspora delbrueckii.
An uracil auxotrophic mutant of baker's yeast Torulaspora delbrueckii, which is resistant to 5-fluoro-orotic acid, was complemented by transformation with YEp24 which harbors 2 microns origin and URA3 derived from Saccharomyces cerevisiae. The phospholipase B in T. delbrueckii cells is active in both acidic and alkaline conditions. However, activity of phospholipase B gene (PLB1) in cells of disruption mutant (plb1:: URA3) was lost in both conditions, which indicates that all phospholipase B activity is encoded by a single gene (or a single polypeptide) in these yeast cells. Over-expression of PLB1 with YEp plasmid vector in T. delbrueckii cells showed approximately 2.5-fold increase in phospholipase B activity, comparing with that in wild-type cells. Cells of plb1 delta mutant showed increased survival when cells of plb1 delta mutant and wild-type strain were incubated in water at 30 degrees C. Cells of PLB1-over-expressed strain died rapidly even during the cultivation period, indicating that phospholipase B activity may be a determinant for the survival of this yeast.
Watanabe
Y
Y
Laboratory of Biochemistry, Faculty of Agriculture, Ehime University, Japan.
Imai
K
K
Oishi
H
H
Tamai
Y
Y
D001939:Bread / Q000382:microbiology*; D005656:Fungal Proteins / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D005816:Genetic Complementation Test; D008245:Lysophospholipase / Q000235:genetics* / Q000378:metabolism; D016296:Mutagenesis / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D004718:Saccharomycetales / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development
D005656:Fungal Proteins; D008245:Lysophospholipase