The concentration of easily assimilable organic carbon (AOC) is widely used for evaluation of the microbiological stability of drinking water. The major disadvantages of the conventional AOC method are a long assay time of 9-12 days, the use of a laborious and time consuming plating technique for cell counting and limited information supplied by the use of pure cultures (Pseudomonas fluorescens P-17 and Spirillum NOX).
These disadvantages can be eliminated by direct cell growth enumeration by elastic light scattering detection. A new method and apparatus described in this article enables growth curves measurement with high sensitivity and resolution.