Characterization of a topologically unique oxygenase from Sphingobium sp. PNB capable of catalyzing a broad spectrum of aromatics

Crude Oil Degradation by a Novel Strain Pseudomonas aeruginosa AQNU-1 Isolated from an Oil-Contaminated Lake Wetland

In this study, a novel crude oil degrading bacterium was isolated from an oil-contaminated freshwater lake using crude oil as the sole carbon source. The strain was named Pseudomonas aeruginosa AQNU-1 based on the analyses of its morphological characteristics and 16S rRNA gene sequencing. Gas chromatography-mass spectrometry (GC-MS) was carried out to investigate the degradation of crude oil fractions under dynamic (37 °C, 180 r/min) and static (37 °C, 0 r/min) cultivation over three months of continuous enrichment in the laboratory. It was found that strain AQNU-1 exhibited stronger biodegradation efficiency for n-alkanes of C13–C35 under dynamic cultivation with degradation ratios of 87–100% compared to ratios of 74–100% under static cultivation. Furthermore, this strain could fully utilize alkylcyclohexane (M/Z 82), alkylbenzene (M/Z 92) and alkyltoluene (M/Z 106) in crude oil under both conditions. It also had better biodegradability of partial aromatic compounds in the crude oil, showing differences within compound families of aromatic hydrocarbons. Further, the potential degradation ability of this isolated strain decreased with increasing molecular weight, with the dynamic condition performing better in general. These results suggest that the isolated strain has great potential to assimilate indigestible crude-oil contaminants under different hydrological conditions, providing a valuable microbiological resource for in situ remediation of natural wetlands.

Draft Whole-Genome Sequence of Sphingobium sp. Strain PNB, a Versatile Polycyclic Aromatic Hydrocarbon-Degrading Bacterium

Sphingobium sp. strain PNB can completely degrade phenanthrene, naphthalene, and biphenyl as the sole carbon and energy source. The strain is also capable of cometabolizing benzo[a]pyrene, pyrene, acenaphthene, fluoranthene, etc. Here, we report the 5.69-Mb assembly and annotation of the genome sequence of strain PNB, obtained using Illumina sequencing.

Estructura y función de las oxigenasas tipo Rieske/mononuclear

Las oxigenasas Rieske/mononuclear son un grupo de metaloenzimas que catalizan la oxidación de una variedad de compuestos, destaca su participación en la degradación de compuestos xenobióticos contaminantes; estas enzimas también participan en la biosíntesis de algunos compuestos de interés comercial. Poseen una amplia especificidad por el sustrato, convirtiéndolas en un grupo de enzimas con un alto potencial de aplicación en procesos biotecnológicos que hasta el momento no ha sido explotado. La presente revisión aborda aspectos generales acerca de la función y estructura de este importante grupo de enzimas.