Adaptation of the "Drop Plate" Method for the Enumeration of Red Halophilic Bacteria

Abstract

The quantitative determination of total numbers of red halophilic bacteria in contaminated solar salts and discoloured salt fish has been made possible through the successful adaptation of the "drop plate" method. The maximum number of colonies is reached after eight days for pure strains of Ps. salinaria, and after 14 days for the red halophiles present in contaminated solar salts. A brief statistical study has shown that a fair degree of reliability can be obtained with the method. From series of counts, the total error expressed as coefficient of variation is shown to vary from 3.34 to 8.72 per cent. Good reproducibility is also obtained when random samples are taken from stocks of contaminated salt.