Topic
Ralstonia
About: Ralstonia is a research topic. Over the lifetime, 355 publications have been published within this topic receiving 13617 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: Based on the results of phenotypic characterization, cellular lipid and fatty acid analysis, phylogenetic analysis of 16S rDNA nucleotide sequences and rRNA‐DNA hybridization, Burkholderia pickettii, Burk holderia solanacearum and Alcaligenes eutrophus are transferred to the new genus Ralstonia, and RAlstonia pickettius (Ralston, Palleroni and Doudoroff 1973) comb.
Abstract: Based on the results of phenotypic characterization, cellular lipid and fatty acid analysis, phylogenetic analysis of 16S rDNA nucleotide sequences and rNA-DNA hybrization, Burkholderia pickettii, Burkholderia solanacearum and Alcaligenes eutrophus are transferred to the new genus Ralstonia, and Ralstonia pickettii (Ralston, Palleroni and Doudoroff 1973) comb. nov., Ralstonia solanacearum (Smith 1896) comb. nov., and R. eutropha (Davis 1969) comb. nov. are proposed. The type species of the new genus is R. pickettii. Type strain of R. pickettii is ATCC 27511T, of R. solanacearum is ATCC 10696T, and of R. eutropha is ATCC 17697T.
627 citations
TL;DR: LC‐MS analyses demonstrated that expression of AiiD in Pseudomonas aeruginosa PAO1 quenched quorum sensing by this bacterium, decreasing its ability to swarm, produce elastase and pyocyanin and to paralyse nematodes.
Abstract: N -acylhomoserine lactones (AHLs) are used as signal molecules by many quorum-sensing Proteobacteria. Diverse plant and animal pathogens use AHLs to regulate infection and virulence functions. These signals are subject to biological inactivation by AHL-lactonases and AHL-acylases. Previously, little was known about the molecular details underlying the latter mechanism. An AHL signal-inactivating bacterium, identified as a Ralstonia sp., was isolated from a mixed-species biofilm. The signal inactivation encoding gene from this organism, which we call aiiD , was cloned and successfully expressed in Escherichia coli and inactivated three AHLs tested. The predicted 794-amino-acid polypeptide was most similar to the aculeacin A acylase (AAC) from Actinoplanes utahensis and also shared significant similarities with cephalosporin acylases and other N-terminal (Ntn) hydrolases. However, the most similar homologues of AiiD are deduced proteins of undemonstrated function from available Ralstonia , Deinococcus and Pseudomonas genomes. LC-MS analyses demonstrated that AiiD hydrolyses the AHL amide, releasing homoserine lactone and the corresponding fatty acid. Expression of AiiD in Pseudomonas aeruginosa PAO1 quenched quorum sensing by this bacterium, decreasing its ability to swarm, produce elastase and pyocyanin and to paralyse nematodes. Thus, AHL-acylases have fundamental implications and hold biotechnological promise in quenching quorum sensing.
513 citations
TL;DR: A polyphasic taxonomic study was conducted to clarify the relationships of eight isolates from root nodules of Mimosa species and one isolate from sputum of a cystic fibrosis patient, which classified as a novel Ralstonia species, for which the name RAlstonia taiwanensis sp.
Abstract: A polyphasic taxonomic study, including 16S rDNA sequence analysis, DNA-DNA hybridizations, DNA base ratio determinations, amplified 165 rDNA restriction analysis, whole-cell protein analyses and extensive biochemical characterization, was conducted to clarify the relationships of eight isolates from root nodules of Mimosa species and one isolate from sputum of a cystic fibrosis patient. All nine isolates were classified as a novel Ralstonia species, for which the name Ralstonia taiwanensis sp. nov. is proposed. The type strain is LMG 19424T (= CCUG 44338T). R. taiwanensis effectively nodulated the Mimosa species and is the first beta-proteobacterium that is known to be capable of root nodule formation and nitrogen fixation.
512 citations
TL;DR: A first inventory of metal resistance genes and operons across R. metallidurans suggests that metal-resistant Ralstonia, through evolution, are particularly well adapted to the harsh environments typically created by extreme anthropogenic situations or biotopes.
Abstract: Ralstonia metallidurans, formerly known as Alcaligenes eutrophus and thereafter as Ralstonia eutropha, is a β-Proteobacterium colonizing industrial sediments, soils or wastes with a high content of heavy metals. The type strain CH34 carries two large plasmids (pMOL28 and pMOL30) bearing a variety of genes for metal resistance. A chronological overview describes the progress made in the knowledge of the plasmid-borne metal resistance mechanisms, the genetics of R. metallidurans CH34 and its taxonomy, and the applications of this strain in the fields of environmental remediation and microbial ecology. Recently, the sequence draft of the genome of R. metallidurans has become available. This allowed a comparison of these preliminary data with the published genome data of the plant pathogen Ralstonia solanacearum, which harbors a megaplasmid (of 2.1 Mb) carrying some metal resistance genes that are similar to those found in R. metallidurans CH34. In addition, a first inventory of metal resistance genes and operons across these two organisms could be made. This inventory, which partly relied on the use of proteomic approaches, revealed the presence of numerous loci not only on the large plasmids pMOL28 and pMOL30 but also on the chromosome. It suggests that metal-resistant Ralstonia, through evolution, are particularly well adapted to the harsh environments typically created by extreme anthropogenic situations or biotopes.
441 citations
TL;DR: Deduced from highly sensitive Real-Time PCR quantification, the ratio of PAH-RHDalpha gene relative to the 16S rRNA gene copy number showed that thePAH-bacterial degraders could represent up to 1% of the total bacterial community in the PAh-contaminated sites.
372 citations