Project description:Background: Pantoea ananatis LMG 2665T synthesizes and utilizes acyl homoserine lactones (AHLs) for signaling. In this strain, short chain AHLs (C4 to C8) are produced by the EanI/R quorum sensing (QS) system that is involved in pathogenicity and biofilm formation. The complete set of genes regulated by the EanI/R system in P. ananatis LMG 2665T is still not fully known. In the present study, RNA-seq was used to analyze the transcriptome profiles controlled by the EanI/R system in this strain by comparing the wild type strain and its QS mutant 2665T ean∆I/R during lag and log stages. The RNA seq data was validated by RT qPCR. Results: The results showed that the EanI/R regulon in P. ananatis LMG 2665T comprised 144 genes, constituting 3.3% of the whole transcriptome under the experimental conditions in this study. The majority of genes regulated by the EanI/R system included genes for flagella assembly, bacterial chemotaxis, pyruvate metabolism, two component system, metabolic pathways, microbial metabolism and biosynthesis of secondary metabolites. Conclusions: This is the first study to identify the EanI/R QS regulon in P. ananatis LMG 2665T. Functional analysis of genes regulated the EanI/R system in LMG 2665T could help unveil genes that play a vital role in pathogenesis and survival strategies of this pathogen.
Project description:Microbiota in the kangaroo gut degrade cellulose, contributing to the kangaroo's energy and survival. In this preliminary study, to discover more about the gut microbes that contribute to the survival of kangaroos, cellulose-degrading bacteria were isolated from kangaroo scats by selection on solidified media containing carboxymethyl cellulose as the main carbon source. One frequently occurring aerobic bacterium was Siccibacter turicensis, a microbe previously isolated in fruit powder and from a patient with angular cheilitis. The whole genome sequence of the kangaroo isolate was obtained using the Illumina MiSeq platform. Its sequence shared 97.98% identity of the S. turicensis Type strain, and the ability of the Type strain to degrade cellulose was confirmed. Analysis of the genomic data focused on the cellulose operon. In addition to genes from the operon, we suggest that a gene following the operon may have an important role in regulating cellulose metabolism by signal transduction. This is the first report of S. turicensis found within microbiota of the animal gut. Because of its frequent presence in the kangaroo gut, we suggest that S. turicensis plays a role in cellulose digestion for kangaroos.
