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1.
Euro Surveill ; 29(32)2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39119721

RESUMO

BackgroundThe Vibrio genus comprises several bacterial species present in the Baltic Sea region (BSR), which are known to cause human infections.AimTo provide a comprehensive retrospective analysis of Vibrio-induced infections in the BSR from 1994 to 2021, focusing on the 'big four' Vibrio species - V. alginolyticus, V. cholerae non-O1/O139, V. parahaemolyticus and V. vulnificus - in eight European countries (Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland and Sweden) bordering the Baltic Sea.MethodsOur analysis includes data on infections, Vibrio species distribution in coastal waters and environmental data received from national health agencies or extracted from scientific literature and online databases. A redundancy analysis was performed to determine the potential impact of several independent variables, such as sea surface temperature, salinity, the number of designated coastal beaches and year, on the Vibrio infection rate.ResultsFor BSR countries conducting surveillance, we observed an exponential increase in total Vibrio infections (n = 1,553) across the region over time. In Sweden and Germany, total numbers of Vibrio spp. and infections caused by V. alginolyticus and V. parahaemolyticus positively correlate with increasing sea surface temperature. Salinity emerged as a critical driver of Vibrio spp. distribution and abundance. Furthermore, our proposed statistical model reveals 12 to 20 unreported cases in Lithuania and Poland, respectively, countries with no surveillance.ConclusionsThere are discrepancies in Vibrio surveillance and monitoring among countries, emphasising the need for comprehensive monitoring programmes of these pathogens to protect human health, particularly in the context of climate change.


Assuntos
Vibrioses , Vibrio , Humanos , Estudos Retrospectivos , Vibrioses/epidemiologia , Vibrioses/microbiologia , Vibrio/isolamento & purificação , Vibrio/classificação , Países Bálticos/epidemiologia , Água do Mar/microbiologia , Europa (Continente)/epidemiologia , Oceanos e Mares
2.
Environ Res ; 234: 116588, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37423368

RESUMO

Microbially induced calcite precipitation (MICP) is an efficient and eco-friendly technique that has attracted significant interest for resolving various problems in the soil (erosion, improving structural integrity and water retention, etc.), remediation of heavy metals, production of self-healing concrete or restoration of different concrete structures. The success of most common MICP methods depends on microorganisms degrading urea which leads to the formation of CaCO3 crystals. While Sporosarcina pasteurii is a well-known microorganism for MICP, other soil abundant microorganisms, such as Staphylococcus bacteria have not been thoroughly studied for its efficiency in bioconsolidation though MICP is a very important proccess which can ensure soil quality and health. This study aimed to analyze MICP process at the surface level in Sporosarcina pasteurii and a newly screened Staphylococcus sp. H6 bacterium as well as show the possibility of this new microorganism to perform MICP. It was observed that Staphylococcus sp. H6 culture precipitated 157.35 ± 3.3 mM of Ca2+ ions from 200 mM, compared to 176 ± 4.8 mM precipitated by S. pasteurii. The bioconsolidation of sand particles was confirmed by Raman spectroscopy and XRD analysis, which indicated the formation of CaCO3 crystals for both Staphylococcus sp. H6 and S. pasteurii cells. The water-flow test suggested a significant reduction in water permeability in bioconsolidated sand samples for both Staphylococcus sp. H6 and S. pasteurii. Notably, this study provides the first evidence that CaCO3 precipitation occurs on the surface of Staphylococcus and S. pasteurii cells within the initial 15-30 min after exposure to the biocementation solution. Furthermore, Atomic force microscopy (AFM) indicated rapid changes in cell roughness, with bacterial cells becoming completely coated with CaCO3 crystals after 90 min incubation with a biocementation solution. To our knowledge, this is the first time where atomic force microscopy was used to visualize the dynamic of MICP on cell surface.


Assuntos
Carbonato de Cálcio , Urease , Urease/química , Urease/metabolismo , Carbonato de Cálcio/química , Carbonato de Cálcio/metabolismo , Staphylococcus/metabolismo , Areia , Bactérias/metabolismo , Solo , Água
3.
World J Microbiol Biotechnol ; 36(3): 41, 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32107645

RESUMO

This study presents a new microbial lipolytic enzyme GD-95RM designed via random mutagenesis using previously characterized GD-95 lipase as a template. The improvement in activity of GD-95 lipase was caused by E100K, F154V and V174I mutations. Compared with GD-95 lipase, the GD-95RM lipase had 1.3-fold increased specific activity (2000 U/mg), demonstrated resistance to higher temperatures (75-85 °C), had fourfold increased Vmax towards p-NP dodecanoate and showed 2.5-fold lower KM for p-NP butyrate. It retained > 50% of its lipolytic activity when hydrolyzing short, medium and long acyl chain substrates at 30 °C and 55 °C reaction temperatures after 20 days' incubation with 25% of ethanol. GD-95RM also displayed long-term tolerance (40 d) to 5% NaCl, trisodium citrate, sodium perborate, urea, 0.1% boric acid, citric acid and Triton X-100. Moreover, oil hydrolysis and transesterification results revealed the capability of GD-95RM lipase to produce fatty acids or fatty acid esters through eco-friendly hydrolysis and transesterification reactions using a broad range of vegetable and fish oils, animal fat and different alcohols as substrates. GD-95RM lipase was successfully applied in synthesis reactions for ethyl oleate, octyl oleate and isoamyl oleate without giving to use additional reaction compounds or special reaction conditions.


Assuntos
Geobacillus/enzimologia , Lipase/genética , Lipase/metabolismo , Mutação , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Butiratos/química , Ésteres/química , Geobacillus/genética , Temperatura Alta , Produtos Domésticos , Lauratos/química , Lipase/química , Modelos Moleculares , Engenharia de Proteínas , Termodinâmica
4.
BMC Microbiol ; 19(1): 73, 2019 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-30943901

RESUMO

BACKGROUND: Skin infections, particularly caused by drug-resistant pathogens, represent a clinical challenge due to being a frequent cause of morbidity and mortality. The objectives of this study were to examine if low concentrations of acetic and formic acids can increase sensitivity of Staphylococcus aureus and Pseudomonas aeruginosa to pulsed electric field (PEF) and thus, promote a fast and efficient treatment methodology for wound treatment. RESULTS: We have shown that the combination of PEF (10-30 kV/cm) with organic acids (0.1% formic and acetic acids) increased the bactericidal properties of treatment. The effect was apparent for both acids. The proposed methodology allowed to reduce the energy of electrical pulses and the inhibitory concentrations of acids, while still maintain high efficiency of bacteria eradication. CONCLUSIONS: Application of weak organic acids as bactericidal agents has many advantages over antibiotics because they do not trigger development of drug-resistance in bacteria. The combination with PEF can make the treatment effective even against biofilms. The results of this study are particularly useful for the development of new methodologies for the treatment of extreme cases of wound infections when the chemical treatment is no longer effective or hinders wound healing.


Assuntos
Ácido Acético/farmacologia , Eletricidade , Formiatos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Infecção dos Ferimentos/terapia
5.
J Membr Biol ; 251(2): 189-195, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28238117

RESUMO

Recently, a novel contactless treatment method based on high-power pulsed electromagnetic fields (PEMF) was proposed, which results in cell membrane permeabilization effects similar to electroporation. In this work, a new PEMF generator based on multi-stage Marx circuit topology, which is capable of delivering 3.3 T, 0.19 kV/cm sub-microsecond pulses was used to permeabilize pathogenic yeast Candida albicans separately and in combination with conventional square wave electroporation (8-17 kV/cm, 100 µs). Bursts of 10, 25, and 50 PEMF pulses were used. The yeast permeabilization rate was evaluated using flow cytometric analysis and propidium iodide (PI) assay. A statistically significant (P < 0.05) combinatorial effect of electroporation and PEMF treatment was detected. Also the PEMF treatment (3.3 T, 50 pulses) resulted in up to 21% loss of yeast viability, and a dose-dependent additive effect with pulsed electric field was observed. As expected, increase of the dB/dt and subsequently the induced electric field amplitude resulted in a detectable effect solely by PEMF, which was not achievable before for yeasts in vitro.


Assuntos
Candida albicans/metabolismo , Campos Eletromagnéticos , Eletroporação/métodos , Candida albicans/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos da radiação , Eletroforese , Propídio
6.
Molecules ; 23(7)2018 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-30037022

RESUMO

Treatment of bacteria-associated infections is complicated and antibiotic treatment alone is often inadequate to overcome biofilm infections. Physical methods allow overcoming this problem and propose solutions that are non-dependent on drug resistance. In this work, we investigated the feasibility of pulsed electric fields for sensitization of MRSA to common antibiotics. We analyzed the efficacy of inactivation of methicillin-resistant Staphylococcus aureus in 5⁻20 kV/cm electric field separately and in combination with gentamicin, doxycycline, ciprofloxacin, sulfamethoxazole, and vancomycin. Combined treatment allowed using up to 1000-fold smaller concentrations of antibiotics to induce the same inactivation of S. aureus.


Assuntos
Antibacterianos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana , Eletroporação , Humanos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos
7.
Int Arch Allergy Immunol ; 170(4): 262-268, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27771694

RESUMO

BACKGROUND: Allergic contact dermatitis (ACD) is an inflammatory skin disease caused by repeated skin exposure to contact allergens. The severity and duration of this disease are associated with many different factors. Some of these factors may represent markers for monitoring disease activity and the individual response to an intervention. METHODS: We used a targeted metabolomics approach to find such factors in the serum of individuals with ACD. Metabolomics profiles were examined and compared in the acute phase of the disease and also in the absence of disease activity. RESULTS: Our study identified a significant remission phase of ACD-associated systemic biochemical shifts in 2 metabolic pathways: tryptophan-kynurenine and phenylalanine-tyrosine. CONCLUSIONS: Although the responsible mechanisms are unclear, these results suggest that the remission phase of ACD is linked to tryptophan metabolism via kynurenine and phenylalanine-tyrosine pathways. However, further replication studies with a larger number of subjects and their subgroups are necessary to validate our results. These studies may provide a new perspective with which to understand the mechanism of and find potential biomarkers of ACD, as well as a new reference for personalized treatment.


Assuntos
Dermatite Alérgica de Contato/metabolismo , Fenilalanina/metabolismo , Triptofano/metabolismo , Adulto , Alérgenos/imunologia , Estudos de Casos e Controles , Dermatite Alérgica de Contato/tratamento farmacológico , Dermatite Alérgica de Contato/imunologia , Suscetibilidade a Doenças , Feminino , Humanos , Masculino , Metaboloma , Metabolômica/métodos , Pessoa de Meia-Idade , Projetos Piloto , Adulto Jovem
8.
Int Arch Allergy Immunol ; 168(3): 161-4, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26790150

RESUMO

BACKGROUND: Allergic contact dermatitis (ACD) is an inflammatory skin disease caused by repeated skin exposure to contact allergens. The goal of this pilot study was to identify inflammatory proteins which can serve as biomarkers for ACD. METHODS: We measured levels of 102 cytokines, chemokines, and growth factors in the sera of 16 ACD patients during acute and remission phases, and 16 healthy volunteers. RESULTS: Serum levels of adiponectin, chemokine (C-C motif) ligand 5 (CCL5), C-reactive protein (CRP), chitinase 3-like 1 (CHI3L1), complement factor D (CFD), endoglin, lipocalin-2, osteopontin, retinol-binding protein 4 (RBP4), and platelet factor 4 (PF4) were significantly higher, whereas levels of trefoil factor 3 (TFF3) were significantly lower, in ACD patients than in healthy controls. In ACD patients, serum levels of CCL5 were elevated, whereas levels of TFF3, soluble intercellular adhesion molecule-1 (sICAM-1), and platelet-derived growth factor (PDGF)-AB/BB were found to be lower during the remission phase of the disease. CONCLUSIONS: Serum levels of adiponectin, CCL5, CRP, CHI3L1, CFD, endoglin, lipocalin-2, osteopontin, RBP4, PF4, and TFF3 might be exploited as biomarkers for ACD, whereas levels of CCL5, TFF3, sICAM-1, and PDGF-AB/BB might be exploited for evaluation of disease progression and efficacy of ACD treatment.


Assuntos
Biomarcadores/sangue , Dermatite Alérgica de Contato/diagnóstico , Adulto , Quimiocinas/sangue , Citocinas/sangue , Dermatite Alérgica de Contato/sangue , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/sangue , Masculino , Pessoa de Meia-Idade , Projetos Piloto
9.
Mycopathologia ; 179(3-4): 205-11, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25481846

RESUMO

Switching between two cell types in fungi is called phenotypic switching, and it is commonly observed in pathogenic yeast. Candida lusitaniae undergoes antifungal resistance-associated phenotypic switching and results in three colony colors: light brown, brown and dark brown. In this study, we included C. lusitaniae as control. This study had two objectives. First, we wanted to evaluate whether also a prevalent human pathogen C. guilliermondii can undergo phenotypic switching. Second, our aim was to determine whether switching can change yeasts susceptibility to antifungals. Yeast suspension (1 × 10(3)-5 × 10(3) c.f.u./ml) was plated on the YPD medium containing 1 mM CuSO4. Colonies exhibiting the original and variant phenotypes were counted and converted to percentage of the population. Minimum inhibitory concentrations of amphotericin B, formic acid and acetic acid for the cells from random colonies of the different phenotypes were determined by microdilution method. After 5 days of incubation, C. guilliermondii switched spontaneously and reversibly among two phenotypes distinguishable on CuSO4 containing agar, white and dark brown. Phenotypes occurred with greater frequency (10(-1)-10(-2)) than spontaneous mutations and were reversible, fulfilling the two phenotypic switching criteria. The study showed that phenotypic switching was associated with filamentation and affected antifungal resistance. Resistance to amphotericin B increased tenfold and was associated with C. lusitaniae dark brown phenotype. C. guilliermondii colonies with brown phenotype displayed 20 and 2 times higher resistance to amphotericin B and acetic acid, respectively.


Assuntos
Candida/crescimento & desenvolvimento , Farmacorresistência Fúngica , Hifas/metabolismo , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Candida/genética , Candida/metabolismo , Candidíase/microbiologia , Humanos , Hifas/efeitos dos fármacos , Hifas/genética , Hifas/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Fenótipo
10.
Biotechnol Appl Biochem ; 61(1): 3-10, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24267639

RESUMO

The acidification of the medium is observed during yeast cell growth. This process contributes to the emission of organic acids, mainly acetic acid. Acetic acid is known as the inducer of apoptosis in the yeast Saccharomyces cerevisiae. In this study, we showed that hydrochloric acid can also induce apoptosis in yeast cells, and the apoptotic phenotype triggered by treating yeast cells with hydrochloric acid is modulated by the Ras/PKA pathway. The Ras/PKA pathway is highly conserved between all eukaryotic organisms, as well as cell processes that are related to apoptosis and aging. In this research, we demonstrated that the activation of the Ras/PKA pathway by insertion of Ras2(Val19) allele or deletion of PDE2 gene increases cell death, displaying the markers of apoptosis in an acidic environment. Downregulation of the pathway by deletion of RAS2, RAS1, PDE1, and insertion of the Ha-ras gene increases the cell viability and diminishes cell death with the apoptotic phenotypes. The deletion of PDE1 gene and double deletion of both phosphodiesterase genes prevent the induction of apoptosis in the cells. Modulations in the Ras/PKA pathway affect cell viability and apoptosis during natural gradual acidification of the medium as well as in acid stress conditions.


Assuntos
Apoptose , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/enzimologia , Transdução de Sinais , Proteínas ras/metabolismo , Concentração de Íons de Hidrogênio
11.
Curr Microbiol ; 69(3): 303-10, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24752490

RESUMO

Cutaneous fungal infections are common and widespread. Antifungal agents used for the treatment of these infections often have undesirable side effects. Furthermore, increased resistance of the microorganisms to the antifungal drugs becomes the growing problem. Accordingly, the search for natural antifungal compounds continues to receive attention. Apoptosis is highly regulated programmed cell death. During yeast cell apoptosis, amino acids and peptides are released and can stimulate regeneration of human epithelium cells. Thus, detection of chemical compounds inducing apoptosis in yeast and nontoxic for humans is of great medical relevance. The aim of this study was to detect chemical compound inducing apoptosis in pathogenic Candida species with the lowest toxicity to the mammalian cells. Five chemical compounds--acetic acid, sodium bicarbonate, potassium carbonate, lithium acetate, and formic acid--were tested for evaluation of antifungal activity on C. albicans, C. guilliermondii, and C. lusitaniae. The results showed that acetic acid and formic acid at the lowest concentrations induced yeast cells death. Apoptosis analysis revealed that cells death was accompanied by activation of caspase. Minimal inhibitory concentrations of potassium carbonate and sodium bicarbonate induced Candida cells necrosis. Toxicity test with mammalian cell cultures showed that formic acid has the lowest effect on the growth of Jurkat and NIH 3T3 cells. In conclusion, our results show that a low concentration of formic acid induces apoptosis-like programmed cell death in the Candida yeast and has a minimal effect on the survivability of mammalian cells, suggesting potential applications in the treatment of these infections.


Assuntos
Ácido Acético/toxicidade , Apoptose , Candida/efeitos dos fármacos , Candida/fisiologia , Formiatos/toxicidade , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Camundongos , Viabilidade Microbiana/efeitos dos fármacos , Dados de Sequência Molecular , Análise de Sequência de DNA
12.
Data Brief ; 55: 110750, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39100785

RESUMO

This strain was isolated from traditionally (homemade) fermented Lithuanian cherry tomatoes. The genome consists of 55 contigs with a total size of 3,326,119 bp, an N50 of 170738, and a GC% of 44.3 %. According to the COG annotation, most of these proteins were divided into three categories related to transcription (K category: 307), amino acid transport and metabolism (E category: 222), and carbohydrate transport and metabolism (G category: 268). No genes associated with antimicrobial resistance or virulence factors were identified. The data presented here can be used in comparative genomics to identify antimicrobial resistance genes and virulence factors that may be present in relevant Lactobacillus species. PlasmidFinder server revealed the presence of plasmid pR18 (assessment number JN601038) in the genome that has lincomycin resistance, can be transferred from one bacterium to another, and is one of the most common plasmids in the genera Bacillus and Lactobacillus. The draft genome sequence data have been deposited with NCBI under Bioproject under accession number PRJNA947394.

13.
J Funct Biomater ; 15(6)2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38921516

RESUMO

Yeasts resistant to antifungals have become an increasing risk to human health. One of the best antimicrobial properties is reported to be present in silver nanoparticles (AgNPs); however, little is known about the antimicrobial potential of AgNPs produced using thermophilic bacteria. How AgNPs cause cell death is different depending on the type of the cell, and the mode of death induced is cell-type specific. Apoptosis, one of the types of regulated cell death, can be extremely useful in the fight against infection because surrounding cells that have phagocytic activity can efficiently absorb the apoptotic bodies formed during apoptosis. In the course of this work, for the first time, comprehensive antifungal studies of AgNPs were performed using thermophilic Geobacillus spp. bacteria against Candida guilliermondii, also with the addition of the model yeast Saccharomyces cerevisiae. The determined minimal inhibitory concentrations (MICs) were 10 µg/mL against C. guilliermondii and 50 µg/mL against S. cerevisiae for Geobacillus sp. strain 25 AgNPs, and for Geobacillus sp. 612 the MICs were 5 µg/mL and 25 µg/mL, respectively. It was shown for the first time that the exposure of the yeast cells leads to caspase activation in both S. cerevisiae and C. guilliermondii after exposure to Geobacillus spp. AgNPs. Also, a statistically significant change in the number of cells with permeable membranes was detected. Moreover, it was shown that the antimicrobial effect of the AgNPs is related to ROS generation and lipid peroxidation in C. guilliermondii yeast.

14.
Plants (Basel) ; 13(12)2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38931148

RESUMO

The use of rhizospheric SynComs can be a new and sustainable strategy in the agrobiotechnology sector. The objective of this study was to create the most appropriate SynCom composition; examine the ability to dissolve natural rock phosphate (RP) from Morocco in liquid-modified NBRIP medium; determine organic acids, and phytohormones; and verify plant growth promoting and nutrition uptake effect in the pot experiments of winter wheat (Triticum aestivum). A total of nine different microorganisms were isolated, which belonged to three different genera: Bacillus, Pseudomonas, and Streptomyces. Out of the 21 treatments tested, four SynComs had the best phosphate-dissolving properties: IJAK-27+44+91 (129.17 mg L-1), IIBEI-32+40 (90.95 µg mL-1), IIIDEG-45+41 (122.78 mg L-1), and IIIDEG-45+41+72 (120.78 mg L-1). We demonstrate that these SynComs are capable of producing lactic, acetic, gluconic, malic, oxalic, citric acids, and phytohormones such as indole-3-acetic acid, zeatin, gibberellic acid, and abscisic acid. In pot experiments with winter wheat, we also demonstrated that the designed SynComs were able to effectively colonize the plant root rhizosphere and contributed to more abundant plant growth characteristics and nutrient uptake as uninoculated treatment or uninoculated treatment with superphosphate (NPK 0-19-0). The obtained results show that the SynCom compositions of IJAK-27+44+91, IIBEI-32+40, IIIDEG-45+41, and IIIDEG-45+41+72 can be considered as promising candidates for developing biofertilizers to facilitate P absorption and increase plant nutrition.

15.
Nanomaterials (Basel) ; 13(4)2023 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-36839070

RESUMO

Silver nanoparticles (AgNPs) are well known for their unique physical and chemical properties, which can be incorporated into a wide range of applications. The growing resistance of microorganisms to antimicrobial compounds promoted the use of AgNPs in antimicrobial therapy. AgNPs can be obtained using physical and chemical methods, but these technologies are highly unfriendly to nature and produce large amounts of side compounds (for example, sodium borohydride and N,N-dimethylformamide). Therefore, alternative technologies are required for obtaining AgNPs. This report focuses on the biosynthesis of silver nanoparticles through the reduction of Ag+ with the cell-free secretomes of four Geobacillus bacterial strains, namely, 18, 25, 95, and 612. Only a few studies that involved Geobacillus bacteria in the synthesis of metal nanoparticles, including AgNPs, have been reported to date. The silver nanoparticles synthesized through bio-based methods were characterized using UV-Vis spectroscopy, scanning electron microscopy (SEM), dynamic light scattering (DLS), and zeta potential measurements. UV-Vis spectroscopy showed a characteristic absorbance peak at 410-425 nm, indicative of AgNPs. SEM analysis confirmed that most nanoparticles were spherical. DLS analysis showed that the sizes of the obtained AgNPs were widely distributed, with the majority less than 100 nm in diameter, while the zeta potential values ranged from -25.7 to -31.3 mV and depended on the Geobacillus spp. strain.

16.
Nanomaterials (Basel) ; 13(10)2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37242035

RESUMO

Silver nanoparticles (AgNPs) are widely known for their antimicrobial activity in various systems from microorganisms to cell cultures. However, the data on their effects on microalgae are very limited. Unicellular green algae Haematococcus pluvialis is known for its ability to accumulate large amounts of astaxanthin under stress conditions. Therefore, it can be used as a suitable model system to test the influence of AgNPs on stress induction in unicellular algae, with visible phenotypic effects, such as astaxanthin synthesis and cell morphology. This study tested different AgNP concentrations (0-8 mg/L) effects on different growth stages (red and green) of H. pluvialis culture. Effects on cell morphology, culture productivity, and astaxanthin synthesis were evaluated. Data showed that the addition of high concentrations of AgNPs to the growing culture had a significant negative impact on culture productivity. Green-stage (HpG) cultures productivity was reduced by up to 85% by increasing AgNPs concentration to 8 mg/L while the impact on red-stage (HpR) culture was lower. Astaxanthin concentration measurements showed that AgNPs do not have any effect on astaxanthin concentration in HpG culture and caused decreased astaxanthin production rate in HpR culture. HpG culture astaxanthin concentration stayed constant at ~0.43% dry weight, while HpR culture astaxanthin concentration was significantly reduced from 1.89% to 0.60% dry weight by increasing AgNP concentration. AgNPs in the media lead to significant changes in cell morphology in both HpG and HpR cultures. Cell deformations and disrupted cytokinesis, as well as AgNPs and induced sexual reproduction, were observed.

17.
Data Brief ; 49: 109436, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37501729

RESUMO

Here we report the draft genome sequence of the Latilactobacillus curvatus PN39MY strain. The strain was isolated from Lithuanian traditionally (homemade) fermented cucumber. The genome consisted of 83 contigs with a total size of 1,899,018 bp, an N50 of 40562 and a GC% of 42.1. After sequence trimming, 83 contigs were annotated and 1910 genes were coding sequences. The average nucleotide identity (ANI) between PN39MY and Latilactobacillus curvatus_ZJUNIT8 was 99.45% identifying the strain as Latilactobacillus curvatus. No genes related to antimicrobial resistance or virulence factors were found. The data presented here can be used in comparative genomics to identify antimicrobial resistant genes, plasmids and/or virulence factors that may be present in related Latilactobacillus species. The draft genome sequence data was deposited at NCBI under Bioproject with the accession number PRJNA941180.

19.
Front Microbiol ; 14: 1213370, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37744916

RESUMO

The present work aimed to identify probiotic candidates from Lithuanian homemade fermented food samples. A total of 23 lactic acid bacteria were isolated from different fermented food samples. Among these, only 12 showed resistance to low pH, tolerance to pepsin, bile salts, and pancreatin. The 12 strains also exhibited antimicrobial activity against Staphylococcus aureus ATCC 29213, Salmonella Typhimurium ATCC 14028, Streptococcus pyogenes ATCC 12384, Streptococcus pyogenes ATCC 19615, and Klebsiella pneumoniae ATCC 13883. Cell-free supernatants of isolate 3A and 55w showed the strongest antioxidant activity of 26.37 µg/mL and 26.06 µg/mL, respectively. Isolate 11w exhibited the strongest auto-aggregation ability of 79.96% as well as the strongest adhesion to HCT116 colon cells (25.671 ± 0.43%). The selected strains were tested for their synbiotic relation in the presence of a prebiotic. The selected candidates showed high proliferation in the presence of 4% as compared to 2% galactooligosaccharides. Among the strains tested for tryptophan production ability, isolate 11w produced the highest L-tryptophan levels of 16.63 ± 2.25 µm, exhibiting psychobiotic ability in the presence of a prebiotic. The safety of these strains was studied by ascertaining their antibiotic susceptibility, mucin degradation, gelatin hydrolysis, and hemolytic activity. In all, isolates 40C and 11w demonstrated the most desirable probiotic potentials and were identified by 16S RNA and later confirmed by whole genome sequencing as Lacticaseibacillus paracasei 11w, and Lactiplantibacillus plantarum 40C: following with the harboring plasmid investigation. Out of all the 23 selected strains, only Lacticaseibacillus paracasei 11w showed the potential and desirable probiotic properties.

20.
Biology (Basel) ; 11(2)2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35205120

RESUMO

In this study, a phosphate solubilizing microorganism was isolated from the soil of an agricultural field in Lithuania. Based on 16S rRNA gene sequence analysis, the strain was identified as Bacillus sp. and submitted to the NCBI database, Sector of Applied Bio-catalysis, University Institute of Biotechnology, Vilnius, Lithuania and allocated the accession number KY882273. The Bacillus sp. was assigned with the number MVY-004. The culture nutrient medium and growth conditions were optimized: molasses was used as a carbon source; yeast extract powder was used as an organic source; NH4H2PO4 was used as a nitrogen source; the culture growth temperature was 30 ± 0.5 °C; the initial value of pH was 7.0 ± 0.5; the partial pressure of oxygen (pO2) was 60 ± 2.0; the mixer revolutions per minute (RPM) were 25-850, and the incubation and the fermentation time was 48-50 h. Analysis using Liquid Chromatography Time-of-Flight Mass Spectrometry (LC-TOF/MS) results showed that Bacillus sp. MVY-004 produced organic acids such as citric, succinic, 2-ketogluconic, gluconic, malic, lactic, and oxalic acids. Furthermore, the experiment showed that Bacillus sp. MVY-004 can also produce the following phytohormones: indole-3-acetic (IAA), jasmonic (JA), and gibberellic (GA3) acids. In the climate chamber, the experiment was performed using mineral fertilizer (NPS-12:40:10 80 Kg ha-1) and mineral fertilizers in combination with Bacillus sp. MVY-004 cells (NPS-12:40:10 80 Kg ha-1 + Bacillus sp. MVY-004) in loamy soil. Analysis was performed in three climate conditions: normal (T = 20 °C; relative humidity 60%); hot and dry (T = 30 °C; relative humidity 30%); hot and humid (T = 30 °C; relative humidity 80%).

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