The effect of pharmaceutical waste-fungal biomass,treated to degrade DNA,on the composition of eubacterial and ammonia oxidizing populations of soil

The aim of this work was to study variations in the composition of eubacteria and ammonia-oxidizing populations of soil, both determined by denaturing gradient gel electrophoresis (DGGE), after the addition of a pharmaceutical fungal biomass, treated to degrade its DNA. This waste can be used as an amendment. The fungal biomass waste was added at three rates: 0.05, 0.1, and 1% per dry weight of soil. Control soil, without any amendment, was also investigated. Total DNA was extracted, purified, and amplified by using either universal (eubacteria) or specific (amoA) primers. Amplicons were separated by DGGE. Sequencing was also carried out to better assess the diversity of ammonia oxidizing bacteria. Changes in the composition of eubacterial community were detected after 3 days only in the soil treated with the highest dose, while the ammonia oxidizing population responded more promptly (after 1 day) with evident modifications at level of Nitrosolobus like sequences.