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1.
Beijing Da Xue Xue Bao Yi Xue Ban ; 53(5): 964-969, 2021 Oct 18.
Artigo em Chinês | MEDLINE | ID: mdl-34650303

RESUMO

OBJECTIVE: To observe the efficacy and safety of Nocardia rubra cell wall skeleton (Nr-CWS) for the treatment of erosive oral lichen planus (EOLP). METHODS: Sixty patients with clinically and pathologically diagnosed EOLP were randomly divided into the experimental group and control group according to the random number. Patients in the experimental group were treated with lyophilized powder containing Nr-CWS combined with normal saline. Patients in the control group received topical placebo without Nr-CWS combined with normal saline. Changes in the EOLP lesion area and the patient's pain level were recorded at the timepoints of weeks 1, 2, and 4 after the two different treatments, respectively. The changes of the patient's REU scoring system (reticulation, erythema, ulceration), the visual analogue scale and the oral health impact score (OHIP-14) were compared between the experimental group and control group after treatment, and the safety indicators of the two groups at the initial diagnosis and after 4 weeks' treatment were also observed, respectively. RESULTS: Totally, 62 patients with clinically and pathologically diagnosed EOLP were enrolled, 2 of whom were lost to the follow-up, with 31 in the experimental group, and 29 in the control group. The mean age of the experimental group and control group were (52.9±12.4) years and (54.07±12.40) years, respectively. There was no significant difference in the oral periodontal index between the experimental group and control group. In the experimental group, the erosive area of oral lichen planus was significantly reduced 1, 2, and 4 weeks after the Nr-CWS's treatment (P < 0.05), the reduction rate was 81.75%, the patient's pain index was also decreased (P < 0.05), and in addition, the OHIP-14 was reduced (P < 0.05). The changes of the REU scoring system, the visual analogue scale and the OHIP-14 were significantly different between the experimental group and control group after treatment. There was no significant difference in the safety index between the two groups. CONCLUSION: The priliminary data show that the Nr-CWS is effective and safe to treat EOLP.


Assuntos
Líquen Plano Bucal , Rhodococcus , Adulto , Idoso , Esqueleto da Parede Celular , Humanos , Líquen Plano Bucal/tratamento farmacológico , Pessoa de Meia-Idade , Medição da Dor
2.
Sheng Wu Gong Cheng Xue Bao ; 37(10): 3653-3662, 2021 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-34708617

RESUMO

Microorganisms are the dominant players driving the degradation and transformation of chloramphenicol (CAP) in the environment. However, little bacterial strains are able to efficiently degrade and mineralize CAP, and the CAP degrading pathways mediated by oxidative reactions remain unclear. In this study, a highly efficient CAP-degrading microbial consortium, which mainly consists of Rhodococcus (relative abundance >70%), was obtained through an enrichment process using CAP-contaminated activated sludge as the inoculum. A bacterial strain CAP-2 capable of efficiently degrading CAP was isolated from the consortium and identified as Rhodococcus sp. by 16S rRNA gene analysis. Strain CAP-2 can efficiently degrade CAP under different nutrient conditions. Based on the biotransformation characteristics of the detected metabolite p-nitrobenzoic acid and the reported metabolites p-nitrobenzaldehyde and protocatechuate by strain CAP-2, a new oxidative pathway for the degradation of CAP was proposed. The side chain of CAP was oxidized and broken to generate p-nitrobenzaldehyde, which was further oxidized to p-nitrobenzoic acid. Strain CAP-2 can be used to further study the molecular mechanism of CAP catabolism, and has the potential to be used in in situ bioremediation of CAP-contaminated environment.


Assuntos
Cloranfenicol , Rhodococcus , Biodegradação Ambiental , RNA Ribossômico 16S/genética , Rhodococcus/genética , Esgotos
3.
Ecotoxicol Environ Saf ; 225: 112789, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34560613

RESUMO

A slow degradation rate and low transformation efficiency are the main problems in the biodegradation of polycyclic aromatic hydrocarbons (PAHs). This study selected pyrene as the target PAH to investigate the effect of ferrous ion and ferric ion on pyrene degradation. The driving effect and mechanism, including the interaction between pyrene and iron ions and the bacterial physiological response during the biodegradation process by Rhodococcus ruber strain L9, were investigated. The results showed that iron ions did not enhance bacterial growth but improved bacteria's pyrene removal capacity, contributing to the total efficiency of pyrene biodegradation. The process started with an initial formation of "cation-π" between Fe (III) and pyrene, which subsequently drove the pyrene removal process and accelerated the bacterial metabolic process. Moreover, a significant increase in the protein concentration, catechol dioxygenase (C12O and C23O) activities, and intracellular protein regulation in crude enzyme solution indicate a positive response of the bacteria during the iron ion-enhanced pyrene degradation process.


Assuntos
Ferro , Rhodococcus , Íons , Pirenos
4.
Int J Mol Sci ; 22(15)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34361010

RESUMO

Biofilms are complex structures formed by a community of microbes adhering to a surface and/or to each other through the secretion of an adhesive and protective matrix. The establishment of these structures requires a coordination of action between microorganisms through powerful communication systems such as quorum-sensing. Therefore, auxiliary bacteria capable of interfering with these means of communication could be used to prevent biofilm formation and development. The phytopathogen Rhizobium rhizogenes, which causes hairy root disease and forms large biofilms in hydroponic crops, and the biocontrol agent Rhodococcus erythropolis R138 were used for this study. Changes in biofilm biovolume and structure, as well as interactions between rhizobia and rhodococci, were monitored by confocal laser scanning microscopy with appropriate fluorescent biosensors. We obtained direct visual evidence of an exchange of signals between rhizobia and the jamming of this communication by Rhodococcus within the biofilm. Signaling molecules were characterized as long chain (C14) N-acyl-homoserine lactones. The role of the Qsd quorum-quenching pathway in biofilm alteration was confirmed with an R. erythropolis mutant unable to produce the QsdA lactonase, and by expression of the qsdA gene in a heterologous host, Escherichia coli. Finally, Rhizobium biofilm formation was similarly inhibited by a purified extract of QsdA enzyme.


Assuntos
Agrobacterium/fisiologia , Biofilmes , Percepção de Quorum , Rhodococcus/fisiologia , Acil-Butirolactonas/metabolismo , Agrobacterium/genética , Agrobacterium/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Rhodococcus/genética , Rhodococcus/metabolismo
5.
Artigo em Inglês | MEDLINE | ID: mdl-34444543

RESUMO

This paper analyzed the degradation pathways of petroleum hydrocarbon degradation bacteria, screened the main degradation pathways, and found the petroleum hydrocarbon degradation enzymes corresponding to each step of the degradation pathway. Through the Copeland method, the best inoculation program of petroleum hydrocarbon degradation bacteria in a polluted site was selected as follows: single oxygenation path was dominated by Streptomyces avermitilis, hydroxylation path was dominated by Methylosinus trichosporium OB3b, secondary oxygenation path was dominated by Pseudomonas aeruginosa, secondary hydroxylation path was dominated by Methylococcus capsulatus, double oxygenation path was dominated by Acinetobacter baylyi ADP1, hydrolysis path was dominated by Rhodococcus erythropolis, and CoA path was dominated by Geobacter metallireducens GS-15 to repair petroleum hydrocarbon contaminated sites. The Copeland method score for this solution is 22, which is the highest among the 375 solutions designed in this paper, indicating that it has the best degradation effect. Meanwhile, we verified its effect by the Cdocker method, and the Cdocker energy of this solution is -285.811 kcal/mol, which has the highest absolute value. Among the inoculation programs of the top 13 petroleum hydrocarbon degradation bacteria, the effect of the best inoculation program of petroleum hydrocarbon degradation bacteria was 18% higher than that of the 13th group, verifying that this solution has the best overall degradation effect. The inoculation program of petroleum hydrocarbon degradation bacteria designed in this paper considered the main pathways of petroleum hydrocarbon pollutant degradation, especially highlighting the degradability of petroleum hydrocarbon intermediate degradation products, and enriching the theoretical program of microbial remediation of petroleum hydrocarbon contaminated sites.


Assuntos
Petróleo , Rhodococcus , Poluentes do Solo , Acinetobacter , Biodegradação Ambiental , Geobacter , Hidrocarbonetos , Solo , Microbiologia do Solo , Poluentes do Solo/análise , Streptomyces
6.
Molecules ; 26(16)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34443455

RESUMO

Bacteria belonging to the Rhodococcus genus are frequent components of microbial communities in diverse natural environments. Some rhodococcal species exhibit the outstanding ability to produce significant amounts of triacylglycerols (TAG) (>20% of cellular dry weight) in the presence of an excess of the carbon source and limitation of the nitrogen source. For this reason, they can be considered as oleaginous microorganisms. As occurs as well in eukaryotic single-cell oil (SCO) producers, these bacteria possess specific physiological properties and molecular mechanisms that differentiate them from other microorganisms unable to synthesize TAG. In this review, we summarized several of the well-characterized molecular mechanisms that enable oleaginous rhodococci to produce significant amounts of SCO. Furthermore, we highlighted the ability of these microorganisms to degrade a wide range of carbon sources coupled to lipogenesis. The qualitative and quantitative oil production by rhodococci from diverse industrial wastes has also been included. Finally, we summarized the genetic and metabolic approaches applied to oleaginous rhodococci to improve SCO production. This review provides a comprehensive and integrating vision on the potential of oleaginous rhodococci to be considered as microbial biofactories for microbial oil production.


Assuntos
Biocombustíveis/microbiologia , Óleos/metabolismo , Rhodococcus/metabolismo , Carbono/farmacologia , Lipogênese/efeitos dos fármacos , Filogenia , Rhodococcus/classificação
7.
Int J Mol Sci ; 22(16)2021 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-34445761

RESUMO

Natural products of microbial origin have inspired most of the commercial pharmaceuticals, especially those from Actinobacteria. However, the redundancy of molecules in the discovery process represents a serious issue. The untargeted approach, One Strain Many Compounds (OSMAC), is one of the most promising strategies to induce the expression of silent genes, especially when combined with genome mining and advanced metabolomics analysis. In this work, the whole genome of the marine isolate Rhodococcus sp. I2R was sequenced and analyzed by antiSMASH for the identification of biosynthetic gene clusters. The strain was cultivated in 22 different growth media and the generated extracts were subjected to metabolomic analysis and functional screening. Notably, only a single growth condition induced the production of unique compounds, which were partially purified and structurally characterized by liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). This strategy led to identifying a bioactive fraction containing >30 new glycolipids holding unusual functional groups. The active fraction showed a potent antiviral effect against enveloped viruses, such as herpes simplex virus and human coronaviruses, and high antiproliferative activity in PC3 prostate cancer cell line. The identified compounds belong to the biosurfactants class, amphiphilic molecules, which play a crucial role in the biotech and biomedical industry.


Assuntos
Antivirais/metabolismo , Glicolipídeos/metabolismo , Rhodococcus/metabolismo , Animais , Antivirais/análise , Chlorocebus aethiops , Técnicas de Cultura , Ensaios de Seleção de Medicamentos Antitumorais , Ésteres/metabolismo , Genoma Bacteriano , Glicolipídeos/química , Humanos , Metaboloma , Testes de Sensibilidade Microbiana , Estrutura Molecular , Células PC-3 , Rhodococcus/química , Rhodococcus/genética , Succinatos/metabolismo , Tensoativos/química , Tensoativos/metabolismo , Células Vero
8.
Syst Appl Microbiol ; 44(5): 126234, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34343788

RESUMO

Rpf protein, a kind of resuscitation promoting factor, was first found in the culture supernatant of Micrococcus luteus. It can resuscitate the growth of M. luteus in "viable but non-culture, VBNC" state and promote the growth of Gram-positive bacteria with high G + C content. This paper investigates the resuscitating activity of M. luteus ACCC 41016T Rpf protein, which was heterologously expressed in E. coli, to cells of M. luteus ACCC 41016T and Rhodococcus marinonascens HBUM200062 in VBNC state, and examines the effect on the cultivation of actinobacteria in soil. The results showed that the recombinant Rpf protein had resuscitation effect on M. luteus ACCC 41016T and R. marinonascens HBUM200062 in VBNC state. 83 strains of actinobacteria, which were distributed in 9 families and 12 genera, were isolated from the experimental group with recombinant Rpf protein in the culture medium. A total of 41 strains of bacteria, which were distributed in 8 families and 9 genera, were isolated from the control group without Rpf protein. The experimental group showed richer species diversity than the control group. Two rare actinobacteria, namely HBUM206391T and HBUM206404T, were obtained in the experimental group supplemented with Rpf protein. Both may be potential new species of Actinomadura and Actinokineospora, indicating that the recombinant expression of M. luteus ACCC 41016T Rpf protein can effectively promote the isolation and culture of actinobacteria in soil.


Assuntos
Actinobacteria , Proteínas de Bactérias/metabolismo , Citocinas/metabolismo , Micrococcus luteus/metabolismo , Microbiologia do Solo , Actinobacteria/crescimento & desenvolvimento , Proteínas de Bactérias/genética , Citocinas/genética , Escherichia coli , Rhodococcus
9.
Folia Microbiol (Praha) ; 66(5): 701-713, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34215934

RESUMO

Rhodococcus spp. strains are widespread in diverse natural and anthropized environments thanks to their high metabolic versatility, biodegradation activities, and unique adaptation capacities to several stress conditions such as the presence of toxic compounds and environmental fluctuations. Additionally, the capability of Rhodococcus spp. strains to produce high value-added products has received considerable attention, mostly in relation to lipid accumulation. In relation with this, several works carried out omic studies and genome comparative analyses to investigate the genetic and genomic basis of these anabolic capacities, frequently in association with the bioconversion of renewable resources and low-cost substrates into triacylglycerols. This review is focused on these omic analyses and the genetic and metabolic approaches used to improve the biosynthetic and bioconversion performance of Rhodococcus. In particular, this review summarizes the works that applied heterologous expression of specific genes and adaptive laboratory evolution approaches to manipulate anabolic performance. Furthermore, recent molecular toolkits for targeted genome editing as well as genome-based metabolic models are described here as novel and promising strategies for genome-scaled rational design of Rhodococcus cells for efficient biosynthetic processes application.


Assuntos
Biodegradação Ambiental , Engenharia Metabólica , Rhodococcus , Biologia de Sistemas , Genoma Bacteriano/genética , Genômica , Rhodococcus/genética , Rhodococcus/metabolismo
10.
Metab Eng ; 67: 250-261, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34265401

RESUMO

Poly(ethylene terephthalate) (PET) is the most abundantly consumed synthetic polyester and accordingly a major source of plastic waste. The development of chemocatalytic approaches for PET depolymerization to monomers offers new options for open-loop upcycling of PET, which can leverage biological transformations to higher-value products. To that end, here we perform four sequential metabolic engineering efforts in Pseudomonas putida KT2440 to enable the conversion of PET glycolysis products via: (i) ethylene glycol utilization by constitutive expression of native genes, (ii) terephthalate (TPA) catabolism by expression of tphA2IIA3IIBIIA1II from Comamonas and tpaK from Rhodococcus jostii, (iii) bis(2-hydroxyethyl) terephthalate (BHET) hydrolysis to TPA by expression of PETase and MHETase from Ideonella sakaiensis, and (iv) BHET conversion to a performance-advantaged bioproduct, ß-ketoadipic acid (ßKA) by deletion of pcaIJ. Using this strain, we demonstrate production of 15.1 g/L ßKA from BHET at 76% molar yield in bioreactors and conversion of catalytically depolymerized PET to ßKA. Overall, this work highlights the potential of tandem catalytic deconstruction and biological conversion as a means to upcycle waste PET.


Assuntos
Polietilenotereftalatos , Pseudomonas putida , Adipatos , Burkholderiales , Etilenos , Hidrolases , Ácidos Ftálicos , Pseudomonas putida/genética , Rhodococcus
11.
Enzyme Microb Technol ; 149: 109832, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34311877

RESUMO

Haloalkane dehalogenase DhaA catalyzes the hydrolytic cleavage of carbon-halogen bonds and produces alcohol, a proton and a halide. However, DhaA suffers from the poor environmental stability, such as sensitivity to high temperature, low pH, hypersaline and organic solvent. In order to improve the environmental stability of DhaA, DhaA was covalently conjugated with inulin, a hydrophilic polysaccharide in the present study. Each DhaA was averagely conjugated with 7∼8 inulin molecules. The conjugated inulin could form a hydration layer around DhaA, which increased the conformational rigidity and decreased the entropy of the enzyme. Conjugation of inulin maintained 75.5 % of the enzymatic activity of DhaA and slightly altered the structure of DhaA. As compared with DhaA, the conjugate (inu-DhaA) showed slightly different kinetic parameters (Km of 2.9 µmol/L and Kcat of 1.0 s-1). Inulin conjugation could delay the structural unfolding and/or slow the protonation process of DhaA under undesirable environment, including the long-term storage, low pH, hypersaline and organic solvent stability. As a result, the environmental stability of DhaA was markedly increased upon conjugation with inulin. Thus, inulin conjugation was an effective approach to enhance the environmental stability of DhaA.


Assuntos
Inulina , Rhodococcus , Hidrolases/genética , Hidrólise
12.
Int J Med Microbiol ; 311(6): 151519, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34280738

RESUMO

Rhodococcus equi is a saprophytic soil bacterium and intracellular pathogen that causes refractory suppurative pneumonia in foals and has emerged as a pathogenic cause of zoonotic disease. Several studies have reported human infections caused by R. equi harboring a recently described third type of virulence plasmid, the ruminant-associated pVAPN, which carries the vapN virulence determinant. Herein, we analyzed pathogenicity and genomic features of nine vapN-harboring R. equi isolated from human patients with and without HIV/AIDS. Four of these strains showed significant VapN production and proliferation in cultured macrophages. These strains were lethally pathogenic after inoculation with 1.0 × 108 CFU in mice and reproduced a necrotizing granulomatous inflammation in the liver and spleen similar to that observed in humans. Additionally, we determined entire genome sequences of all nine strains. Lengths of sequences were 5.0-5.3 Mbp, and GC contents were 68.7 %-68.8 %. All strains harbored a 120- or 125-kbp linear plasmid carrying vapN (Type I or Type II pVAPN) classified on the basis of differences in the distal sequences on the 3' side. Interestingly, VapN production differed significantly among strains harboring nearly identical types of pVAPN with variation limited to several SNPs and short base pair indels. The pVAPN sequences possessed by the VapN-producing strains did not retain any common genetic characteristics, and more detailed analyses, including chromosomal genes, are needed to further elucidate the VapN expression mechanism.


Assuntos
Infecções por Actinomycetales , Rhodococcus equi , Rhodococcus , Infecções por Actinomycetales/veterinária , Animais , Genômica , Cavalos , Humanos , Camundongos , Plasmídeos/genética , Rhodococcus equi/genética , Virulência
13.
Artigo em Inglês | MEDLINE | ID: mdl-34264809

RESUMO

Two novel actinobacterial strains, designated C9-5T and C3-43, were isolated from soil samples of a cave in Jeju Island, Republic of Korea, and subjected to taxonomic study by a polyphasic approach. The organisms exhibited a typical rod-coccus developmental cycle during growth and grew at 10-30 °C, pH 5-9 and 0-3 % (w/v) NaCl. In 92 single-copy core gene sequence analysis, strain C9-5T was loosely associated with Rhodococcus tukisamuensis, albeit sharing low 16S rRNA gene sequence similarity (97.4 %). A combination of morphological and chemotaxonomic characteristics supported assignment with the genus Rhodococcus. With respect to 16S rRNA gene sequence similarity, the novel isolates showed the highest identity to the type strain of Rhodococcus subtropicus (98.7 % sequence similarity), followed by Rhodococcus olei (98.5 %) and Rhodococcus pedocola (98.4 %).The average nucleotide identity and digital DNA-DNA hybridization values between strain C9-5T and members of the genus Rhodococcus were ≤81.5 and ≤37.1 %, respectively. A set of physiological and chemotaxonomic properties together with overall genomic relatedness differentiated the novel isolates from members of the genus Rhodococcus, for which the name Rhodococcus spelaei sp. nov. is proposed. The type strain is C9-5T (=KACC 19822T=DSM 107558T). Based on genome analysis performed here, it is also proposed that Rhodococcus biphenylivorans Su et al. 2015 is a later heterotypic synonym of Rhodococcus pyridinivorans Yoon et al. 2000, Rhodococcus qingshengii Xu et al. 2007 and Rhodococcus baikonurensis Li et al. 2004 are later heterotypic synonyms of Rhodococcus erythropolis (Gray and Thornton 1928) Goodfellow and Alderson 1979 (Approved Lists 1980), and Rhodococcus percolatus Briglia et al. 1996 and Rhodococcus imtechensis Ghosh et al. 2006 are later heterotypic synonyms of Rhodococcus opacus Klatte et al. 1995.


Assuntos
Cavernas/microbiologia , Filogenia , Rhodococcus/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , República da Coreia , Rhodococcus/isolamento & purificação , Análise de Sequência de DNA
14.
Artigo em Inglês | MEDLINE | ID: mdl-34296990

RESUMO

Two novel Rhodococcus strains, LHW50502T and LHW51113T, were isolated from marine sponges obtained on Xisha Island, Hainan Province, PR China. Rods and cocci, typical characteristics of the genus Rhodococcus, were observed. The strains contained meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall hydrolysates and galactose, arabinose, ribose and glucose as the whole-cell sugars. The major fatty acid identified was C16 : 0. MK-8(H4) was the predominat menaquinone of both strains. Stains LHW50502T and LHW51113T had almost identical (99.6 %) 16S rRNA gene sequences but shared relatively low similarities with previously characterized Rhodococcus species (well below 98.7 %). The results of phylogenetic analysis supported their closest relationship; however, the average nucleotide identity and digital DNA-DNA hybridization values between these two strains indicated that they belonged to distinct species. Taken together, the results of this study indicate that strains LHW50502T and LHW51113T represent two novel species of the genus Rhodococcus, for which the names Rhodococcus spongiicola sp. nov. (type strain LHW50502T=DSM 106291T=CCTCC AA 2018033T) and Rhodococcus xishaensis sp. nov. (type strain LHW51113T=DSM 106204T=CCTCC AA 2018034T) are proposed.


Assuntos
Filogenia , Poríferos/microbiologia , Rhodococcus/classificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Rhodococcus/isolamento & purificação , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
15.
Antonie Van Leeuwenhoek ; 114(10): 1497-1516, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34324106

RESUMO

Biosynthesis of silver nanoparticles (AgNPs) from marine actinobacteria offers a promising avenue for exploring bacterial extracts as reducing and stabilizing agents. We report extracellular extracts of Rhodococcus rhodochrous (MOSEL-ME29) and Streptomyces sp. (MOSEL-ME28), identified by 16S rRNA gene sequencing for synthesis of AgNPs. Ultrafine silver nanoparticles were biosynthesized using the extracts of R. rhodochrous and Streptomyces sp. and their possible therapeutic applications were studied. The physicochemical properties of nanoparticles were established by HR-SEM/TEM, SAED, UV-Vis, EDS, XRD, and FTIR. UV-Vis spectra displayed characteristic absorption at 430 nm and 412 nm for AgNPs from Streptomyces sp. (S-AgNPs) and Rhodococcus sp. (R-AgNPs), respectively. HR-SEM/TEM, XRD, EDS analysis confirmed the spherical shape, crystalline nature, and elemental formation of silver. Crystallite or grain size was deduced as 5.52 nm for R-AgNPs and 35 nm for S-AgNPs. Zeta-potential indicated electrostatic negative charge for AgNPs, while FTIR revealed the presence of diverse functional groups. Disc diffusion assay indicated the broad-spectrum antibacterial potential of S-AgNPs with the maximum inhibition of B. subtilis while R-AgNPs revealed potency against P. aeruginosa at 10 µg/mL concentration. Biogenic AgNPs revealed antileishmanial activity and the IC50 was calculated as 164 µg/mL and 184 µg/mL for R-AgNPs and S-AgNPs respectively. Similarly, the R-AgNPs and S-AgNPs revealed anti-cancer potential against HepG2 and the IC50 was calculated as 49 µg/mL and 69 µg/mL for R-AgNPs and S-AgNPs, respectively. Moreover, the antioxidant activity showed significant results. MTT assay on RD cells, L20B cells, and Hep-2C indicated intensification in viability by reducing the concentration of R-AgNPs and S-AgNPs. The R-AgNPs and S-AgNPs inhibited sabin-like poliovirus (1TCID50 infection in RD cells). Furthermore, hemocompatibility at low concentrations has been confirmed. Hence, it is concluded that biogenic-AgNPs has the potential to be used in diverse biological applications and that the marine actinobacteria are an excellent resource for fabrication of AgNPs.


Assuntos
Actinobacteria , Nanopartículas Metálicas , Actinobacteria/genética , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Extratos Vegetais , RNA Ribossômico 16S/genética , Rhodococcus , Prata/farmacologia
16.
J Clin Microbiol ; 59(10): e0114921, 2021 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-34319806

RESUMO

Clonal multidrug resistance recently emerged in Rhodococcus equi, complicating the therapeutic management of this difficult-to-treat animal- and human-pathogenic actinomycete. The currently spreading multidrug-resistant (MDR) "2287" clone arose in equine farms upon acquisition, and coselection by mass macrolide-rifampin therapy, of the pRErm46 plasmid carrying the erm(46) macrolide-lincosamide-streptogramin resistance determinant, and of an rpoBS531F mutation. Here, we screened a collection of susceptible and macrolide-resistant R. equi strains from equine clinical cases using a panel of 15 antimicrobials against rapidly growing mycobacteria (RGM) and nocardiae and other aerobic actinomycetes (NAA). R. equi isolates-including MDR ones-were generally susceptible to linezolid, minocycline, tigecycline, amikacin, and tobramycin according to Staphylococcus aureus interpretive criteria, plus imipenem, cefoxitin, and ceftriaxone based on Clinical and Laboratory Standards Institute (CLSI) guidelines for RGM/NAA. Susceptibility to ciprofloxacin and moxifloxacin was borderline according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. Molecular analyses linked pRErm46 to significantly increased MICs for trimethoprim-sulfamethoxazole and doxycycline, in addition to clarithromycin, within the RGM/NAA panel, and to streptomycin, spectinomycin, and tetracycline resistance. pRErm46 variants with spontaneous deletions in the class 1 integron (C1I) region, observed in ≈30% of erm(46)-positive isolates, indicated that the newly identified resistances were attributable to the C1I's sulfonamide (sul1) and aminoglycoside (aaA9) resistance cassettes and adjacent tetRA(33) determinant. Most MDR isolates carried the rpoBS531F mutation of the 2287 clone, while different rpoB mutations (S531L, S531Y) detected in two cases suggest the emergence of novel MDR R. equi strains.


Assuntos
Rhodococcus equi , Rhodococcus , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana , Cavalos , Humanos , Macrolídeos/farmacologia , Testes de Sensibilidade Microbiana , Rhodococcus equi/genética
17.
Chemosphere ; 285: 131466, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34271468

RESUMO

Here, we explore effects of metallophore-producing rhizobacteria on the plant availability of germanium (Ge) and rare earth elements (REEs). Five isolates of the four species Rhodococcus erythropolis, Arthrobacter oxydans, Kocuria rosea and Chryseobacterium koreense were characterized regarding their production of element-chelators using genome-mining, LC-MS/MS analysis and solid CAS-assay. Additionally, a soil elution experiment was conducted in order to identify isolates that increase solubility of Ge and REEs in soil solution. A. oxydans ATW2 and K. rosea ATW4 released desferrioxamine-, bacillibactin- and surfactin-like compounds that mobilized Ge and REEs as well as P, Fe, Si and Ca in soil. Subsequently, oat, rapeseed and reed canary grass were cultivated on soil and sand and treated with cells and iron depleted culture supernatants of A. oxydans ATW2 and K. rosea ATW4. Inoculation increased plant yield and shoot phosphorus (P), manganese (Mn), Ge and REE concentrations. However, effects of the inoculation varied substantially between the growth substrates and plant species. On sand, A. oxydans ATW2 increased accumulation of REEs in all plant species and root-shoot translocation in rapeseed, while K. rosea ATW4 enhanced REE accumulation in rapeseed only, without effects on other plant species. Sand-cultured oat plants showed increased Ge accumulation and root-shoot translocation in presence of A. oxydans ATW2 cells and K. rosea ATW4 supernatant; however, there was no effect on other plant species, irrespective the growth substrate used. In contrast, soil-cultured rapeseed showed enhanced REE accumulation in presence of cells of A. oxydans ATW2 while there were no effects on other plant species and Ge. The processes involved are not yet fully understood. Nevertheless, we demonstrated that chemical microbe-soil-plant relationships influence plant availability of nutrients together with Ge and REEs, which has major implications on our understanding of biogeochemical element cycling and development of sustainable bioremediation and biomining technologies.


Assuntos
Germânio , Metais Terras Raras , Micrococcaceae , Poluentes do Solo , Cromatografia Líquida , Chryseobacterium , Metais Terras Raras/análise , Rizosfera , Rhodococcus , Solo , Poluentes do Solo/análise , Espectrometria de Massas em Tandem
18.
Chemosphere ; 285: 131538, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34273699

RESUMO

Anode biofilm thickness is a key point for high and sustainable power generation in microbial fuel cells (MFCs). Over time, the formation of a thicker biofilm on anode electrode hinders the power generation performance of MFC by causing a longer electron transfer path and the accumulation of undesirable components in anode biofilm. To overcome these limitations, we used a novel strategy named quorum quenching (QQ) for the first time in order to control the biofilm thickness on the anode surface by inactivation of signal molecules among microorganisms. For this purpose, the isolated QQ bacteria (Rhodococcus sp. BH4) were immobilized into alginate beads (20, 40, and 80 mg/10 ml sodium alginate) and added to the anode chamber of MFCs. The MFC exhibited the best electrochemical activity (1924 mW m-2) with a biofilm thickness of 26 µm at 40 mg Rhodococcus sp. BH4/10 ml sodium alginate. The inhibition of signal molecules in anode chamber reduced the production of extracellular polymeric substance (EPS) by preventing microbial communication amonganode microorganisms. Microscopic observations revealed that anode biofilm thickness and the abundance of dead bacteria significantly decreased with an increase in Rhodococcus sp. BH4 concentration in MFCs. Microbiome diversity showed an apparent difference among the microbial community structures of anode biofilms in MFCs containing vacant and Rhodococcus sp. BH4 beads. The data revealed that the QQ strategy is an efficient application for improving MFC performance and may shed light on future studies.


Assuntos
Fontes de Energia Bioelétrica , Rhodococcus , Biofilmes , Eletricidade , Eletrodos , Matriz Extracelular de Substâncias Poliméricas , Percepção de Quorum
19.
Chemosphere ; 282: 130973, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34091296

RESUMO

Nonpathogenic effective bacterial hydrocarbon degraders, Rhodococcus ruber S103, Mycolicibacterium parafortuitum J101 and Mycolicibacterium austroafricanum Y502, were isolated from mixed polycyclic aromatic hydrocarbon (PAH)-enriched river sediments. They possessed broad substrate specificities toward various PAHs and aliphatic compounds as sole carbon sources. These strains exhibited promising characteristics, including biosurfactant production, high cell hydrophobicity, biofilm formation and no antagonistic interactions, and contained genes encoding hydrocarbon-degrading enzymes. The mixed bacterial consortium combining S103, J101 and Y502, showed more effective syntrophic degradation of two types of refined petroleum products, diesel and fuel oils, than monocultures. The defined consortium immobilized on plastic balls achieved over 50% removal efficiency of high fuel oil concentration (3000 mg L-1) in a synthetic medium and contaminated freshwater. Furthermore, the immobilized cells simultaneously degraded more than 46% of total fuel oil adsorbed on plastic balls in both culture systems. SEM imaging confirmed that the immobilized consortium exhibited biofilm formation with the bacterial community covering most of the bioball surface, resulting in high bacterial survival against toxic contaminants. The results of this study showed the potential use of the cooperative interaction between Rhodococcus and Mycolicibacterium as immobilized bioballs for the bioremediation of fuel oil-contaminated environments. Additionally, this research has motivated further investigations into the development of bioremediation products for fuel oil degradation.


Assuntos
Óleos Combustíveis , Petróleo , Rhodococcus , Biodegradação Ambiental , Água Doce , Mycobacteriaceae , Rhodococcus/genética
20.
Chemosphere ; 282: 130975, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34111638

RESUMO

Even though the genetic attributes suggest presence of multiple degradation pathways, most of rhodococci are known to transform PCBs only via regular biphenyl (bph) pathway. Using GC-MS analysis, we monitored products formed during transformation of 2,4,4'-trichlorobiphenyl (PCB-28), 2,2',5,5'-tetrachlorobiphenyl (PCB-52) and 2,4,3'-trichlorobiphenyl (PCB-25) by previously characterized PCB-degrading rhodococci Z6, T6, R2, and Z57, with the aim to explore their metabolic pleiotropy in PCB transformations. A striking number of different transformation products (TPs) carrying a phenyl ring as a substituent, both those generated as a part of the bph pathway and an array of unexpected TPs, implied a curious transformation ability. We hypothesized that studied rhodococcal isolates, besides the regular one, use at least two alternative pathways for PCB transformation, including the pathway leading to acetophenone formation (via 3,4 (4,5) dioxygenase attack on the molecule), and a third sideway pathway that includes stepwise oxidative decarboxylation of the aliphatic side chain of the 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate. Structure of the identified chlorinated benzoic acids and acetophenones allowed us to hypothesize that the first two pathways were the outcome of a ring-hydroxylating dioxygenase with the ability to attack both the 2,3 (5,6) and the 3,4 (4,5) positions of the biphenyl ring as well as dechlorination activity at both, -ortho and -para positions. We propose that several TPs produced by the bph pathway could have caused the triggering of the third sideway pathway. In conclusion, this study proposed ability of rhodococci to use different strategies in PCB transformation, which allows them to circumvent potential negative aspect of TPs on the overall transformation pathway.


Assuntos
Dioxigenases , Bifenilos Policlorados , Rhodococcus , Biodegradação Ambiental
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