Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 1980
Anaerobic fermentation of carbohydrates can yield a range of alcohols, fatty acids, esters and th... more Anaerobic fermentation of carbohydrates can yield a range of alcohols, fatty acids, esters and the gases hydrogen and methane. In the microbial conversions for ethanol and methane, 93—95 % of the calorific value of the carbohydrate is retained in the product. However, the capital and energy costs of operating microbial conversions industrially are generally high. At present, fermentation processes for fuels are generally uneconomic without waste disposal credits, or tax credits. The developments required to improve the economics of bioconversion are (i) higher rates of fermentation, (ii) fermentations at higher concentrations of raw material and products, (iii) product recovery methods which consume little energy. Ethanol production is unlikely to contribute to liquid fuel supplies in Britain unless cellulose-based processes using crop wastes or urban refuse are developed. Methane is already produced from some wastes and further development of the anaerobic digestion technology can ...
The kinetics of penicillin production by Penicillium chrysogenum Wis 54-1255 in a glucose-limited... more The kinetics of penicillin production by Penicillium chrysogenum Wis 54-1255 in a glucose-limited chemostat and in batch cultures are reported. The specific production rate of penicillin, q(pen) (units per milligram of dry weight per hour) was independent of specific growth rate over the range 0.014 to 0.086 hr. Growth was stopped by restricting the glucose supply to the "maintenance ration," that is, the glucose requirement of the organism at zero growth rate with all other nutrients in excess. Under such conditions, the organism dry weight remained constant, but the q(pen) fell approximately linearly to zero at a rate inversely related to the previous growth rate. Glucose supplied in excess of the maintenance ration inhibited the decay of q(pen). At a critical growth rate between 0.009 and 0.014 hr, the decay was completely inhibited. Quantitative expressions for the q(pen) of growing and nongrowing cultures were derived and used to predict the steady-state concentration...
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 1980
Anaerobic fermentation of carbohydrates can yield a range of alcohols, fatty acids, esters and th... more Anaerobic fermentation of carbohydrates can yield a range of alcohols, fatty acids, esters and the gases hydrogen and methane. In the microbial conversions for ethanol and methane, 93—95 % of the calorific value of the carbohydrate is retained in the product. However, the capital and energy costs of operating microbial conversions industrially are generally high. At present, fermentation processes for fuels are generally uneconomic without waste disposal credits, or tax credits. The developments required to improve the economics of bioconversion are (i) higher rates of fermentation, (ii) fermentations at higher concentrations of raw material and products, (iii) product recovery methods which consume little energy. Ethanol production is unlikely to contribute to liquid fuel supplies in Britain unless cellulose-based processes using crop wastes or urban refuse are developed. Methane is already produced from some wastes and further development of the anaerobic digestion technology can ...
The kinetics of penicillin production by Penicillium chrysogenum Wis 54-1255 in a glucose-limited... more The kinetics of penicillin production by Penicillium chrysogenum Wis 54-1255 in a glucose-limited chemostat and in batch cultures are reported. The specific production rate of penicillin, q(pen) (units per milligram of dry weight per hour) was independent of specific growth rate over the range 0.014 to 0.086 hr. Growth was stopped by restricting the glucose supply to the "maintenance ration," that is, the glucose requirement of the organism at zero growth rate with all other nutrients in excess. Under such conditions, the organism dry weight remained constant, but the q(pen) fell approximately linearly to zero at a rate inversely related to the previous growth rate. Glucose supplied in excess of the maintenance ration inhibited the decay of q(pen). At a critical growth rate between 0.009 and 0.014 hr, the decay was completely inhibited. Quantitative expressions for the q(pen) of growing and nongrowing cultures were derived and used to predict the steady-state concentration...
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