Growth of Protozoa in Glassware Cleaned with Sulphuric Acid-Potassium Bichromate Solution

Abstract

Pure cultures of Euglena gracilis, Astasia sp., and Tetrahymena geleii were grown in flasks cleaned with acid-bichromate solution followed by a variable number of water rinses, and in flasks cleaned with Calgonite. As compared to bichromate-cleaned flasks rinsed 100 times or flasks cleaned with Calgonite, twice-rinsed bichromate-cleaned flasks did not cause inhibited growth of these spp. in organic media. No cumulative effect resulting in growth inhibition was observed when Astasia was cultured in organic medium in twice-rinsed flasks for a number of serial transfers. When grown in inorganic media, twice-rinsed flasks did not cause any inhibition of either growth rate or yield of Euglena, but did cause a slower rate of growth of Astasia. This slower growth rate was not observed, however, after serial transfers had been carried out in these twice-rinsed vessels.