Fluorescent pseudomonas M18, one of plant growth promoting rhizobacteria which can inhibit growth of several phytopathogenes, produces several secondary metabolites including antibiotics phenazine-1-carboxylic acid (PCA) and pyoluteorin (Plt). The rpoD gene encoding the housekeeping sigma factor sigma70 was cloned and sequenced from M18. Through sequencing and homogeneous comparison, the deduced RpoD amino acid sequence between M18 strain and Pseudomonasfluorescens CHAO shows 100% identity. It indicates that rpoD gene is very conserved in different members of fluorescent pseudomonads. The rpoD gene was placed downstream of the constitutive Ptac promoter in the shuttle vector pME6032 between E. coli and Pseudomonas fluorescens and the recombinant plasmid was introduced into M18. It was found that the time of both PCA and Plt began to accumulate was 4 and 8 hours earlier and the yield of these antibiotics was increased one and six times more respectively in M18 in comparison with the control.
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Int J Syst Evol Microbiol
December 2024
Department of Plant Pathology, University of Florida, Gainesville, FL, USA.
Three fluorescent bacterial strains, K1, K13 and K18, were obtained from watermelon () foliage symptomatic of bacterial leaf spot of cucurbits in Florida. The strains underwent phenotypic characterization, including LOPAT (levan production, oxidase activity, pectolytic activity on potato, arginine dihydrolase production and hypersensitive response (HR) on both tobacco and tomato) and pathogenicity testing on watermelon and squash seedlings. Whole-genome sequencing of the isolates was performed, and multi-locus sequence analysis (MLSA) utilizing housekeeping genes , , and placed the isolates into two distinct clades within the genus.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
November 2024
Key Laboratory for Polar Science, Polar Research Institute of China, Ministry of Natural Resources, Shanghai 200136, PR China.
Two Gram-stain-negative bacterial strains, BSw22131 and DMSP-1, were isolated from seawater of Arctic Kongsfjorden in the Ny-Ålesund area, Svalbard. Strains BSw22131 and DMSP-1 were within the genus and presented 98.1 and 99.
View Article and Find Full Text PDFUnlabelled: The capsular polysaccharide synthesis ( ) locus of is implicated in invasive meningococcal disease. The synthesis ( ) and transport ( ) operons are transcribed in opposite directions from a common intergenic region and expression is negatively regulated by the bacterial two-component system and thermosensitive RNA folding. However, these mechanisms do not fully explain the stationary phase responses and the cis-acting elements remain to be fully characterized.
View Article and Find Full Text PDFPLoS Genet
October 2024
School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea.
Three RpoD-family sigma factors, RpoD, RpoS, and RpoH, play critical roles in transcriptional regulation in Salmonella enterica serovar Typhimurium under heat shock conditions. However, the genome-wide regulatory mechanisms of these sigma factors in response to heat stress have remained elusive. In this study, we comprehensively identified 2,319, 2,226, and 213 genome-wide binding sites for RpoD, RpoS, and RpoH, respectively, under sublethal heat shock conditions (42°C).
View Article and Find Full Text PDFWorld J Microbiol Biotechnol
October 2024
Department of Agricultural Biotechnology, Faculty of Agriculture, Ondokuz Mayıs University, Samsun, 55139, Türkiye.
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