الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 162 |  |  |
| | | from | 162 | | |
Abstract
The Main Objective of This Study Was Undertaken to Obtain Novel Hybrids of Yeast That May Showed Best – Parent Heterosis Making Them Interesting Candidate for Ethanol Production from Sugarcane Refuse Sub- Products, Which is the Main Source of Carbohydrates for Ethanol Productivity and Biomass Formation. It Contains Sugars as a Good Alternative Material for Ethanol Production from Yeast to Meet the Large-scale Consumption of Petroleum Fuels. Five Parental Isolates and Their 15 Genotypes Derived from Three Crosses Were Used in This Study to Be Evaluated for Heterosis Estimates of Ethanol Productivity. Bioethanol Produced Can Contribute to a Cleaner Environment Using a Cheap Substrate Such as Sugarcane Juice Sub – Products Used in This Study. The Results Obtained from These Studies Were Summarized as Follows: 1.in Most Cases Negative Correlations Was Obtained Between Ethanol Production and Biomass Formation as Shown from Genotypes of Crosses the Two P1 X P4 and P3 X P5.2.High Productivity of Ethanol Was Associated With a Lower Biomass Formation Due to Ethanol Toxicity on the Viability of Yeast Cells.
3.Genotypes Resulted from Cross Between P2 X P5 Showed Positive Correlation Values Between Both Parameters at 0.02 and 0.06 G of Sugarcane Juice Sub - Products. 4.the Greater Use of Sugars for Growing Yeast Cells Resulting in a Lower Ethanol Productivity and Vice – Versa. 5.Genome Shuffling via Hybridization is a Powerful Tool for Inducing Genetic Recombinants in Yeast for Desirable Industrial Phenotypes. 6.Some of Recombinant Genotypes Showed Glucose – Repressed or Derepressed to Higher Concentrations of Sugarcane Juice Sub – Products. 7.When the Hybrid Genotypes Were Grown in a Culture Containing 0.02 Sub – Products They Are Exhibited Positive Hybrid Vigor Estimates for Ethanol Production Overall the Genotypes Compared to the Mid – Parent. 8.All Hybrids Exhibited Negative Heterosis Estimates When They Were Cultivated in the Culture Containing 0.04 Sub – Products, Indicating That They Were Glucose – Sensitive Due to Glucose Pulses at This Concentration. 9.the Hybrids Resulted from the Cross Between P1 X P4 Grown in a Fermentation Culture Containing 0.06 Sub – Products Exhibited Negative Heterosis for Estimates Ethanol Productivity.10.the Hybrids Derived from the Two Crosses Between P2 X P5 and P3 X P5 Overcoming Glucose Repression of 0.06 Sub – Products Containing Medium Because Heterosis Seemed to Appear at This Level of Carbohydrates.11.at 0.02 G Sugar Cane Juice Wastes, the Hybrids Resulted from the Mating Between P1 X P4 Showed Positive Correlation Values Between Consumed Sugars and Ph, as Well as, Between Ethanol Production and Ph of the Fermentation Medium.12.at 0.04 G Concentration of Dissolved Solids, the Hybrids Resulted from P2 X P5 Showed Negative Correlation Value Between Consumed Sugars and Ph, as Well as, Positive Correlation Between Value Ethanol Production and Ph.13.at 0.06 of Dissolved Solids, the Hybrids Resulted from the Crosses Between P2 X P5 Showed the Above Trend of Negative Correlation Value Between Consumed Sugars and Ph, as Well as, Positive Value Correlation Between Ethanol Production and Ph.