An occurrence of petite colonie mutation in an alcohol distillery yeast.

During the early part of March, 1956, it was noticed in one of the Colonial Sugar Refining Company's alcohol distilleries that, under the microscope, the cells of the yeast culture in use (Saccharomyces cerevisiae) were not as uniform in appearance as the cells of that strain had been in the past. The particular culture on which this observation was made was a reserve culture of the yeast which had been brought into daily use in the distillery 10 days previously.