Oxidation of organic compounds by propane monooxygenase ofRhodococcus erythropolis 3/89
The ability of propane monooxygenase ofRhodococcus erythropolis 3/89 to catalyze oxidation of higher liquid alkenes and aromatic hydrocarbons was studied. Optimal conditions of tetradecene epoxidation and benzene hydroxylation were found. Under these conditions, oxidation was shown to be accompanied by a 100% conversion of benzene to phenol.
Isolation of Rhodococcus sp. CMGCZ Capable to Degrade High Concentration of Fluoranthene
A bacterial strain CMGCZ was isolated from an abandoned oil field soil sample and identified as Rhodococcus sp. by 16S rRNA sequencing. Rhodococcus sp. CMGCZ was investigated for the degradation of model polycyclic aromatic hydrocarbons (PAHs) and Iranian light crude oil (ILCO) as a sole carbon source in minimal medium. Biodegradation enhancement was attained by supplementing the minimal medium with yeast extract (YE). Rhodococcus sp. CMGCZ was capable to degrade 13.2 % naphthalene (Nap), 13.1 % phenanthrene (Phe), and 99.3 % fluoranthene (Fla) in 1 week and 11 % aliphatic fraction of ILCO in 2 weeks as a sole carbon and energy source. Effect of YE supplementation on degradation potential of Rhodococcus sp. CMGCZ depended upon the added hydrocarbon in the medium. YE completely inhibited Nap degradation, slightly enhanced degradation of Phe (14.8 %) and ILCO aliphatics (13.2 %), and promoted a more rapid degradation of Fla (100 %). YE addition promoted rapid degradation of Fla and eliminated delay of 24 h in Fla degradation that was observed in minimal medium. Rhodococcus sp. CMGCZ was capable to degrade high concentrations of Fla (1000 mg l−1). Rieske [Fe2-S2] center was amplified in Rhodococcus sp. CMGCZ that exhibited homology with Rieske [Fe2-S2] domain protein of Mycobacterium species and pahAC gene of uncultured bacterium clones.
Utilization of acetate by Methanomonas emthanooxidans
Methanomonas methanooxidans incorporates both carbon atoms of acetate into the glutamate and aspartate families of amino acids during growth on methane; carbon dioxide is also evolved from both carbon atoms of acetate. The distribution of carboxyl-labeled acetate incorporated into convalently bound glutamate is consistent with the operation of the tricarboxylic acid cycle in this species, and the presence of alpha-ketoglutarate dehydrogenase was demonstrated in cell-free extracts.