An evaluation of cellobiose as an alternative reference substance for isothermal microcalorimetry measurements of soil microbial activity

Cellobiose biodegradation in soil samples containing different doses of phosphogypsum was investigated by isothermal microcalorimetry. The results were compared with glucose biodegradation data in identical soil samples. A similar tendency was observed in cellobiose and glucose biodegradation processes. The rate of decomposition of the analyzed saccharides decreased with a rise in phosphogypsum doses in soil samples. During cellobiose and glucose biodegradation, the rate of heat production and the apparent growth rate constant decreased, whereas peak time and generation time increased with a rise in the phosphogypsum content of the investigated soil samples. The heat of cellobiose and glucose biodegradation increased in response to higher phosphogypsum doses in the soil.