A Study of the Effects of Orthene Upon Sulfate Production of Thiobacillus novellus Sharkey, in Soil and Culture
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.