XYLITOL FORMATION BY CANDIDA-BOIDINII IN OXYGEN LIMITED CHEMOSTAT CULTURE

Production of xylitol by Candida boidinii NRRL Y-17213 occurs under co nditions of an oxygen limitation. The extent to which substrate is con verted to xylitol and its coproducts (ethanol, other polyols, acetic a cid), and the relative flow rates of substrate to energetic and biosyn thetic pathways is controlled by the degree of oxygen limitation. With decrease in oxygen concentration in the inlet gas, for a constant dil ution rate of 0.05 1/h, the specific oxygen uptake rate decreased from 1.30 to 0.36 mmol/gh Xylitol was not produced at specific oxygen upta ke rates above 0.91 mmol/gh. Upon shift to lower oxygen rates, specifi c xylitol production rate increased more rapidly than specific ethanol production rate: