Amylolytic industrial polyploid strains of Saccharomyces cerevisiae (ATCC 4126, ATCC 9763 and ATCC 24858) expressing a glucoamylase gene (GAM1) or an alpha-amylase gene (AMY) from Debaryomyces occidentalis were developed. The glucoamylase activity of S. cerevisiae ATCC 9763 expressing the GAM1 gene was 3.7-times higher than that of D. occidentalis. On the other hand, alpha-amylase activity in the corresponding strain expressing the D. occidentalis AMY gene increased 10-times relative to D. occidentalis. These two recombinant yeast strains expressing the GAM1 gene and AMY gene, respectively were cultured simultaneously to produce both glucoamylase and alpha-amylase for efficient one-step utilization of starch. Growth, substrate utilization and enzyme activity of these strains are described.

Platelet-activating factor (PAF) augments angiogenesis by promoting the synthesis of a variety of angiogenic factors, via the nuclear factor (NF)-jB activation. Recently, we reported that PAF upregulates MMP-9 expression in a NF-jB-dependent manner. In this study, we investigated the signaling pathway involved in PAF-induced MMP-9 expression in ECV304 cells. Our current data indicate that the Ca 2+ -or phosphatidylinositol 3-kinase (PI3K)-dependent signaling pathway is necessary for PAF-induced MMP-9 expression. Furthermore, PAF-induced NF-jB activation was blocked by selective inhibitors of Ca 2+ , PI3K, or extracellular signal-regulated kinase (ERK). Our results suggest that PAF-induced MMP-9 expression, in a NF-jB-dependent manner, is regulated by Ca 2+ , PI3K and ERK signaling pathways.

To develop a strain of Saccharomyces cerevisiae that produces ethanol directly from starch, two integrative vectors were constructed to allow the simultaneous multiple integration of the Aspergillus awamori glucoamylase gene (GA1) and the Debaryomyces occidentalis alpha-amylase gene (AMY) and glucoamylase with debranching activity gene (GAM1) into the chromosomes of an industrial strain of S. cerevisiae. The GA1 and AMY genes were constitutively expressed under the ADC1 promoter in S. cerevisiae using the double delta-integration system. The GAM1 gene was constitutively expressed under the corresponding promoter using the double 18S rDNA-integration system. The recombinant industrial strain secreting biologically active alpha-amylase, glucoamylase and debranching enzyme was able to ferment starch to ethanol in a single step. The new strain produced 8% (v/v) ethanol (62.8 g l(-1)) from 20% (w/v) soluble starch after 2 days, fermentation.

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.

The inhibitory effects of chitosan on germination and production of zoospore, and growth of vegetative hyphae of Saprolegnia parasitica Coker were examined. Zoospore germination was completely inhibited by chitosan at the concentration of 0.06%. Mycelial growth was not observed on GY media containing 0.05% chitosan. Zoospore production from sporangium was also completely inhibited by 0.05% chitosan. The hyphae affected by chitosan were markedly shrunk and contracted.