Microbial oxidation of glucose to free gluconic acid by growing G.oxydans batch cultures was investigated. Kinetic data for the discussed process were obtained and attention was paid mainly to the influence of the initial glucose concentration and of the conversion degree on the course of the process. It was determined that relatively high maximum specific growth rates of about 0,39 h(.1) and gluconic acid volumetric productivities up to 53 mmol/h could be reached using G.oxydans NBIMCC 1043 in runs without pH control. A maximum conversion degree of 90,4 % was achieved.