Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Azo Compounds”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed1991

Degradation of azo compounds by ligninase from Phanerochaete chrysosporium: involvement of veratryl alcohol.

Phanerochaete chrysosporium decolorized several polyaromatic azo dyes in ligninolytic culture. The oxidation rates of individual dyes depended on their structures. Veratryl alcohol stimulated azo dye oxidation by pure lignin peroxidase (ligninase, LiP) in vitro. Accumulation of compound II of lignin peroxidase, an oxidized form of the enzyme, was observed after short incubations with these azo substrates. When veratryl alcohol was also present, only the native form of lignin peroxidase was observed. Azo dyes acted as inhibitors of veratryl alcohol oxidation. After an azo dye had been degraded, the oxidation rates of veratryl alcohol recovered, confirming that these two compounds competed for ligninase during the catalytic cycle. Veratryl alcohol acts as a third substrate (with H2O2 and the azo dye) in the lignin peroxidase cycle during oxidations of azo dyes.

Agaricales↗
PubMed1993

Reduction of nitro and azo compounds by NADPH-cytochrome P-450 reductase-cytochrome c heme peptide system.

Octa heme peptide, an enzymic digestion product of Candida Krusei cytochrome c, was found to catalyze nitro and azo reduction in the presence of NADPH and NADPH-cytochrome P-450 reductase under anerobic conditions. The reduction was dependent on the concentrations of heme peptide and reductase, and inhibited by carbon monoxide and oxygen. Comparison of the activities of the reductase-heme peptide system with liver microsomes revealed that heme peptide was as effective as cytochrome P-450 in nitro reduction, although less effective in azo reduction. Thus, cytochrome c heme peptide may serve as an artificial substitute for cytochrome P-450 at least in the reductive metabolism of xenobiotics.

Amino Acid Sequence↗
PubMed2006

Respiration and growth of Shewanella decolorationis S12 with an Azo compound as the sole electron acceptor.

The ability of Shewanella decolorationis S12 to obtain energy for growth by coupling the oxidation of various electron donors to dissimilatory azoreduction was investigated. This microorganism can reduce a variety of azo dyes by use of formate, lactate, pyruvate, or H(2) as the electron donor. Furthermore, strain S12 grew to a maximal density of 3.0 x 10(7) cells per ml after compete reduction of 2.0 mM amaranth in a defined medium. This was accompanied by a stoichiometric consumption of 4.0 mM formate over time when amaranth and formate were supplied as the sole electron acceptor and donor, respectively, suggesting that microbial azoreduction is an electron transport process and that this electron transport can yield energy to support growth. Purified membranous, periplasmic, and cytoplasmic fractions from S12 were analyzed, but only the membranous fraction was capable of reducing azo dyes with formate, lactate, pyruvate, or H(2) as the electron donor. The presence of 5 microM Cu(2+) ions, 200 microM dicumarol, 100 microM stigmatellin, and 100 microM metyrapone inhibited anaerobic azoreduction activity by both whole cells and the purified membrane fraction, showing that dehydrogenases, cytochromes, and menaquinone are essential electron transfer components for azoreduction. These results provide evidence that the microbial anaerobic azoreduction is linked to the electron transport chain and suggest that the dissimilatory azoreduction is a form of microbial anaerobic respiration. These findings not only expand the number of potential electron acceptors known for microbial energy conservation but also elucidate the mechanisms of microbial anaerobic azoreduction.

Amaranth Dye↗