Open AccessBiotransformation and biodegradation of N ‐substituted aromatics in methanogenic granular sludge
Author(s) -
RazoFlores Elı́as,
Donlon Brian,
Lettinga Gatze,
Field Jim A
Publication year - 1997
Publication title -
fems microbiology reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.91
H-Index - 212
eISSN - 1574-6976
pISSN - 0168-6445
DOI - 10.1111/j.1574-6976.1997.tb00335.x
Subject(s) - biodegradation , biotransformation , chemistry , mineralization (soil science) , methanogenesis , anaerobic exercise , bacteria , detoxification (alternative medicine) , environmental chemistry , anaerobic bacteria , anaerobic digestion , microbial metabolism , organic chemistry , methane , biology , nitrogen , physiology , medicine , genetics , alternative medicine , pathology , enzyme
N ‐Substituted aromatic compounds are environmental contaminants associated with the production and use of dyes, explosives, pesticides and pharmaceuticals. In this article, we examine the potential of anaerobic granular sludge from anaerobic treatment systems towards the detoxification, transformation, and mineralization of nitroaromatic and azo compounds. Nitroaromatics and azo dyes with strong electron withdrawing are highly inhibitory to acetoclastic methanogenic bacteria. However, nitro and azo substituted aromatics are readily reductively detoxified in methanogenic consortia to their respective aromatic amines, which are several orders of magnitude less toxic. This reductive detoxification has allowed the successful operation of anaerobic reactors for the treatment of highly toxic aromatic compounds. In the course of the experiments it was discovered that some aromatic amines were mineralized. These results indicate that some N ‐substituted aromatic compounds can be completely mineralized and serve as a carbon and energy source for anaerobic bacteria.