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1.
Chem Biol Interact ; 350: 109685, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34653397

RESUMO

The increasing levels of estrogens and pollution by other steroids pose considerable challenges to the environment. In this study, the genome of Gordonia polyisoprenivorans strain R9, one of the most effective 17 beta-estradiol- and steroid-degrading bacteria, was sequenced and annotated. The circular chromosome of G. polyisoprenivorans R9 was 6,033,879 bp in size, with an average GC content of 66.91%. More so, 5213 putative protein-coding sequences, 9 rRNA, 49 tRNA, and 3 sRNA genes were predicted. The core-pan gene evolutionary tree for the genus Gordonia showed that G. polyisoprenivorans R9 is clustered with G. polyisoprenivorans VH2 and G. polyisoprenivorans C, with 93.75% and 93.8% similarity to these two strains, respectively. Altogether, the three G. polyisoprenivorans strains contained 3890 core gene clusters. Strain R9 contained 785 specific gene clusters, while 501 and 474 specific gene clusters were identified in strains VH2 and C, respectively. Furthermore, whole genome analysis revealed the existence of the steroids and estrogens degradation pathway in the core genome of all three G. polyisoprenivorans strains, although the G. polyisoprenivorans R9 genome contained more specific estrogen and steroid degradation genes. In strain R9, 207 ABC transporters, 95 short-chain dehydrogenases (SDRs), 26 monooxygenases, 21 dioxygenases, 7 aromatic ring-hydroxylating dioxygenases, and 3 CoA esters were identified, and these are very important for estrogen and steroid transport, and degradation. The results of this study could enhance our understanding of the role of G. polyisoprenivorans R9 in estradiol and steroid degradation as well as evolution within the G. polyisoprenivorans species.


Assuntos
Actinobacteria/genética , Actinobacteria/metabolismo , Poluentes Ambientais/metabolismo , Estradiol/metabolismo , Esteroides/metabolismo , Actinobacteria/classificação , Animais , Composição de Bases , Biodegradação Ambiental , Disruptores Endócrinos/metabolismo , Estrogênios/metabolismo , Genoma Bacteriano , Humanos , Família Multigênica , Filogenia , Especificidade da Espécie
2.
Molecules ; 26(20)2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34684816

RESUMO

The cultivation of one actinobacteria strain, Herbidospora yilanensis, was isolated from sediment samples collected from Yilan County City in Taiwan, resulting in the isolation of five previously undescribed compounds: herbidosporayilanensins A-E (1-5), and four compounds isolated from nature for the first time: herbidosporayilanensins F-I (6-9). Their structures were elucidated by spectroscopic analyses, including 1D- and 2D-NMR experiments with those of known analogues, and on the basis of HR-EI-MS mass spectrometry, their antimycobacterial activities were also evaluated.


Assuntos
Actinobacteria/metabolismo , Antibacterianos/química , Antibacterianos/metabolismo , Actinobacteria/isolamento & purificação , Antibacterianos/farmacologia , Antituberculosos/química , Antituberculosos/metabolismo , Antituberculosos/farmacologia , Sedimentos Geológicos/microbiologia , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Mycobacterium tuberculosis/efeitos dos fármacos , Microbiologia do Solo , Taiwan
3.
Int J Mol Sci ; 22(17)2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34502147

RESUMO

Tetramethrin is a pyrethroid insecticide that is commonly used worldwide. The toxicity of this insecticide into the living system is an important concern. In this study, a novel tetramethrin-degrading bacterial strain named A16 was isolated from the activated sludge and identified as Gordonia cholesterolivorans. Strain A16 exhibited superior tetramethrin degradation activity, and utilized tetramethrin as the sole carbon source for growth in a mineral salt medium (MSM). High-performance liquid chromatography (HPLC) analysis revealed that the A16 strain was able to completely degrade 25 mg·L-1 of tetramethrin after 9 days of incubation. Strain A16 effectively degraded tetramethrin at temperature 20-40 °C, pH 5-9, and initial tetramethrin 25-800 mg·L-1. The maximum specific degradation rate (qmax), half-saturation constant (Ks), and inhibition constant (Ki) were determined to be 0.4561 day-1, 7.3 mg·L-1, and 75.2 mg·L-1, respectively. The Box-Behnken design was used to optimize degradation conditions, and maximum degradation was observed at pH 8.5 and a temperature of 38 °C. Five intermediate metabolites were identified after analyzing the degradation products through gas chromatography-mass spectrometry (GC-MS), which suggested that tetramethrin could be degraded first by cleavage of its carboxylester bond, followed by degradation of the five-carbon ring and its subsequent metabolism. This is the first report of a metabolic pathway of tetramethrin in a microorganism. Furthermore, bioaugmentation of tetramethrin-contaminated soils (50 mg·kg-1) with strain A16 (1.0 × 107 cells g-1 of soil) significantly accelerated the degradation rate of tetramethrin, and 74.1% and 82.9% of tetramethrin was removed from sterile and non-sterile soils within 11 days, respectively. The strain A16 was also capable of efficiently degrading a broad spectrum of synthetic pyrethroids including D-cyphenothrin, chlorempenthrin, prallethrin, and allethrin, with a degradation efficiency of 68.3%, 60.7%, 91.6%, and 94.7%, respectively, after being cultured under the same conditions for 11 days. The results of the present study confirmed the bioremediation potential of strain A16 from a contaminated environment.


Assuntos
Actinobacteria/metabolismo , Inseticidas/metabolismo , Piretrinas/metabolismo , Poluentes do Solo/metabolismo , Actinobacteria/crescimento & desenvolvimento , Biotransformação , Microbiologia Industrial/métodos
4.
Biomolecules ; 11(8)2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34439747

RESUMO

Endo-ß-1,3-glucanase plays an essential role in the deconstruction of ß-1,3-d-glucan polysaccharides through hydrolysis. The gene (1650-bp) encoding a novel, bi-modular glycoside hydrolase family 64 (GH64) endo-ß-1,3-glucanase (GluY) with a ricin-type ß-trefoil lectin domain (RICIN)-like domain from Cellulosimicrobium funkei HY-13 was identified and biocatalytically characterized. The recombinant enzyme (rGluY: 57.5 kDa) displayed the highest degradation activity for laminarin at pH 4.5 and 40 °C, while the polysaccharide was maximally decomposed by its C-terminal truncated mutant enzyme (rGluYΔRICIN: 42.0 kDa) at pH 5.5 and 45 °C. The specific activity (26.0 U/mg) of rGluY for laminarin was 2.6-fold higher than that (9.8 U/mg) of rGluYΔRICIN for the same polysaccharide. Moreover, deleting the C-terminal RICIN domain in the intact enzyme caused a significant decrease (>60%) of its ability to degrade ß-1,3-d-glucans such as pachyman and curdlan. Biocatalytic degradation of ß-1,3-d-glucans by inverting rGluY yielded predominantly d-laminaripentaose. rGluY exhibited stronger growth inhibition against Candida albicans in a dose-dependent manner than rGluYΔRICIN. The degree of growth inhibition of C. albicans by rGluY (approximately 1.8 µM) was approximately 80% of the fungal growth. The superior anti-fungal activity of rGluY suggests that it can potentially be exploited as a supplementary agent in the food and pharmaceutical industries.


Assuntos
Actinobacteria/metabolismo , Antifúngicos/farmacologia , Glucana Endo-1,3-beta-D-Glucosidase/metabolismo , Polissacarídeos/química , Antifúngicos/química , Candida albicans/metabolismo , Catálise , Clonagem Molecular , Glucanos/química , Concentração de Íons de Hidrogênio , Hidrólise , Filogenia , Ligação Proteica , Domínios Proteicos , Proteínas Recombinantes/química , Temperatura , beta-Glucanas/química
5.
Molecules ; 26(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34361657

RESUMO

The current review aims to summarise the biodiversity and biosynthesis of novel secondary metabolites compounds, of the phylum Actinobacteria and the diverse range of secondary metabolites produced that vary depending on its ecological environments they inhabit. Actinobacteria creates a wide range of bioactive substances that can be of great value to public health and the pharmaceutical industry. The literature analysis process for this review was conducted using the VOSviewer software tool to visualise the bibliometric networks of the most relevant databases from the Scopus database in the period between 2010 and 22 March 2021. Screening and exploring the available literature relating to the extreme environments and ecosystems that Actinobacteria inhabit aims to identify new strains of this major microorganism class, producing unique novel bioactive compounds. The knowledge gained from these studies is intended to encourage scientists in the natural product discovery field to identify and characterise novel strains containing various bioactive gene clusters with potential clinical applications. It is evident that Actinobacteria adapted to survive in extreme environments represent an important source of a wide range of bioactive compounds. Actinobacteria have a large number of secondary metabolite biosynthetic gene clusters. They can synthesise thousands of subordinate metabolites with different biological actions such as anti-bacterial, anti-parasitic, anti-fungal, anti-virus, anti-cancer and growth-promoting compounds. These are highly significant economically due to their potential applications in the food, nutrition and health industries and thus support our communities' well-being.


Assuntos
Actinobacteria/metabolismo , Antibacterianos/isolamento & purificação , Antibacterianos/metabolismo , Produtos Biológicos , Enzimas/isolamento & purificação , Enzimas/metabolismo , Metabolismo Secundário
6.
Chem Biodivers ; 18(8): e2100211, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34323355

RESUMO

Cultivation of the actinobacteria strain Isoptericola chiayiensis, a mangrove-derived actinobacteria that was isolated from a mangrove soil collected in Chiayi County, resulted in the isolation of one new 2-furanone derivative, isopterfuranone (1), one new sesquiterpenoid, isopterchiayione (2), one new benzenoid derivative, isopterinoid (3), five new flavonoids, chiayiflavans A-E (4-8), and 4 metabolites isolated for the first time from nature source, methyl 3-(4-methyl-2,5-dioxopyrrolidin-3-yl)propanoate (9), 3-ethyl-4-methylpyrrolidine-2,5-dione (10), chiayiensol (11) and chiayiensic acid (12). Their structures were determined through in-depth spectroscopic and mass-spectrometric analyses. Most of the isolates showed potent inhibitory effects on NO production in LPS-stimulated RAW 264.7 murine macrophages cells with IC50 values ranging from 9.36 to 40.02 µM. Of these isolates, 4 and 5 showed NO inhibitory activity with IC50 values of 17.14 and 9.36 µM, stronger than the positive control quercetin (IC50 =36.95 µM). This is the first report on flavan metabolites from the genus Isoptericola.


Assuntos
Actinobacteria/química , Flavonoides/química , Sesquiterpenos/química , Actinobacteria/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Lipopolissacarídeos/farmacologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Espectroscopia de Ressonância Magnética , Camundongos , Conformação Molecular , Óxido Nítrico/metabolismo , Células RAW 264.7 , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Microbiologia do Solo
7.
Front Immunol ; 12: 632482, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34276644

RESUMO

Recent evidence suggests that inflammation was participated in the pathogenesis of PD, thus, to understand the potential mechanism of gut microbiota in the pathogenesis of Parkinson's disease (PD), we performed a metagenomic analysis of fecal samples from PD patient and controls. Using a two-stage metagenome-wide association strategy, fecal DNA samples from 69 PD patients and 244 controls in three groups (comprising 66 spouses, 97 age-matched, and 81 normal samples, respectively) were analyzed, and differences between candidate gut microbiota and microbiota-associated epitopes (MEs) were compared. In the study, 27 candidate bacterial biomarkers and twenty-eight candidate epitope peptides were significantly different between the PD patients and control groups. Further, enriched 4 and 13 MEs in PD were positively associated with abnormal inflammatory indicators [neutrophil percentage (NEUT.1), monocyte count/percentage (MONO/MONO.1), white blood cell count (WBC)] and five candidate bacterial biomarkers (c_Actinobacteria, f_Bifidobacteriaceae, g_Bifidobacterium, o_Bifidobacteriales, p_Actinobacteria) from Actinobacteria phylum, and they were also positively associated with histidine degradation and proline biosynthesis pathways, respectively. Additionally, enriched 2 MEs and 1 ME in PD were positively associated with above inflammatory indicators and two bacteria (f_Lactobacillaceae, g_Lactobacillus) from Firmicutes phylum, and they were also positively associated with pyruvate fermentation to propanoate I and negatively associated with isopropanol biosynthesis, respectively. Of these MEs, two MEs from GROEL2, RPSC were derived from Mycobacterium tuberculosis, triggered the T cell immune response, as previously reported. Additionally, other candidate epitope peptides derived from Mycobacterium tuberculosis and Mycobacterium leprae may also have potential immune effects in PD. In all, the altered MEs in PD may relate to abnormalities in immunity and glutamate and propionate metabolism, which furthers our understanding of the pathogenesis of PD.


Assuntos
Actinobacteria/imunologia , Epitopos/imunologia , Firmicutes/imunologia , Doença de Parkinson/microbiologia , Actinobacteria/classificação , Actinobacteria/genética , Actinobacteria/metabolismo , Idoso , Biomarcadores , Vias Biossintéticas , Citocinas/sangue , Fezes/microbiologia , Feminino , Firmicutes/classificação , Firmicutes/genética , Firmicutes/metabolismo , Microbioma Gastrointestinal/genética , Microbioma Gastrointestinal/imunologia , Humanos , Inflamação , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/imunologia
8.
Int J Mol Sci ; 22(13)2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34208885

RESUMO

We previously demonstrated that flavonoid metabolites inhibit cancer cell proliferation through both CDK-dependent and -independent mechanisms. The existing evidence suggests that gut microbiota is capable of flavonoid biotransformation to generate bioactive metabolites including 2,4,6-trihydroxybenzoic acid (2,4,6-THBA), 3,4-dihydroxybenzoic acid (3,4-DHBA), 3,4,5-trihyroxybenzoic acid (3,4,5-THBA) and 3,4-dihydroxyphenylacetic acid (DOPAC). In this study, we screened 94 human gut bacterial species for their ability to biotransform flavonoid quercetin into different metabolites. We demonstrated that five of these species were able to degrade quercetin including Bacillus glycinifermentans, Flavonifractor plautii, Bacteroides eggerthii, Olsenella scatoligenes and Eubacterium eligens. Additional studies showed that B. glycinifermentans could generate 2,4,6-THBA and 3,4-DHBA from quercetin while F. plautii generates DOPAC. In addition to the differences in the metabolites produced, we also observed that the kinetics of quercetin degradation was different between B. glycinifermentans and F. plautii, suggesting that the pathways of degradation are likely different between these strains. Similar to the antiproliferative effects of 2,4,6-THBA and 3,4-DHBA demonstrated previously, DOPAC also inhibited colony formation ex vivo in the HCT-116 colon cancer cell line. Consistent with this, the bacterial culture supernatant of F. plautii also inhibited colony formation in this cell line. Thus, as F. plautii and B. glycinifermentans generate metabolites possessing antiproliferative activity, we suggest that these strains have the potential to be developed into probiotics to improve human gut health.


Assuntos
Ácido 3,4-Di-Hidroxifenilacético/farmacologia , Antineoplásicos/farmacologia , Bactérias/classificação , Bromobenzoatos/farmacologia , Ácido Gálico/farmacologia , Hidroxibenzoatos/farmacologia , Quercetina/química , Ácido 3,4-Di-Hidroxifenilacético/química , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Actinobacteria/metabolismo , Antineoplásicos/química , Bacillus/genética , Bacillus/isolamento & purificação , Bacillus/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Proteínas de Bactérias , Bacteroides/genética , Bacteroides/isolamento & purificação , Bacteroides/metabolismo , Bromobenzoatos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Clostridiales/genética , Clostridiales/isolamento & purificação , Clostridiales/metabolismo , Eubacterium/genética , Eubacterium/isolamento & purificação , Eubacterium/metabolismo , Ácido Gálico/química , Microbioma Gastrointestinal , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Células HCT116 , Humanos , Hidroxibenzoatos/química , Filogenia , Análise de Sequência de RNA
9.
ACS Chem Biol ; 16(8): 1456-1468, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34279911

RESUMO

Actinobacteria have been a rich source of novel, structurally complex natural products for many decades. Although the largest genus is Streptomyces, from which the majority of antibiotics in current and past clinical use were originally isolated, other less common genera also have the potential to produce a wealth of novel secondary metabolites. One example is the Kutzneria genus, which currently contains only five reported species. One of these species is Kutzneria albida DSM 43870T, which has 46 predicted biosynthetic gene clusters and is known to produce the macrolide antibiotic aculeximycin. Here, we report the isolation and structural characterization of two novel 30-membered glycosylated macrolides, epemicins A and B, that are structurally related to aculeximycin, from a rare Kutzneria sp. The absolute configuration for all chiral centers in the two compounds is proposed based on extensive 1D and 2D NMR studies and bioinformatics analysis of the gene cluster. Through heterologous expression and genetic inactivation, we have confirmed the link between the biosynthetic gene cluster and the new molecules. These findings show the potential of rare Actinobacteria to produce new, structurally diverse metabolites. Furthermore, the gene inactivation represents the first published report to genetically manipulate a representative of the Kutzneria genus.


Assuntos
Actinobacteria/química , Antibacterianos/farmacologia , Macrolídeos/farmacologia , Actinobacteria/genética , Actinobacteria/metabolismo , Antibacterianos/biossíntese , Antibacterianos/química , Antibacterianos/isolamento & purificação , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Descoberta de Drogas , Macrolídeos/química , Macrolídeos/isolamento & purificação , Macrolídeos/metabolismo , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Família Multigênica , Policetídeo Sintases/química , Policetídeo Sintases/genética , Policetídeo Sintases/metabolismo , Domínios Proteicos , Estereoisomerismo
10.
World J Microbiol Biotechnol ; 37(7): 120, 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34132920

RESUMO

The diversity of actinobacteria associated with marine ascidian Phallusia nigra from Andaman Islands was investigated. A total of 10 actinobacteria were isolated and based on the biochemical and molecular characterization, the isolates were assigned to 7 different actinobacterial genera. Eight putatively novel species belonging to genera Rhodococcus, Kineococcus, Kocuria, Janibacter, Salinispora and Arthrobacter were identified based on 16S rDNA sequence similarity with the NCBI database. The organic extracts of ten isolates displayed considerable bioactivity against test pathogens, which were Gram-positive and Gram-negative in nature. PCR-based screening for type I and type II polyketide synthases (PKS-I, PKS-II) and nonribosomal peptide synthetases (NRPS) revealed that, 10 actinobacterial isolates encoded at least one type of polyketide synthases biosynthesis gene. Majority of the isolates found to produce industrially important enzymes; amylase, protease, gelatinase, lipase, DNase, cellulase, urease, phosphatase and L-asparaginase. The present study emphasized that, ascidians are a prolific resource for novel bioactive actinobacteria with potential for novel drug discovery. This result expands the scope to functionally characterize the novel ascidian associated marine actinobacteria and their metabolites could be a source for the novel molecules of commercial interest.


Assuntos
Actinobacteria/classificação , Actinobacteria/enzimologia , Actinobacteria/genética , Organismos Aquáticos/microbiologia , Simbiose , Urocordados/microbiologia , Actinobacteria/metabolismo , Amilases/metabolismo , Animais , Antibacterianos/metabolismo , Asparaginase/metabolismo , Proteínas de Bactérias/metabolismo , Técnicas de Tipagem Bacteriana , Biodiversidade , Celulase/metabolismo , Celulose/metabolismo , DNA Bacteriano , Microbiologia Industrial , Ilhas , Lipase/metabolismo , Peptídeo Hidrolases/metabolismo , Peptídeo Sintases/genética , Policetídeo Sintases/genética , RNA Ribossômico 16S , Análise de Sequência de DNA
11.
Arch Microbiol ; 203(7): 4525-4538, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34148152

RESUMO

Cellulosimicrobium strain SE3T was isolated from the San Elijo coastal lagoon near San Diego. A whole genome-based phylogenetic comparison shows great heterogeneity within the Cellulosimicrobium genus. Based on average nucleotide identity, whole genome-based comparison, and the presence of a unique L-fucose metabolic pathway, strain SE3T was shown to belong to a novel species within the genus, together with five other strains. The name Cellulosimicrobium fucosivorans sp. nov. is proposed, with strain SE3T as the type strain. The strain encodes a unique alpha-L-fucosidase and the L-fucose metabolic pathway is homologous to the one recently described in Campylobacter jejuni. C. fucosivorans is able to grow on L-fucose, and interestingly, the biosynthesis of the yellow carotenoid is dependent on the presence of L-fucose in the media. The ability to metabolize fucose and the linked production of carotenoids are expected to provide C. fucosivorans with a competitive advantage in the sunny coastal lagoon area.


Assuntos
Actinobacteria , Carotenoides , Redes e Vias Metabólicas , Actinobacteria/classificação , Actinobacteria/genética , Actinobacteria/metabolismo , California , Carotenoides/metabolismo , Ácidos Graxos/análise , Fucose/metabolismo , Redes e Vias Metabólicas/genética , Filogenia , RNA Ribossômico 16S/genética , Água do Mar/microbiologia , Especificidade da Espécie
12.
Molecules ; 26(9)2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34062889

RESUMO

The pollution of arable lands and water with petroleum-derived products is still a valid problem, mainly due the extensive works aimed to improve their production technology to reduce fuel consumption and protect engines. An example of the upgraded fuels is the BP 98 unleaded petrol with Active technology. A pot experiment was carried out in which Eutric Cambisol soil was polluted with petrol to determine its effect on the microbiological and biochemical properties of this soil. Analyses were carried out to determine soil microbiome composition-with the incubation and metagenomic methods, the activity of seven enzymes, and cocksfoot effect on hydrocarbon degradation. The following indices were determined: colony development index (CD); ecophysiological diversity index (EP); index of cocksfoot effect on soil microorganisms and enzymes (IFG); index of petrol effect on soil microorganisms and enzymes (IFP); index of the resistance of microorganisms, enzymes, and cocksfoot to soil pollution with petrol (RS); Shannon-Weaver's index of bacterial taxa diversity (H); and Shannon-Weaver's index of hydrocarbon degradation (IDH). The soil pollution with petrol was found to increase population numbers of bacteria and fungi, and Protebacteria phylum abundance as well as to decrease the abundance of Actinobacteria and Acidobacteria phyla. The cultivation of cocksfoot on the petrol-polluted soil had an especially beneficial effect mainly on the bacteria belonging to the Ramlibacter, Pseudoxanthomonas, Mycoplana, and Sphingobium genera. The least susceptible to the soil pollution with petrol and cocksfoot cultivation were the bacteria of the following genera: Kaistobacter, Rhodoplanes, Bacillus, Streptomyces, Paenibacillus, Phenylobacterium, and Terracoccus. Cocksfoot proved effective in the phytoremediation of petrol-polluted soil, as it accelerated hydrocarbon degradation and increased the genetic diversity of bacteria. It additionally enhanced the activities of soil enzymes.


Assuntos
Actinobacteria/metabolismo , Actinomycetales/metabolismo , Poluentes Ambientais/análise , Poluição por Petróleo , Microbiologia do Solo , Poluentes do Solo , Biodegradação Ambiental , Monitoramento Ambiental , Gasolina , Hidrocarbonetos , Metagenoma , Microbiota
13.
Cells ; 10(6)2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070467

RESUMO

The DNA repair endonuclease EndoMS/NucS is highly conserved in Archaea and Actinobacteria. This enzyme is able to recognize and cleave dsDNA carrying a mismatched base pair, and its activity is enhanced by the interaction with the sliding clamp of the replisome. Today, EndoMS/NucS has been established as the key protein of a non-canonical mismatch repair (MMR) pathway, acting specifically in the repair of transitions and being essential for maintaining genome stability. Despite having some particularities, such as its lower activity on transversions and the inability to correct indels, EndoMS/NucS meets the main hallmarks of a MMR. Its absence leads to a hypermutator phenotype, a transition-biased mutational spectrum and an increase in homeologous recombination. Interestingly, polymorphic EndoMS/NucS variants with a possible effect in mutation rate have been detected in clinical isolates of the relevant actinobacterial pathogen Mycobacterium tuberculosis. Considering that MMR defects are often associated with the emergence of resistant bacteria, the existence of EndoMS/NucS-defective mutators could have an important role in the acquisition of antibiotic resistance in M. tuberculosis. Therefore, a further understanding of the EndoMS/NucS-mediated non-canonical MMR pathway may reveal new strategies to predict and fight drug resistance. This review is focused on the recent progress in NucS, with special emphasis on its effect on genome stability and evolvability in Actinobacteria.


Assuntos
Actinobacteria , Proteínas de Bactérias/metabolismo , Reparo de Erro de Pareamento de DNA , Actinobacteria/genética , Actinobacteria/metabolismo , Pareamento Incorreto de Bases , Instabilidade Genômica , Taxa de Mutação
14.
Methods Mol Biol ; 2296: 59-75, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33977442

RESUMO

Extremophilic actinomycetes strains can survive extreme saline and alkaline environments and produce antimicrobial agents. In this chapter, we discuss laboratory methods that can be used to isolate and characterize actinomycetes strains capable of potentially producing novel antimicrobial agent(s) when cultured in conditions that mimic the environments from which they were isolated. Methods used to screen for antibacterial and antiviral activities from these producer strains, and microbiological and molecular approaches used to identify these strains are described. Here we describe three methods. Method 1 focuses on the strategy to select optimal conditions to synthesize and accumulate the antibiotics from the studied actinomycetes strains by preparing crude extracts. In Method 2, we describe the screening strategies used to test the actinomycetes strains against gram-negative and gram-positive bacteria, antifungal agents, multidrug-resistant pathogens (MDR), and viral pathogens. Thus, the specific techniques to test for MDR pathogens such as the disk diffusion assay and wells assay are outlined. We also describe the antiviral activity screening of the selected actinomycetes extracts in Method 2 of this chapter. Specifically, we concentrate on methods used to test for antiviral activities such as primary hemolytic, hemagglutination, neuraminidase, and specific virus-inhibitory activities. Finally, the Method 3 section reveals the microbiological techniques used to morphologically characterize the actinomycetes strains that depend on the culture medium utilized for growth. Additionally, the method used to perform a detailed characterization of the morphology that actinomycetes strains possess is specified by the protocol for sample preparation and visualization using the scanning electron microscopy (SEM). Finally, we summarize the molecular approaches used to characterize actinomycetes strains, focusing specifically on the PCR and sequencing techniques.


Assuntos
Actinobacteria/metabolismo , Anti-Infecciosos/metabolismo , Extremófilos/metabolismo , Anti-Infecciosos/farmacologia , Antivirais/metabolismo , Antivirais/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos
15.
Methods Mol Biol ; 2296: 143-149, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33977445

RESUMO

Screening extracts from the fermentation broth of a collection of actinomycetes can be performed conveniently on a microtiter plate format. Here we describe a method suited for the screening of antibacterial extracts or compounds against Gram-positive and Gram-negative aerobic, non-fastidious bacteria, Escherichia coli and Kocuria rhizophila. Both bacteria have been chosen to minimize the need for containment as they belong to risk group 1.


Assuntos
Actinobacteria/metabolismo , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Fermentação/fisiologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos
16.
Methods Mol Biol ; 2296: 217-225, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33977451

RESUMO

Antifungal assay in vitro is a useful tool for the characterization of biological activity of microbial extracts. Here we describe a simple in vitro test at two final extract concentrations that allows long-term storage of the plates containing dry extracts before using. The assay protocol is described for two fungal strains, a unicellular yeast, with clinical interest (Candida albicans), and a sporulated and phytopathogenic filamentous fungus (Botrytis cinerea). They could serve as models for adapting other filamentous/yeast-like fungi.Plates are prepared by placing 100 and 10 µg, respectively, of the organic extracts in microtiter 96-well plates, where the test will be performed. The assay develops by adding 200 µL of a spore suspension 104 spores/mL for B. cinerea and 106 cells/mL for C. albicans in Sabouraud medium.After the incubation of the plates at 25 °C, for 2 days for C. albicans and 5 days for B. cinerea , the growth of the fungal targets is evaluated in a plate reader for unicellular yeast , or visually under the microscope for filamentous fungi. If visually evaluated, observed growth can be assigned to different categories by comparison with growth control and inhibition control. Inhibition effect on C. albicans at eight concentrations of amphotericin B (8-4-2-1-0.5-0.25-0.125-0.00625 µg/mL) or B. cinerea exposed of eight concentrations of iprodione (100-50-10-5-1-0.5-0.1-0.05 µg/mL) are used as inhibition controls, respectively.


Assuntos
Actinobacteria/metabolismo , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Botrytis/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Esporos Fúngicos/efeitos dos fármacos
17.
Nat Commun ; 12(1): 3209, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-34050180

RESUMO

Recent studies have demonstrated that drought leads to dramatic, highly conserved shifts in the root microbiome. At present, the molecular mechanisms underlying these responses remain largely uncharacterized. Here we employ genome-resolved metagenomics and comparative genomics to demonstrate that carbohydrate and secondary metabolite transport functionalities are overrepresented within drought-enriched taxa. These data also reveal that bacterial iron transport and metabolism functionality is highly correlated with drought enrichment. Using time-series root RNA-Seq data, we demonstrate that iron homeostasis within the root is impacted by drought stress, and that loss of a plant phytosiderophore iron transporter impacts microbial community composition, leading to significant increases in the drought-enriched lineage, Actinobacteria. Finally, we show that exogenous application of iron disrupts the drought-induced enrichment of Actinobacteria, as well as their improvement in host phenotype during drought stress. Collectively, our findings implicate iron metabolism in the root microbiome's response to drought and may inform efforts to improve plant drought tolerance to increase food security.


Assuntos
Actinobacteria/metabolismo , Secas , Ferro/metabolismo , Microbiota/fisiologia , Sorghum/fisiologia , Aclimatação , Actinobacteria/genética , Produção Agrícola , Segurança Alimentar , Metagenômica/métodos , Raízes de Plantas/microbiologia , RNA-Seq , Rizosfera , Microbiologia do Solo , Sorghum/microbiologia , Estresse Fisiológico
18.
FEMS Microbiol Lett ; 368(10)2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-34057181

RESUMO

Their biochemical versatility and biotechnological importance make actinomycete bacteria attractive targets for ambitious genetic engineering using the toolkit of synthetic biology. But their complex biology also poses unique challenges. This mini review discusses some of the recent advances in synthetic biology approaches from an actinomycete perspective and presents examples of their application to the rational improvement of industrially relevant strains.


Assuntos
Actinobacteria/genética , Biologia Sintética/métodos , Actinobacteria/metabolismo , Microbiologia Industrial/métodos , Microbiologia Industrial/tendências , Engenharia Metabólica , Biologia Sintética/tendências
19.
Microbiol Res ; 248: 126768, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33873141

RESUMO

The increase in the number of deaths from infections caused by multidrug-resistant bacteria and cancer diseases highlights the need for new molecules with biological activity. Actinobacteria represent a potential source of new compounds, as these microorganisms have already produced a great diversity of clinically employed antibiotics. Endophytes from unexplored biomes, such as the Pantanal (the largest wetland in the world), can be a source of new molecules. Hymenachne amplexicaulis is among the unexplored native plants of the Pantanal in terms of its endophytic community. This plant is considered a weed in other countries due to its ability to adapt and compete with native plants, and there is evidence to suggest that the endophytic community of H. amplexicaulis plays an important role in this competitiveness. To explore its therapeutic potential, the present study isolated, identified (using partial sequence of the 16S rDNA) and bioprospected H. amplexicaulis endophytic actinobacteria. Ten isolates belonging to the genera Streptomyces, Microbispora, Leifsonia, and Verrucosispora were obtained from root fragments. The susceptibility profile of the isolates to the different classes of antibiotics was evaluated, with 80 % of the isolates showing resistance to the antibiotics Nalidixic Acid, Ampicillin, Chloramphenicol, Oxacillin, and Rifampicin. To assess antibacterial and antitumor activities, methanolic extracts were obtained by fermentation in SG culture medium at 36 °C at 180 rpm for 10 days. The extract produced from the S. albidoflavus CMRP4854 isolate was the only one to show activity against the Gram-negative bacterium Acinetobacter baumanii. Due to the great clinical importance of this pathogen and the difficulty in obtaining active compounds against it, the CMRP4854 isolate should be further investigated for the identification of active compounds and mode of action. We also emphasize the results obtained by the extract of the isolates Streptomyces albidoflavus CMRP4852 and Verrucosispora sp. CMRP4860 that presented antibacterial effect against Methicilin-resistant Staphylococcus aureus (MRSA) (MIC: 1.5 µg/mL and 13 µg/mL, respectively) and Vancomycin-resistant Enterococcus (VRE) (MIC: 40 µg/mL for both extracts). Extracts (200 µg/mL) of these two endophytes also showed selective cytotoxicity action against murine B16-F10 melanoma cells. However, the CMRP4852 extract also affected the density of normal cells. Due to these results, the crude extract of isolate CMRP4860 Verrucosispora sp., which was the only one that presented cytotoxicity and reduced cell density only in tumor cells, was selected for subsequent analysis involving scale-up fermentation of the CMRP4860 resulting in 9 fractions that were tested against both bacteria and tumor cells, with particular fractions showing promise and meriting further investigation. Taken together, the results of this study not only show for the first time that the endophytic community of H. amplexicaulis actinobacteria can produce secondary metabolites that potentially possess important antibacterial and cytotoxic properties, but also reinforce the pressing need to conserve biomes such as the Brazilian Pantanal.


Assuntos
Actinobacteria/química , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Endófitos/química , Poaceae/microbiologia , Actinobacteria/classificação , Actinobacteria/isolamento & purificação , Actinobacteria/metabolismo , Animais , Antibacterianos/química , Antibacterianos/metabolismo , Antineoplásicos/química , Antineoplásicos/metabolismo , Brasil , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Endófitos/classificação , Endófitos/isolamento & purificação , Endófitos/metabolismo , Enterococcus/efeitos dos fármacos , Enterococcus/crescimento & desenvolvimento , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Camundongos , Áreas Alagadas
20.
J Ind Microbiol Biotechnol ; 48(3-4)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-33928358

RESUMO

Sulfonamides and sulfamates are a group of organosulfur compounds that contain the signature sulfamoyl structural motif. These compounds were initially only known as synthetic antibacterial drugs but were later also discovered as natural products. Eight highly potent examples have been isolated from actinomycetes to date, illustrating the large biosynthetic repertoire of this bacterial genus. For the biosynthesis of these compounds, several distinct and unique biosynthetic machineries have been discovered, capable to generate the unique S-N bond. For the creation of novel, second generation natural products by biosynthetic engineering efforts, a detailed understanding of the underlying enzyme machinery toward potent structural motifs is crucial. In this review, we aim to summarize the current state of knowledge on sulfonamide and sulfamate biosynthesis. A detailed discussion for the secondary sulfamate ascamycin, the tertiary sulfonamide sulfadixiamycin A, and the secondary sulfonamide SB-203208 is provided and their bioactivities and mode of actions are discussed.


Assuntos
Actinobacteria/metabolismo , Antibacterianos/metabolismo , Sulfonamidas/metabolismo , Ácidos Sulfônicos/metabolismo , Actinobacteria/química , Actinobacteria/genética , Antibacterianos/química , Produtos Biológicos/química , Produtos Biológicos/metabolismo , Sulfonamidas/química , Ácidos Sulfônicos/química
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