Showing papers by "David J. Leak published in 2008"
TL;DR: An improved, versatile shuttle vector has been created for the metabolic engineering of Geobacillus spp.
77 citations
TL;DR: It is demonstrated that Pdc from Zymomonas mobilis can be expressed in an active form in Geobacillusthermoglucosidasius at up to 52°C, while expression of Pdc polypeptides up to 54°C was evident from Western blotting.
Abstract: Expression of a pyruvate decarboxylase (Pdc) pathway in metabolically versatile thermophilic bacteria could create novel ethanologenic organisms, but no suitable thermostable Pdc is available We have demonstrated that Pdc from Zymomonas mobilis can be expressed in an active form in Geobacillus thermoglucosidasius at up to 52 degrees C, while expression of Pdc polypeptides up to 54 degrees C was evident from Western blotting By using an unstable lactate dehydrogenase (ldh) mutant of G thermoglucosidasius, indirect evidence of Pdc activity in vivo was also obtained
39 citations
TL;DR: This work investigated this species succession and isolated a new dominant strain, identified as Pandoraea pnomenusa sp.
Abstract: We have previously reported the disappearance of a specific strain degrading chlorobenzene from a func- tionally stable bioreactor. In the present work, we investi- gated this species succession and isolated a new dominant strain, identified as Pandoraea pnomenusa sp. strain MCB032. A specific 16S rRNA-targeted oligonucleotide probe was designed and validated to identify strain MCB032 using fluorescence in situ hybridisation (FISH). The results confirmed the presence of strain MCB032 in samples collected over time, and showed that it was pri- marily located within the biofilm. Denaturing gradient gel electrophoresis (DGGE) provided evidence that the species succession occurred early in the operating period. The application of these biomolecular tools highlighted the remarkable stability of this new strain during the 15 months of reactor operation. The succession was attributed to the competitive kinetic behaviour of strain MCB032, which exhibited faster growth (mmax ¼0.34 h � 1 ) and higher sub- strate affinity (Ks ¼0.35 mgL � 1 ) than strain JS150. Finally, this study contributed to the characterisation of the recently established Pandoraea genus, an emerging group in the biodegradation field. Biotechnol. Bioeng. 2008;99: 68-74. 2007 Wiley Periodicals, Inc.
27 citations
TL;DR: A strain utilizing cyclohexylamine as the sole source of carbon and nitrogen, designated NyZ12, was isolated from soil and identified by 16S rDNA sequencing as Pseudomonas plecoglossicida, suggesting that degradation involves an initial deamination step.
Abstract: A strain utilizing cyclohexylamine as the sole source of carbon and nitrogen, designated NyZ12, was isolated from soil and identified by 16S rDNA sequencing as Pseudomonas plecoglossicida. This bacterium released ammonia into the medium when grown on cyclohexylamine, and also grows readily on cyclohexanone as the sole carbon source, suggesting that degradation involves an initial deamination step.
10 citations