The negative interaction between the degradation of phenanthrene and tricyclazole in medium, soil and soil/compost mixture.

To assess the co-catabolism of phenanthrene and tricyclazole in different samples, the interaction during the degradation of phenanthrene and tricyclazole were investigated in medium, soil and soil/spent mushroom compost (SMC) mixture. Generally, tricyclazole showed a negative influence on the activity of phenanthrene dioxygenase and it inhibited the degradation of phenanthrene prominently, both in cultures of phenanthrene catabolic isolates (Sphingomonas paucimobilis ZX4 and the mixed flora M1) and soils, while a similar inhibition caused by phenanthrene was also found for the degradation of tricyclazole in soil/SMC. However, the inhibition effect on phenanthrene degradation was eliminated in soil/SMC mixture, due to the abundant microorganisms and enormous catabolic potential in SMC. Furthermore, it was proved that the negative influence between phenanthrene and tricyclazole was most likely derived from the molecular similarity and it tended to decrease with improved microbial diversity in environment.