Volume 29, Issue 3
DOI: 10.24205/03276716.2020.703
Optimization of Sterilization Methods, Counting Rule and Yield Coefficient for AOC Determination Based on Flow Cytometry
Abstract
Assimilable organic carbon (AOC) is an important and a well-accepted indictor for evaluating the biological stability in water. Flow cytometry combined with fluorescence staining now has become a most-used protocol. Sterilization methods and counting rules were applied by scholars are not uniform. Besides, the empirical value for yield coefficient is not rigorous. The paper mainly compared the disputes in AOC determination protocol. Firstly, sterilization method including membrane filtration, autoclaving, pasteurization, chlorination were compared. Pasteurization after 0.22μm membrane filtration could keep the integrity of bacterial cells and reveal the AOC value most accurately. Secondly, the counting rules of total cells counts and intact cells counts were compared. ICC avoids repeated counting of P17 during AOC measurement. Thirdly, control group with 0, 25, 50, 75, 100 and 200 μg Acetate carbon/L were conducted to confirm yield coefficient. The control group below 75 μg carbonic acid carbon/L were suggested.
Keywords
AOC, sterilization method, counting rule, yield coefficient