Project description:In this study the transcriptomes of Acinetobacter baumannii strains ATCC 17978 and 17978hm were compared. Strain 17978hm is a hns knockout derivative of strain ATCC 17978. Strain 17978hm displays a hyper-motile phenotype on semi-solid Mueller-Hinton (MH) media (0.25% agar). ATCC 17978 and 17978hm from an 37C overnight culture were transferred to the centre of the semi-solid MH plate and incubated at 37C for 8 hours. Only 17978hm cells displayed a motile phenotype and covered the complete surface of the plate. These motile 17978hm cells and the non-motile wild-type ATCC 17978 cells were harvested and RNA was isolated. The comparative transcriptome analysis was performed using the FairPlay labeling kit and a custom made Agilent MicroArray with probes designed to coding regions of the ATCC 17978 genome. The data was analyzed using Agilent GeneSpring GX9 and the significance analysis of microarray MS Excel add-on.
Project description:Corynebacterium glutamicum strain ATCC 21831 is a producer of L-arginine that was created by random mutagenesis. It is resistant to the arginine structural analogue canavanine. In order to identify potential bottlenecks in the biosynthetic pathway that leads to this industrially important amino acid, relative metabolite abundances of biosynthetic intermediates were determined in comparison to the type strain ATCC 13032. An extract of U13C-labeled biomass was used as internal standard, to correct for different ionization efficiencies. Metabolites were identified using the ALLocator web platform.
Project description:We report here lead optimisation efforts for molecule GW861072X, one of 177 leads published in a GSK-led phenotypic screening campaign by Balell et al. (2013), generating the AX series. Along with the parent compound AX-35, four other derivatives with mild to no cytotoxicity showed potent in vitro and ex vivo activity in infected THP-1 macrophages against M. tuberculosis. Isolation of resistant mutants to AX compounds in M. tuberculosis revealed mutations in the QcrB of the cytochrome bc1 oxidase, one of two terminal oxidases of the mycobacterial electron transport chain. Cross-resistance studies, transcriptomic analyses and bioenergetics flux assays provide further evidence of QcrB as the target of the AX compounds, and that AX compounds likely interact differently with the quinol binding pocket compared to other QcrB inhibitors. The transcriptomic and bioenergetic profiles obtained when M. tuberculosis was treated with AX-35 are similar to transcriptomic and respiratory signatures of other cytochrome bc1 oxidase inhibitors, whereby the pronounced role of the alternate terminal oxidase cytochrome bd in the respiratory adaptation of M. tuberculosis could be observed. Genes involved in utilisation and synthesis of triacylglycerol (TAG) were also additionally observed to be up-regulated with AX treatment, indicating a switch induced towards lipid metabolism under this particular stress.