Résumé
This paper reports the isolation and characterization of a new o-nitrobenzaldehyde (ONBA)-degrading bacterium, Alcaligenes sp. ND1. ND1 degraded almost all ONBA (100 mg L-1) in M9 medium within 36 hours. The key enzyme(s) involved in the initial biodegradation was a constitutively intracellular enzyme(s). This bacterium has great potential utility for bioremediation.
Esse trabalho relata o isolamento e a caracterização de uma nova bactéria degradadora de o-nitrobenzaldeido (ONBA), Alcaligenes sp ND1. A bactéria ND1 decompôs todo o ONBA (100 mg.L-1) do meio M9 em 36 horas. A enzima-chave envolvida na biodegradação inicial foi uma enzima constitutiva intracelular. Esta bactéria apresenta um potencial de aplicação para bioremediação.
Sujets)
Alcaligenes/isolement et purification , Enzymes , Nitro-benzoates/isolement et purification , Dépollution biologique de l'environnement , Méthodes , MéthodesRésumé
Effect of p-nitrophenol shock on microbial populations and sludge activity in UASB reactor was studied by DGGE-PCR of 16S rDNA fragments and detection of COD removing and biogas yield.The results showed that p-nitrophenol seriously inhibited the sludge activity,resulting in the drop of biogas and COD removing rate.The 40mg/L p-nitrophenol had more inhibition than 20mg/L p-nitrophenol.It would take 27 and 16 days respectively for reactor to recover after 40mg/L and 20mg/L p-nitrophenol shock.The diversity of eubacteria and methanogens were also effected by the p-nitrophenol shock.The variation of eubacteria was more than that of methanogens after p-nitrophenol shock.The drop of biogas was mainly related to the variation of Methanosaeta sp.and Methanomicrobia sp.after p-nitrophenol shock.Among the eubacteria the population of Chloroflexi sp.、Bacteroide sp.and Anaerovibrio sp.decreased greatly after p-nitrophenol shock.And more,the Rheinheimera sp disappeared after 40mg/L p-NP treatment.But the Flavobacteria sp.appeared after p-nitrophenol shock,which was probably related to the degradation of p-NP.