Aerobic degradation of 2- and 3-fluoroaniline in mixed culture systems and microbial community analysis.
J Environ Sci Health A Tox Hazard Subst Environ Eng
; 55(3): 305-317, 2020.
Article
in En
| MEDLINE
| ID: mdl-31707907
ABSTRACT
Among three monofluoroanilines, 2-fluoroaniline (2-FA) and 3-fluoroaniline (3-FA) exhibit relatively poor biodegradability. This work examined their degradation characteristics in a mixed culture system and also analyzed the microorganism community. After acclimation for 58 d and 43 d, the high removal efficiency of 100% of 2-FA and 95.3% of 3-FA was obtained by adding 25 mg L-1 of 2-FA or 3-FA to the two reactors, respectively. In addition, the high defluorination rates of 2-FA and 3-FA were observed to be 87.0% and 89.3%, respectively. The degradation kinetics showed that the maximum specific degradation rates of 2-FA and 3-FA were (21.23 ± 0.91) mg FA (gâ¢VSS·h)-1, and (11.75 ± 0.99) mg FA (gâ¢VSS·h)-1, respectively. PCR-DGGE analysis revealed that the unique bacteria degrading 2-FA were mainly composed of six genera (Novosphingobium, Bradyrhizobium, Aquaspirillum, Aminobacter, Ochrobactrum, and Labrys), and five genera that degraded 3-FA (Ochrobactrum, Aquaspirillum, Lachnobacterium, Bradyrhizobium, and Variovorax). Analysis of the key catabolic enzyme activities indicated that the simultaneous hydroxylation and dehalogenation were involved in monooxygenase elimination of 2-FA and conversion of 3-FA to 4-fluorocatechol by dioxygenase, indicating that enriched mixed cultures were effective to metabolize 2-FA or 3-FA by unconventional pathways to prevent the accumulation of toxic metabolites.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Microbiota
/
Fluorobenzenes
/
Aniline Compounds
Language:
En
Journal:
J Environ Sci Health A Tox Hazard Subst Environ Eng
Journal subject:
TOXICOLOGIA
Year:
2020
Type:
Article