The removal of short/long chain alkanes (from C6 to C19), cyclohexanes and BTE X during the crude oil degradation are presented in Table 2. All measured hydrocarbons were significantly biodegraded by both bacteria and their mixture. Removal of investigated hydrocarbons was different, from 97% (for hexane degraded by the mixture of the isolates) to 22% (for tridecane degraded by Alcaligenes piechaudii SRS). Hexadecane, pristane and cyclohexane were degraded with high efficiency between 72-91% by both isolates and their mixture. Among BTE X, toluene was found to be degraded very well by both strains and their mixture. Benzene and m+p-xylenes were efficiently degraded by a mixture of the isolates, and removal values were 78% and 87%, respectively.