Employing a novel fiber optic detection system to monitor the dynamics of in situ lux bioreporter activity in porous media: system performance update

One of the major constraints to successful implementation of in situ bioremediation is our lack of understanding of how microbial activity is influenced by the physicochemical conditions in the subsurface environment. Our laboratory has successfully developed a novel fiber optic detection system that employs a lux bioreporter organism to non-invasively monitor real-time, in situ microbial activity in porous media. An evaluation of potential system limitations indicates that the system is not adversely affected by biofilm formation on the optical fiber tips or by bioluminescence attenuation in the porous medium employed. Additionally, the detection system effectively captures the dynamics of in situ bacterial gene expression during naphthalene catabolism under changing physicochemical conditions in saturated porous media. Therefore, this system enables laboratory-based studies of how physicochemical conditions in the subsurface influence microbial activity and will assist in improving: (1) our fundamental understanding of how transformation-related non-ideality, such as non-steady-state microbial activity, affects contaminant transport and fate; and (2) our ability to predict the efficacy of in situ bioremediation in dynamic, heterogeneous subsurface environments.