Non-invasive characterization of real time biofilm analyte flux

Abstract

The use of tools (such as sensors) which are capable of real time analysis of compounds in temporally and spatially dynamic environmental conditions is one of the most important areas of research within environmental engineering. Recent technological advancements in electrochemistry, data acquisition, and optics have made possible the development of highly selective/sensitive sensing tools with high temporal spatial resolution. In addition to ongoing research aimed at developing new and enhanced sensors (e.g., increased sensitivity, enhanced analyte selectivity, reduced response time, and novel microfabrication approaches), work over the last few decades has also advanced sensor utility through new sensing modalities that extend and enhance the data recorded by the sensor. When combined with recent advancements in nanoscale technology, these tools are commonly utilized in a variety of applications and sensing modalities (e.g., lab-on-chip devices and chemical assays). One of the most complex and dynamic areas of research in environmental science and engineering is the design of bioprocessors for treating complex wastestreams. Application of tools which are at the forefront of the scientific frontier for characterizing phenomena within these bioprocesses provides invaluable information on non steady state phenomena. One of the most commonly studied microorganisms in bioprocesses (due to its rate limiting role in the nitrogen cycle) is the obligate aerobic chemoautotroph Nitrosomonas europaea. Inhibition studies and fundamental analysis of metabolomics are important in efficient bioprocess design, as N. europaea lack the catabolic flexibility of other bacteria; and are generally more susceptible to decreased kinetic rates (or even cell lysis). Thus, much research is conducted for N. europaea within self-assembled matrices (biofilms); which are significantly different than their planktonic counterpart; demonstrating unique resistance to toxicity, varying growth kinetics, and community dynamics. The ecological and chemical dynamics within N. europaea biofilms are extremely important to the field of environmental engineering, and characterization of physiological phenomena requires in vivo analysis using non-invasive techniques. The use of a novel sensing modality established in other biological disciplines (e.g., biomedicine, plant physiology) to investigate dynamic analyte flux in environmental biofilms is presented (special focus is on N. europaea biofilms). The major challenges associated with use of this technique are addressed, and successful use of the technique for analyzing biologically active transport is demonstrated. Results from this research will be used to enhance fundamental understanding of complex phenomena within biofilms, improve biofilm modeling, develop real time monitoring devices, and improve in situ remediation of complex compounds