Study of the Influence of Different Diphenol Compounds on Soil Microbial Activity by Microcalorimetry

Microcalorimetry was applied to follow the toxic effects caused by different diphenol compounds oil microbial activity of Chinese fir soil The activity of the microorganisms in soil was stimulated by adding 0.3 mL of a nutrient solution containing 2.5 mg of glucose and 2.5 mg of ammonium sulfate and the measurements were performed under it 35% controlled humidity at 28 degrees C Power-time Curves recorded oil a microcalorimeter were followed by increasing the amount of diphenol of compounds, which affected directly the total thermal effects evolved by the microorganisms The curves showed a synergism on total thermal effect obtained by the addition of 2000 mg.kg(-1) of resorcinol. causing it consumption of resorcinol by the microorganisms as a new source Of nutrients. Above tills dose, the total thermal effect decreased exponentially. However, the addition of catechol and hydroquinone caused the total thermal effects to decrease directly It wits concluded that the increase in the diphenol concentration strongly affected the microbial life in this ecosystem Microcalorimetry appears as it suitable technique to carry out both qualitative and quantitative comparative studies of microbial activity in soil.