Date of Award

Spring 1979

Document Type



Life & Environmental Sciences

First Advisor

John Christenson

Second Advisor

Jean Smith

Third Advisor

John Semmens


Four concentrations of Thiobacillus novellus Sharkey, were cultured in Thiobacillus growth Medium containing five concentrations of Orthene. Ten-gram soil samples were also treated with the five concentrations of Orthene. All samples were incubated at room temperature for 1 week, then assayed for sulfate concentration. Sulfate production served as an indicator of biochemical activity of Thiobacillus novellus. Thus, increased production of sulfate was indicative of a stimulatory effect, while decreased production indicated an inhibitory effect. Orthene exhibited the same effect on sulfate production in the soil samples and in the Thiobacillus novellus cultures. All concentrations of Orthene tested inhibited sulfate production. Intermediate concentrations of Orthene were more effective than the higher and lower concentrations in inhibiting sulfate production.

Included in

Bacteriology Commons