A dynamic resazurin microassay allowing accurate quantification of cells and suitable for acid-forming bacteria.

A resazurin micro-assay was developed to quantify acidifying bacteria. The resorufin fluorescent signal was measured over time and the determined time to reach the max slope (TMS) was plotted against CFU (colony forming unit) counts. This dynamic assay enabled to quantify nine lactic acid bacteria and a Bacillus licheniformis strain despite the increasing acidity of the medium.