Most of ethanol production processes are limited by low ethanol production rate and recyclable problem of ethanologenic organisms. In the present study Saccharomyces cerevisiae TISTR 5339 entrapped in an aqueous mixture of alginate and pretreated-bagasse was used for ethanol production of immobilization parameter of yeast cells consisting of amount of bagasse and alginate concentration on ethanol production were investigated. The results showed that increase in alginate concentration and the amount of bagasse can increase structural strength and reduce deterioration of bead. The optimal condition of immobilization was 1.0% (w/v) bagasse and 2.5% alginate. Ethanol yield (Yp/s) ethanol production rate (Qp) and efficiency of fermentation (Ey) obtained from the bagasse-alginate immobilized yeast cell was 3.39±0.72 g/l0.14±0.03 g/l/h and 70.98±14.08% respectively. The ultrastructure obtained from SEM illustrated that S. cerevisiae TISTR 5339 was well incorporated within the bagasse-alginate matrix. Moreover the bagasse-alginate immobilized yeast cells were reusable at least 5 times with Ey higher than 50% of 1st round of fermentation. Therefore the pretreated bagasse-alginate immobilized yeast cells is an alternatively interesting techniques with effiiciency for ethanol production in the future.

The objective of this study was to determine the effects of malate level and yeast in concentrate on ruminal fermentation and digestibility of nutrients in heifers. The results revealed that rumen fermentation ruminal microorganisms and digestibility of nutrients were significantly different (P<0.05) as affected by malate level and yeast. In conclusion the combined use of concentrate containing high level of cassava chip at 70%DM with malate at 1000 g and yeast at 2000 g in concentrate could improve rumen fermentation and digestibility of nutrients in dairy heifers.