Improvements in Efficiency of Yeasts for Ethanol Production

<p><strong>DISSERTATION</strong></p><p>Submitted to the Punjab Agricultural University Ludhiana in partial fulfillment of the requirements for the degree of</p><p>DOCTOR OF PHILOSOPHY IN <strong>MICROBIOLOGY</strong>. Year 1995.</p><p><br></p><p><u>ABSTRACT</u></p><p>Eight strains of yeasts namely S. cerevisiae-220 S. cerevisiae-360 S. cerevisiae-181/3c Trichosporon beigelli Candida haemulonii C. parapsilosis Candida sp.-3(1) and Candida sp.-5(2) have been evaluated for their potential to ferment cane sugars to ethanol at three temperatures. S. cerevisiae-220 utilized 84.0% substrate in 60 h at 30 ± 1 °C. S. cerevisiae-360 fermented substrate more efficiently (69.3%) at 38 ± 1 °C. S. cerevisiae-220 multiply faster at 30 ± 1 as well as at 38 ± 1 °C.</p><p><br></p><p>S. cerevisiae-220 could withstand 13.0% ethanol whereas S. cerevisiae-360 tolerated only 8.0% of ethanol supplemented in the growth medium. The protoplasts of S. cerevisiae-220 and S. cerevisiae-360 fused together could not generate ethanol more efficiently than their parents at 38 ± 1 °C. S. cerevisiae-220 adapted at 38 ± 1 °C utilized 64.4% of substrate during 60 h.</p><p><br></p><p>Wine with <strong>commercially outstanding quality</strong> has been prepared from Zingiber officianale with S. cerevisiae-220-A at 38 ± 1 °C.</p>