Effect of Agave tequilana juice on cell wall polysaccharides of three Saccharomyces cerevisiae strains from different origins.

In this study, a characterization of cell wall polysaccharide composition of three yeasts involved in the production of agave distilled beverages was performed. The three yeast strains were isolated from different media (tequila, mezcal and bakery) and were evaluated for the beta(1,3)-glucanase lytic activity and the beta-glucan/ mannan ratio during the fermentation of Agave tequilana juice and in YPD media (control). Fermentations were performed in shake flasks with 30 g l(-1) sugar concentration of A. tequilana juice and with the control YPD using 30 g l(-1) of glucose. The three yeasts strains showed different levels of beta-glucan and mannan when they were grown in A. tequilana juice in comparison to the YPD media. The maximum rate of cell wall lyses was 50% lower in fermentations with A. tequilana juice for yeasts isolated from tequila and mezcal than compared to the bakery yeast.

[Effects of companion fungus on several enzymatic activities of Grofola umbellata].

OBJECTIVE: To study the effect of companion fungus on several enzymatic activities of Grifola umbellata. METHOD: Chitinase, beta-1,3-glucanase, proteinase and extracellular enzymes of G. umbellata were measured during dual culturing with companion fungus. RESULT: Companion fungus could induce the increase of chitinase and beta-1, 3-glucanase activities of G. umbellata. noevident changeswere found in proteinase activity. When in liquid culture, the activities of extracellular enzymes in dual cultured filtrate were between of these of G. umbellata and companion fungus in monocultures. CONCLUSION: Sclerotia differentiation related materials supplied by mutual nutritional supplement between G. umbellata and companion fungus conduce to sclerotial formation of G. umbellata.