By-product formation by a novel glycerol-producing yeast, Candida glycerinogenes, with different O2 supplies.

Candida glycerinogenes is an aerobe which does not depend on sulphite for production of glycerol. With a sufficient O2 supply, up to 130 g glycerol l(-1) was produced with 2.6 g acetic acid l(-1) as by-product. However, with an insufficient O2 supply--with higher volumes of medium or at higher corn steep liquid concentrations--the glycerol concentration was lower because the by-products, ethanol, pyruvate and lactic acid, were produced in greater amounts, up to 45 g l(-1), 4.3 g l(-1), 1.6 g l(-1), respectively, whereas, less acetic acid (0.6 g l(-1)) was produced. In addition, ethanol decreased to 0.4 g l(-1) and the glycerol yield improved from 34 to 50% (w/w) by adding 50 g sulphite l(-1), nevertheless, acetic acid increased to 7.8 g l(-1).