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1.
Microorganisms ; 9(11)2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34835348

RESUMO

Wine reflects the specificity of a terroir, including the native microbiota. In contrast to the use of Saccharomyces cerevisiae commercial starters, a way to maintain wines' microbial terroir identities, guaranteeing at the same time the predictability and reproducibility of the wines, is the selection of autochthonous Saccharomyces and non-Saccharomyces strains towards optimal enological characteristics for the chosen area of isolation. This field has been explored but there is a lack of a compendium covering the main methods to use. Autochthonous wine yeasts from different areas of Slovakia were identified and tested, in the form of colonies grown either on nutrient agar plates or in grape must micro-fermentations, for technological and qualitative enological characteristics. Based on the combined results, Saccharomyces cerevisiae PDA W 10, Lachancea thermotolerans 5-1-1 and Metschnikowia pulcherrima 125/14 were selected as potential wine starters. This paper, as a mixture of experimental and review contributions, provides a compendium of methods used to select autochthonous wine yeasts. Thanks to the presence of images, this compendium could guide other researchers in screening their own yeast strains for wine production.

3.
Polymers (Basel) ; 13(16)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34451232

RESUMO

From environmental aspects, the recovery of keratin waste is one of the important needs and therefore also one of the current topics of many research groups. Here, the keratin hydrolysate after basic hydrolysis was used as a filler in plasticized polylactic acid/poly(3-hydroxybutyrate) blend under loading in the range of 1-20 wt%. The composites were characterized by infrared spectroscopy, and the effect of keratin on changes in molar masses of matrices during processing was investigated using gel permeation chromatography (GPC). Thermal properties of the composites were investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effect of keratin loading on the mechanical properties of composite was investigated by tensile test and dynamic mechanical thermal analysis. Hydrolytic degradation of matrices and composites was investigated by the determination of extractable product amounts, GPC, DSC and NMR. Finally, microbial growth and degradation were investigated. It was found that incorporation of keratin in plasticized PLA/PHB blend provides material with good thermal and mechanical properties and improved degradation under common environmental conditions, indicating its possible application in agriculture and/or packaging.

4.
Int J Pharm ; 606: 120846, 2021 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-34216769

RESUMO

Essential oils (EOs) of Thymus capitatus (Th) carvacrol chemotype and Origanum vulgare (Or) thymol and carvacrol chemotype were encapsulated in biocompatible poly(ε-caprolactone) nanocapsules (NCs). These nanosystems exhibited antibacterial, antifungal, and antibiofilm activities against Staphylococcus aureus, Escherichia coli, and Candida albicans. Th-NCs and Or-NCs were more effective against all tested strains than pure EOs and at the same time were not cytotoxic on HaCaT (T0020001) human keratinocyte cell line. The genotoxic effects of EO-NCs and EOs on HaCaT were evaluated using an alkaline comet assay for the first time, revealing that Th-NCs and Or-NCs did not induce DNA damage compared with untreated control HaCaT cells in vitro after 24 h. The cells morphological changes were assessed by label-free live cell Raman imaging. This study demonstrate the ability of poly(ε-caprolactone) nanocapsules loaded with thyme and oregano EOs to reduce microbial and biofilm growth and could be an ecological alternative in the development of new antimicrobial strategies.


Assuntos
Nanocápsulas , Óleos Voláteis , Antibacterianos/toxicidade , Biofilmes , Linhagem Celular , Dano ao DNA , Humanos , Queratinócitos , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Poliésteres
5.
Front Microbiol ; 12: 658010, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34248871

RESUMO

We present a biological profile of 16 Aspergillus niger environmental isolates from different types of soils and solid substrates across a pH range, from an ultra-acidic (<3.5) to a very strongly alkaline (>9.0) environment. The soils and solid substrates also differ in varying degrees of anthropic pollution, which in most cases is caused by several centuries of mining activity at old mining sites, sludge beds, ore deposits, stream sediments, and coal dust. The values of toxic elements (As, Sb, Zn, Cu, Pb) very often exceed the limit values. The isolates possess different macro- and micromorphological features. All the identifications of Aspergillus niger isolates were confirmed by molecular PCR analysis and their similarity was expressed by RAMP analysis. The biochemical profile of isolates based on FF-MicroPlate tests from the Biolog system showed identical biochemical reactions in 50 tests, while in 46 tests the utilisation reactions differed. The highest similarity of strains isolated from substrates with the same pH, as well as the most suitable biochemical tests for analysis of the phenotypic similarity of isolated strains, were confirmed when evaluating the biochemical profile using multicriterial analysis in the Canoco program. The isolates were screened for mycotoxin production by thin-layer chromatography (TLC), as well. Two of them were able to synthesise ochratoxin A, while none produced fumonisins under experimental conditions. Presence of toxic compounds in contaminated sites may affect environmental microscopic fungi and cause the genome alteration, which may result in changes of their physiology, including the production of different (secondary) metabolites, such as mycotoxins.

6.
J Biotechnol ; 335: 55-64, 2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34090948

RESUMO

Biocleaning of cultural heritage items is mainly performed using living microorganisms. Approaches utilizing the enzymes of isolated microorganisms have not been frequently investigated. To find an enzymatic alternative for the removal of an oil-based overpainting, we focused on the characterization and use of a yeast Extracellular Enzymatic Mixture (EEM). A historical silk yeast was selected for its lipolytic properties and its EEM was extracted after cultivation on a medium supplemented with linseed oil. The EEM protein content was visualized by SDS-PAGE, its concentration assessed by fluorimeter and the enzymatic activity evaluated by p-NPP spectrophotometric lipase assay. The yeast growth was suppressed by adding diverse metal ions (Cd, Zn, Cr and Cu) in Reasoner's 2A (R2A) broth, while the quantity and activity of EEM were affected by adding Fe and Pb. Various delivery systems (agar-agar, tylose and klucel G) alone or in a combination with EEM were assayed on the historical painting surface. The colorimetric measurements and the ATR-FTIR analysis indicated that the combinations tylose-EEM and klucel G-EEM can be easily and effectively applied as biocleaning procedures to remove oil-based overpainting from fragile and valuable historical painting surfaces.


Assuntos
Metais , Saccharomyces cerevisiae , Ágar , Meios de Cultura , Lipase
7.
Microbiol Res ; 247: 126727, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33652267

RESUMO

The MinION single-molecule sequencing system has been attracting the attention of the community of microbiologists involved in the conservation of cultural heritage. The use of MinION for the conservation of cultural heritage is extremely recent, but surprisingly the only few applications available have been exploring many different substrates: stone, textiles, paintings and wax. The use of MinION sequencing is mainly used to address the metataxonomy (with special emphasis on non-cultivable microorganisms) with the effort to identify species involved in the degradation of the substrates. In this review, we show the current applications available on different artworks, showing how this technology can be a useful tool for microbiologists and conservators also in light of its low cost and the easy chemistry.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Metagenômica/métodos , Microbiota/genética , Bactérias/classificação , Bactérias/genética , DNA Bacteriano/genética , Sequenciamento de Nucleotídeos em Larga Escala/instrumentação , Metagenômica/instrumentação , Pinturas , Análise de Sequência de DNA , Têxteis
8.
Antibiotics (Basel) ; 10(1)2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33401404

RESUMO

Nanotechnology is a new frontier of this century that finds applications in various fields of science with important effects on our life and on the environment. Nanoencapsulation of bioactive compounds is a promising topic of nanotechnology. The excessive use of synthetic compounds with antifungal activity has led to the selection of resistant fungal species. In this context, the use of plant essential oils (EOs) with antifungal activity encapsulated in ecofriendly nanosystems could be a new and winning strategy to overcome the problem. We prepared nanoencapsules containing the essential oils of Origanum vulgare (OV) and Thymus capitatus (TC) by the nanoprecipitation method. The colloidal suspensions were characterized for size, polydispersity index (PDI), zeta potential, efficiency of encapsulation (EE) and loading capacity (LC). Finally, the essential oil nanosuspensions were assayed against a panel of fourteen fungal strains belonging to the Ascomycota and Basidiomycota phyla. Our results show that the nanosystems containing thyme and oregano essential oils were active against various fungal strains from natural environments and materials. In particular, the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values were two to four times lower than the pure essential oils. The aqueous, ecofriendly essential oil nanosuspensions with broad-spectrum antifungal activity could be a valid alternative to synthetic products, finding interesting applications in the agri-food and environmental fields.

9.
Med Phys ; 48(1): 313-328, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33232521

RESUMO

PURPOSE: To develop and evaluate the diagnostic performance of an algorithm for multi-marker radiomic-based classification of breast masses in dedicated breast computed tomography (bCT) images. METHODS: Over 1000 radiomic descriptors aimed at quantifying mass and border heterogeneity, morphology, and margin sharpness were developed and implemented. These included well-established texture and shape feature descriptors, which were supplemented with additional approaches for contour irregularity quantification, spicule and lobe detection, characterization of degree of infiltration, and differences in peritumoral compartments. All descriptors were extracted from a training set of 202 bCT masses (133 benign and 69 malignant), and their individual diagnostic performance was investigated in terms of area under the receiver operating characteristics (ROC) curve (AUC) of single-feature-based linear discriminant analysis (LDA) classifiers. Subsequently, the most relevant descriptors were selected through a multiple-step feature selection process (including stability analysis, statistical significance, evaluation of feature interaction, and dimensionality reduction), and used to develop a final LDA radiomic model for classification of benign and malignant masses, which was then tested on an independent test set of 82 cases (45 benign and 37 malignant). RESULTS: The majority of the individual radiomic descriptors showed, on the training set, an AUC value deriving from a linear decision boundary higher than 0.65, with the lower limit of the associated 95% confidence interval (C.I.) not overlapping with random chance (AUC = 0.5). The final LDA radiomic model resulted in a test set AUC of 0.90 (95% C.I. 0.80-0.96). CONCLUSIONS: The proposed multi-marker radiomic approach achieved high diagnostic accuracy in bCT mass classification, using a radiomic signature based on different feature types. While future studies with larger datasets are needed to further validate these results, quantitative radiomics applied to bCT shows potential to improve the breast cancer diagnosis pipeline.


Assuntos
Neoplasias da Mama , Mama , Algoritmos , Mama/diagnóstico por imagem , Neoplasias da Mama/diagnóstico por imagem , Humanos , Curva ROC , Tomografia Computadorizada por Raios X
10.
PeerJ ; 8: e9601, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879789

RESUMO

Thymol is a substance with a great therapeutic potential possessing antibacterial and antifungal activity, with a characteristic odour that remains long after application but is not pleasant at higher concentrations. In this study, attention has been focused on describing the chemical and biological properties of the simply prepared trimethylsilyl ether of thymol (kubicin). Interestingly, kubicin has similar volatility as thymol, undergoes hydrolysis in the water (moisture; forming thymol and trimethylsilanol) and can be used at 6,000 times higher concentration than thymol without any negative and irritating odour. Kubicin showed diverse fungistatic and fungicidal activities when tested by direct contact assay, or in vapour phase. The volatile vapour of kubicin was effective on all tested fungal strains. These results suggest that vapours of kubicin might provide an alternative way to fight against fungal contamination.

11.
FEMS Microbiol Lett ; 367(18)2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32897314

RESUMO

Wine production is a complex procedure in which an important role is played by many microorganisms, particularly yeasts and bacteria. In modern wineries, alcoholic fermentation is usually carried out by adding microbial starter cultures of Saccharomyces cerevisiae strains for precisely controlled production. Nowadays, in the Slovak Republic, autochthonous vinification is getting more popular. The present article deals with the comparison of two vinification approaches, namely spontaneous fermentation and fermentation controlled by a standard commercial S. cerevisiae starter, from the point of view of microbiota dynamics and the chemical characteristics of the wines produced. The dynamics of microbial populations were determined during the fermentation process by a 16S and 28S rRNA next-generation sequencing approach. A profile of the volatile compounds during these fermentation processes was identified by solid-phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS). In summary, the microbial diversity in the m1 phase (initial must) was higher, despite the presence of the starter culture. In the m3 phase (young wine), the microbiome profiles of both batches were very similar. It seems that the crucial phase in order to study the relationship of the microbiome and the resulting product should be based on the m2 phase (fermented must), where the differences between the autochthonous and inoculated batches were more evident.


Assuntos
Microbiota , Vinho/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Fermentação , Microbiologia de Alimentos , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Microbiota/genética , Odorantes/análise , RNA Ribossômico 16S/genética , RNA Ribossômico 28S/genética , Saccharomyces cerevisiae/metabolismo , Eslováquia , Compostos Orgânicos Voláteis/análise , Vinho/análise
12.
Antibiotics (Basel) ; 9(6)2020 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-32575356

RESUMO

Essential oils (EOs) are well-known for their beneficial properties against a broad range of microorganisms. For the better understanding of their mechanism of action in fungi, a microarray approach was used in order to evaluate the gene expression of Penicillium chrysogenum (recently renamed P. rubens) exposed to the indirect contact (vapors) of eight EOs. The selection of assayed EOs was based on their antifungal activity. The extraction of RNA and the microarray hybridization procedure were optimized for the analysis of P. rubens. Gene ontology annotation was performed to investigate the functional analysis of the genes. To uncover the metabolic pathway of these differentially expressed genes, they were mapped into the KEGG BRITE pathway database. The transcriptomic analysis showed that, from a total of 12,675 genes, only 551 genes are annotated, and the other 12,124 genes encoded hypothetical proteins. Further bioinformatic analysis demonstrated that 1350 genes were upregulated and 765 downregulated at least with half (four) of the utilizing EOs. A microarray investigation has confirmed the main impact of EOs to metabolic processes in P. rubens involved in vital functions. Presumably, this is the first time that a microarray hybridization analysis was performed in order to evaluate the gene expression of P. rubens exposed to various EOs.

13.
Comput Biol Med ; 118: 103629, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32174316

RESUMO

A deep learning (DL) network for 2D-based breast mass segmentation in unenhanced dedicated breast CT images was developed and validated, and its robustness in radiomic feature stability and diagnostic performance compared to manual annotations of multiple radiologists was investigated. 93 mass-like lesions were extensively augmented and used to train the network (n = 58 masses), which was then tested (n = 35 masses) against manual ground truth of a qualified breast radiologist with experience in breast CT imaging using the Conformity coefficient (with a value equal to 1 indicating a perfect performance). Stability and diagnostic power of 672 radiomic descriptors were investigated between the computerized segmentation, and 4 radiologists' annotations for the 35 test set cases. Feature stability and diagnostic performance in the discrimination between benign and malignant cases were quantified using intraclass correlation (ICC) and multivariate analysis of variance (MANOVA), performed for each segmentation case (4 radiologists and DL algorithm). DL-based segmentation resulted in a Conformity of 0.85 ± 0.06 against the annotated ground truth. For the stability analysis, although modest agreement was found among the four annotations performed by radiologists (Conformity 0.78 ± 0.03), over 90% of all radiomic features were found to be stable (ICC>0.75) across multiple segmentations. All MANOVA analyses were statistically significant (p ≤ 0.05), with all dimensions equal to 1, and Wilks' lambda ≤0.35. In conclusion, DL-based mass segmentation in dedicated breast CT images can achieve high segmentation performance, and demonstrated to provide stable radiomic descriptors with comparable discriminative power in the classification of benign and malignant tumors to expert radiologist annotation.


Assuntos
Inteligência Artificial , Aprendizado Profundo , Mama/diagnóstico por imagem , Humanos , Radiologistas , Tomografia Computadorizada por Raios X
14.
Environ Microbiol ; 22(4): 1517-1534, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31291047

RESUMO

A multidisciplinary approach was carried out in order to study the biodeterioration and the associated microbiome of a XVIII Century wax seal coloured with minium. A small wax seal fragment was observed by scanning electron microscopy combined with energy dispersive spectroscopy in non-destructive mode. The same object was analysed by Raman and Fourier-transform infrared spectroscopy. The identification of the microbiota growing on the seal was performed with both a culture-dependent strategy, combined with hydrolytic assays, and high-throughput sequencing using the MinION platform. The whole bacterial 16S rRNA gene and the fungal markers ITS and 28S rRNA were targeted. It was observed that the carnauba wax coloured with lead tetroxide (minium) was covered by a biofilm consisting of a network of filaments and other structures of microbial origin. The culture-dependent and culture-independent investigations showed the presence of a complex microbiota composed mainly by fungal members, which demonstrated interesting properties related to lipids and lead processing. The formation of lead soaps and secondary biogenic minerals was also described.


Assuntos
Microbiota , Ceras , Bactérias/genética , Bactérias/ultraestrutura , Biodiversidade , Corantes , Fungos/genética , Fungos/ultraestrutura , Chumbo , Microscopia Eletrônica de Varredura , RNA Ribossômico 16S/genética , RNA Ribossômico 28S/genética , Sabões , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman
15.
J Biotechnol ; 309: 29-33, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31884046

RESUMO

Hydroxytyrosol is a phenolic phytochemical with antioxidant properties in vitro. It is a natural compound that can be found in olive leaves and oil. The main dietary source of hydroxytyrosol is extra virgin olive oil. Due to its bioavailability, chemical properties and easy formulation along with its lack of toxicity, hydroxytyrosol is considered an excellent food supplement by the nutraceutical and food industries. The purpose of this review is to discuss the potential therapeutic effects of hydroxytyrosol in vivo. To do so, we conducted an electronic search in PubMed and other literature databases using "hydroxytyrosol", "beneficial effect/s", "pharmacology" as key-words. From this search, we found that hydroxytyrosol has anti-inflammatory, anti-tumor, antiviral, antibacterial and antifungal properties. Hydroxytyrosol also improves endothelial dysfunction, decreases oxidative stress, and is neuro- and cardio-protective. Due to all these biological properties, hydroxytyrosol is currently the most actively investigated natural phenol. The evidence presented in this review suggests that hydroxytyrosol has great pharmacological potential.


Assuntos
Antioxidantes/farmacologia , Azeite de Oliva/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Álcool Feniletílico/análogos & derivados , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Humanos , Olea/química , Azeite de Oliva/química , Fenóis/química , Fenóis/farmacologia , Álcool Feniletílico/química , Álcool Feniletílico/farmacologia , Folhas de Planta/química
16.
Molecules ; 24(24)2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31847159

RESUMO

In this study, we determined the antimicrobial activity of ten essential oils (EOs)-oregano, thyme, clove, arborvitae, cassia, lemongrass, melaleuca, eucalyptus, lavender, and clary sage-against drug-resistant microorganisms previously isolated from patients with skin infections. The essential oil compositions were determined using gas chromatography coupled to mass spectrometry (GC/MS). The assayed bacteria included Pseudomonas aeruginosa, Proteus vulgaris, Citrobacter koseri, and Klebsiella pneumoniae. Two drug-resistant yeasts (Candida albicans and Candida parapsilosis) were also involved in our survey. Oregano, thyme, cassia, lemongrass and arborvitae showed very strong antibacterial and antifungal activity against all tested strains. These results show that these essential oils may be effective in preventing the growth of the drug-resistant microorganisms responsible for wound infections. In this study, the genotoxic effects of tested essential oils on healthy human keratinocytes HaCaT were evaluated using the comet assay for the first time. These results revealed that none of the essential oils induced significant DNA damage in vitro after 24 h. Moreover, the treatment of HaCaT cells with essential oils increased the total antioxidant status (TAS) level. The obtained results indicate that EOs could be used as a potential source of safe and potent natural antimicrobial and antioxidant agents in the pharmaceutical and food industries.


Assuntos
Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Fúngica/efeitos dos fármacos , Óleos Voláteis/química , Óleos Vegetais/química , Dermatopatias Infecciosas/microbiologia , Candida albicans/efeitos dos fármacos , Candida parapsilosis/efeitos dos fármacos , Cassia/química , Linhagem Celular , Citrobacter koseri/efeitos dos fármacos , Cymbopogon/química , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Origanum/química , Óleos Vegetais/farmacologia , Proteus vulgaris/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Thuja/química , Thymus (Planta)/química
17.
Food Microbiol ; 82: 416-425, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31027801

RESUMO

The catabolism of milk protein in cheese is one way how the microorganisms influence the sensorial characteristics of the final product. In this investigation, we paid attention to four genes [prtP (cell-envelope proteinase gene), pepX (X-prolyl dipeptidyl aminopeptidase gene), pepN (aminopeptidase gene) and bcaT (branched chain aminotransferase gene)] responsible for the production of volatile aroma-active compounds from milk proteins by lactic acid bacteria (LAB). We studied the dynamics of these genes and their corresponding LAB host, during the maturation of a raw ewes' milk-based cheese, using metagenomics and metatranscriptomics approaches. The transcriptome-oriented experiments included the analysis of total RNA (at three stages of cheese maturation) and also the construction of specific cDNA sub-libraries of the abovementioned genes. The proteolytic transcriptome analysis was supported by following the transcription activity of 16S rRNA gene and by metagenomic investigation. The combination of the described methods permitted to screen the dynamics of targeted genes throughout the cheese production. Lactococci were the major players in the LAB group, but the analysis provided also information on the role and properties of members of the genus Lactobacillus, such as Lb. rhamnosus, Lb. helveticus, Lb. pentosus, Lb. curvatus, Lb. parabuchneri, Lb. plantarum, Lb. brevis, Lb. delbrueckii, Lb. paracasei, Lb. fermentum and Lb. heilongjiangensis, proteolysis-related genes of which were active during cheese ripening.


Assuntos
Proteínas de Bactérias/genética , Queijo/microbiologia , Microbiologia de Alimentos , Lactobacillales/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Feminino , Perfilação da Expressão Gênica , Lactobacillales/classificação , Lactobacillales/genética , Lactobacillales/isolamento & purificação , Metagenômica , Microbiota/genética , Leite/microbiologia , Proteólise , RNA Ribossômico 16S/genética , Ovinos , Transcrição Genética
18.
Bioprocess Biosyst Eng ; 42(7): 1151-1163, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30944995

RESUMO

The potential of K2FeO4 as a pretreatment agent of a lignocellulosic material was examined on leaves of Acer platanodides as the sole substrate for biogas production by anaerobic digestion carried out through modelling laboratory-scaled semi-continuous reactors differing in loading rates and substrate (pretreated and untreated leaves). The quality of bioagas produced by K2FeO4-pretreated leaves was significantly better in terms of higher methane content and lower content of H2S. K2FeO4 had no crucial influence on growth inhibition of biogas-producing bacteria, which were analysed by comprehensive culture-independent methods utilising high-throughput sequencing of specific genes [bacterial and archaeal 16S rRNA, formyltetrahydrofolate synthetase gene (fhs), methyl-coenzyme M reductase α subunit gene (mcrA) and fungal internal transcribed spacers (ITS)]. The higher amount of CH4 in biogas utilising pretreated leaves as substrate could be caused by a shift to acetoclastic methanogenesis pathway, which was indicated by the higher amount of homoacetogenic bacteria and acetotrophic methanogens detected in those reactors.


Assuntos
Acer/química , Biocombustíveis , Reatores Biológicos , Compostos de Ferro/química , Metano , Consórcios Microbianos/efeitos dos fármacos , Folhas de Planta/química , Compostos de Potássio/química
19.
Ecotoxicol Environ Saf ; 172: 194-202, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30708231

RESUMO

Distribution and biodiversity of soil microscopic fungi in 5 areas of old environmental loads in Slovakia were studied in relation to very low amount of organic matter (%TOC from 0.2 to 3.54) and to the pH gradient from ultra-acidic (< 3.5) to very strongly alkaline (> 9.0). All soil samples were affected by several hundred years of mining activities and contained heavy metals and other toxic elements: arsenic, cadmium, copper, zinc, antimony, lead. Concentrations of toxicants highly exceeded their limited values. Fifty-three genera and 112 species of microscopic fungi were identified. Among them, Zygomycota occurred very rarely (8 genera and 12 species), except of samples with the highest content of TOC (2.01-3.54% - samples 2 and 6), regardless their pH. Though, on the other hand, from some similar samples (3, 5 and 9), incl. those with relatively high TOC (0.14-2.62%), the lower fungi were not recovered. Forty one genera and 95 species of Ascomycota represented the most abundant fungal phylum in all investigated samples. Among them, Penicillium chrysogenum var. chrysogenum, Aspergillus niger and Neosartorya fischeri were isolated the most often. Phytopathogenic moulds of Bionectria ochroleuca, Lewia infectoria, Phoma macrostoma and Phlebia acerina were also occurred frequently. The highest biodiversity of microfungal community was recorded in the extreme acidic environment, followed by the neutral, ultra-acidic and the very strong acidic ones. There was no similarity in microfungal spectrum found in the samples studied. Except of the ultra acidic and extreme acidic samples (1-2) as well as the ultra acidic and strong acidic ones (1-4) with the most rich mycobiota, that may indicate a certain similarity degree.


Assuntos
Biodiversidade , Fungos/isolamento & purificação , Metais Pesados/análise , Mineração , Microbiologia do Solo , Poluentes do Solo/análise , Ácidos , Arsênio/análise , Cádmio/análise , Cobre/análise , Fungos/classificação , Eslováquia , Solo/química , Zinco/análise
20.
Environ Microbiol ; 20(9): 3294-3308, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30051567

RESUMO

This microbiological survey was performed to determine the conservation state of a mummy in the Slovak castle of Krásna Hôrka and its surrounding environment. Culture-dependent identification was coupled with biodegradation assays on keratin, gelatin and cellulose. Next Generation Sequencing (NGS) using Illumina platform was used for a deeper microbial investigation. Three environmental samples were collected: from the glass of the sarcophagus, from the air inside it, and from the air of the chapel where the mummy is located. Seven different samples were taken from mummy's surface: from the left ear, left-hand palm, left-hand nail, left instep, right hand, abdomen and mineral crystals embedded within the skin. Three internal organ samples, from the lung, pleura and stomach, were also included in this study. Together, the culture-dependent and culture-independent analyses revealed that the bacterial communities present had fewer taxa than the fungal ones. The mycobiome showed the largest variability and included Epicoccum nigrum, Penicillium spp., Alternaria spp., Aspergillus spp., Cladosporium spp. and Aureobasidium pullulans; many other Ascomycota and Basidiomycota genera were detected by NGS. The most interesting results came from the skin mineral crystals and the internal organs. The hydrolytic assays revealed those microorganisms which might be considered dangerous 'mummy pathogens'. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.


Assuntos
Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Microbiota , Múmias/microbiologia , Microbiologia do Ar , Bactérias/classificação , Bactérias/genética , Fungos/classificação , Fungos/genética , Sequenciamento de Nucleotídeos em Larga Escala , História do Século XVIII , Humanos , Múmias/história , Eslováquia
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