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Although Medicago sativa forms highly effective symbioses with the comparatively acid-sensitive genus Ensifer, its introduction into acid soils appears to have selected for symbiotic interactions with acid-tolerant R. favelukesii strains. Rhizobium favelukesii has the unusual ability of being able to nodulate and fix nitrogen, albeit sub-optimally, not only with M. sativa but also with the promiscuous host Phaseolus vulgaris. Here we describe the genome of R. favelukesii OR191 and genomic features important for the symbiotic interaction with both of these hosts. The OR191 draft genome contained acid adaptation loci, including the highly acid-inducible lpiA/acvB operon and olsC, required for production of lysine- and ornithine-containing membrane lipids, respectively. The olsC gene was also present in other acid-tolerant Rhizobium strains but absent from the more acid-sensitive Ensifer microsymbionts. The OR191 symbiotic genes were in general more closely related to those found in Medicago microsymbionts. OR191 contained the nodA, nodEF, nodHPQ, and nodL genes for synthesis of polyunsaturated, sulfated and acetylated Nod factors that are important for symbiosis with Medicago, but contained a truncated nodG, which may decrease nodulation efficiency with M. sativa. OR191 contained an E. meliloti type BacA, which has been shown to specifically protect Ensifer microsymbionts from Medicago nodule-specific cysteine-rich peptides. The nitrogen fixation genes nifQWZS were present in OR191 and P. vulgaris microsymbionts but absent from E. meliloti-Medicago microsymbionts. The ability of OR191 to nodulate and fix nitrogen symbiotically with P. vulgaris indicates that this host has less stringent requirements for nodulation than M. sativa but may need rhizobial strains that possess nifQWZS for N2-fixation to occur. OR191 possessed the exo genes required for the biosynthesis of succinoglycan, which is required for the Ensifer-Medicago symbiosis. However, 1H-NMR spectra revealed that, in the conditions tested, OR191 exopolysaccharide did not contain a succinyl substituent but instead contained a 3-hydroxybutyrate moiety, which may affect its symbiotic performance with Medicago hosts. These findings provide a foundation for the genetic basis of nodulation requirements and symbiotic effectiveness with different hosts.

In order to take advantage of the increasing sophistication of technology for harnessing renewable energy resources, serious attention must be paid to how to store and re-access this energy. Electrochemical storage, in the guise of batteries, supercapacitors and pseudocapacitors, has attracted much attention as a viable option for enhanced energy storage applications. But in order for these technologies to be implemented successfully we need to find materials that perform better and are relatively easy to synthesise. Bimetallic transition metal oxides are materials that are readily synthesised and may be multifunctional, i.e. have a role at the electrochemical atomic level as well as the device level. In order for these materials to work efficiently in new generation systems based on sodium and lithium they also need to be mesoporous. This can be achieved by trying to find synthetic techniques that produce specific, highly regulated nanostructures or by adding a ‘templating’ agent during the bulk synthesis step. We have investigated the simple hydrothermal preparation of a number of nickel cobaltate (NiCo2O4) materials using polymer templates, eggshell membrane (ESM) and poly methyl methacrylate (PMMA), as potential electrode materials for supercapacitors. The ESM was expected to act as a fibrous, random polymeric template while the PMMA should produce a much more ordered material. Electrochemical testing showed that the different templates have led to changes in material morphology and these have resulted in a difference in electrochemical properties. Templated materials increased specific capacitance compared to non-templated and the choice of template could influence the capacitance by as much as 30%.

The formation of volatile substancessuch as hydrogen, methane, ketones, and aldehydes during alumina productionusing the Bayer process is of interest because of their process andoccupational safety and health implications. To better understandhow these substances are generated in the Bayer process, the decompositionof a selection of low- and high-molecular-weight organic materialshas been studied at 180 °C in a synthetic Bayer liquor consistingof 6 mNaOH. The main vapor-phase products were identifiedusing gas chromatography with thermal conductivity or mass spectrometrydetection. The results showed that caustic degradation of organiccompounds commonly occurring in Bayer process liquors produces a rangeof substances known to be present in alumina refinery emissions. Themain volatile products were H2, CH4, and certaincarbonyl compounds with low odor thresholds, such as 2-butanone andpropanone. There was also some evidence for the production of volatilepentacyclic compounds. [ABSTRACT FROM AUTHOR]