SEARCH · PubMed Health

Results for “Rhodococcus”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources

PubMed2004

Degradation of 5-nitroguaiacol by soil bacteria of the genus Rhodococcus.

Two bacterial strains were isolated from forest soil by selective enrichment of the mineral medium containing 4-nitropyrocatechol as the sole carbon and energy source. Both strains could utilize 4-nitropyrocatechol and 5-nitroguaiacol. Degradation of 5-nitroguaiacol and stoichiometric release of nitrites was measured during its degradation both in growing culture and for resting cells. Both strains were unable to degrade other nitroaromatic compounds such as 4-nitroguaiacol, 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 2,4-dinitrobenzoic acid, 4,5-dimethoxy-2-nitrobenzoic acid and 2,3-difluoro-6-nitrophenol. One strain was identified as Rhodococcus opacus and the second one as Rhodococcus sp.

Biodegradation, Environmental↗

PubMed2001

Rhodococcus sp. RB1 grows in the presence of high nitrate and nitrite concentrations and assimilates nitrate in moderately saline environments.

Rhodococcus sp. RB1 was able to thrive in media with up to 0.9 M NaCl or KCl and in the presence of high concentrations of nitrate (up to 0.9 M) and nitrite (up to 60 mM), but only under oxic conditions. An adaptation period was not required for salt tolerance, but a rapid extrusion of K+ and intake of Na+ was observed after addition of 0.5 M NaCl. Nitrate assimilation was limited by the carbon supply, but nitrite was not accumulated in the culture medium, even at nitrate concentrations as high as 0.8 M, thus suggesting that nitrite reduction does not limit nitrate assimilation. The presence of NaCl or KCl did not affect nitrate or nitrite uptake, which were completely inhibited by ammonium or glutamine. Rhodococcus sp. RB1 nitrate reductase had an apparent molecular mass of 142 kDa and used NADH and reduced bromophenol blue or viologens as electron donors, independently of the presence of salt. The enzyme was associated with an NADH-diaphorase activity and was induced by nitrate and repressed by ammonium or glutamine, thus showing typical biochemical and regulatory properties of bacterial assimilatory NADH-nitrate reductases. The enzyme was active in vitro in the presence of 3 M NaCl or KCI, but the maximal activity was observed at 0.5 M salt. Addition of 2 M NaCl increased the optimal temperature of the enzyme from 12 to 32 degrees C, but the optimal pH (10.3) was unaffected.

Cell Division↗

PubMed2001

Alkanesulfonate degradation by novel strains of Achromobacter xylosoxidans, Tsukamurella wratislaviensis and Rhodococcus sp., and evidence for an ethanesulfonate monooxygenase in A. xylosoxidans strain AE4.

Novel isolates of Achromobacter xylosoxidans, Tsukamurella wratislaviensis and a Rhodococcus sp. are described. These grew with short-chain alkanesulfonates as their sole source of carbon and energy. T. wratislaviensis strain SB2 grew well with C(3)-C(6) linear alkanesulfonates, isethionate and taurine, Rhodococcus sp. strain CB1 used C(3)-C(10) linear alkanesulfonates, taurine and cysteate, but neither strain grew with ethanesulfonate. In contrast, A. xylosoxidans strain AE4 grew well with ethanesulfonate, making it the first bacterium to be described which can grow with this compound. It also grew with unsubstituted C(3)-C(5) alkanesulfonates and isethionate. Hydrolysis was excluded as a mechanism for alkanesulfonate metabolism in these strains; and evidence is given for a diversity of uptake and desulfonatase systems. We provide evidence for an initial monooxygenase-dependent desulfonation in the metabolism of ethanesulfonate and propanesulfonate by A. xylosoxidans strain AE4.

Actinomycetales↗

PubMed1997

Dense Rhodococcus cerebral abscesses in an HIV-positive patient.

Rhodococcus equi, formerly known as Corynebacterium equi, an aerobic, gram-positive, pleomorphic coccobacillus, is a well-known pathogen for domestic livestock. We present a biopsy- and culture-proven case of Rhodococcus equi brain abscesses in a patient seropositive for HIV, having an appearance not described previously.

AIDS-Related Opportunistic Infections↗

PubMed2002

Alkanotrophic Rhodococcus ruber as a biosurfactant producer.

In this report we examined the structure and properties of surface-active lipids of Rhodococcus ruber. Most historical interest has been in the glycolipids of Rhodococcus erythropolis, which have been extensively characterised. R. erythropolis has been of interest due to its great metabolic diversity. Only recently has the metabolic potential of R. ruber begun to be explored. One major difference in the two species is that most R. ruber strains are able to oxidise the gaseous alkanes propane and butane. In preparation for investigation of the effects of gas metabolism on biosurfactant production, we set out to characterise the biosurfactants produced during growth on liquid n-alkanes and to compare these with R. erythropolis glycolipids.

Alkanes↗

PubMed2005

Characterization of four Rhodococcus alcohol dehydrogenase genes responsible for the oxidation of aromatic alcohols.

Four genes were isolated and characterized for alcohol dehydrogenases (ADHs) catalyzing the oxidation of aromatic alcohols such as benzyl alcohol to their corresponding aldehydes, one from o-xylene-degrading Rhodococcus opacus TKN14 and the other three from n-alkane-degrading Rhodococcus erythropolis PR4. Various aromatic alcohols were bioconverted to their corresponding carboxylic acids using Escherichia coli cells expressing each of the four ADH genes together with an aromatic aldehyde dehydrogenase gene (phnN) from Sphingomonas sp. strain 14DN61. The ADH gene (designated adhA) from strain TKN14 had the ability to biotransform a wide variety of aromatic alcohols, i.e., 2-hydroxymethyl-6-methylnaphthalene, 2-hydroxymethylnaphthalene, xylene-alpha,alpha'-diol, 3-chlorobenzyl alcohol, and vanillyl alcohol, in addition to benzyl alcohol with or without a hydroxyl, methyl, or methoxy substitution. In contrast, the three ADH genes of strain PR4 (designated adhA, adhB, and adhC) exhibited lower ability to degrade these alcohols: these genes stimulated the conversion of the alcohol substrates by only threefold or less of the control value. One exception was the conversion of 3-methoxybenzyl alcohol, which was stimulated sevenfold by adhB. A phylogenetic analysis of the amino acid sequences of these four enzymes indicated that they differed from other Zn-dependent ADHs.

Alcohol Dehydrogenase↗

PubMed2001

Purification and characterization of the enantioselective nitrile hydratase from Rhodococcus equi A4.

The nitrile hydratase from Rhodococcus equi A4 consisted of two kinds of subunits which slightly differed in molecular weight (both approximately 25 kDa) and showed a significant similarity in the N-terminal amino acid sequences to those of the nitrile hydratase from Rhodococcus sp. N-774. The enzyme preferentially hydrated the S-isomers of racemic 2-(2-, 4-methoxyphenyl)propionitrile, 2-(4-chlorophenyl)propionitrile and 2-(6-methoxynaphthyl)propionitrile (naproxennitrile) with E-values of 5-15. The enzyme functioned in the presence of 5-98% (v/v) of different hydrocarbons, alcohols or diisopropyl ether. The addition of 5% (v/v) of n-hexane, n-heptane, isooctane, n-hexadecane, pristane and methanol increased the E-value for the enzymatic hydration of 2-(6-methoxynaphthyl)propionitrile.

Amino Acid Sequence↗

PubMed2001

Microbial desulfurization of alkylated dibenzothiophene and alkylated benzothiophene by recombinant Rhodococcus sp. strain T09.

The dibenzothiophene (DBT) desulfurizing operon, dsz, was introduced into various benzothiophene (BT)-desulfurizing bacteria using a Rhodococcus-E. coli shuttle vector. Of the tested recombinant bacteria, only those from Rhodococcus sp. strain T09 grew with both DBT and BT as the sole sulfur source. These recombinant cells desulfurized not only alkylated BTs, but also various alkylated DBTs, producing alkylated hydroxybiphenyls as the desulfurized products. Recombinant strain T09 also desulfurized alkylated DBT in an oil-water, two-phase resting-cell reaction. The dsz operon had the same desulfurizing activity when inserted into the vector in either orientation, indicating that the promoter region of the operon was functional in strain T09.

Alkylation↗

PubMed1999

Establishment of a gene transfer system for Rhodococcus opacus PD630 based on electroporation and its application for recombinant biosynthesis of poly(3-hydroxyalkanoic acids).

A gene transfer system for Rhodococcus opacus PD630 based on electroporation was established and optimized employing the Escherichia coli-Rhodococcus shuttle vectors pNC9501 and pNC9503 as well as the E. coli-Corynebacterium glutamicum shuttle vector pJC1 as suitable cloning vectors for R. opacus PD630, resulting in transformation efficiencies up to 1.5 x 10(5) CFUs/microgram plasmid DNA. Applying the optimized electroporation protocol to the pNC9501-derivatives pAK68 and pAK71 harboring the entire PHB synthesis operon from Ralstonia eutropha and the PHA synthase gene phaC1 from Pseudomonas aeruginosa, respectively, recombinant PHA biosynthesis was established in R. opacus PD630 and the TAG-negative mutant ROM34. Plasmid pAK68 enabled synthesis and accumulation of poly(3HB) in R. opacus PD630 and ROM34 during cultivation under storage conditions from 1% (w/v) gluconate, of poly(3HB-co-3HV) from 0.2% (w/v) propionate and of poly(3HV) from 0.1% (w/v) valerate. Under storage conditions, recombinant strains of PD630 and ROM34 harboring pAK71 were able to synthesize and accumulate PHA of the medium chain length hydroxyalkanoic acids 3HHx, 3HO, 3HD and 3HDD from 0.1% (w/v) hexadecane or octadecane and a copolyester composed of 3HHp, 3HN and 3HUD from 0.1% (w/v) pentadecane or heptadecane. In the recombinant strains of PD630 and ROM34, the thiostrepton-induced overexpression of a 20 kDa protein was observed with its N-terminus exhibiting a homology of 60% identical amino acids to TipA from Streptomyces lividans.

Acyltransferases↗

PubMed1999

Characterization of IS1676 from Rhodococcus erythropolis SQ1.

To develop a transposable element-based system for mutagenesis in Rhodococcus, we used the sacB gene from Bacillus subtilis to isolate a novel transposable element, IS1676, from R. erythropolis SQ1. This 1693 bp insertion sequence is bounded by imperfect (10 out of 13 bp) inverted repeats and it creates 4 bp direct repeats upon insertion. Comparison of multiple insertion sites reveals a preference for the sequence 5'-(C/T)TA(A/G)-3' in the target site. IS1676 contains a single, large (1446 bp) open reading frame with coding potential for a protein of 482 amino acids. IS1676 may be similar to an ancestral transposable element that gave rise to repetitive sequences identified in clinical isolates of Mycobacterium kansasii. Derivatives of IS1676 should be useful for analysis of Rhodococcus strains, for which few other genetic tools are currently available.

Base Sequence↗

PubMed2002

Recombinant Rhodococcus sp. strain T09 can desulfurize DBT in the presence of inorganic sulfate.

The putative Rhodococcus rrn promoter region was cloned from the benzothiophene desulfurizing Rhodococcus sp. strain T09, and the dibenzothiophene desulfurizing gene, dsz, was expressed under the control of the putative rrn promoter in the strain T09 using a Rhodococcus-E.coli shuttle vector. Strain T09 harboring the expression vector, pNT, could desulfurize dibenzothiophene in the presence of inorganic sulfate, methionine, or cysteine, while the Dsz phenotype was completely repressed in recombinant cells carrying the gene under the control of the native dsz promoter under the same conditions. Among the sulfur sources examined, no intermediates were detected and only the final desulfurized product, 2-hydroxy-biphenyl, was produced using ammonium sulfate as the sulfur source.

Cloning, Molecular↗

PubMed2006

Characterization of Rhodococcus-E. coli shuttle vector pNC9501 constructed from the cryptic plasmid of a propene-degrading bacterium.

Rhodococcus-E. coli shuttle vector pNC9501 was constructed using circular cryptic plasmid pNC903 from propene-degrading Rhodococcus ruber P-II-123-1. Sequence analysis of pNC903 revealed two open-reading frames encoding the replication proteins Reps A and B. In the amino acid sequence of the putative Rep B, a helix-turn-helix motif, which is responsible for the binding of DNA, was found. Sequencing of the upstream region of the putative Rep A and incompatibility tests revealed that pNC903 is a Mycobacterium-derived pAL5000-related plasmid. pNC9501 could also be transformed into Mycobacterium sp. showing good segregation stability (<0.1% plasmid loss/generation) in the absence of selective pressure.

Alkenes↗

PubMed1996

Identification of a Rhodococcus gene cluster encoding a homolog of the 17-kDa antigen of Brucella and a putative regulatory protein of the AsnC-Lrp family.

By sequence analysis, a gene encoding a homolog of the 17-kDa protein antigen of the Gram-negative pathogen Brucella abortus (Hemmen et al., Clin Diagn Lab Immunol 2: 263, 1995) was identified in the nocardioform actinomycete Rhodococcus sp. NI86/21. Database searching also revealed a partial human cDNA sequence for a putative eukaryotic homolog of this presumptive Brucella-specific protein. These proteins display a low but significant level of similarity with lumazine synthases involved in bacterial riboflavin biosynthesis. In the upstream region, a Rhodococcus gene for a putative regulatory protein of the AsnC family is located.

Amino Acid Sequence↗

PubMed1998

Rhodococcus equi and Nocardia brasiliensis infection of the brain and liver in a patient with acute nonlymphoblastic leukemia.

Resolution of neutropenia is usually followed by resolution of fever in patients with febrile neutropenia. However, in some cases fever continues even when the patient is no longer neutropenic. Described here is a case of acute myeloblastic leukemia complicated by brain abscess, pulmonary nodules, and hepatic lesions. The patient's fever had continued after the neutropenia resolved; brain and hepatic cultures grew Rhodococcus equi and Nocardia brasiliensis. Although Rhodococcus infections occur frequently in patients with HIV infection, they are uncommon in patients with acute leukemia.

Actinomycetales Infections↗

PubMed2004

Biodegradation of seven polychlorinated biphenyls by a newly isolated aerobic bacterium (Rhodococcus sp. R04).

An aerobic bacterial strain, designated R04, belonging to the genus Rhodococcus has been isolated and characerized by 16S rDNA analysis. The capability of this strain to degrade seven different polychlorinated biphenyls (CBs), 500 ppm 3-CB, 3,4-CB, 4,4'-CB, 2,4,6-CB, 2,4',5-CB, 2,3,4,5-CB and 3,4,3',4'-CB in liquid medium, was evaluated. After 5 days of incubation, the concentration of chloride increased to 0.35 mM in cultures containing 3-CB and R04, whereas in cultures with 3,4-CB, 2,3,4,5-CB or 3,4,3',4'-CB plus R04 the chloride content increased to 0.1 mM. However, non-stoichiometric amounts of chloride were produced in cultures with R04 and 4,4'-CB, 2,4,6-CB and 2,4',5-CB. The spectrum of supernatants from R04 grown on seven PCBs had a UV-visible (UV-VIS) absorption at 200-500 nm, characteristic of biphenyl-derived cleavage products. Gas-chromatographic (GC) analysis showed that R04 was able to transform 100% of 3-CB and 3,4-CB after 1 day of incubation, and 95% of 4,4'-CB, 2,4,6-CB, 2,4',5-CB, 2,3,4,5-CB and 3,4,3',4'-CB after 5 days of incubation. The position of the chlorine substituents on the rings strongly influenced the degradation of polychlorinated biphenyls (PCBs) and their intermediate metabolites by Rhodococcus sp. R04. The degradation of PCBs was further evaluated by monitoring intermediate metabolites of PCBs.

Biodegradation, Environmental↗

PubMed2026

The removal of iron and phosphate from culture medium by Rhodococcus ruber SiAl.

The microbial accumulation of heavy metals and phosphate is of interest for the bioremediation of polluted waters. In this work, we showed that at cultivation of the bacterium Rhodococcus ruber SiAl in the medium with 2.0 mM Fe³⁺ for stationary growth stage, up to 99% of the iron was associated with the biomass. Magnesium ion accumulation from the medium with 2 mM Mg²⁺ did not exceed 5% of the initial content. The cells did not remove manganese ions from the medium; moreover, the presence of MnSO4 inhibited growth. The cells of Rhodococcus ruber SiAl removed phosphate from the medium: 75, 20, and 10% of the initial phosphate content was removed during cultivation in the presence of 6 mM phosphate and 2 mM Fe³⁺, 2 mM Mg²⁺, or 2 mM Mn²⁺, respectively. In the genome of R. ruber SiAl, genes encoding proteins of the siderophore synthesis systems and phosphate transport systems were identified. The strain was the most efficient for iron accumulation, which suggests a promising application for the removal of phosphate and iron from polluted waters.

Rhodococcus ruber↗

PubMed1993

Major structural features of the cell wall arabinogalactans of Mycobacterium, Rhodococcus, and Nocardia spp.

The cell wall arabinogalactans of strains of Mycobacterium, Rhodococcus, and Nocardia were per-O-methylated, partially hydrolyzed with acid, and the resulting oligosaccharides were reduced and per-O-ethylated to yield per-O-alkylated oligoglycosyl alditol fragments. Analyses of these fragments by gas chromatography-mass spectrometry and of the intact solubilized polysaccharides by 1H and 13C NMR revealed the major structural features of the different arabinogalactans from representatives of the different genera. All of the mycobacterial products contained a homogalactan segment of alternating 5-linked alpha-galactofuranosyl (Galf) and 6-linked beta-Galf residues. The arabinan segment consisted of three major domains, linear 5-linked alpha-arabinofuranosyl (Araf) residues and branched (3-->5)-linked Araf units substituted with either 5-linked Araf or the disaccharide beta-Araf-(1-->2)-alpha-Araf at both branched positions. The recognition of these features in in vivo grown Mycobacterium leprae is an important development. The arabinan from strains of Nocardia contains a nonreducing-end motif composed of the linear trisaccharide, beta-Araf-(1-->2)-alpha-Araf-(1-->5)-Araf, attached to linear 5-linked alpha-Araf units. The galactan segment of the arabinogalactan of Nocardia sp. is composed of linear 5-linked beta-Galf units substituted in part at O-6 with terminal beta-glucosyl units. The two representative strains of Rhodococcus also differed in the composition of the galactan moiety; in addition to the 5-linked Galf, 2- and 3-linked beta-Galf units are present. The reducing end of the galactans, and therefore, apparently, of the entire arabinogalactans from all species from all genera, are apparently composed of the unit, rhamnosyl-(1-->3)-N-acetyl-glucosamine, which, in turn, is apparently attached to peptidoglycan via phosphodiester linkage.

Actinomycetales↗

PubMed1991

A case of Rhodococcus equi brain abscess.

We treated a patient with acquired immunodeficiency syndrome for a brain abscess caused by Rhodococcus equi, an actinomycete that usually infects the lung in immunosuppressed hosts. Rhodococcus equi brain abscess is an extremely rare lesion that has never been reported in a patient with acquired immunodeficiency syndrome. The infection was cured by lengthy therapy with multiple antibiotics after aspiration of the lesion to identify the infective organism and determine its sensitivity to antibiotics.

Acquired Immunodeficiency Syndrome↗