Project description:Arthrobacter chlorophenolicus A6 is a 4-chlorophenol degrading soil bacterium with high phyllosphere colonization capacity. Till now the genetic basis for the phyllosphere competency of Arthrobacter or other pollutant-degrading bacteria is uncertain. We investigated global gene expression profile of A. chlorophenolicus grown in the phyllosphere of common bean (Phaseolus vulgaris) compared to growth on agar surfaces.
Project description:Arthrobacter chlorophenolicus A6 is a 4-chlorophenol degrading soil bacterium with high phyllosphere colonization capacity. Till now the genetic basis for the phyllosphere competency of Arthrobacter or other pollutant-degrading bacteria is uncertain. We investigated global gene expression profile of A. chlorophenolicus grown in the phyllosphere of common bean (Phaseolus vulgaris) compared to growth on agar surfaces. We designed transcriptome arrays and investigated which genes had different transcript levels in the phyllosphere of common bean (Phaseolus vulgaris) as compared to agar surfaces. Since water availability is considered an important factor in phyllosphere survival and activity, we included both high and low relative humidity treatments for the phyllosphere-grown cells. In addition, we determined the expression profile under pollutant exposure by the inclusion of two agar surface treatments, i.e. with and without 4-chlorophenol.
Project description:Plants are colonized by a variety of microorganisms, the plant microbiota. In the phyllosphere, the above-ground parts of plants, bacteria are the most abundant inhabitants. Most of these microorganisms are not pathogenic and the plant responses to commensals or to pathogen infection in the presence of commensals are not well understood. We report the Arabidopsis leaf transcriptome after 3 to 4 weeks of colonization by Methylobacterium extorquens PA1 and Sphingomonas melonis Fr1, representatives of two abundant genera in the phyllosphere, compared to axenic plants. In addition, we also sequenced the transcriptome of Arabidopsis 2 and 7 days after spray-infection with a low dose of P. syringae DC3000 and in combination with the commensals.
Project description:The study investigated the impact of environment on the composition of the gut microbiota and mucosal immune development and function at gut surfaces in early and adult life. Piglets of similar genotype were reared in indoor and outdoor environments and in an experimental isolator facility. Mucosa-adherent microbial diversity in the pig ileum was characterized by sequence analysis of 16S rRNA gene libraries. Host-specific gene responses in gut ileal tissues to differences in microbial composition were investigated using Affymetrix microarray technology and Real-time PCR. Experiment Overall Design: Animals were reared on the sow at an outdoor or indoor facility. Additional piglets from the indoor facility were transferred to individual isolator units at 24 hours of age, and given a daily dose of antibiotic cocktail for the duration of the study. Piglets were weaned at day 28. From day 29 onwards, piglets were fed creep feed ad libitum. Ileal tissue samples were excised from N=6 piglets per group at day 5, 28 and 56.