The endophytic actinobacteria associated with Artemisia herba-alba (synonym: Seriphidium herba-alba) are highly diverse. This study aimed to illustrate the extent of their differences from the free-living actinobacteria in the surrounding environment. A selection of eighteen actinobacteria inhabiting A. herba-alba were compared with twenty and ten actinobatceria isolates from the surrounding desert and groundwater, respectively, representing six genera. Antagonistic and enzymatic activities, plant growth-promoting traits, and the occurrence of biosynthetic genes were compared among the isolates. Data were analyzed statistically using principal component analysis (PCA) and were visualized using heat map. Endophytic strains showed higher antimicrobial activity and production of plant growth promoters compared to desert and groundwater strains. Polyketide synthase and non-ribosomal peptide synthetase gene clusters were detected at higher frequencies in the endophytic strains (8 and 11 strains, respectively) than the desert strains (1 and 2 strains, respectively). In contrast, both gene clusters were not detected in the groundwater strains. The PCA revealed unique metabolic characteristics of the endophytes. The heatmap clustered the endophytic strains apart from the free-living strains, indicating distinctive qualitative and quantitative bioactivities. Analysis of 16S rRNA genes confirmed the chemotaxonomic identity of all but two strains, with > 94.5% similarity. Six endophytes displayed < 99.5% similarity with their closest type strains, which might indicate species novelty. This study provides an evidence of functional differences and possible species novelty of the endophytic actinobacteria inhabiting A. herba-alba, compared with the free-living species.

• MeSH
• Actinobacteria * genetics   MeSH
• Endophytes genetics   MeSH
• Phylogeny MeSH
• Artemisia * MeSH
• RNA, Ribosomal, 16S genetics   MeSH
• Publication type
• Journal Article MeSH

The emergence of communicable and non-communicable diseases has posed a health challenge for millions of people worldwide and is a major threat to the economic and social development in the coming century. The occurrence of the recent pandemic, SARS-CoV-2, caused by lethal severe acute respiratory syndrome coronavirus 2, is one such example. Rapid research and development of drugs for the treatment and management of these diseases have become an incredibly challenging task for the pharmaceutical industry. Although, substantial attention has been paid to the discovery of therapeutic compounds from natural sources having significant medicinal potential, their synthesis has made a slow progress. Hence, the discovery of new targets by the application of the latest biotechnological and synthetic biology approaches is very much the need of the hour. Polyketides (PKs) and non-ribosomal peptides (NRPs) found in bacteria, fungi and plants are a diverse family of natural products synthesized by two classes of enzymes: polyketide synthases (PKS) and non-ribosomal peptide synthetases (NRPS). These enzymes possess immense biomedical potential due to their simple architecture, catalytic capacity, as well as diversity. With the advent of the latest in-silico and in-vitro strategies, these enzymes and their related metabolic pathways, if targeted, can contribute highly towards the biosynthesis of an array of potentially natural drug leads that have antagonist effects on biopolymers associated with various human diseases. In the face of the rising threat from multidrug-resistant pathogens, this will further open new avenues for the discovery of novel and improved drugs by combining natural and synthetic approaches. This review discusses the relevance of polyketides and non-ribosomal peptides and the improvement strategies for the development of their derivatives and scaffolds, and how they will be beneficial for future bioprospecting and drug discovery.

• MeSH
• COVID-19 * MeSH
• COVID-19 Drug Treatment MeSH
• Humans MeSH
• Peptides pharmacology   therapeutic use   MeSH
• Polyketides * chemistry   metabolism   pharmacology   MeSH
• SARS-CoV-2 MeSH
• Drug Development MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

The main bottleneck in the return of industrial butanol production from renewable feedstock through acetone-butanol-ethanol (ABE) fermentation by clostridia, such as Clostridium beijerinckii, is the low final butanol concentration. The problem is caused by the high toxicity of butanol to the production cells, and therefore, understanding the mechanisms by which clostridia react to butanol shock is of key importance. Detailed analyses of transcriptome data that were obtained after butanol shock and their comparison with data from standard ABE fermentation have resulted in new findings, while confirmed expected population responses. Although butanol shock resulted in upregulation of heat shock protein genes, their regulation is different than was assumed based on standard ABE fermentation transcriptome data. While glucose uptake, glycolysis, and acidogenesis genes were downregulated after butanol shock, solventogenesis genes were upregulated. Cyclopropanation of fatty acids and formation of plasmalogens seem to be significant processes involved in cell membrane stabilization in the presence of butanol. Surprisingly, one of the three identified Agr quorum-sensing system genes was upregulated. Upregulation of several putative butanol efflux pumps was described after butanol addition and a large putative polyketide gene cluster was found, the transcription of which seemed to depend on the concentration of butanol.

• MeSH
• Biological Transport genetics   MeSH
• Bioreactors microbiology   MeSH
• Cell Membrane metabolism   MeSH
• Butanols toxicity   MeSH
• Clostridium beijerinckii drug effects   genetics   metabolism   MeSH
• Stress, Physiological genetics   MeSH
• Glucose metabolism   MeSH
• Glycolysis genetics   physiology   MeSH
• Fatty Acids metabolism   MeSH
• Plasmalogens biosynthesis   MeSH
• Heat-Shock Proteins metabolism   MeSH
• Quorum Sensing genetics   MeSH
• Gene Expression Profiling MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Efektivní vyhledávání producentů nových, farmaceuticky atraktivních, přírodních látek vyžaduje uplatnění nových skríningových technik s využitím genomových informací. Rostoucí informace o genetice biosyntézy přírodních látek a jejich strukturních komponent umožňuje využít nově charakterizované enzymové systémy jako markery při genetickém skríningu potenciálních producentů strukturně a funkčně unikátních aktivních látek, které se mohou uplatnit jako nová antibiotika, imunomodulátory a kancerostatika. V projektu budou takto využity dva modelové enzymy aktinomycet, cyklizující aminolevulinátsyntáza a nový typ polyketidsyntázy specifický pro krátké lineární polyketidy.; Effective search for producers of novel, pharmaceutically attractive natural compounds requires application of new screening techniques using genomic data. Growing information on the genetics of biosynthesis of natural compounds and their structural components, brings the possibility to use newly characterized enzymatic systems as markers in genetic screening of potential producers of structuraly and functionaly unique active metabolites, which may find it application as novel antibiotics, immunomodulators and cancerostatics. Two model enzymes of actinomycetes, the cyclizing aminolevulinate synthase and a novel type of type II polyketides synthase specific for short linear polyketide chains, will be employed in the project.

• MeSH
• Actinomycetaceae isolation & purification   MeSH
• Anti-Bacterial Agents MeSH
• Biomarkers analysis   MeSH
• Biosynthetic Pathways MeSH
• Enzymes MeSH
• Genetic Testing methods   MeSH
• Immunologic Factors MeSH
• Humans MeSH
• Drug Discovery methods   MeSH
• Check Tag
• Humans MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• biochemie
• farmacie a farmakologie
• NML Publication type
• závěrečné zprávy o řešení grantu AZV MZ ČR

Microbiota can significantly contribute to colorectal cancer initiation and development. It was described that E. coli harbouring polyketide synthase (pks) genes can synthetize bacterial toxin colibactin, which was first described by Nougayrede's group in 2006. E. coli positive for pks genes were overrepresented in colorectal cancer biopsies and, therefore, prevalence and the effect of pks positive bacteria as a risk factor in colorectal cancer development is in our interest. Interestingly, pks gene cluster in E. coli shares a striking 100% sequence identity with K. pneumoniae, suggesting that their function and regulation are conserved. Moreover, K. pneumoniae can express a variety of virulence factors, including capsules, siderophores, iron-scavenging systems, adhesins and endotoxins. It was reported that pks cluster and thereby colibactin is also related to the hypervirulence of K. pneumoniae. Acquisition of the pks locus is associated with K. pneumoniae gut colonisation and mucosal invasion. Colibactin also increases the likelihood of serious complications of bacterial infections, such as development of meningitis and potentially tumorigenesis. Even though K. pneumoniae is undoubtedly a gut colonizer, the role of pks positive K. pneumoniae in GIT has not yet been investigated. It seems that CRC-distinctive microbiota is already present in the early stages of cancer development and, therefore, microbiome analysis could help to discover the early stages of cancer, which are crucial for effectiveness of anticancer therapy. We hypothesize, that pks positive K. pneumoniae can be a potential biomarker of tumour prevalence and anticancer therapy response.

• MeSH
• Bacterial Toxins * MeSH
• Escherichia coli MeSH
• Klebsiella pneumoniae MeSH
• Colorectal Neoplasms * chemically induced   MeSH
• Humans MeSH
• Peptides MeSH
• Polyketides * toxicity   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Systematic Review MeSH

(1) Background: Manumycins are small actinomycete polyketides with prominent cancerostatic and immunosuppressive activities via inhibition of various eukaryotic enzymes. Their overall activity towards human cells depends on the structural variability of both their polyketide chains, mainly the upper one. In our genetic screening project to find novel producers of anti-inflammatory manumycins, the strain Saccharothrix espanaensis DSM44229 was identified as containing a novel manumycin-type biosynthetic gene cluster (BGC). (2) Methods: The biosynthetic genes appeared to be silent under all assayed laboratory conditions. Several techniques were used to activate the BGC, including: (i) heterologous expression in various hosts, (ii) overexpression of putative pathway-specific regulatory genes, and (iii) overexpression of a bottleneck cyclizing aminolevulinate synthase gene in both natural and heterologous producers. (3) Results: Multiple novel manumycin-type compounds were produced at various levels by genetically-modified strains, sharing a tetraene lower chain structure with a colabomycin subgroup of manumycins, but possessing much shorter and saturated upper chains. (4) Conclusions: A cryptic manumycin-type BGC was successfully activated by genetic means to gain production of novel manumycin-type compounds for future comparative activity assays. Heterologously produced compounds were identical to those found after final activation of the BGC in the original strain, proving the intactness of the cloned BGC.

• Publication type
• Journal Article MeSH

Some aromatic polyketides such as dietary flavonoids have gained reputation as miraculous molecules with preeminent beneficial effects on human health, for example, as antioxidants. However, there is little conclusive evidence that dietary flavonoids provide significant leads for developing more effective drugs, as the majority appears to be of negligible medicinal importance. Some aromatic polyketides of limited distribution have shown more interesting medicinal properties and additional research should be focused on them. Combretastatins, analogues of phenoxodiol, hepatoactive kavalactones, and silymarin are showing a considerable promise in the advanced phases of clinical trials for the treatment of various pathologies. If their limitations such as adverse side effects, poor water solubility, and oral inactivity are successfully eliminated, they might be prime candidates for the development of more effective and in some case safer drugs. This review highlights some of the newer compounds, where they are in the new drug pipeline and how researchers are searching for additional likely candidates.

• MeSH
• Antioxidants * chemistry   therapeutic use   MeSH
• Flavonoids * chemistry   therapeutic use   MeSH
• Clinical Trials as Topic MeSH
• Humans MeSH
• Polyketides * chemistry   therapeutic use   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

Fatty acids are essential components of biological membranes, important for the maintenance of cellular structures, especially in organisms with complex life cycles like protozoan parasites. Apicomplexans are obligate parasites responsible for various deadly diseases of humans and livestock. We analyzed the fatty acids produced by the closest phototrophic relatives of parasitic apicomplexans, the chromerids Chromera velia and Vitrella brassicaformis, and investigated the genes coding for enzymes involved in fatty acids biosynthesis in chromerids, in comparison to their parasitic relatives. Based on evidence from genomic and metabolomic data, we propose a model of fatty acid synthesis in chromerids: the plastid-localized FAS-II pathway is responsible for the de novo synthesis of fatty acids reaching the maximum length of 18 carbon units. Short saturated fatty acids (C14:0-C18:0) originate from the plastid are then elongated and desaturated in the cytosol and the endoplasmic reticulum. We identified giant FAS I-like multi-modular enzymes in both chromerids, which seem to be involved in polyketide synthesis and fatty acid elongation. This full-scale description of the biosynthesis of fatty acids and their derivatives provides important insights into the reductive evolutionary transition of a phototropic algal ancestor to obligate parasites.

• MeSH
• Apicomplexa classification   genetics   metabolism   MeSH
• Biosynthetic Pathways genetics   MeSH
• Fatty Acid Desaturases classification   genetics   metabolism   MeSH
• Species Specificity MeSH
• Fatty Acid Elongases classification   genetics   metabolism   MeSH
• Phylogeny MeSH
• Humans MeSH
• Fatty Acids biosynthesis   MeSH
• Evolution, Molecular MeSH
• Protozoan Infections parasitology   MeSH
• Protozoan Proteins classification   genetics   metabolism   MeSH
• Fatty Acid Synthase, Type II classification   genetics   metabolism   MeSH
• Fatty Acid Synthase, Type I classification   genetics   metabolism   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Current treatment of chronic diseases includes, among others, application of cytokines, monoclonal antibodies, cellular therapies, and immunostimulants. As all the underlying mechanisms of a particular diseases are not always fully clarified, treatment can be inefficient and associated with various, sometimes serious, side effects. Small secondary metabolites produced by various microbes represent an attractive alternative as future anti-inflammatory drug leads. Compared to current drugs, they are cheaper, can often be administered orally, but still can keep a high target-specificity. Some compounds produced by actinomycetes or fungi have already been used as immunomodulators-tacrolimus, sirolimus, and cyclosporine. This work documents strong anti-inflammatory features of another secondary metabolite of streptomycetes-manumycin-type polyketides. We compared the effect of four related compounds: manumycin A, manumycin B, asukamycin, and colabomycin E on activation and survival of human monocyte/macrophage cell line THP-1. The anti-cancer effect of manucycine A has been demonstrated; the immunomodulatory capacities of manumycin A are obvious when using micromolar concentrations. The application of all four compounds in 0.25-5 μM concentrations leads to efficient, concentration-dependent inhibition of IL-1β and TNF expression in THP-1 upon LPS stimulation, while the three latter compounds show a significantly lower pro-apoptotic effect than manumycin A. We have demonstrated the anti-inflammatory capacity of selected manumycin-type polyketides.

• Publication type
• Journal Article MeSH

From undisturbed Antarctic habitats (permafrost sediments 30-150 thousand years of age, water of Radok Lake) and superficial deposits contaminated with petroleum products, we isolated 14 and 9 strains of Penicillium fungi, respectively. Comparison of the fungal complexes showed them to differ by species composition; only two species-P. palitans and P. solitum-were in the species lists of both groups. The identified secondary metabolites in the investigated strains belonged to diketopiperazine (group of roquefortines, rugulosuvin B), benzodiazepine (anacin, cyclopenins), quinoline alkaloids (viridicatins), clavine ergot alkaloids (α-cyclopiazonic acid, festuclavine, fumigaclavines), polycyclic indole alkaloids (communesin B, chaetoglobosin A), amino acid derivatives (N-acetyltryptamine, chrysogins, penicillin G), polyketides (citreoviridin A, mycophenolic acid), and terpenes (andrastins, phomenone). Strains isolated from anthropogenically altered habitats produced a more complete and characteristic profile of exometabolites, as compared with strains isolated from undisturbed habitats. It is only from contaminated soils there were isolated fungi that produced more structurally diverse secondary metabolites pertaining to polycyclic indole alkaloids and terpenoids. The fungi isolated from contaminated samples can be used in biodegradation of oil spills and bioremediation of the environment, and also as producers of promising biologically active compounds.

• MeSH
• Alkaloids analysis   classification   MeSH
• Biodegradation, Environmental MeSH
• Ecosystem MeSH
• Lakes microbiology   MeSH
• Penicillium chemistry   MeSH
• Polyketides analysis   MeSH
• Soil Microbiology * MeSH
• Secondary Metabolism * MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Antarctic Regions MeSH