ISON, R . W . 1987. A revised method for the application of API 50 CH carbohydrate kits to yeasts. Letters in Applied Microbiology 49-11. A revised method is described for the application of the API 50 CH carbohydrate kit to yeasts. The method permits an objective assessment of positive assimilation with a high degree of reproducibility.

Molar conductivities of dilute solutions of sorbic acid in water, and in the mixed solvents water +lo, 20,30,40 and 50% glycerol by mass at 25°C are reported. The results have been analysed with the Pitts conductance equation and pK, values for sorbic acid in these solvent mixtures are tabulated. Similar data for sorbic acid in water+30% glycerol at 10°C are also included. The implications of the results for the role of sorbic acid in food preservation are discussed.

A simple method is described for the determination of the carbonation tolerance of yeasts. Using the method, data are presented for the carbonation tolerance of some common soft drink spoilage yeasts.