A two-phase biotransformation process for selective hydroxylation of n-octane to 1-octanol via Pseudomonas putida KT2440 harboring heterologously expressed P450 monooxygenase from Mycobacterium marinum is presented. Maximum cell-specific conversion rates of 12.7mg(octanol)g(CDW)h(-1) were observed not only in shaking flasks but also in 3.7-L-bioreactor studies. The bioreactor experiments were performed avoiding explosive gas mixtures by lowering volumetric power input, aeration rates and substrate concentrations. Based on a stoichiometric network of P. putida KT2440 topological studies were carried out. As a conclusion, potential limitations of NAD(P)H and/or ATP supply at production conditions can be excluded. Hence, the great potential of the host for further increasing conversion is outlined.