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1.
PLoS One ; 16(11): e0260032, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34793540

RESUMEN

The article expands our knowledge on the variety of biodegraders of ibuprofen, one of the most frequently detected non-steroidal anti-inflammatory drugs in the environment. We studied the dynamics of ibuprofen decomposition and its relationship with the physiological status of bacteria and with additional carbon and energy sources. The involvement of cytoplasmic enzymes in ibuprofen biodegradation was confirmed. Within the tested actinobacteria, Rhodococcus cerastii IEGM 1278 was capable of complete oxidation of 100 µg/L and 100 mg/L of ibuprofen in 30 h and 144 h, respectively, in the presence of an alternative carbon source (n-hexadecane). Besides, the presence of ibuprofen induced a transition of rhodococci from single- to multicellular lifeforms, a shift to more negative zeta potential values, and a decrease in the membrane permeability. The initial steps of ibuprofen biotransformation by R. cerastii IEGM 1278 involved the formation of hydroxylated and decarboxylated derivatives with higher phytotoxicity than the parent compound (ibuprofen). The data obtained indicate potential threats of this pharmaceutical pollutant and its metabolites to biota and natural ecosystems.


Asunto(s)
Ibuprofeno/toxicidad , Rhodococcus/metabolismo , Actinobacteria/efectos de los fármacos , Actinobacteria/metabolismo , Alcanos , Antiinflamatorios no Esteroideos , Biodegradación Ambiental/efectos de los fármacos , Biotransformación , Carbono , Ecosistema , Contaminantes Ambientales/toxicidad , Hidroxilación , Ibuprofeno/farmacología , Oxidación-Reducción , Rhodococcus/efectos de los fármacos
2.
ACS Synth Biol ; 10(9): 2383-2395, 2021 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-34428025

RESUMEN

The development of microbial cell factories requires robust synthetic biology tools to reduce design uncertainty and accelerate the design-build-test-learn process. Herein, we developed a suite of integrative genetic tools to facilitate the engineering of Rhodococcus, a genus of bacteria with considerable biocatalytic potential. We first created pRIME, a modular, copy-controlled integrative-vector, to provide a robust platform for strain engineering and characterizing genetic parts. This vector was then employed to benchmark a series of strong promoters. We found PM6 to be the strongest constitutive rhodococcal promoter, 2.5- to 3-fold stronger than the next in our study, while overall promoter activities ranged 23-fold between the weakest and strongest promoters during exponential growth. Next, we used an optimized variant of PM6 to develop hybrid-promoters and integrative vectors to allow for tetracycline-inducible gene expression in Rhodococcus. The best of the resulting hybrid-promoters maintained a maximal activity of ∼50% of PM6 and displayed an induction factor of ∼40-fold. Finally, we developed and implemented a uLoop-derived Golden Gate assembly strategy for high-throughput DNA assembly in Rhodococcus. To demonstrate the utility of our approaches, pRIME was used to engineer Rhodococcus jostii RHA1 to grow on vanillin at concentrations 10-fold higher than what the wild-type strain tolerated. Overall, this study provides a suite of tools that will accelerate the engineering of Rhodococcus for various biocatalytic applications, including the sustainable production of chemicals from lignin-derived aromatics.


Asunto(s)
Ingeniería Metabólica/métodos , Rhodococcus/metabolismo , Aldehído Oxidorreductasas/genética , Aldehído Oxidorreductasas/metabolismo , Proteínas Bacterianas/genética , Benzaldehídos/farmacología , Biblioteca de Genes , Plásmidos/genética , Plásmidos/metabolismo , Regiones Promotoras Genéticas , Rhodococcus/efectos de los fármacos , Rhodococcus/crecimiento & desarrollo
3.
Braz J Microbiol ; 52(3): 1405-1415, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33956334

RESUMEN

We present a new methodological approach for the assessment of the susceptibility of Rhodococcus erythropolis strains from specific sampling sites in response to increasing heavy metal concentration (Cu2+, Ni2+, and Co2+) using the droplet-based microfluid technique. All isolates belong to the species R. erythropolis identified by Sanger sequencing of the 16S rRNA. The tiny step-wise variation of metal concentrations from zero to the lower mM range in 500 nL droplets not only provided accurate data for critical metal ion concentrations but also resulted in a detailed visualization of the concentration-dependent response of bacterial growth and autofluorescence activity. As a result, some of the isolates showed similar characteristics in heavy metal tolerance against Cu2+, Ni2+, and Co2+. However, significantly different heavy metal tolerances were found for other strains. Surprisingly, samples from the surface soil of ancient copper mining areas supplied mostly strains with a moderate sensitivity to Cu2+, Ni2+, and Co2+, but in contrast, a soil sample from an excavation site of a medieval city that had been covered for about eight centuries showed an extremely high tolerance against cobalt ion (up to 36 mM). The differences among the strains not only may be regarded as results of adaptation to the different environmental conditions faced by the strains in nature but also seem to be related to ancient human activities and temporal partial decoupling of soil elements from the surface. This investigation confirmed that microfluidic screening offers empirical characterization of properties from same species which has been isolated from sites known to have different human activities in the past.


Asunto(s)
Metales Pesados , Rhodococcus/metabolismo , Contaminantes del Suelo , Monitoreo del Ambiente , Metales Pesados/análisis , Microfluídica , ARN Ribosómico 16S/genética , Rhodococcus/efectos de los fármacos , Suelo , Contaminantes del Suelo/análisis
4.
FEMS Microbiol Lett ; 368(9)2021 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-33974050

RESUMEN

Rhodococcus spp. have broad potential applications related to the degradation of organic contaminants and the transformation or synthesis of useful compounds. However, some Gram-positive bacteria are difficult to manipulate genetically due to low transformation efficiency. In this study, we investigated the effects of chemicals including glycine, isonicotinic acid hydrazide (INH), Tween 80 and penicillin G, as well as cell growth status, competent cell concentration, electroporation field strength, electroporation time and heat shock time, on the electrotransformation efficiency of the tetrahydrofuran-degrading bacterium Rhodococcus ruber YYL with low transformation efficiency. The highest electrotransformation efficiency was 1.60 × 106 CFU/µg DNA after parameter optimization. GmhD (D-glycero-D-manno-heptose 1-phosphate guanosyltransferase) gene, which is important in the biosynthesis of lipopolysaccharide, was deleted via the optimized electrotransformation method. Compared with wild-type strain, YYL ΔgmhD showed extremely high electrotransformation efficiency because the surface of it had no mushroom-like extracellular polymeric substances (EPS). In addition, the results showed that cell wall-weakening reagents might cause some translucent substances like EPS, to detach from the cells, increasing the electrotransformation efficiency of strain YYL. We propose that these results could provide a new strategy for unique bacteria that are rich in EPS, for which genetic manipulation systems are difficult to establish.


Asunto(s)
Electroporación/métodos , Rhodococcus/genética , Rhodococcus/metabolismo , Pared Celular , ADN Bacteriano/genética , Matriz Extracelular de Sustancias Poliméricas , Glicina/farmacología , Isoniazida/farmacología , Penicilina G/farmacología , Polisorbatos/farmacología , Rhodococcus/efectos de los fármacos , Rhodococcus/crecimiento & desarrollo , Transformación Bacteriana
5.
Int J Mol Sci ; 22(9)2021 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-33925499

RESUMEN

The paper presents a study of the effect of chemically synthesized selenium nanocomposites (Se NCs) in natural polymer matrices arabinogalactan (AG) and starch (ST) on the viability of the potato ring rot pathogen Clavibacter sepedonicus (Cms), potato plants in vitro, and the soil bacterium Rhodococcus erythropolis. It was found that the studied Se NCs have an antibacterial effect against the phytopathogenic Cms, reducing its growth rate and ability to form biofilms. It was revealed that Se NC based on AG (Se/AG NC) stimulated the growth and development of potato plants in vitro as well as their root formation. At the same time, Se did not accumulate in potato tissues after the treatment of plants with Se NCs. The safety of the Se NCs was also confirmed by the absence of a negative effect on the growth and biofilm formation of the soil bacterium R. erythropolis. The obtained results indicate that Se NCs are promising environmentally safe agents for the protection and recovery of cultivated plants from phytopathogenic bacteria.


Asunto(s)
Clavibacter/efectos de los fármacos , Nanocompuestos/química , Selenio/farmacología , Solanum tuberosum/microbiología , Antibacterianos/química , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Clavibacter/patogenicidad , Galactanos/química , Microscopía Electrónica de Transmisión , Enfermedades de las Plantas/microbiología , Rhodococcus/efectos de los fármacos , Rhodococcus/fisiología , Selenio/química , Selenio/farmacocinética , Microbiología del Suelo , Solanum tuberosum/efectos de los fármacos , Solanum tuberosum/crecimiento & desarrollo , Espectrometría por Rayos X , Almidón/química
6.
Dokl Biochem Biophys ; 492(1): 117-120, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32632586

RESUMEN

We studied the effect of acrylamide on the content of intracellular ATP in the cells of bacteria of the genera Rhodococcus and Alcaligenes, the luminescence of the genetically engineered strain Escherichia coli K12 TG1 (pXen7), and the survival of bacteria of various systematic groups. According to the level of decrease in the concentration of intracellular ATP, it was found that the strain with lower amidase activity (R. erythropolis 6-21) and Gram-negative proteobacteria A. faecalis 2 were the most sensitive to acrylamide after a 20-min exposure, while the strain R. ruber gt 1 was stable, having a high nitrile hydratase activity in combination with a low amidase activity. EC50 of acrylamide for 2 h was 7.1 g/L for E. coli K12 TG1 (pXen7). Acrylamide at a concentration of 10-20 mM added to the culture medium led to a slight decrease in the number of CFUs of Rhodococcus, A. faecalis 2, and E. coli compared to the control. At an acrylamide concentration of 250 mM, from 0.016 to 0.116% of viable bacterial cells remained, and a solution of 500 mM and higher inhibited the growth of the majority of the studied strains. The results confirm that acrylamide is much less toxic to prokaryotes than to eukaryotes.


Asunto(s)
Acrilamida/toxicidad , Adenosina Trifosfato/metabolismo , Alcaligenes/crecimiento & desarrollo , Amidohidrolasas/metabolismo , Escherichia coli/crecimiento & desarrollo , Hidroliasas/metabolismo , Rhodococcus/crecimiento & desarrollo , Alcaligenes/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Rhodococcus/efectos de los fármacos
7.
Braz J Microbiol ; 51(3): 1317-1326, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32399689

RESUMEN

Bacterial adhesion on surfaces is an essential initial step in promoting bacterial mobilization for soil bioremediation process. Modification of the cell surface is required to improve the adhesion of bacteria. The modification of physicochemical properties by rhamnolipid to Pseudomonas putida KT2442, Rhodococcus erythropolis 3586 and Aspergillus brasiliensis ATCC 16404 strains was analysed using contact angle measurements. The surface energy and total free energy of adhesion were calculated to predict the adhesion of both bacteria strains on the A. brasiliensis surface. The study of bacterial adhesion was carried out to evaluate experimental value with the theoretical results. Bacteria and fungi physicochemical properties were modified significantly when treated with rhamnolipid. The adhesion rate of P. putida improved by 16% with the addition of rhamnolipid (below 1 CMC), while the increase of rhamnolipid concentration beyond 1 CMC did not further enhance the bacterial adhesion. The addition of rhamnolipid did not affect the adhesion of R. erythropolis. A good relationship has been obtained in which water contact angle and surface energy of fungal surfaces are the major factors contributing to the bacterial adhesion. The adhesion is mainly driven by acid-base interaction. This finding provides insight to the role of physicochemical properties in controlling the bacterial adhesion on the fungal surface to enhance bacteria transport in soil bioremediation.


Asunto(s)
Aspergillus/efectos de los fármacos , Glucolípidos/farmacología , Interacciones Microbianas/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Rhodococcus/efectos de los fármacos , Aspergillus/fisiología , Adhesión Bacteriana/efectos de los fármacos , Pseudomonas aeruginosa/fisiología , Rhodococcus/fisiología
8.
Metallomics ; 12(1): 8-11, 2020 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-31913381

RESUMEN

After exposure to micron-sized TiO2 particles, anatase and/or rutile, Rhodococcus ruber GIN-1 accumulates an increased concentration (2.2 ± 0.2 mg kg-1) of mobilized Ti into its biomass with concomitant decreases in cellular biometals Fe, Zn, and possibly Mn, while levels of Cu and Al are unaffected.


Asunto(s)
Rhodococcus/efectos de los fármacos , Rhodococcus/metabolismo , Titanio/farmacología , Elementos de Transición/metabolismo , Aluminio/metabolismo , Biomasa , Cobre/metabolismo , Hierro/metabolismo , Manganeso/metabolismo , Zinc/metabolismo
9.
ACS Appl Mater Interfaces ; 11(42): 38519-38530, 2019 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-31609105

RESUMEN

We fabricated surface-rough mesoporous silica nanoparticles ("ghost" SiO2NPs) by using composite mesoporous copper oxide nanoparticles ("host" CuONPs) as templates, which allowed us to mimic their surface morphology. The "host" CuONPs used here as templates, however, had a very high antibacterial effect, with or without functionalization. To evaluate the surface roughness effect on the "ghost" SiO2NPs antibacterial action, we functionalized them with (3-glycidyloxypropyl)trimethoxysilane (GLYMO) to permit additional covalent coupling of 4-hydroxyphenylboronic acid (4-HPBA). The diol groups on the bacterial membrane can form reversible covalent bonds with boronic acid (BA) groups on the "ghost" SiO2NPs surface and bind to the bacteria, resulting in a very strong amplification of their antibacterial activity, which does not depend on electrostatic adhesion. The BA-functionalized "ghost" SiO2NPs showed a very significant antibacterial effect as compared to smooth SiO2NPs of the same surface coating and particle size. We attribute this to the "ghost" SiO2NPs mesoporous surface morphology, which mimics to a certain extent those of the original mesoporous CuONPs used as templates for their preparation. We envisage that the "ghost" SiO2NPs effectively acquire some of the antibacterial properties from the "host" CuONPs, with the same functionality, despite being completely free of copper. The antibacterial effect of the functionalized "ghost" SiO2NPs/GLYMO/4-HPBA on Rhodococcus rhodochrous (R. rhodochrous) and Escherichia coli (E. coli) is much higher than that of the nonfunctionalized "ghost" SiO2NPs or the "ghost" SiO2NPs/GLYMO. The results indicate that the combination of rough surface morphology and strong adhesion of the particle surface to the bacteria can make even benign material such as silica act as a strong antimicrobial agent. Additionally, our BA-functionalized nanoparticles ("ghost" SiO2NPs/GLYMO/4-HPBA) showed no detectable cytotoxic impact against human keratinocytes at particle concentrations, which are effective against bacteria.


Asunto(s)
Nanopartículas/química , Dióxido de Silicio/química , Ácidos Borónicos/química , Línea Celular , Supervivencia Celular/efectos de los fármacos , Cobre/química , Escherichia coli/efectos de los fármacos , Humanos , Nanopartículas/toxicidad , Rhodococcus/efectos de los fármacos , Silanos/química , Propiedades de Superficie , Rayos Ultravioleta
10.
World J Microbiol Biotechnol ; 35(11): 164, 2019 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-31637528

RESUMEN

Odd-chain fatty acids (OCFAs) have been reported to possess pharmacological activity and have been used in the manufacture of agricultural and industrial chemicals. We here provided a new method to increase the OCFAs content in oil produced by Rhodococcus opacus PD630 through addition of 1-propanol to the fermentation media. The OCFAs in oil of R. opacus PD630 are primarily pentadecanoic acid (C15:0), heptadecanoic acid (C17:0) and heptadecenoic acid (C17:1). After adding 0.5-1.5% (v/v) 1-propanol, the production of oil increased from 1.27 g/L to 1.31-1.61 g/L, and the OCFAs content in oil increased by 46.7-55.1%. Metabolic intermediates determination and transcriptome analysis revealed that R. opacus assimilated 1-propanol through methylmalonyl-CoA pathway. When the nitrogen source was limited, propionyl-CoA was converted to propionyl-acyl carrier protein (ACP) which could be used as primer during the elongation of fatty acid synthesis. Then OCFAs were produced when odd number of propionyl-ACP was incorporated in the cycles of fatty acid synthesis.


Asunto(s)
1-Propanol/farmacología , Ácidos Grasos/biosíntesis , Rhodococcus/efectos de los fármacos , Rhodococcus/metabolismo , 1-Propanol/metabolismo , Acilcoenzima A , Alcoholes/farmacología , Biomasa , Ácidos Grasos/metabolismo , Ácidos Grasos Monoinsaturados/metabolismo , Fermentación , Redes y Vías Metabólicas , Rhodococcus/crecimiento & desarrollo , Transcriptoma
11.
Photochem Photobiol Sci ; 18(7): 1700-1708, 2019 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-31214675

RESUMEN

The ever growing world-population poses challenges concerning the need for more food free of pesticide residues. The most common means to control plant pathogens is through the application of pesticides, which raises concerns over safety for humans and the environment. Recently, Photodynamic Inactivation (PDI) of microorganisms using natural photosensitizers has shown itself to be a powerful tool to combat bacteria and fungi. This study investigates the efficacy of PDI against the Gram(+) bacterial plant pathogen Rhodococcus fascians and Gram(-) Xanthomonas axonopodis and Erwinia amylovora using two chlorin e6 derivatives as photosensitizers: anionic sodium magnesium chlorophyllin (Chl, approved as food additive E140) in combination with cell wall permeabilizing agents (Na2EDTA or Polyaspartic acid sodium salt (PA)) and B17-0024, a mixture of chlorin e6 derivatives with cationic moieties at physiological pH. Both photosensitizers show excellent efficacy against R. fascians, whereby B17-0024 is phototoxic at a one order of magnitude lower concentration than Chl (10 µM B17-0024: relative inactivation (r.i.) >7.5 × 106, 100 µM Chl: r.i. 2.2 × 106, illumination with 26.6 J cm-2, 395 nm). The phototreatment of Gram(-) bacteria with Chl requires the obligatory use of cell wall permeabilizing agents like Na2EDTA (X. axonopodis) or PA (E. amylovora) to induce significant killing (more than 7 log units at 100 µM). On the other hand, B17-0024 proves to be a highly effective photosensitizer inducing bacterial inactivation at very low concentrations (10 µM for R. fascians and X. axonopodis, 100 µM for E. amylovora) without additives. In summary, PDI using both the natural photosensitizer Chl in combination with cell wall permeabilizing agents is effective and environmentally friendly. As an alternative, B17-0024 is highly photoactive against all model strains tested - even without cell wall permeabilizing agents. The photodynamic approach based on chlorin e6 derivatives should add to the growers' toolbox as a preferred alternative for the control of phytopathogens.


Asunto(s)
Productos Agrícolas/microbiología , Erwinia amylovora/efectos de la radiación , Luz , Rhodococcus/efectos de la radiación , Xanthomonas axonopodis/efectos de la radiación , Pared Celular/efectos de los fármacos , Pared Celular/metabolismo , Clorofilidas , Erwinia amylovora/efectos de los fármacos , Péptidos/química , Péptidos/farmacología , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacología , Porfirinas/química , Porfirinas/farmacología , Especies Reactivas de Oxígeno/metabolismo , Rhodococcus/efectos de los fármacos , Xanthomonas axonopodis/efectos de los fármacos
12.
Plant Mol Biol ; 101(1-2): 95-112, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31236845

RESUMEN

KEY MESSAGE: Sorghum glycine rich proline rich protein (SbGPRP1) exhibit antimicrobial properties and play a crucial role during biotic stress condition. Several proteins in plants build up the innate immune response system in plants which get triggered during the occurrence of biotic stress. Here we report the functional characterization of a glycine-rich proline-rich protein (SbGPRP1) from Sorghum which was previously demonstrated to be involved in abiotic stresses. Expression studies carried out with SbGPRP1 showed induced expression upon application of phytohormones like salicylic acid which might be the key in fine-tuning the expression level. Upon challenging the Sorghum plants with a compatible pathogen the SbGprp1 transcript was found to be upregulated. SbGPRP1 encodes a 197 amino acid polypeptide which was bacterially-expressed and purified for in vitro assays. Gram-positive bacteria like Bacillus and phytopathogen Rhodococcus fascians showed inhibited growth in the presence of the protein. The NPN assay, electrolytic leakage and SEM analysis showed membrane damage in bacterial cells. Ectopic expression of SbGPRP1 in tobacco plants led to enhanced tolerance towards infection caused by R. fascians. Though the N-terminal part of the protein showed disorderness the C-terminal end was quite capable of forming several α-helices which was correlated with CD spectroscopic analysis. Here, we have tried to determine the structural model for the protein and predicted the association of antimicrobial activity with the C-terminal region of the protein.


Asunto(s)
Antiinfecciosos/metabolismo , Enfermedades de las Plantas/inmunología , Reguladores del Crecimiento de las Plantas/farmacología , Proteínas de Plantas/metabolismo , Ácido Salicílico/farmacología , Sorghum/genética , Bacillus/efectos de los fármacos , Expresión Génica Ectópica , Glicina/metabolismo , Filogenia , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/genética , Prolina/metabolismo , Rhodococcus/efectos de los fármacos , Sorghum/inmunología , Sorghum/metabolismo , Sorghum/microbiología , Estrés Fisiológico , Nicotiana/genética , Nicotiana/inmunología , Nicotiana/metabolismo , Nicotiana/microbiología
13.
Sci Rep ; 9(1): 9159, 2019 06 24.
Artículo en Inglés | MEDLINE | ID: mdl-31235798

RESUMEN

This study investigated the ability of rhodococci to biodegrade diclofenac (DCF), one of the polycyclic non-steroidal anti-inflammatory drugs (NSAIDs) most frequently detected in the environment. Rhodococcus ruber strain IEGM 346 capable of complete DCF biodegradation (50 µg/L) over 6 days was selected. It is distinguished by the ability to degrade DCF at high (50 mg/L) concentrations unlike other known biodegraders. The DCF decomposition process was accelerated by adding glucose and due to short-term cell adaptation to 5 µg/L DCF. The most typical responses to DCF exposure observed were the changed ζ-potential of bacterial cells; increased cell hydrophobicity and total cell lipid content; multi-cellular conglomerates formed; and the changed surface-to-volume ratio. The obtained findings are considered as mechanisms of rhodococcal adaptation and hence their increased resistance to toxic effects of this pharmaceutical pollutant. The proposed pathways of bacterial DCF metabolisation were described. The data confirming the C-N bond cleavage and aromatic ring opening in the DCF structure were obtained.


Asunto(s)
Diclofenaco/metabolismo , Rhodococcus/metabolismo , Contaminantes Químicos del Agua/metabolismo , Biodegradación Ambiental , Diclofenaco/química , Diclofenaco/toxicidad , Relación Dosis-Respuesta a Droga , Farmacorresistencia Bacteriana , Interacciones Hidrofóbicas e Hidrofílicas , Rhodococcus/efectos de los fármacos , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/toxicidad
14.
Microbiologyopen ; 8(9): e00855, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31119875

RESUMEN

In this study, we compared the expression of CYP153, sodA, sodC, and recA genes and ROS generation in hydrocarbon-degrading Rhodococcus erythropolis in the presence of cyclohexane, naphthalene, and diesel fuel. The expression of cytochrome P450, sodA (encoding Fe/Mn superoxide dismutase), recA, and superoxide anion radical generation rate increased after the addition of all studied hydrocarbons. The peak of CYP153, sodA, and recA gene expression was registered in the presence of naphthalene. The same substrate upregulated the Cu/Zn superoxide dismutase gene, sodC. Cyclohexane generated the highest level of superoxide anion radical production. Hydrogen peroxide accumulated in the medium enriched with diesel fuel. Taken together, hydrocarbon biotransformation leads to oxidative stress and upregulation of antioxidant enzymes and CYP153 genes, and increases DNA reparation levels in R. erythropolis cells.


Asunto(s)
Ciclohexanos/toxicidad , Gasolina/toxicidad , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Naftalenos/toxicidad , Estrés Oxidativo , Rhodococcus/efectos de los fármacos , Rhodococcus/metabolismo , Proteínas Bacterianas/biosíntesis , Proteínas Bacterianas/genética , Biotransformación , Ciclohexanos/metabolismo , Perfilación de la Expresión Génica , Naftalenos/metabolismo , Especies Reactivas de Oxígeno/análisis
15.
J Biotechnol ; 297: 1-8, 2019 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-30853637

RESUMEN

Rhodococcus opacus PD630 was used to produce biomass and lipids in molasses-based media with and without osmotic stress. In a 7-day aerobic batch culture at 30 °C, the biomass and lipid concentrations were maximized using an initial molasses concentration of 80 g/L and ammonium acetate (nitrogen source) concentration of 2.14 g/L. At a fixed initial molasses concentration of 80 g/L, the concentration of the nitrogen source was further fine-tuned to 2.25 g/L, to maximize the lipid content of the biomass to around 30% by dry mass. This medium was used to test the effects of stressing salts (sodium acetate, magnesium sulfate, sodium chloride) on production of lipids and biomass. A two-step bolus feeding with magnesium sulfate and sodium acetate, enhanced the final biomass concentration to around 19 g/L (a 50% increase relative to control), but the lipid content in the biomass was reduced to around 16% w/w. A 33% enhancement in lipid concentration relative to control, was achieved by feeding magnesium sulfate and sodium acetate. Sugarcane molasses could be effectively used to produce biomass and lipids instead of using the much more expensive pure carbon sources such as glucose and sucrose.


Asunto(s)
Biomasa , Medios de Cultivo/química , Lípidos/biosíntesis , Melaza , Presión Osmótica , Rhodococcus/metabolismo , Acetatos/farmacología , Sulfato de Magnesio/farmacología , Presión Osmótica/efectos de los fármacos , Rhodococcus/efectos de los fármacos , Sales (Química)/farmacología , Factores de Tiempo
16.
Ecotoxicol Environ Saf ; 169: 282-291, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30458394

RESUMEN

To reveal the molecular mechanism at the level of regulation of proteins in Rhodococcus sp. BAP-1 induced by fluoranthene comparative proteomic analysis was performed on proteins extracted from fluoranthene-exposed cells on 1 d, 3 d, 6 d and 8 d compared with control cells using isobaric tags for relative and absolute quantization (iTRAQ) labeling and LC-MS/MS analysis to access differentially expressed proteins. As a result, we detected a total of 897 significantly differentially expressed proteins, including 30 shared proteins in four comparison clusters. We were able to short-list 190, 329, 101 and 90 proteins that were over-represented, and 394, 234, 65 and 49 under-represented proteins, in 1d/control, 3d/control, 6d/control and 8d/control comparisons, respectively. Functional analysis relied on Clusters of Orthologous Groups (COG), gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that fluoranthene significantly altered the expression of proteins involved in metabolic and biosynthesis processes. Furthermore, BAP-1 up-regulates aldehyde dehydrogenase, cytochrome c oxidase, and oligopeptide transport ATP-binding protein, while down-regulates several other proteins in order to adapt to fluoranthene exposure. These findings provide important clues to reveal fluoranthene degradation mechanism in BAP-1 and promote its bioremediation applications.


Asunto(s)
Proteínas Bacterianas/biosíntesis , Contaminantes Ambientales/toxicidad , Fluorenos/toxicidad , Proteómica/métodos , Rhodococcus/efectos de los fármacos , Proteínas Bacterianas/metabolismo , Biodegradación Ambiental , Análisis por Conglomerados , Regulación hacia Abajo , Rhodococcus/crecimiento & desarrollo , Rhodococcus/metabolismo , Transducción de Señal , Regulación hacia Arriba
17.
J Antibiot (Tokyo) ; 72(2): 71-78, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30410008

RESUMEN

Coptidis rhizome (CR) is a widely used herbal medicine that contains protoberberine-type alkaloids. CR extract exhibits various pharmacologic activities. A previous study reported the isolation of Rhodococcus sp. strain BD7100 as a berberine (BBR)-utilizing bacterium, and the BBR-degradation pathway has been investigated. When we incubated strain BD7100 cells with CR extract, the number of viable cells declined with the degradation of components in the CR extract, and the culture broth exhibited antibacterial activity against strain BD7100. These results suggest that CR extract cultured in the presence of strain BD7100 contains one or more antibacterial agents. In this study, we isolated coptirhoquinone A (1) from CR extract incubated with strain BD7100 in Luria-Bertani (LB) medium, and the structure was elucidated using NMR and MS analysis. We also report the total synthesis and antimicrobial activities of 1 against bacteria, fungi, and Pythium sp.


Asunto(s)
Antibacterianos/farmacología , Medicamentos Herbarios Chinos/farmacología , Rhodococcus/crecimiento & desarrollo , Rhodococcus/metabolismo , Antibacterianos/química , Antifúngicos/farmacología , Antiprotozoarios/farmacología , Berberina/metabolismo , Coptis chinensis , Medicamentos Herbarios Chinos/química , Hongos/efectos de los fármacos , Extractos Vegetales/química , Extractos Vegetales/farmacología , Pythium/efectos de los fármacos , Quinonas/química , Quinonas/aislamiento & purificación , Quinonas/farmacología , Rhodococcus/efectos de los fármacos
18.
Biosci Biotechnol Biochem ; 83(4): 768-773, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30572801

RESUMEN

Rhodococcus sp. 2N was found as a 1,3-propanediols-oxidizing strain from soil samples through enrichment culture using 2,2-diethyl-1,3-propanediol (DEPD) as the sole carbon source. The culture condition of the strain 2N was optimized, and the highest activity was observed when 0.3% (w/v) DEPD was added in the culture medium as an inducer. Chiral HPLC analysis of the hydroxyalkanoic acid converted from 2-ethyl-2-methyl-1,3-propanediol (EMPD) revealed that the strain 2N catalyzed the (R)-selective oxidation of EMPD. The reaction products and intermediates from DEPD and EMPD were identified by nuclear magnetic resonance analyses, and the results suggested that only one hydroxymethyl group of the propanediols was converted to carboxy group via two oxidation steps. Under optimized conditions and after a 72-h reaction time, the strain 2N produced 28 mM (4.1 g/L) of 2-(hydroxymethyl)-2-methylbutanoic acid from EMPD with a molar conversion yield of 47% and 65% ee (R).


Asunto(s)
Butiratos/metabolismo , Glicoles de Propileno/metabolismo , Rhodococcus/metabolismo , Biodegradación Ambiental , Butiratos/química , Medios de Cultivo/química , Medios de Cultivo/farmacología , Cinética , Espectroscopía de Resonancia Magnética , Oxidación-Reducción , Glicoles de Propileno/química , Rhodococcus/química , Rhodococcus/efectos de los fármacos
19.
PLoS One ; 13(12): e0209275, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30592730

RESUMEN

Complete genome sequencing of dozens of strains of the soil bacterium Rhodococcus has revealed the presence of many cryptic biosynthetic gene clusters, presumably dedicated to the production of small molecules. This has sparked a renewed interest in this underexplored member of the Actinobacteria as a potential source of new bioactive compounds. Reported here is the discovery of a potent inhibitory molecule produced by a newly isolated strain of Rhodococcus, strain MTM3W5.2. This small inhibitory molecule shows strong activity against all Rhodococcus species tested, including the veterinary pathogen R. equi, and some closely related genera. It is not active against other Gram positive or Gram negative bacteria. A screen of random transposon mutants identified a gene required to produce this inhibitory compound. This gene is a large multi-domain, type I polyketide synthase that is part of a very large multi-gene biosynthetic gene cluster in the chromosome of strain MTM3W5.2. The high resolution mass spectrum of a major chromatogram peak from a broth culture extract of MTM3W5.2 shows the presence of a compound at m/z 911.5490 atomic mass units. This compound is not detected in the culture extracts from a non-producing mutant strain of MTM3W5.2. A large gene cluster containing at least 14 different type I polyketide synthase genes is proposed to be required to synthesize this antibiotic-like compound.


Asunto(s)
Antibacterianos/farmacología , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/farmacología , Rhodococcus/efectos de los fármacos , Rhodococcus/metabolismo , Infecciones por Actinomycetales/tratamiento farmacológico , Antibacterianos/aislamiento & purificación , Antibacterianos/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/aislamiento & purificación , Elementos Transponibles de ADN , Genoma Bacteriano , Mutación , Rhodococcus/genética , Rhodococcus/aislamiento & purificación , Suelo
20.
Appl Microbiol Biotechnol ; 102(23): 10055-10065, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30244278

RESUMEN

Nitrilases are of commercial interest in the selective synthesis of carboxylic acids from nitriles. Nitrilase induction was achieved here in three bacterial strains through the incorporation of a previously unrecognised and inexpensive nitrilase inducer, dimethylformamide (DMF), during cultivation of two Rhodococcus rhodochrous strains (ATCC BAA-870 and PPPPB BD-1780), as well as a closely related organism (Pimelobacter simplex PPPPB BD-1781). Benzonitrile, a known nitrilase inducer, was ineffective in these strains. Biocatalytic product profiling, enzyme inhibition studies and protein sequencing were performed to distinguish the nitrilase activity from that of sequential nitrile hydratase-amidase activity. The expressed enzyme, a 40-kDa protein with high sequence similarity to nitrilase protein Uniprot Q-03217, hydrolyzed 3-cyanopyridine to produce nicotinic acid exclusively in strains BD-1780 and BD-1781. These strains were capable of synthesising both the vitamin nicotinic acid as well as ß-amino acids, a compound class of pharmaceutical interest. The induced nitrilase demonstrated high enantioselectivity (> 99%) in the hydrolysis of 3-amino-3-phenylpropanenitrile to the corresponding carboxylic acid.


Asunto(s)
Aminohidrolasas/biosíntesis , Dimetilformamida/farmacología , Rhodococcus/metabolismo , Biocatálisis , Ácidos Carboxílicos/metabolismo , Inducción Enzimática , Hidrólisis , Microbiología Industrial , Estructura Molecular , Niacina/metabolismo , Nitrilos/farmacología , Piridinas/metabolismo , Rhodococcus/efectos de los fármacos , Espectrometría de Masas en Tándem
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