Subdivision of the Escherichia coli K-12 genome for sequencing: manipulation and DNA sequence of transposable elements introducing unique restriction sites.

A transposon-based method of introducing unique restriction sites was used for subdivision of the Escherichia coli genome into a contiguous series of large non-overlapping segments spanning 2.5Mb. The segments, sizes ranging from 150 to 250kb, were isolated from the chromosome using the inserted restriction sites and shotgun cloned into an M13 vector for DNA sequencing. These shotgun sizes proved easily manageable, allowing the genomic sequence of E. coli to be completed more efficiently and rapidly than was possible by previously available methods. The 9bp duplication generated during transposition was used as a tag for accurate splicing of the segments; no further sequence redundancy at the junction sites was needed. The system is applicable to larger genomes even if they are not already well-characterized. We present the technology for segment sequencing, results of applying this method to E. coli, and the sequences of the transposon cassettes

Hydrogenation of Furfural as Model Reaction of Bio-Oil Stabilization under Mild Conditions Using Multiwalled Carbon Nanotube (MWNT)-Supported Pt Catalysts

Pt nanoparticles supported on multiwalled carbon nanotubes (MWNT) were synthesized and applied in the catalytic hydrogenation of furfural, the model reaction of mild stabilization of reactive bio-oil. The catalytic properties of the catalysts were modified by changing the surface concentration of oxygen-containing groups (OCGs) of MWNT. Various characterization techniques, including fluorescent labeling, nitrogen physisorption, powder X-ray diffraction, transmission electron microscopy, and in situ DRIFTS analysis, were employed to study both the supports and catalysts. Pt nanoparticles supported on MWNT with high OCGs show high activity and selectivity, attributed to the formation of small Pt particles as a result of the high concentration of OCGs.ASTAR (Agency for Sci., Tech. and Research, S’pore