A mixture of alkanes in the range of C-12 to C-16, byproducts Of distillation processes in the petroleum industry, was used as an oxygen-vector. The effect on the oxygen transfer rate of addition of the alkane mixture to the medium in a tower bioreactor was investigated. A concentration of 4% (v/v) of the alkane mixture increased the volumetric oxygen transfer coefficient (k(L)a) and yeast production rate by 1.26- and 1.3-fold, respectively, compared with these values in a medium without oxygen-vector.