Kinetics of biodegradation of mixtures of substrates in soil
Year: 1989
Type: article
Abstract: A number of organic compounds were added to soil to determine their effects on the mineralization of P-nitrophenol (PNP) by indigenous soil microorganisms. At a concentration of 10 μgg−1 of soil, phenol slowed the initial rate but increased the final extent of mineralization (cumulative evolution of 14CO2) of 5 ng of radiolabeled PNP g −1 of soil, whereas glucose and glutamate had no effect. Glucose and glutamate at 500μg g−1 reduced the extent of PNP mineralization but did not change the shape of the mineralization curve. The reduction in extent was not a result of deficiencies of inorganic nutrients. The addition of phenol at 10μg g−1 of soil changed the curve of PNP mineralization from a nongrowth shape to a sigmoidal shape reflecting growth; however, no growth of the PNP-mineralizing population was indicated by most-probable-number counts. At 250 μg g−1 of soil, phenol prolonged the initial lag phase, the final extent of PNP mineralization and the abundance of PNP-mineralizing microorganisms. The simultaneous curves of phenol and PNP mineralization were fit by models describing the kinetics of mineralization of single and dual substrates, and the results indicate that the growth rates were the same for the populations using 5 ng PNP and 250 μg phenol g−1. Phenol at 10 and 250 μg g−1 was not toxic to the populations carrying out the initial mineralization of acetate or glucose at 5 ng g−1. The data show that growth on a second compound may substantially alter the kinetics of mineralization of low concentrations of organic chemicals in soil.
Source: Soil Biology and Biochemistry
Authors: K.M. Scow, S.K. Schmidt, M. Alexander
Language: English
Subfield: Pollution
Field: Environmental Science
Domain: Physical Sciences
SDG: Life on land
Open Access status: hybrid
Estimated APC paid: $4,950
OpenAlex ID: W2092197367