Biodegradation Mechanism of Aromatic Compounds by Comamonas testosteroni ZD 4-1 and Pseudomonas aeruginosa ZD4-3
丛毛睾丸酮单胞菌ZD4-1和铜绿假单胞菌ZD4-3降解芳香烃化合物的机理

To investigate the characteristic and biochemical mechanism about the biodegradation of aromatic compounds by bacteria, bacterial strains ZD 4 1 and ZD 4 3 were isolated from pesticide manufacturing factory sludge, by growth on phenol as the sole source of carbon and energy, and were identified as Comamonas testosteroni and Pseudomonas aeruginosa . Based on the sequences of 16S rDNA, bacterial strains ZD 4 1 and ZD 4 3 were positioned into two different subgroups. The identification of the intermediates and the detection of the corresponding catabolic enzymes in crude extracts indicated that the strains ZD 4 1 and ZD 4 3 metabolized phenol via ortho pathways and meta pathways, respectively. The results of induction experiment showed that the catechol dioxygenases, both catechol 1,2 dioxygenase (C12O) and catechol 2,3 dioxygenase (C23O), were all inducible. Finally, the results of biodegradation and enzyme assays showed that the biodegradation efficiency of phenol by meta pathways was higher than that by ortho pathways but the former is in an inferiority position in terms of adaptation to pH fluctuation and of growth ability on other aromatic compounds compared with the latter.