scholarly journals Response to vanadate exposure in Ochrobactrum tritici strains

PLoS ONE ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. e0229359 ◽  
Author(s):  
Mariana Cruz Almeida ◽  
Rita Branco ◽  
Paula V. Morais
Keyword(s):  
Ochrobactrum Tritici

scholarly journals First Case Report of Human Infection With Ochrobactrum tritici Causing Bacteremia and Cholecystitis

2016 ◽  
Vol 36 (3) ◽  
pp. 278-280 ◽  
Author(s):  
Duck Jin Hong ◽  
Keon-Han Kim ◽  
Jung Ok Kim ◽  
Jun Sung Hong ◽  
Seok Hoon Jeong ◽  
...  
Keyword(s):  
Case Report ◽  
Human Infection ◽  
First Case ◽  
Ochrobactrum Tritici

Ochrobactrum tritici strain 5bvl1 — characterization of a Cr(VI)-resistant and Cr(VI)-reducing strain

2004 ◽  
Vol 50 (9) ◽  
pp. 697-703 ◽  
Author(s):  
Rita Branco ◽  
M Carmen Alpoim ◽  
Paula V Morais
Keyword(s):  
Heavy Metal ◽  
Growth Rate ◽  
Type Strain ◽  
Treatment Plant ◽  
The Other ◽  
Reducing Ability ◽  
High Concentrations ◽  
Ph Range ◽  
Ochrobactrum Tritici

Bacterial strain 5bvl1, isolated from a chromium-contaminated wastewater treatment plant and identified as Ochrobactrum tritici, was resistant to a broad range of antibiotics, to Cr(VI), Ni(II), Co(II), Cd(II), and Zn(II), and was able to grow in the presence of 5% NaCl and within the pH range 4–10. Characterization showed that strain 5bvl1 could be considered a halotolerant and alkalitolerant microorganism resistant to high concentrations of Cr(VI). This strain was able to grow aerobically in up to 10 mmol·L–1 Cr(VI). Cr(VI) resistance was independent of sulphate concentration. Under aerobic conditions strain 5bvl1 was also able to reduce high Cr(VI) concentrations (up to 1.7 mmol·L–1). Increasing concentrations of Cr(VI) in the medium lowered the growth rate of strain 5bv11 but the reduction in growth rate could not be directly correlated with the amount of Cr(VI) reduced. Unlike the type strain, which was only able to reduce Cr(VI), strain 5bvl1 was resistant to Cr(VI) and able to reduce it. Moreover, in strain 5bvl1, the rate and extent of Cr(VI)-reduction were higher than in the other strains of the genus Ochrobactrum. Ochrobactrum strain 5bvl1 resists high Cr(VI) concentrations and has a high Cr(VI)-reducing ability, making it a valuable tool in bioremediation.Key words: Ochrobactrum, Cr(VI) resistance, Cr(VI)-reduction, heavy metal, bioremediation.

Metal-induced phosphate extracellular nanoparticulate formation in Ochrobactrum tritici 5bvl1

2011 ◽  
Vol 198 ◽  
pp. 31-39 ◽  
Author(s):  
Romeu Francisco ◽  
Pedro de Abreu ◽  
Bradley A. Plantz ◽  
Vicki L. Schlegel ◽  
Rui A. Carvalho ◽  
...  
Keyword(s):  
Ochrobactrum Tritici

Biodegradation of synthetic pyrethroids by Ochrobactrum tritici strain pyd-1

2011 ◽  
Vol 27 (10) ◽  
pp. 2315-2324 ◽  
Author(s):  
Bao-zhan Wang ◽  
Yun Ma ◽  
Wei-you Zhou ◽  
Jin-wei Zheng ◽  
Jian-chun Zhu ◽  
...  
Keyword(s):  
Synthetic Pyrethroids ◽  
Ochrobactrum Tritici

scholarly journals Identification of an aox System That Requires Cytochrome c in the Highly Arsenic-Resistant Bacterium Ochrobactrum tritici SCII24

2009 ◽  
Vol 75 (15) ◽  
pp. 5141-5147 ◽  
Author(s):  
Rita Branco ◽  
Romeu Francisco ◽  
Ana Paula Chung ◽  
Paula Vasconcelos Morais
Keyword(s):  
Toxic Elements ◽  
Oxidation Process ◽  
Structural Genes ◽  
Arsenite Oxidase ◽  
Arsenite Resistance ◽  
Two Component ◽  
Two Component Signal Transduction ◽  
Life On Earth ◽  
Ochrobactrum Tritici

ABSTRACT Microbial biotransformations have a major impact on environments contaminated with toxic elements, including arsenic, resulting in an increasing interest in strategies responsible for how bacteria cope with arsenic. In the present work, we investigated the metabolism of this metalloid in the bacterium Ochrobactrum tritici SCII24. This heterotrophic organism contains two different ars operons and is able to oxidize arsenite to arsenate. The presence of arsenite oxidase genes in this organism was evaluated, and sequence analysis revealed structural genes for an As(III) oxidase (aoxAB), a c-type cytochrome (cytC), and molybdopterin biosynthesis (moeA). Two other genes coding for a two-component signal transduction pair (aoxRS) were also identified upstream from the previous gene cluster. The involvement of aox genes in As(III) oxidation was confirmed by functionally expressing them into O. tritici 5bvl1, a non-As(III) oxidizer. Experiments showed that the As(III) oxidation process in O. tritici requires not only the enzyme arsenite oxidase but also the cytochrome c encoded in the operon. The fundamental role of this cytochrome c, reduced in the presence of arsenite in strain SCII24 but not in an O. tritici ΔaoxB mutant, is surprising, since to date this feature has not been found in other organisms. In this strain the presence of an aox system does not seem to confer an additional arsenite resistance capability; however, it might act as part of an As(III)-detoxifying strategy. Such mechanisms may have played a crucial role in the development of early stages of life on Earth and may one day be exploited as part of a potential bioremediation strategy in toxic environments.

Chromium resistance strategies and toxicity: what makes Ochrobactrum tritici 5bvl1 a strain highly resistant

BioMetals ◽  
2011 ◽  
Vol 24 (3) ◽  
pp. 401-410 ◽  
Author(s):  
Paula Vasconcelos Morais ◽  
Rita Branco ◽  
Romeu Francisco
Keyword(s):  
Resistance Strategies ◽  
Chromium Resistance ◽  
Ochrobactrum Tritici

scholarly journals The Chromate-Inducible chrBACF Operon from the Transposable Element TnOtChr Confers Resistance to Chromium(VI) and Superoxide

2008 ◽  
Vol 190 (21) ◽  
pp. 6996-7003 ◽  
Author(s):  
Rita Branco ◽  
Ana Paula Chung ◽  
Tatiana Johnston ◽  
Volkan Gurel ◽  
Paula Morais ◽  
...  
Keyword(s):  
Large Scale ◽  
Efflux Pump ◽  
Specific Resistance ◽  
Genetic System ◽  
Aerobic Growth ◽  
Chromium Vi ◽  
Redox Active ◽  
Tetrazolium Staining ◽  
Industrial Use ◽  
Ochrobactrum Tritici

ABSTRACT Large-scale industrial use of chromium(VI) has resulted in widespread contamination with carcinogenic chromium(VI). The abilities of microorganisms to survive in these environments and to detoxify chromate require the presence of specific resistance systems. Here we report identification of the transposon-located (TnOtChr) chromate resistance genes from the highly tolerant strain Ochrobactrum tritici 5bvl1 surviving chromate concentrations of >50 mM. The 7,189-bp-long TnOtChr of the mixed Tn21/Tn3 transposon subfamily contains a group of chrB, chrA, chrC, and chrF genes situated between divergently transcribed resolvase and transposase genes. The chrB and chrA genes, but not chrF or chrC, were essential for establishment of high resistance in chromium-sensitive O. tritici. The chr promoter was strongly induced by chromate or dichromate, but it was completely unresponsive to Cr(III), oxidants, sulfate, or other oxyanions. Plasmid reporter experiments identified ChrB as a chromate-sensing regulator of chr expression. Induction of the chr operon suppressed accumulation of cellular Cr through the activity of a chromate efflux pump encoded by chrA. Expression of chrB, chrC, or chrF in an Escherichia coli sodA sodB double mutant restored its aerobic growth in minimal medium and conferred resistance to superoxide-generating agents menadione and paraquat. Nitroblue tetrazolium staining on native gels showed that ChrC protein had superoxide dismutase activity. TnOtChr appears to represent a mobile genetic system for the distribution of the chromate-regulated resistance operon. The presence of three genes protecting against superoxide toxicity should provide an additional survival advantage to TnOtChr-containing cells in the environments with multiple redox-active contaminants.

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