Project description:This study examines genome-wide expression of the phenanthrene-degrading Sphingomonas sp. LH128 as a response to short-term starvation stress. For this purpose, the strain was subjected to complete nutrient starvation for 4h after growth on a rich medium. Survival was monitored by plating and transcriptomic response was determined by whole-genome microarray analysis. The data showed no major differences were obsrved in gene expression and the viability of the cells were not affected during short-term incubation time Transcriptomic response of phenanthrene degrading Sphingomonas sp. LH128 starved for 4h in isotonic solution of 0.01 mM MgS04 was studied using genome-wide gene expression analysis. For this purpose, the strain was pregrown in minimal medium to an OD600 of 0.5, washed twice with 0.01 mM MgS04 and resuspended in the same solution to an OD of 0.5. RNA was extracted both from starved cells and from the initial culture (non-starved cells) and cDNA was synthesized and labeled with Cy3. Transcriptomic response of three replicates were analyzed and compared with the initial inoculum
Project description:This study examines the transcriptomic response of biofilms of the PAH-degrading Sphingomonas sp. LH128 on solute stress when actively degrading and growing on the PAH compound. To address the effect of solute stress on bacterial physiology and transcriptomic response, NaCl was used as osmolyte. Both acute and chronic solute stress was invoked to assess differences in short-term and long-term responses. Transcriptomic response of phenanthrene degrading Sphingomonas sp. LH128 biofilms as a response to short-term and long-term solute (NaCl) stress was studied using genome-wide gene expression analysis. For this purpose, the strain was grown in customized continuous glass flow chambers that contain solid phenanthrene as a sole carbon source and that allow easy recovery of biofilm cells for transcriptomic and physiological analysis. A NaCl stress of 450 mM was imposed on LH128 biofilms growing on phenanthrene crystals coated on glass slides either for 4 hours (acute stress) or for 3 days (chronic stress). RNA was extracted from the biofilm and cDNA was synthesized and labeled with Cy3. Transcriptomic response in the stressed biofilms of three replicates per conditions were analyzed and compared with non-stressed
