RESUMEN
Aim: To determine the impacts of some non-oxidizing biocides such as glutaradehyde, sodium azide, isothiazolone on the functional group activities of some oil field microorganisms Methodology: Samples of non-oxidizing biocides were obtained from Microcheck and the inhibition of some functional group activities in produced and injection water samples were determined using CSB-K medium. Results: Glutaradehyde and sodium azide exhibited relatively high level inhibition while isothiazolones exhibited low level inhibition. Glutaradehyde further demonstrated a positive selective inhibitory activity. While SRB activities were inhibited by over 78%, that of hNRB and so-NRB were affected by less than 38%. Conclusion: Glutaradehyde can be developed to an efficient biocide with a positive selective action and can work in synergy with beneficial microbes to eliminate the problem causing ones.