A multi-channel thermal activity monitor was applied to study soil microbial activity in Wuhan brown sandy soil in the presence of different concentrations of hexavalent chromium (K2 Cr2 O7). In order to stimulate the soil microbial activity, 5.0 mg of glucose and 5.0 mg of ammonium sulfate were added to a 1.20-g soil sample under a controlled humidity of 35%. The results show that the poisonous species of K2 Cr2 O7 at an half inhibitory concentration (IC50) value of 4.27 μ g mL- 1 against soil microbe, and an increase of the amount of hexavalent chromium is associated to a decrease in the microbial activity of the soil, probably due to an increase in the toxicity of hexavalent chromium, affecting strongly the life in this soil microbial environment. Our work also suggests that microcalorimetry is a fast, simple and more sensitive method that can be easily performed to study the toxicity of different species of heavy metals on microorganism compared to other biological methods.
Scopus Subject Areas
- Public Health, Environmental and Occupational Health
- Health, Toxicology and Mutagenesis
- Hexavalent chromium
- Soil microbial activity