RESUMO
In nature, the vast majority of sesquiterpenes are produced by type I mechanisms, and glycosylated sesquiterpenes are rare in actinobacteria. Streptomyces olindensis DAUFPE 5622 produces the sesquiterpenes olindenones A-G, a new class of rearranged drimane sesquiterpenes. Olindenones B-D are oxygenated derivatives of olindenone A, while olindenones E-G are analogs glycosylated with dideoxysugars. 13C-isotope labeling studies demonstrated olindenone A biosynthesis occurs via the methylerythritol phosphate (MEP) pathway and suggested the rearrangement is only partially concerted. Based on the structures, one potential mechanism of olindenone A formation proceeds by cyclization of the linear terpenoid precursor, likely occurring via a terpene cyclase-mediated type II mechanism whereby the terminal alkene of the precursor is protonated, triggering carbocation-driven cyclization followed by rearrangement. Diphosphate hydrolysis may occur either before or after cyclization. Although a biosynthetic route is proposed, the terpene cyclase gene responsible for producing olindenones currently remains unidentified.
Assuntos
Sesquiterpenos , Streptomyces , Sesquiterpenos/química , Terpenos/metabolismo , Streptomyces/metabolismo , CiclizaçãoRESUMO
Resorting to a One Strain Many Compounds (OSMAC) approach, the marine Streptomyces sp. BRB081 strain was grown in six different media settings over 1, 2, 3 or 7 days. Extractions of mycelium and broth were conducted separately for each media and cultivation period by sonication using methanol/acetone 1:1 and agitation with ethyl acetate, respectively. All methanol/acetone and ethyl acetate crude extracts were analysed by HPLC-MS/MS and data treatment was performed through GNPS platform using MZmine 2 software. In parallel, the genome was sequenced, assembled and mined to search for biosynthetic gene clusters (BGC) of secondary metabolites using the AntiSMASH 5.0 software. Spectral library search tool allowed the annotation of desferrioxamines, fatty acid amides, diketopiperazines, xanthurenic acid and, remarkably, the cyclic octapeptides surugamides. Molecular network analysis allowed the observation of the surugamides cluster, where surugamide A and the protonated molecule corresponding to the B-E isomers, as well as two potentially new analogues, were detected. Data treatment through MZmine 2 software allowed to distinguish that the largest amount of surugamides was obtained by cultivating BRB081 in SCB medium during 7 days and extraction of culture broth. Using the same data treatment, a chemical barcode was created for easy visualization and comparison of the metabolites produced overtime in all media. By genome mining of BRB081 four regions of biosynthetic gene clusters of secondary metabolites were detected supporting the metabolic data. Cytotoxic evaluation of all crude extracts using MTT assay revealed the highest bioactivity was also observed for extracts obtained in the optimal conditions as those for surugamides production, suggesting these to be the main active compounds herein. This method allowed the identification of compounds in the crude extracts and guided the selection of best conditions for production of bioactive compounds.
Assuntos
Antineoplásicos/isolamento & purificação , Metabolômica/métodos , Metabolismo Secundário , Streptomyces/crescimento & desenvolvimento , Proteínas de Bactérias/genética , Técnicas Bacteriológicas , Vias Biossintéticas , Biologia Marinha , Família Multigênica , Filogenia , Streptomyces/química , Streptomyces/classificação , Sequenciamento Completo do GenomaRESUMO
Burkholderia species have different lifestyles establishing mutualist or pathogenic associations with plants and animals. Changes in the ecological behavior of these bacteria may depend on genetic variations in response to niche adaptation. Here, we studied 15 Burkholderia strains isolated from different environments with respect to genetic and phenotypic traits. By Multilocus Sequence Analysis (MLSA) these isolates fell into 6 distinct groups. MLSA clusters did not correlate with strain antibiotic sensitivity, but with the bacterial ability to produce antimicrobial compounds and control orchid necrosis. Further, the B. seminalis strain TC3.4.2R3, a mutualistic bacterium, was inoculated into orchid plants and the interaction with the host was evaluated by analyzing the plant response and the bacterial oxidative stress response in planta. TC3.4.2R3 responded to plant colonization by increasing its own growth rate and by differential gene regulation upon oxidative stress caused by the plant, while reducing the plant's membrane lipid peroxidation. The bacterial responses to oxidative stress were recapitulated by bacterial exposure to the herbicide paraquat. We suggest that the ability of Burkholderia species to successfully establish in the rhizosphere correlates with genetic variation, whereas traits associated with antibiotic resistance are more likely to be categorized as strain specific.
Assuntos
Adaptação Biológica/genética , Infecções por Burkholderia , Burkholderia , Interações entre Hospedeiro e Microrganismos , Orchidaceae/microbiologia , Aclimatação/genética , Anti-Infecciosos/farmacologia , Agentes de Controle Biológico/farmacologia , Burkholderia/genética , Burkholderia/crescimento & desenvolvimento , Burkholderia/isolamento & purificação , Burkholderia/metabolismo , Resistência Microbiana a Medicamentos/genética , Endófitos/genética , Endófitos/crescimento & desenvolvimento , Endófitos/isolamento & purificação , Endófitos/metabolismo , Genes Bacterianos , Ilhas Genômicas , Genótipo , Peroxidação de Lipídeos , Tipagem de Sequências Multilocus , Orchidaceae/fisiologia , Estresse Oxidativo/genética , Fenótipo , Filogenia , Doenças das Plantas/microbiologia , Doenças das Plantas/terapia , RNA Ribossômico 16S/genética , Simbiose , TranscriptomaRESUMO
[This corrects the article DOI: 10.1128/genomeA.00552-17.].
RESUMO
The genus Micromonospora comprises actinomycetes with high biotechnological potential, due to their ability to produce secondary metabolites and enzymes. In this study, we report the draft genome sequence of Micromonospora sp. NBS 11-29, which showed antibacterial, cellulolytic, and xylanolytic activities under in vitro conditions.
RESUMO
Streptomyces olindensis DAUFPE 5622, which was isolated from a Brazilian soil sample, produces the antitumor anthracycline cosmomycin D. The genome sequence is 9.4 Mb in length, with a G+C content of 71%. Thirty-four putative secondary metabolite biosynthetic gene clusters were identified, including the cosmomycin D cluster.
RESUMO
PURPOSE: Anthracyclines have been widely used as antitumor agents, playing a crucial role in the successful treatment of many types of cancer, despite some side effects related to cardiotoxicity. New anthracyclines have been designed and tested, but the first ones discovered, doxorubicin and daunorubicin, continue to be the drugs of choice. Despite their extensive use in chemotherapy, little is known about the DNA repair mechanisms involved in the removal of lesions caused by anthracyclines. The anthracycline cosmomycin D is the main product isolated from Streptomyces olindensis, characterized by a peculiar pattern of glycosylation with two trisaccharide rings attached to the A ring of the tetrahydrotetracene. METHODS: We assessed the induction of apoptosis (Sub-G1) by cosmomycin D in nucleotide excision repair-deficient fibroblasts (XP-A and XP-C) as well as the levels of DNA damage (alkaline comet assay). RESULTS: Treatment of XP-A and XP-C cells with cosmomycin D resulted in apoptosis in a time-dependent manner, with highest apoptosis levels observed 96 h after treatment. The effects of cosmomycin D were equivalent to those obtained with doxorubicin. The broad caspase inhibitor Z-VAD-FMK strongly inhibited apoptosis in these cells, and DNA damage induced by cosmomycin D was confirmed by alkaline comet assay. CONCLUSIONS: Cosmomycin D induced time-dependent apoptosis in nucleotide excision repair-deficient fibroblasts. Despite similar apoptosis levels, cosmomycin D caused considerably lower levels of DNA damage compared to doxorubicin. This may be related to differences in structure between cosmomycin D and doxorubicin.
Assuntos
Antraciclinas/toxicidade , Antineoplásicos/toxicidade , Dano ao DNA , Antraciclinas/química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular , Ensaio Cometa , Reparo do DNA , Fibroblastos/efeitos dos fármacos , HumanosRESUMO
Glycosylation pattern in cosmomycins is a distinctive feature among anthracyclines. These antitumor compounds possess two trisaccharide chains attached at C-7 and C-10, each of them with structural variability, mainly at the distal deoxysugar moieties. We have characterized a 14-kb chromosomal region from Streptomyces olindensis containing 13 genes involved in cosmomycin biosynthesis. Two of the genes, cosG and cosK, coding for glycosyltransferase were inactivated with the generation of five new derivatives. Structural elucidation of these compounds showed altered glycosylation patterns indicating the capability of both glycosyltransferases of transferring deoxysugars to both sides of the aglycone and the flexibility of CosK with respect to the deoxysugar donor. A model is proposed for the glycosylation steps during cosmomycins biosynthesis.
Assuntos
Antraciclinas/química , Antraciclinas/metabolismo , Glicosiltransferases/genética , Streptomyces/metabolismo , Proteínas de Bactérias/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Deleção de Genes , Ordem dos Genes , Teste de Complementação Genética , Glicosilação , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Estrutura Molecular , Análise de Sequência de DNA , Streptomyces/enzimologia , Streptomyces/genéticaRESUMO
The effect of pH on cell growth and retamycin production in batch bioreactor cultures of Streptomyces olindensis ICB20 was investigated. In fermentations pH-controlled over the range 6.0-8.0, the highest retamycin production was achieved at pH 7.0, and the maximum concentration of retamycin, about 1.36 A (absorbance) units, was about 43, 58 and 232% higher than the values obtained at pH 7.5, 6.0 and 8.0 respectively.
Assuntos
Antraciclinas/metabolismo , Antibióticos Antineoplásicos/biossíntese , Reatores Biológicos/microbiologia , Técnicas de Cultura de Células/métodos , Concentração de Íons de Hidrogênio , Streptomyces/crescimento & desenvolvimento , Streptomyces/metabolismo , Proliferação de Células , Streptomyces/químicaRESUMO
Cosmomycin D (CosD) is the major constituent fraction isolated from a culture of Streptomyces olindensis ICB20. The ability of this compound to intercalate with double-stranded DNA was studied by gel mobility shift assays and electrospray ionization mass spectrometry (ESI-MS). ESI-MS experiments showed that the complex of CosD with 16-mer double-stranded DNA was at least as stable as a complex of daunorubicin with the same DNA sequence. This is the first study showing DNA binding properties of an anthracycline containing a beta-rhodomycinone aglycone chromophore O-linked to two trisaccharide chains.