CELL-GROWTH AND ACCUMULATION OF THIOBACILLUS-THIOOXIDANS S3 IN A PH-CONTROLLED THIOSULFATE MEDIUM

The Thiobacillus thiooxidans S3 strain was grown on modified Silverman 9K medium containing thiosulfate as a sole energy source instead of sulfur. When the pH of medium was controlled at 5.0 during the cultivation, the growth rate greatly increased to 0.067 h-1 and the cell yield obtained with 1% thiosulfate was 210 mg/l. When cell growth declined, placing the culture in fresh medium effectively prolonged the period of linear growth and the cell concentration reached 891 mg/l in 309 h of cultivation. The cells obtained in the replacement culture efficiently oxidized the sulfite.