ABSTRACT: Cypermethrin-degrading and biosurfactant-producing bacterial strains isolated from the Northern Chilean Patagonia Genome sequencing and assembly
Project description:Pathogenicity of the phytopathogenic enterobacterium Erwinia chrysanthemi, the causative agent of soft rot disease in many plants, is a complex process involving several factors whose production is subject to temporal regulation during infection. After penetrating into its host plant, E. chrysanthemi resides latently in the plant intercellular spaces without provoking any symptoms, and disease occurs only when the environmental conditions are favourable for massive bacterial multiplication and production of plant cell wall degrading enzymes. PecS is a transcriptional regulator of the MarR family that represses production of plant cell wall degrading enzymes. Here, we used microarray analysis to define the PecS regulon and demonstrated that PecS exerts wide-ranging effects on gene expression in E. chrysanthemi. However, the major effects of PecS are largely confined to specific genes that could be linked to pathogenicity and to a group of genes concerned with evading host defences. Among the identified targets are the genes encoding plant cell wall degrading enzymes, secretion systems, the genes involved in flagella synthesis, in biosurfactant synthesis, in oxidative stress response as well as genes encoding toxin-like virulence factors such as NipE and Hemolysin-coregulated proteins. Electromobility shift assays and DNAse I footprinting demonstrated that PecS directly interacts with the regulatory regions of five new targets, ahpC, rhlA, nipE, virK, avrL, that define three different functional classes of genes: oxidative stress response genes (ahpC), biosurfactant synthesis gene (rhlA), genes encoding exported proteins related to other plant associated bacteria proteins (nipE, virK, avrL). Based on this work, we propose a pivotal role of PecS in the switch from a saprophytic to a parasitic lifestyle.
Project description:Proteomic analysis of iron restriction of the marine pathogen Renibacterium salmoninarum that causes the disease (BKD), in this study two isolated Chilean H-2 strains and the type strain ATCC33209 have been used. These results show that changes are generated at the level of protein expression in pathways involved in iron metabolism and uptake.
Project description:Bacteria isolated from potato scab lesions in Finland or northern Sweden were analyzed using microarrays, PCR, and sequencing. Data indicate wide genetic variability in pathogenicity islands among S.turgidiscabies and S.scabies strains.
Project description:The genus Rhodococcus comprises numerous strains recognized for pollutant degradation, secondary metabolite production including biosurfactant, lignin breakdown, or utilization of volatile organic compounds. Often gene redundancies and evolution of alternative pathways are attributed to such characteristics. Rhodococcus opacus 1CP initially isolated as a chlorophenol degrading strain was found to be a model organism comprising several such features. In this study, we analyzed the genome and transcriptome and demonstrated that the strain 1CP undergo three different routes of ortho, meta, and side chain attack in degrading aromatic compounds. The wild type strain, single or double knock-out mutant of phenol hydroxylases, well compensated the loss and chooses the classical ortho-route to attack substituted phenols, while the triple knock-out mutant takes the meta-pathway to act on p-cresol indicating that this pathway serves as a reserve in strain 1CP. Growth of 1CP in phenol, p-cresol and styrene induces several gene clusters that are associated in lignin metabolization. Catechol, protocatechuate, and phenylacetic acid are major key intermediates that are funneled into central pathways which enable the strain 1CP to degrade acetophenone, benzoate, phenol, 2-phenylethanol, and styrene. Strain 1CP has an alternative option with the modified ortho-cleavage pathway which enables it to degrade 2-chlorophenol. Interestingly, in almost all cases, redundant genes were identified, but only in minor cases as phenol hydroxylases, they were found to be active and simultaneously involved in metabolic activities. The transcriptome and kinetic data showed that the redundant styrene-oxide isomerase is upregulated and involved in styrene degradation.
