Effective diffusion coefficient of sucrose in calcium alginate gel.
The effective diffusion coefficient of sucrose in 5% calcium alginate gel containing 41.6 g.d.c. l-1. Saccharomyces cerevisiae was investigated. Both free and immobilized S. cerevisiae in 0.175 cm and 0.3 cm diameter particles were used and the reactions were achieved in a medium containing 100 g l-1 sucrose and 0.05 M CaCl2. With the assumption that the microorganisms did not grow or die in this medium, the results were analyzed according to Michaelis-Menten kinetics and the values of the parameters were determined as: Vm = 0.256 g ml-1 gel h-1, Km0 = 0.097 g ml-1, Km1 = 0.125 g ml-1, and Km2 = 0.165 g ml-1. Using these values, effectiveness factors were calculated as eta 1 = 0.89 and eta 2 = 0.76, and effective diffusion coefficients for sucrose in calcium alginate gel were determined as De1 = 4.1 X 10(-6) cm2 s-1 and De2 = 4.0 X 10(-6) cm2 s-1, for the particle size involved.
Mehmetoğlu
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Department of Chemical Engineering, Science Faculty, Ankara University, Tandogan, Turkey.
D000464:Alginates; D002118:Calcium; D004058:Diffusion; D005782:Gels; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D007700:Kinetics; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism
D000464:Alginates; D005782:Gels; D006603:Hexuronic Acids; D013395:Sucrose; D020723:Glucuronic Acid; D002118:Calcium