Foliar and root applications of the rare sugar tagatose control powdery mildew in soilless grown cucumbers

Summary

Biodegradation of a mixture of PAHs was assessed in forest soil microcosms performed either without or
with bioaugmentation using individual fungi and bacterial and a fungal consortia. Respiratory activity,
metabolic intermediates and extent of PAH degradation were determined. In all microcosms the low
molecular weight PAH’s naphthalene, phenanthrene and anthracene, showed a rapid initial rate of
removal. However, bioaugmentation did not significantly affect the biodegradation efficiency for these
compounds. Significantly slower degradation rates were demonstrated for the high molecular weight
PAH’s pyrene, benz[a]anthracene and benz[a]pyrene. Bioaugmentation did not improve the rate or extent
of PAH degradation, except in the case of Aspergillus sp. Respiratory activity was determined by CO2 evolution
and correlated roughly with the rate and timing of PAH removal. This indicated that the PAHs were
being used as an energy source. The native microbiota responded rapidly to the addition of the PAHs and
demonstrated the ability to degrade all of the PAHs added to the soil, indicating their ability to remediate
PAH-contaminated soils.