الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
With the inevitable depletion of the world’s energy supply, there has been an increasing worldwide interest in alternative sources of energy. It’s now understood that it is important to use biomass energy as a means of providing modern energy to the billions who lack it. Bioethanol continues to be offered as a viable solution for complex problems ranging from global warming and national energy security to local economic development. Fuel bioethanol burns cleaner than gasoline, is derived from renewable agricultural products.
The aim of the current study is the isolation of local yeast isolate has the ability to produce bioethanol from molasses. The local isolate of yeast E10 from sugar cane waste (bagasse) which identified as(Candida tropicalis strain JH8 26S ribosomal RNA gen) was employed for ethanol production in submerged fermentation conditions compared with standard Saccaromyces cerevisiae EMCC number 71T.
The production of bioethanol is influenced to a great extent by a variety of physical factors (incubation time, temperature, pH, agitation speed) also; bioethanol production by yeast depends upon the nature and concentrations of carbon and nitrogen sources. The optimization of these factors is prerequisite for the development of commercial process. The use of seed culture inocula (24 h) age at rate of (8% v/v) also enhances the production. The results showed that, the maximum ethanol production in local strain Candida tropicalis was 30.28 g/l achieved at incubation temperature 30 °C, with pH 5, incubation time 48 hr, agitation rate 150 rpm. Also, the best ethanol production in standard Saccharomyces cerevisiae was 42.57 g/l at the same conditions. . Low doses of gamma radiation (0.2 kGy) stimulate bioethanol production and microbial growth by the local Candida isolate. Batch fermentation was also investigated