, 2008). As expected, there was no glnR expression in the GlnR deletion strain (Fig. 2
and Table 3). In summary, this study demonstrates that the GlnR-mediated transcriptomic response to nitrogen limitation in M. smegmatis cannot proceed in the absence of GlnR or in the absence of the putative GlnR phosphorylation site. This indicates that the proposed phosphorylation site of GlnR (D48) is essential for the GlnR-mediated transcriptional response to nitrogen limitation in mycobacteria. In addition, this study experimentally verifies four novel genes as part of the GlnR regulon. Current efforts are also focussed on further investigating see more the underlying mechanism of GlnR activation. We thank Professor Graham Hatfull and his laboratory for the kind gift of the recombineering plasmids and for helpful
discussions. We also thank Elliott Hind for technical assistance. V.A.J. is funded by a PhD studentship from the UK Medical Research Council, and K.J.W. is funded by Grant BB/G020434/1 from the Biotechnology and Biological Sciences Research Council. “
“A bacterial community with strong cellulose [filter paper (FP) and microcrystalline cellulose] click here degradation ability was isolated from the coastal marine environment. They were isolated under thermophilic (60 °C) and anaerobic cultivation conditions. The library of 16S rRNA gene clones revealed a total of 16 operational taxonomic units after 50 clones were surveyed. Sixty percent of the clones were most related to the type strain of Clostridium thermocellum with 16S rRNA gene identity around 87–89%. All of them showed
extremely Guanylate cyclase 2C low sequence similarities and were novel at least in species level. The gene clone libraries of glycosyl hydrolase family 48 showed low gene and amino acid sequence similarities around 70–72%. The results indicated that the cellulose degradation systems in the specific environment have not been well studied. The enrichment could disrupt FP within 3 days in a basal medium. The cellulase activity of the community was comparable to that of C. thermocellum LQR1. The main fermentation products were ethanol, acetic acid and butyric acid. This work identified a novel microbial resource with a potential in lignocellulose conversion and biofuel production. Lignocellulose is one of the most abundant polysaccharides on the earth. The prospect of using lignocellulose as biofuel source has increased interest in identifying new lignocellulose-degrading microorganisms. Complex enzyme components, such as beta-1,4-endoglucanses (EC 22.214.171.124), beta-1,4-exoglucanases or cellobiohydrolases (EC 126.96.36.199), beta-glucosidases (EC 188.8.131.52) and xylanase (EC 184.108.40.206), have been shown to be involved in the digestion of lignocellulose. A few cellulolytic systems have been intensively studied, for example in the anaerobic bacterium Clostridium thermocellum (Zverlov et al.