Yeast Feed (II) For Enhanced Growth For Ethanol Production

Abstract

Ethanol is one of the organic solvents produced from various sugar substrates through the action of microbial enzymes. Besides bacteria and yeast e.g. Saccharomyces cerevisiae are the most domesticated fungal group for ethanol production. These cells have their characteristic features in terms of shape, size and mode of nutrition. They are able to provide the best possible combination of characteristics for the biological reactions with the given substrates. The intake of feed system-II and water are the essential elements of Saccharomyces cerevisiae for its growth and for the industrial processes. Our work highlights the stimulation of the growth of baker’s yeast strains, isolated from bakery (Strain S5) and also from the soil samples of the industrial area (Strain S6) respectively. The pure culture was grown on various broth media but the peak of growth enhancement was reported in malt extract, yeast nitrogen base, glucose medium, their characteristics were determined by different parameters and revealed 72 h incubation, 0.5-1 ml inoculum size, 4.0 pH, 30°C, 110 rpm agitation were required for the enhancement of the growth at absorption 600 nm. Tolerance was reported on sun light and moist heat at 30°C but they showed sensitivity to the exposure of UV rays after 15 minutes incubation and the mutagenic chemicals after 72 h. Ethanol and methanol tolerance was reported higher when grown in growth media (Gm 5 and 6) containing optimized concentration of glucose, vitamins, amino acids along with the previously reported feed-I.