Among bacteria, only a single styrene-specific degradation pathway has been reported so far. It comprises the activity of styrene monooxygenase, styrene oxide isomerase, and phenylacetaldehyde dehydrogenase, yielding phenylacetic acid as the central metabolite. The alternative route comprises ring-hydroxylating enzymes and yields vinyl catechol as central metabolite, which undergoes -cleavage. This was reported to be unspecific and also allows the degradation of benzene derivatives. However, some bacteria had been described to degrade styrene but do not employ one of those routes or only parts of them. Here, we describe a novel "hybrid" degradation pathway for styrene located on a plasmid of foreign origin. As putatively also unspecific, it allows metabolizing chemically analogous compounds (e.g., halogenated and/or alkylated styrene derivatives). CWB2 was isolated with styrene as the sole source of carbon and energy. It employs an assembled route of the styrene side-chain degradation and isoprene degradation pathways that also funnels into phenylacetic acid as the central metabolite. Metabolites, enzyme activity, genome, transcriptome, and proteome data reinforce this observation and allow us to understand this biotechnologically relevant pathway, which can be used for the production of ibuprofen. The degradation of xenobiotics by bacteria is not only important for bioremediation but also because the involved enzymes are potential catalysts in biotechnological applications. This study reveals a novel degradation pathway for the hazardous organic compound styrene in CWB2. This study provides an impressive illustration of horizontal gene transfer, which enables novel metabolic capabilities. This study presents glutathione-dependent styrene metabolization in an (actino-)bacterium. Further, the genomic background of the ability of strain CWB2 to produce ibuprofen is demonstrated.
T is an aerobic, Gram-negative soil bacterium that was isolated in Freiberg, Saxony,Germany. The cells were motile and rod-shaped. Optimal growth was observed at 20-30 8C.The fatty acids of strain Kp5.2 T comprised mainly C 18 : 1 v7c and summed feature 3 (C 16 : 1 v7c/iso-C 15 : 0 2-OH). The major respiratory quinone was Q-10. et al., 2003). In this study, we report on a novel isolate of the genus Sphingopyxis that was designated strain Kp5.2 T . This strain was identified as being able to degrade styrene via the metabolic intermediate phenylacetic acid (Oelschlägel et al., 2015) (see Fig. S1, available in the online Supplementary Material). To the best of our knowledge, utilization of styrene or phenylacetic acid has not been reported before for a member of the genus Sphingopyxis. Strain Kp5.2 T was isolated from soil as described by Oelschlägel et al. (2014). The genome of the isolate was subsequently sequenced. For this purpose, biomass of a phenylacetic acid-grown culture of strain Kp5.2 T [200 ml mineral medium in a 500 ml baffled flask; in total 3 mmol (515 mM) phenylacetic acid added in 1 mmol portions (55 mM) over 7 days] was harvested by centrifugation (16 100 g, 5 min, 4 8C). Genomic DNA was extracted and purified by phenol/chloroform extraction by a modification of the method of Wilson (2001). A sample of the DNA obtained was checked by gel electrophoresis (0.7 % agarose, 90 V) and stained with ethidium bromide. Genomic DNA Abbreviation: SEM, scanning electron microscopy.The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain Kp5.2 T is CP009122.1 (positions 159052-160528). The accession numbers for the sequences of the chromosome (genome), plasmid pSfKp5.2 (genome) and the FadJ protein in the paa-gene cluster of strain Kp5.2 T are CP009122, CP009123 and AJA07148.1.Six supplementary figures are available with the online Supplementary Material.
In this paper, the 3rd part of a series of publications on the sinterability and characteristics of TiAl–Ti3AlC2 composites, the microstructure development during the synthesis and sintering processes was studied by scanning electron microscopy (SEM). Chemical evaluation of various phases in the developed microstructures was performed using energy-dispersive X-ray spectroscopy (EDS) in different ways such as point, line scan and two-dimensional elemental map analyses. For this purpose, five samples were fabricated with different percentages of Ti3AlC2 MAX phase additive (10, 15, 20, 25 and 30 wt%). Ball-milling and spark plasma sintering (SPS: 900 °C/7 min/40 MPa) of as-purchased Al and Ti powders with already-synthesized Ti3AlC2 additive were selected as composite making methodology. SEM/EDS analyses verified the in-situ manufacturing of TiAl/Ti3Al intermetallics as the matrix during the SPS process and the presence of Ti3AlC2 as the ex-situ added secondary phase. Moreover, the in-situ synthesis of Ti2AlC, another member of MAX phases in Ti-Al-C system, was also detected in titanium aluminide grain boundaries and attributed to a chemical reaction between TiC (an impurity in the initial Ti3AlC2 additive) and TiAl components.
A novel thermoacidophilic archeaon, strain J1T (=DSM 112778T,=JCM 34702T), was isolated from a hot pool in a volcanic area of Java, Indonesia. Cells of the strain were irregular, motile cocci of 1.0–1.2 µm diameter. Aerobic, organoheterotrophic growth with casamino acids was observed at an optimum temperature of 70 °C in a range of 55–78 °C and at an optimum pH of 3 in a range of 1.5 to 5. Various organic compounds were utilized, including a greater variety of sugars than has been reported for growth of other species of the genus. Chemolithoautotrophic growth was observed with reduced sulphur compounds, including mineral sulphides. Ferric iron was reduced during anaerobic growth with elemental sulphur. Cellular lipids were calditoglycerocaldarchaeol and caldarchaeol with some derivates. The organism contained the respiratory quinone caldariellaquinone. On the basis of phylogenetic and chemotaxonomic comparison with its closest relatives, it was concluded that strain J1T represents a novel species, for which the name Metallosphaera javensis is proposed. Low DNA–DNA relatedness values (16S rRNA gene <98.4%, average nucleotide identity (ANI) <80.1%) distinguished J1T from other species of the genus Metallosphaera and the DNA G+C content of 47.3% is the highest among the known species of the genus.
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