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1.
Science ; 368(6495): 1135-1140, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32499444

RESUMO

Determining where an object has been is a fundamental challenge for human health, commerce, and food safety. Location-specific microbes in principle offer a cheap and sensitive way to determine object provenance. We created a synthetic, scalable microbial spore system that identifies object provenance in under 1 hour at meter-scale resolution and near single-spore sensitivity and can be safely introduced into and recovered from the environment. This system solves the key challenges in object provenance: persistence in the environment, scalability, rapid and facile decoding, and biocontainment. Our system is compatible with SHERLOCK, a Cas13a RNA-guided nucleic acid detection assay, facilitating its implementation in a wide range of applications.


Assuntos
Código de Barras de DNA Taxonômico/métodos , DNA Bacteriano/isolamento & purificação , DNA Fúngico/isolamento & purificação , Microbiologia Ambiental , Microbiota/genética , Esporos/genética , Sistemas CRISPR-Cas , DNA Bacteriano/genética , DNA Fúngico/genética , RNA Guia
2.
Ying Yong Sheng Tai Xue Bao ; 31(5): 1707-1714, 2020 May.
Artigo em Chinês | MEDLINE | ID: mdl-32530250

RESUMO

Drainage severely changes the environment and ecological process in peatlands, but how does it affect the germinability of Sphagnum spores in peat remains unclear. In this study, we took two peat cores from a near-pristine stand dominated by Sphagnum and a drained stand dominated by dwarf shrubs in Baijianghe Peatland in the Changbai Mountains as experimental materials. Those peat cores were cut into slices. Physicochemical characteristics were measured while Sphagnum spores from each slice were extracted to count spore density and test spore germinability. After dating and determining relationship between peat depth and age, we tried to figure out the mechanism underlying the responses of Sphagnum spore germinability to drainage. The average number of spores in the near-pristine stand was slightly higher than that in the drained stand. There was no difference in average spore germinability between the two stands. The drained stand showed higher peat bulk density, total carbon and total nitrogen relative to the near-pristine stand. Upper peat core showed no significant difference in spore accumulation rate between the two stands after drainage (in 1987), with lower average spore germinability (34%) in the near-pristine stand relative to the drained stand (72%). For the whole peat cores, C/N was positively correlated with spore ger-minability in the near-pristine stand while total carbon, pH and burial time were negatively correlated with spore germinability in the drained stand. The drainage 30 years ago had limited effect on spore accumulation, but improved germinability of spores in shallow peat by changing physicochemical properties of peat due to accelerating decomposition, and thus reduced the persistence of spore bank. This may reduce the persistent regeneration potential of Sphagnum after catastrophic distur-bances.


Assuntos
Sphagnopsida , Carbono , China , Solo , Esporos
4.
Nature ; 580(7801): 81-86, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32238944

RESUMO

The mid-Cretaceous period was one of the warmest intervals of the past 140 million years1-5, driven by atmospheric carbon dioxide levels of around 1,000 parts per million by volume6. In the near absence of proximal geological records from south of the Antarctic Circle, it is disputed whether polar ice could exist under such environmental conditions. Here we use a sedimentary sequence recovered from the West Antarctic shelf-the southernmost Cretaceous record reported so far-and show that a temperate lowland rainforest environment existed at a palaeolatitude of about 82° S during the Turonian-Santonian age (92 to 83 million years ago). This record contains an intact 3-metre-long network of in situ fossil roots embedded in a mudstone matrix containing diverse pollen and spores. A climate model simulation shows that the reconstructed temperate climate at this high latitude requires a combination of both atmospheric carbon dioxide concentrations of 1,120-1,680 parts per million by volume and a vegetated land surface without major Antarctic glaciation, highlighting the important cooling effect exerted by ice albedo under high levels of atmospheric carbon dioxide.


Assuntos
Atmosfera/química , Dióxido de Carbono/análise , Dióxido de Carbono/história , Clima , Floresta Úmida , Temperatura , Regiões Antárticas , Fósseis , Sedimentos Geológicos/química , História Antiga , Modelos Teóricos , Nova Zelândia , Pólen , Esporos/isolamento & purificação
5.
PLoS Genet ; 16(3): e1008660, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32203501

RESUMO

Many bacterial species are capable of forming long-lived dormant cells. The best characterized are heat and desiccation resistant spores produced by many Gram-positive species. Less characterized are dormant cysts produced by several Gram-negative species that are somewhat tolerant to increased temperature and very resistant to desiccation. While there is progress in understanding regulatory circuits that control spore germination, there is scarce information on how Gram-negative organisms emerges from dormancy. In this study, we show that R. centenum cysts germinate by emerging a pair of motile vegetative cells from a thick cyst cell wall coat ~ 6 hrs post induction of germination. Time-lapse transcriptomic analysis reveals that there is a defined temporal pattern of gene expression changes during R. centenum cyst germination. The first observable changes are increases in expression of genes for protein synthesis, an increase in expression of genes involved in the generation of a membrane potential and the use of this potential for ATP synthesis via ATPase expression. These early events are followed by expression changes that affect the cell wall and membrane composition, followed by expression changes that promote chromosome replication. Midway through germination, expression changes occur that promote the flow of carbon through the TCA cycle to generate reducing power and parallel synthesis of electron transfer components involved in oxidative phosphorylation. Finally, late expression changes promote the synthesis of a photosystem as well as flagellar and chemotaxis components for motility.


Assuntos
Rhodospirillum centenum/genética , Rhodospirillum centenum/metabolismo , Esporos Bacterianos/genética , Parede Celular/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação Bacteriana da Expressão Gênica/genética , Biossíntese de Proteínas/genética , Esporos/genética , Esporos/isolamento & purificação , Esporos Bacterianos/isolamento & purificação , Esporos Bacterianos/metabolismo , Transcriptoma/genética
6.
BMC Ecol ; 20(1): 15, 2020 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-32143610

RESUMO

BACKGROUND: The most severe bacterial disease of honeybees is American foulbrood (AFB). The epidemiology of AFB is driven by the extreme spore resilience, the difficulty of bees to remove these spores, and the considerable incidence of undetected spore-producing colonies. The honeybee collective defence mechanisms and their feedback on colony development, which involves a division of labour at multiple levels of colony organization, are difficult to model. To better predict disease outbreaks we need to understand the feedback between colony development and disease progression within the colony. We therefore developed Bayesian models with data from forty AFB-diseased colonies monitored over an entire foraging season to (i) investigate the relationship between spore production and symptoms, (ii) disentangle the feedback loops between AFB epidemiology and natural colony development, and (iii) discuss whether larger insect societies promote or limit within-colony disease transmission. RESULTS: Rather than identifying a fixed spore count threshold for clinical symptoms, we estimated the probabilities around the relationship between spore counts and symptoms, taking into account modulators such as brood amount/number of bees and time post infection. We identified a decrease over time in the bees-to-brood ratio related to disease development, which should ultimately induce colony collapse. Lastly, two contrasting theories predict that larger colonies could promote either higher (classical epidemiological SIR-model) or lower (increasing spatial nest segregation and more effective pathogen removal) disease prevalence. CONCLUSIONS: AFB followed the predictions of the SIR-model, partly because disease prevalence and brood removal are decoupled, with worker bees acting more as disease vectors, infecting new brood, than as agents of social immunity, by removing infected brood. We therefore established a direct link between disease prevalence and social group size for a eusocial insect. We furthermore provide a probabilistic description of the relationship between AFB spore counts and symptoms, and how disease development and colony strength over a season modulate this relationship. These results help to better understand disease development within honeybee colonies, provide important estimates for further epidemiological modelling, and gained important insights into the optimal sampling strategy for practical beekeeping and honeybee research.


Assuntos
Esporos , Animais , Teorema de Bayes , Abelhas , Larva , Estados Unidos
7.
PLoS One ; 15(1): e0227250, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31910244

RESUMO

Oomycete plant pathogens are difficult to control and routine genetic research is challenging. A major problem is instability of isolates. Here we characterize >600 field and single zoospore isolates of Phytophthora capsici for inheritance of mating type, sensitivity to mefenoxam, chromosome copy number and heterozygous allele frequencies. The A2 mating type was highly unstable with 26% of 241 A2 isolates remaining A2. The A1 mating type was stable. Isolates intermediately resistant to mefenoxam produced fully resistant single-spore progeny. Sensitive isolates remained fully sensitive. Genome re-sequencing of single zoospore isolates revealed extreme aneuploidy; a phenomenon dubbed Dynamic Extreme Aneuploidy (DEA). DEA is characterized by the asexual inheritance of diverse intra-genomic combinations of chromosomal ploidy ranging from 2N to 3N and heterozygous allele frequencies that do not strictly correspond to ploidy. Isolates sectoring on agar media showed dramatically altered heterozygous allele frequencies. DEA can explain the rapid increase of advantageous alleles (e.g. drug resistance), mating type switches and copy neutral loss of heterozygosity (LOH). Although the mechanisms driving DEA are unknown, it can play an important role in adaptation and evolution and seriously hinders all aspects of P. capsici research.


Assuntos
Aneuploidia , Phytophthora/fisiologia , Doenças das Plantas/microbiologia , Reprodução Assexuada/genética , Verduras/microbiologia , Alelos , Evolução Biológica , Mapeamento Cromossômico , Cucumis sativus/microbiologia , Variação Genética , Genótipo , Perda de Heterozigosidade , Phytophthora/isolamento & purificação , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Análise de Célula Única , Esporos/genética
8.
PLoS Pathog ; 16(1): e1008138, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31961913

RESUMO

Eukaryotic heterotrimeric guanine nucleotide-binding proteins consist of α, ß, and γ subunits, which act as molecular switches to regulate a number of fundamental cellular processes. In the oomycete pathogen Phytophthora sojae, the sole G protein α subunit (Gα; encoded by PsGPA1) has been found to be involved in zoospore mobility and virulence, but how it functions remains unclear. In this study, we show that the Gα subunit PsGPA1 directly interacts with PsYPK1, a serine/threonine protein kinase that consists of an N-terminal region with unknown function and a C-terminal region with a conserved catalytic kinase domain. We generated knockout and knockout-complemented strains of PsYPK1 and found that deletion of PsYPK1 resulted in a pronounced reduction in the production of sporangia and oospores, in mycelial growth on nutrient poor medium, and in virulence. PsYPK1 exhibits a cytoplasmic-nuclear localization pattern that is essential for sporangium formation and virulence of P. sojae. Interestingly, PsGPA1 overexpression was found to prevent nuclear localization of PsYPK1 by exclusively binding to the N-terminal region of PsYPK1, therefore accounting for its negative role in sporangium formation. Our data demonstrate that PsGPA1 negatively regulates sporangium formation by repressing the nuclear localization of its downstream kinase PsYPK1.


Assuntos
Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Phytophthora/enzimologia , Proteínas Serina-Treonina Quinases/metabolismo , Esporos/crescimento & desenvolvimento , Núcleo Celular/genética , Núcleo Celular/metabolismo , Subunidades alfa de Proteínas de Ligação ao GTP/química , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Phytophthora/genética , Phytophthora/crescimento & desenvolvimento , Phytophthora/patogenicidade , Doenças das Plantas/parasitologia , Ligação Proteica , Domínios Proteicos , Transporte Proteico , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Soja/parasitologia , Esporos/enzimologia , Esporos/genética , Esporos/metabolismo , Virulência
9.
Parasitol Res ; 119(1): 85-96, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31768684

RESUMO

Examination of 35 barramundi (Lates calcarifer) from aquaculture cages in Setiu Wetland, Malaysia, revealed a single fish infected with three Henneguya spp. (Cnidaria: Myxosporea). Characterization of the infections using tissue tropism, myxospore morphology and morphometry and 18S rDNA sequencing supported description of three new species: Henneguya setiuensis n. sp., Henneguya voronini n. sp. and H. calcarifer n. sp. Myxospores of all three species had typical Henneguya morphology, with two polar capsules in the plane of the suture, an oval spore body, smooth valve cell surfaces, and two caudal appendages. Spores were morphometrically similar, and many dimensions overlapped, but H. voronini n. sp. had shorter caudal appendages compared with H. calcarifer n. sp. and H. setiuensis n. sp. Gross tissue tropism distinguished the muscle parasite H. calcarifer n. sp. from gill parasites H. setiuensis n. sp. and H. voronini n. sp.; and these latter two species were further separable by fine-scale location of developing plasmodia, which were intra-lamellar for H. setiuensis n. sp. and basal to the filaments for H. voronini n. sp. small subunit ribosomal DNA sequences distinguished all three species: the two gill species H. setiuensis n. sp. and H voronini n. sp. were only 88% similar (over 1708 bp), whereas the muscle species H. calcarifer n. sp. was most similar to H. voronini n. sp. (98% over 1696 bp). None of the three novel species was more than 90% similar to any known myxosporean sequence in GenBank. Low infection prevalence of these myxosporeans and lack of obvious tissue pathology from developing plasmodia suggested none of these parasites are currently a problem for barramundi culture in Setiu Wetland; however additional surveys of fish, particularly at different times of the year, would be informative for better risk assessment.


Assuntos
Doenças dos Peixes/parasitologia , Myxozoa/classificação , Myxozoa/isolamento & purificação , Doenças Parasitárias em Animais/diagnóstico , Doenças Parasitárias em Animais/parasitologia , Perciformes/parasitologia , Animais , Aquicultura , Cnidários/classificação , DNA Ribossômico/genética , Doenças dos Peixes/diagnóstico , Peixes , Brânquias/parasitologia , Malásia , Filogenia , RNA Ribossômico 18S/genética , Subunidades Ribossômicas Menores/genética , Esporos/genética , Áreas Alagadas
10.
Phytopathology ; 110(3): 593-602, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31774360

RESUMO

Lysobacter enzymogenes strain C3 (LeC3) is a potential biocontrol agent for plant diseases caused by fungi and oomycetes. Understanding the interaction between LeC3 and soybean pathogens at the molecular level could help improve its biocontrol efficacy. In this study, we obtained mutants with decreased abilities in inhibiting hypha growth of the white mold pathogen Sclerotinia sclerotiorum. Insertion sites for 50 mutants, which no longer inhibited S. sclerotiorum hypha growth in dual cultural assay, were determined and seven mutants were selected for further characterization. These seven mutants also completely lost their abilities in suppressing spore germination of Fusarium virguliforme, the causal agent of soybean sudden death syndrome. Furthermore, mutation of the seven genes, which encode diguanylate cyclase, transcriptional regulators from the TetR family, hemolysin III family channel protein, type IV secretion system VirB10 protein, phenol hydroxylase, and phosphoadenosine phosphosulfate reductase, respectively, led to reduced production or secretion of four extracellular enzymes and heat-stable antifungal factor (HSAF). These results suggest that these seven genes play important roles in L. enzymogenes in suppressing hypha growth and spore germination of fungal pathogens, probably by influencing production or secretion of extracellular enzymes and HSAF.


Assuntos
Lysobacter , Proteínas de Bactérias , Fungos , Germinação , Hifas , Doenças das Plantas , Soja , Esporos
11.
Forensic Sci Int ; 306: 110061, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31841931

RESUMO

The use of pollen as a forensic tool for geolocation is a well-established practice worldwide in cases ranging from the provenance of drugs and other illicit materials to tracking the travel of individuals in criminal investigations. Here we propose a novel approach to generation of pollen databases that uses pollen vacuumed from mammal pelts collected historically from international areas that are now deemed too high risk to visit. We present the results of a study we conducted using mammal pelts collected from Mexico. This new investigative technique is important because, although it would seem that the ubiquitous and geo-specific nature of pollen would make pollen analysis among the most promising forensic tools for law enforcement and intelligence agencies, it is not the case. The process is notoriously slow because pollen identification is a tedious task requiring trained specialists (palynologists) who are few in number worldwide, and the reference materials necessary for geolocation usually are rare or absent, especially from regions of the world that are no longer safe to visit because of war or threat of terrorism. Current forensic palynological work is carried out by a few highly trained palynologists who require accurate databases of pollen distribution, especially from sensitive areas, to do their jobs accurately and efficiently. Our project shows the suitability of using the untapped museum pelt resources to support homeland security programs. This first palynological study using museum pelts yielded 133 different pollen and spore types, including 8 moss or fern families, 12 gymnosperm genera and 112 angiosperm species. We show that the palynological print from each region is statistically different with some important clustering, demonstrating the potential to use this technique for geolocation.


Assuntos
Botânica/métodos , Ciências Forenses/métodos , Museus , Pólen , Esporos , Bases de Dados Factuais , Ecossistema , Humanos
12.
J Parasitol ; 105(6): 918-927, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31829908

RESUMO

The pirate perch Aphredoderus sayanus is a relatively small fish species found in rivers throughout much of the eastern United States. Due to their cryptic nature, relatively little is known regarding their parasite fauna. A survey of pirate perch from the upper Mississippi River revealed 2 novel myxozoans. Hennegoides flockae n. sp. was observed in heavily infected gills where the lamellae featured irregular expansion by bulbous myxozoan polysporic plasmodia, typically affecting the middle to distal half of the filaments. When severe, infection of sequential filaments was such that the filaments were fused, forming what appeared as multicystic/lobular parasitic aggregates subdivided by fine epithelial cords. The total myxospore length of Hennegoides flockae was 35.4-46.4 (41.3 ± 3.3) and the spore body, asymmetrically ovoid in valvular view, was 15.4-18.7 (17.0 ± 0.7) × 7.1-8.7 (7.9 ± 0.4). Henneguya marcquenskiae n. sp. was observed in the liver with plasmodia present randomly and infrequently in the hepatocellular parenchyma. The total myxospore length for Henneguya marcquenskiae was 39.5-55.9 (48.4 ± 4.2), with the spore body being lanceolate, 13.9-16.5 (15.4 ± 0.7) × 7.1-9.0 (8.3 ± 0.5). Phylogenetic analysis of the SSU rRNA gene placed both Hennegoides flockae and Henneguya marcquenskiae as sisters to each other in a clade containing other Myxozoans known to infect the gills of esocids, percids, and centrarchids. These parasites represent the first reports of Henneguya and Hennegoides from pirate perch, with the latter being the first report of this genus outside of the Asian continent.


Assuntos
Doenças dos Peixes/parasitologia , Myxozoa/isolamento & purificação , Doenças Parasitárias em Animais/parasitologia , Percas/parasitologia , Animais , Sequência de Bases , Teorema de Bayes , Doenças dos Peixes/epidemiologia , Brânquias/parasitologia , Funções Verossimilhança , Fígado/parasitologia , Cadeias de Markov , Microscopia de Interferência/veterinária , Método de Monte Carlo , Myxozoa/classificação , Myxozoa/genética , Doenças Parasitárias em Animais/epidemiologia , Filogenia , Prevalência , RNA Ribossômico/química , RNA Ribossômico/genética , Rios , Esporos/ultraestrutura , Wisconsin/epidemiologia
13.
Environ Sci Technol ; 53(24): 14285-14295, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31578063

RESUMO

Although spores/pollens are so abundant and ubiquitous in the environment, the role of these natural organic matter concerning fate and transport of organic pollutants in the environment is neglected. Lipid-free fractions and sporopollenins were isolated from seven spores/pollens collected from lower and higher biota species and were characterized by elemental analysis, CO2 adsorption techniques, and advanced solid-state 13C nuclear magnetic resonance spectroscopy. Then, the sorption isotherms of phenanthrene (Phen) on all the samples were investigated by a batch technique. The sporopollenins were a highly cross-linked polymer including alkyl carbon, poly(methylene) carbon, and aromatic carbon as well as oxygen functionalities; additionally, their sorption capacities (Koc) for Phen reached up to 1 170 000 mL/g, suggesting that some of the sporopollenins were good biopolymeric sorbents for the removal of hydrophobic organic contaminants in aquatic media. A highly significant and positive correlation between the sorption capacity of Phen and the aliphaticity of the sporopollenins suggested that their structure was critical to Phen sorption. Meanwhile, the (O + N)/C atomic ratios and polar groups were significantly and negatively correlated with the sorption capacity of Phen, indicating that accessibility also played a significant role in the sorption process. Moreover, variable correlations between the sorption capacities (Koc) and the micropore volumes of the spore/pollen fractions were observed. This study sheds light on the importance of the polarity, microporosity, and structure of sporopollenins in the sorption process of Phen.


Assuntos
Fenantrenos , Adsorção , Biopolímeros , Biota , Carotenoides , Pólen , Esporos
14.
J Photochem Photobiol B ; 199: 111627, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31536925

RESUMO

Photobiomodulation relies on the transfer of energy from incident photons to a cell photoacceptor. For many years the concept of photobiomodulation and its outcome has been based upon a belief that the sole receptor within the cell was the mitochondrion. Recently, it has become apparent that there are other photoacceptors operating in different regions of the electromagnetic spectrum. Alternative photoacceptors would appear to be water and mechanisms regulating calcium homeostasis, despite a direct effect of laser photonic energy on intracellular calcium concentration outwith mitochondrial activity or influence, have not been clearly demonstrated. Therefore, to increase the knowledge of intracellular­calcium and laser photon interaction, as well as to demonstrate differences in irradiation profiles with modern hand-pieces, we tested and compared the photobiomodulatory effect of 808 nm and 980 nm diode laser light by low- and higher-energy (60s, 100 mW/cm2, 100 mW/cm2, 500 mW/cm2, 1000 mW/cm2, 1500 mW/cm2, 2000 mW/cm2) irradiated with a "standard" (Gaussian fluence distribution) hand-piece or with a "flat-top" (uniform fluence) hand-piece. For this purpose, we used the eukaryote unicellular-model Dictyostelium discoideum. The 808 nm and 980 nm infrared laser light, at the energy tested directly affect the stored Ca2+ homeostasis, independent of the mitochondrial respiratory chain activities. From an organism perspective, the effect on Ca2+-dependent signal transduction as the regulator of spore germination in Dictyostelium, demonstrates how a cell can respond quickly to the correct laser photonic stimulus through a different cellular pathway than the known light-chromophore(mitochondria) interaction. Additionally, both hand-piece designs tested were able to photobiomodulate the D. discoideum cell; however, the hand-piece with a flat-top profile, through uniform fluence levels allows more effective and reproducible effects.


Assuntos
Cálcio/metabolismo , Dictyostelium/metabolismo , Germinação/efeitos da radiação , Homeostase/efeitos da radiação , Esporos/metabolismo , Raios Infravermelhos , Lasers Semicondutores , Terapia com Luz de Baixa Intensidade , Mitocôndrias/metabolismo , Temperatura , Fatores de Tempo
15.
J Dairy Sci ; 102(12): 10799-10813, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31521346

RESUMO

Spore formers are common spoilage-causing microorganisms in dairy products; however, their modes of spoilage (proteolysis, lipolysis, etc.) have not been described in detail for cultured dairy products such as sour cream and yogurt. The objective of the present study was to test the ability of spore-forming strains isolated from dairy environments for their spoilage-causing activities at typical sour cream (24°C) and yogurt (42°C) fermentation temperatures. A total of 25 spore-forming strains were isolated from different sources, including raw milk, pasteurizer balance tank, biofilms formed on heat exchangers, and milk powder. These strains were tested for proteolytic and lipolytic activities and for their ability to degrade phospholipids, common stabilizers (starch, gelatin, xanthan gum, pectin), and exopolysaccharides (EPS) at sour cream and yogurt fermentation temperatures. A higher percentage of positive strains was observed for selected activities at yogurt fermentation temperature compared with sour cream fermentation temperature. Identified proteolytic spore-forming strains, based on a skim milk agar method, were subsequently quantified for their level of proteolysis using non-casein nitrogen (NCN) content and sodium dodecyl sulfate-PAGE (SDS-PAGE). The proteolytic strains that showed the highest levels of proteolysis (highest percentages of NCN content) at 24°C were Bacillus mojavensis BC, Bacillus cereus DBC, Bacillus subtilis DBC, B. mojavensis DBC1, and Paenibacillus polymyxa DBC1. At 42°C the strains with the highest levels of proteolysis (highest percentages of NCN content) were B. subtilis DBC, B. mojavensis BC, B. mojavensis DBC1, B. cereus DBC, and Bacillus licheniformis DBC6. Results of SDS-PAGE demonstrated that proteolytic strains had primarily hydrolyzed ß- and κ-CN. A viscometric method was used to evaluate the susceptibility of exopolysaccharides (EPS) to degradation by selected spore formers. This method helped to determine that EPS produced by commercial yogurt and sour cream cultures is susceptible to degradation by spore formers present in dairy environments.


Assuntos
Bacillus/metabolismo , Proteínas do Leite/metabolismo , Leite/microbiologia , Fosfolipídeos/metabolismo , Animais , Fermentação , Microbiologia de Alimentos , Leite/metabolismo , Paenibacillus/metabolismo , Pasteurização , Esporos , Temperatura , Iogurte/microbiologia
16.
Adv Mater ; 31(43): e1903793, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31490587

RESUMO

Spores, the dormant life forms of probiotics, can germinate to metabolically active vegetative cells with the disintegration of their hydrophobic protein coat in the intestinal microenvironment, which provides the possibility for the formation of nanoparticles (NPs) in vivo. Inspired by the natural physiological process of spores, herein, an oral autonomous NPs generator is developed to overcome the spatially variable gastrointestinal tract environment and multibiological barriers. Spores modified with deoxycholic acid (DA) and loaded with chemotherapeutic drugs (doxorubicin and sorafenib, DOX/SOR) serve as an autonomous production line of NPs, which can efficaciously protect the drugs passing through the rugged environment of the stomach and furthermore can be transported to the intestinal environment and colonized rapidly. Subsequently, the DOX/SOR/Spore-DA NPs are produced by the autonomous NPs generator in the intestinal regions based on the disintegrated hydrophobic protein and the hydrophilic DA, and they can efficiently penetrate the epithelial cells via the bile acid pathway, increasing basolateral drug release. In vitro and in vivo studies confirm that this biological nanogenerator can autonomously produce substantial NPs in the intestine, providing a promising strategy for cancer therapy.


Assuntos
Neoplasias do Colo/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Nanomedicina/métodos , Nanopartículas/metabolismo , Nanopartículas/uso terapêutico , Probióticos/metabolismo , Esporos/metabolismo , Administração Oral , Animais , Bacillus/metabolismo , Transporte Biológico , Células CACO-2 , Linhagem Celular Tumoral , Neoplasias do Colo/patologia , Doxorrubicina/química , Doxorrubicina/metabolismo , Doxorrubicina/farmacologia , Humanos , Absorção Intestinal , Camundongos , Sorafenibe/química , Sorafenibe/metabolismo , Sorafenibe/farmacologia
17.
Parasitol Res ; 118(10): 3099-3103, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31486945

RESUMO

Myxobolus pelecicola Voronin et Dudin, 2015 was recently described from the skeletal musculature of sichel Pelecus cultratus. However, another species, Myxobolus ladogensis Rumyantsev et Schulman, 1997, was described previously from the same host, displaying identical tissue localization and spore morphology as in M. pelecicola. Unfortunately, M. ladogensis was overlooked when M. pelecicola was described, resulting in the superfluous description of the latter species, which, according to the International Code of Zoological Nomenclature, is a junior synonym of M. ladogensis. The description of M. ladogensis is supplemented with SSU rDNA sequence analysis supporting the conspecificity with M. pelecicola. The closest relatives of Myxobolus ladogensis (syn. M. pelecicola) include several muscle-infecting Myxobolus spp. with sequence similarity below 97%.


Assuntos
Cyprinidae/parasitologia , Doenças dos Peixes/parasitologia , Músculo Esquelético/parasitologia , Myxobolus/classificação , Doenças Parasitárias em Animais/parasitologia , Animais , DNA Ribossômico/genética , Myxobolus/genética , Filogenia , Federação Russa , Esporos
18.
Forensic Sci Int ; 302: 109903, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400618

RESUMO

First used over 50 years ago, forensic palynology is an important tool for law enforcement agencies. In most countries that use forensic palynology, microscopic pollen grains and spores are traditionally used in criminal investigations to link suspects to crime scenes or items. While still underutilized in many parts of the world, forensic palynology is increasingly being used to determine the region of origin, or geolocation, for persons and items of interest. Drawing upon the experience of the authors using trace pollen and spores to geolocate forensic samples, the types, methods, and variables of this type of analysis are discussed and demonstrated using the Baby Doe case from Massachusetts, USA as a case study. This is not an exhaustive list and every forensic sample is unique so the methods and experience presented here are intended to be a guide for future forensic and anti-terrorism investigations as forensic palynology becomes more commonplace in law enforcement agencies around the world.


Assuntos
Botânica , Vítimas de Crime , Ciências Forenses/métodos , Homicídio , Pólen , Esporos , Pré-Escolar , Vestuário , Ecossistema , Cabelo , Humanos , Massachusetts , Manejo de Espécimes
19.
Molecules ; 24(14)2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31315175

RESUMO

There is a growing interest in a potential use of essential oils (EOs) as a replacement for traditional pesticides and herbicides. The aims of this study were to: (i) Identify the chemical composition of the two EOs derived from Origanum heracleoticum L. and O. majorana L., (ii) evaluate the in vitro antifungal activity of the EOs against some postharvest phytopathogens (Botrytis cinerea, Penicillium expansum, Aspergillus niger and Monilinia fructicola), (iii) evaluate the in vitro antibacterial activity against Bacillus megaterium, Clavibacter michiganensis, Xanthomonas campestris, Pseudomonas fluorescens and P. syringae pv. phaseolicola, (iv) evaluate the effect of both studied EOs on the spore germination percentage and their minimum inhibitory concentration (MIC) against M. fructicola, and (v) study the possible phytotoxicity of the two EOs and their major constituents, carvacrol for O. heracleoticum and terpinen-4-ol for O. majorana, against tha germination and initial radicle growth of radish, lettuce, garden cress and tomato. The two EOs demonstrated promising in vitro antimicrobial and antifungal activities against all tested microorganisms. EOs showed high inhibition of spore germination percentage at the minimal inhibitory concentration of 500 and 2000 µg/mL, respectively. Moreover, both germination and radical elongation of selected plant species were sensitive to the oils.


Assuntos
Anti-Infecciosos/química , Óleos Voláteis/química , Origanum/química , Esporos/efeitos dos fármacos , Anti-Infecciosos/farmacologia , Cimenos/farmacologia , Lepidium sativum/crescimento & desenvolvimento , Lepidium sativum/microbiologia , Alface/crescimento & desenvolvimento , Alface/microbiologia , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/microbiologia , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Óleos Vegetais/química , Óleos Vegetais/farmacologia , Raphanus/crescimento & desenvolvimento , Raphanus/microbiologia , Terpenos/farmacologia
20.
Food Funct ; 10(8): 4782-4791, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31313784

RESUMO

ß-Galactosidase (ß-Gal) as a dietary supplement can alleviate symptoms of lactose intolerance. However, ß-Gal is deactivated due to the highly acidic conditions and proteases in the digestive tract. In this work, ß-Gal was encapsulated into L. clavatum sporopollenin exine capsules (SECs) to fabricate an oral-controlled release system and increase the stability of ß-Gal in the digestive tract. The SEC extraction process was optimized. A 3-hour vacuum loading was determined as the optimal loading time. Five different initial ratios of SECs : ß-Gal were optimized with the maximum enzyme retention rate reaching 79.40 ± 1.96%. Furthermore, ß-Gal-loaded SECs entrapped in carboxymethylpachymaran (CMP) could control the release of ß-Gal under simulated gastrointestinal conditions (SGC). The optimal enzyme retention rate reached 65.33 ± 1.46% within 24 h under SGC. Collectively, these results indicated that the entrapped SECs could be used as an effective oral delivery vehicle of ß-Gal to improve its performance as a dietary supplement in the digestion of lactose.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Glucanos/química , Lycopodium/química , Extratos Vegetais/química , beta-Galactosidase/química , Biopolímeros/química , Cápsulas/química , Cápsulas/metabolismo , Carotenoides/química , Preparações de Ação Retardada/química , Preparações de Ação Retardada/metabolismo , Composição de Medicamentos , Estabilidade Enzimática , Trato Gastrointestinal/metabolismo , Glucanos/metabolismo , Extratos Vegetais/metabolismo , Esporos/química , beta-Galactosidase/metabolismo
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