1990 Volume 36 Issue 1 Pages 41-46
We studied different factors which affect sulfite oxidation in Thiobacillus thiooxidans S3 cells during storage. The cells continued the oxidation for 27 days when they were preserved at 4°C in a 0.1M citrate buffer (pH 6.0), or for 22 days when 20% glycerol was added to the same buffer and storage was at -20°C. When the cells were stored at 4°C, they kept full activity even after 45 days. If the cells were immobilized before they were stored at 4°C in the buffer, they kept their full activity for 90 days. The cells treated by lyophilization or drying at room temperature lost about 90% of the original activity. T. thiooxidans S3 cells were more stable than T. novellus cells under the same storage conditions.