Glucose ethanol from

The absolute pH range for the growth of most yeasts is 2.4-S.6 with the optimum being about 4.5 (Atkinson and Mavituna, 1983). The specific rate of ethanol production is very sensitive to pH values above 5 and at pH 6 it is only 50% of the maximum value (Jones and Greenfield, 1984). With increasing pH there is a reduction in the yield of ethanol from glucose and a rise in the yields of both glycerol and acetic acid. 

Fig. 5.20. The alcoholic fermentation sequence results in 2 molecules of ethanol from glucose, 2 molecules of ATP and a balanced redox process...

Figure 15.8 shows a simple apparatus for obtaining ethanol from glucose in the laboratory. 

Other bacteria Typically studied or used to produce one product of interest. One example is Zymmonas mobilis for producing ethanol from glucose Genetics less understood than E. coli... 

Wastewater treatment is relatively simple in that the sole purpose is the degradation of all the organic species present in the liquid to remove both biological oxygen demand (BOD) and chemical oxygen demand (COD). Three-phase fluidization is also of interest for bioremediation of contaminated soils. Production of alcohols by fermentation (e.g., ethanol from glucose) has been practiced commercially. Other fermentation processes have been examined for production of enzymes, acetic acid, stem cells, monoclonal antibodies, antibiotics, and other pharmaceutical products. 

In Illustration 15.9-4 we considered the production of ethanol from glucose using the yeast Saccharomyces cerevisiae. In that illustration 0.451 C-moles of ethanol and 0.235 C-moles of biomass of elemental composition CHi.80o.56No.n were produced per C-mole of glucose, using 0.0399 moles of ammonia. Assuming the inlet and outlet streams are maintained at 25°C, and that the work input is negligible, what is the heat load on the reactor ... 

Since the second-law constraint has been satisfied, the data reponed for the production of ethanol from glucose using the yeast Sacchaioinyces cerevisiae are thermodynamically consistent. 

When the bacterium Zymomonas mobilis is used to produce ethanol from glucose in an anaerobic process with ammonia as the nitrogen source, it is found that bacteria biomass is produced to the extent of 0.06 C-moles per C-mole of glucose. The biomass has an elemental composition of CHi.sObjNo. . What are the fractional conversion of glucose to ethanol (on a C-mole basis), the amount of ammonia used, and the amount of carbon dioxide produced per C-moIe of glucose consumed ... 

Figure 4. Dependence of biocatalytic activities for the batch fermentation of ethanol from glucose with immobilized yeast cells as a function of incubation time (time for cellgrowth in the carrier) for various initial cell loadings in epoxy carriers.

The fermentation of the corn fiber hydrolysate generated by the initial hydrolysis method proved to be successful in producing a high concentration of ethanol from glucose and xylose. The total carbohydrate conversion is lower than the best possible, but the fermentation method has not been optimized. 

Capable of producing ethanol from glucose will grow in the presence of bile salts some will multiply in competition with actively growing yeast in a brewery fermentation, e.g. genera of Enterobacteriaceae [10,11]. 

Incapable of producing ethanol from glucose, anaerobic, flagella emanating from one side of the rod-like cell, e.g. Pectinatus [12]... 

Occasionally the synthesis of a microbial product, for example that of ethanol from glucose, is catalysed by non-viable cells (section 6.2.1.1). Then the process is properly catalytic because the Saccharomyces cerevisiae cells do not change, for a time at least. However there are some industrially important reactions in which micro-organisms are first grown to a high biomass and are then added to a substrate which is almost quantitatively converted to a product. These are effectively catalytic processes in which one or a few enzymes in the organism transform an added substrate into a useful product. These transformations are divorced from cell growth, in contrast to syntheses such as those in which carbohydrates are converted into citric acid or complex feedstocks into secondary metabolites. 

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