CONTINUOUS NONDESTRUCTIVE MONITORING OF MICROBIAL BIOFILMS - A REVIEWOF ANALYTICAL TECHNIQUES

A fundamental requirement for the understanding and control of biofilm s is the continuous nondestructive monitoring of biofilm processes. Th is paper reviews research analytical techniques that monitor biofilm p rocesses in a continuous nondestructive manner and that could also be modified for industrial applications. To be considered 'continuous' an d 'nondestructive' for the purpose of this review a technique must: (a ) function in an aqueous system; (b) not require sample removal; (c) m inimize signal from organisms or contaminants in the bulk phase; and ( d) provide real-time data. Various microscopic, spectrochemical, elect rochemical, and piezoelectrical analysis methods fulfill these criteri a. These techniques monitor the formation of biofilms, the physiology of the microorganisms within biofilms, and/or the interaction of the b iofilms with their environment. It is hoped that this review will stim ulate development and use of biofilm monitoring techniques in industri al and environmental settings.