ABSTRACT
In interpreting the data, several possible sources of inaccuracy need to be taken into consideration. Substrates containing Sand N in their chemical structure will produce ammonia and sulfur oxides, in addition to CO2 , during biodegradation. These will interfere with the acid-base titration procedure employed to estimate the CO2 evolved. There is also the chance that some fraction of the C02 remains sorbed in the soil itself and is not available for reaction with the alkali in the biometer flask. At the end of the experiment some acid is added into the soil to liberate any CO2 bound in the form of inorganic carbonates in the soil water, to take this error into account. It is important to appreciate that the rate of biodegradation obtained, and in complex substrates even the Ymax == a value, can depend on the concentration and the nature of microbial inoculum used in the experiment. The values of k therefore, are not absolute values and are meaningful only as relative measures in comparison with those of reference materials, such as cellulose powder or cellophane.
