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1.
Artigo em Inglês | MEDLINE | ID: mdl-36795096

RESUMO

Six strains, KI11_D11T, KI4_B1, KI11_C11T, KI16_H9T, KI4_A6T and KI3_B9T, were isolated from insects and flowers on Kangaroo Island, South Australia. On the basis of 16S rRNA gene phylogeny, strains KI11_D11T, KI4_B1, KI11_C11T, KI16_H9T, KI4_A6T were found to be closely related to Fructilactobacillus ixorae Ru20-1T. Due to the lack of a whole genome sequence for this species, whole genome sequencing of Fructilactobacillus ixorae Ru20-1T was undertaken. KI3_B9T was found to be closely related to Fructobacillus tropaeoli F214-1T. Utilizing core gene phylogenetics and whole genome analyses, such as determination of AAI, ANI and dDDH, we propose that these six isolates represent five novel species with the names Fructilactobacillus cliffordii (KI11_D11T= LMG 32130T = NBRC 114988T), Fructilactobacillus hinvesii (KI11_C11T = LMG 32129T = NBRC 114987T), Fructilactobacillus myrtifloralis (KI16_H9T= LMG 32131T = NBRC 114989T) Fructilactobacillus carniphilus (KI4_A6T = LMG 32127T = NBRC 114985T) and Fructobacillus americanaquae (KI3_B9T = LMG 32124T = NBRC 114983T). Chemotaxonomic analyses detected no fructophilic characters for these strains of member of the genus Fructilactobacillus. KI3_B9T was found to be obligately fructophilic, similarly to its phylogenetic neighbours in the genus Fructobacillus. This study represents the first isolation, to our knowledge, of novel species in the family Lactobacillaceae from the Australian wild.


Assuntos
Lactobacillales , Animais , Lactobacillales/genética , Filogenia , RNA Ribossômico 16S/genética , Austrália do Sul , Análise de Sequência de DNA , DNA Bacteriano/genética , Composição de Bases , Ácidos Graxos/química , Austrália , Técnicas de Tipagem Bacteriana , Lactobacillus , Insetos , Flores/microbiologia
2.
FEMS Yeast Res ; 232023 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-36255399

RESUMO

A key driver of quality in wines is the microbial population that undertakes fermentation of grape must. Winemakers can utilise both indigenous and purposefully inoculated yeasts to undertake alcoholic fermentation, imparting wines with aromas, flavours and palate structure and in many cases contributing to complexity and uniqueness. Importantly, having a toolbox of microbes helps winemakers make best use of the grapes they are presented with, and tackle fermentation difficulties with flexibility and efficiency. Each year the number of strains available commercially expands and more recently, includes strains of non-Saccharomyces, strains that have been improved using both classical and modern yeast technology and mixed cultures. Here we review what is available commercially, and what may be in the future, by exploring recent advances in fermentation relevant strain improvement technologies. We also report on the current use of microbes in the Australian wine industry, as reported by winemakers, as well as regulations around, and sentiment about the potential use of genetically modified organisms in the future.


Assuntos
Saccharomyces cerevisiae , Vinho , Austrália , Fermentação , Aromatizantes
3.
Appl Microbiol Biotechnol ; 105(23): 8575-8592, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34694447

RESUMO

The widespread existence of bacteriophage has been of great interest to the biological research community and ongoing investigations continue to explore their diversity and role. They have also attracted attention and in-depth research in connection to fermented food processing, in particular from the dairy and wine industries. Bacteriophage, mostly oenophage, may in fact be a 'double edged sword' for winemakers: whilst they have been implicated as a causal agent of difficulties with malolactic fermentation (although not proven), they are also beginning to be considered as alternatives to using sulphur dioxide to prevent wine spoilage. Investigation and characterisation of oenophage of Oenococcus oeni, the main species used in winemaking, are still limited compared to lactococcal bacteriophage of Lactococcus lactis and Lactiplantibacillus plantarum (formally Lactobacillus plantarum), the drivers of most fermented dairy products. Interestingly, these strains are also being used or considered for use in winemaking. In this review, the genetic diversity and life cycle of phage, together with the debate on the consequent impact of phage predation in wine, and potential control strategies are discussed. KEY POINTS: • Bacteriophage detected in wine are diverse. • Many lysogenic bacteriophage are found in wine bacteria. • Phage impact on winemaking can depend on the stage of the winemaking process. • Bacteriophage as potential antimicrobial agents against spoilage organisms.


Assuntos
Bacteriófagos , Oenococcus , Vinho , Fermentação , Lactobacillus , Vinho/análise
4.
MicroPubl Biol ; 20212021.
Artigo em Inglês | MEDLINE | ID: mdl-34549174

RESUMO

BRR6 and BRL1 are two paralogs that encode transmembrane proteins of the nuclear envelope (NE) involved in membrane fluidity and nuclear pore complex biogenesis in organisms that undergo a closed mitosis. We show that mutation of a conserved cysteine in the intralumenal domain of Saccharomyces cerevisiae Brr6p results in a novel temperature sensitive allele, brr6-Y100H, that arrests growth due to defects in spindle formation. Analysis of brr6-Y100H cells by electron tomography and Brr6p localization by super-resolution imaging supports the idea that Brr6p is involved in insertion of the newly duplicated spindle pole body into the NE.

5.
Front Cell Dev Biol ; 8: 594092, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33195270

RESUMO

The H2A.Z histone variant is deposited into the chromatin by the SWR1 complex, affecting multiple aspects of meiosis. We describe here a SWR1-independent localization of H2A.Z at meiotic telomeres and the centrosome. We demonstrate that H2A.Z colocalizes and interacts with Mps3, the SUN component of the linker of nucleoskeleton, and cytoskeleton (LINC) complex that spans the nuclear envelope and links meiotic telomeres to the cytoskeleton, promoting meiotic chromosome movement. H2A.Z also interacts with the meiosis-specific Ndj1 protein that anchors telomeres to the nuclear periphery via Mps3. Telomeric localization of H2A.Z depends on Ndj1 and the N-terminal domain of Mps3. Although telomeric attachment to the nuclear envelope is maintained in the absence of H2A.Z, the distribution of Mps3 is altered. The velocity of chromosome movement during the meiotic prophase is reduced in the htz1Δ mutant lacking H2A.Z, but it is unaffected in swr1Δ cells. We reveal that H2A.Z is an additional LINC-associated factor that contributes to promote telomere-driven chromosome motion critical for error-free gametogenesis.

6.
G3 (Bethesda) ; 10(12): 4649-4663, 2020 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-33109728

RESUMO

The nuclear envelope (NE) contains a specialized set of integral membrane proteins that maintain nuclear shape and integrity and influence chromatin organization and gene expression. Advances in proteomics techniques and studies in model organisms have identified hundreds of proteins that localize to the NE. However, the function of many of these proteins at the NE remains unclear, in part due to a lack of understanding of the interactions that these proteins participate in at the NE membrane. To assist in the characterization of NE transmembrane protein interactions we developed an arrayed library of integral and peripheral membrane proteins from the fission yeast Schizosaccharomyces pombe for high-throughput screening using the split-ubiquitin based membrane yeast two -hybrid system. We used this approach to characterize protein interactions for three conserved proteins that localize to the inner nuclear membrane: Cut11/Ndc1, Lem2 and Ima1/Samp1/Net5. Additionally, we determined how the interaction network for Cut11 is altered in canonical temperature-sensitive cut11-ts mutants. This library and screening approach is readily applicable to characterizing the interactomes of integral membrane proteins localizing to various subcellular compartments.


Assuntos
Proteínas de Saccharomyces cerevisiae , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mitose , Membrana Nuclear/metabolismo , Complexo de Proteínas Formadoras de Poros Nucleares , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo
7.
8.
Appl Microbiol Biotechnol ; 104(5): 1939-1953, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31953561

RESUMO

Producers often utilise some of the many available yeast species and strains in the making of fermented alcoholic beverages in order to augment flavours, aromas, acids and textural properties. But still, the demand remains for more yeasts with novel phenotypes that not only impact sensory characteristics but also offer process and engineering advantages. Two strategies for finding such yeasts are (i) bioprospecting for novel strains and species and (ii) genetic modification of known yeasts. The latter enjoys the promise of the emerging field of synthetic biology, which, in principle, would enable scientists to create yeasts with the exact phenotype desired for a given fermentation. In this mini review, we compare and contrast advances in bioprospecting and in synthetic biology as they relate to alcoholic fermentation in brewing and wine making. We explore recent advances in fermentation-relevant recombinant technologies and synthetic biology including the Yeast 2.0 Consortium, use of environmental yeasts, challenges, constraints of law and consumer acceptance.


Assuntos
Bebidas Alcoólicas/análise , Bioprospecção/métodos , Biologia Sintética/métodos , Leveduras/metabolismo , Bebidas Alcoólicas/microbiologia , Etanol/análise , Etanol/metabolismo , Fermentação , Leveduras/genética
9.
JAMA Dermatol ; 156(1): 57-64, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31721989

RESUMO

Importance: Melanoma is epidemiologically linked to UV exposure, particularly childhood sunburn. Public health campaigns are increasing sun-protective behavior in the United States, but the effect on melanoma incidence is unknown. Objective: To examine the incidence of melanoma in the United States and whether any age-specific differences are present. Design, Setting, and Participants: Observational, population-based registry data were extracted on July 3, 2018, from the combined National Program of Cancer Registries-Surveillance Epidemiology and End Results United States Cancer Statistics database for 2001-2015. Deidentified data for 988 103 cases of invasive melanoma, with International Classification of Diseases for Oncology histologic categorization codes 8720 to 8790, were used for analysis. Data analysis was performed from July 1, 2018, to March 1, 2019. Main Outcomes and Measures: The annual rates of melanoma in pediatric, adolescent, young adult, and adult age groups were determined. Analyses were stratified by sex, and incidence rates were age-adjusted to the 2000 US standard population. Annual percentage change (APC) in incidence rate was calculated over the most recent decade for which data were available (2006-2015) using the weighted least squares method. Results: In 2015, 83 362 cases of invasive melanoma were reported in the United States, including 67 in children younger than 10 years, 251 in adolescents (10-19 years), and 1973 in young adults (20-29 years). Between 2006 and 2015, the overall incidence rate increased from 200.1 to 229.1 cases per million person-years. In adults aged 40 years or older, melanoma rates increased by an APC of 1.8% in both men (95% CI, 1.4%-2.1%) and women (95% CI, 1.4%-2.2%). In contrast, clinically and statistically significant decreases were seen in melanoma incidence for adolescents and young adults. Specifically, incidence rates decreased by an APC of -4.4% for male adolescents (95% CI, -1.7% to -7.0%), -5.4% for female adolescents (95% CI, -3.3% to -7.4%), -3.7% for male young adults (95% CI, -2.5% to -4.8%), and -3.6% for female young adults (95% CI, -2.8% to -4.5%). Data on skin pigmentation and sun protection history were unavailable; similar trends were observed with data limited to non-Hispanic whites. Young adult women appeared to have twice the risk of melanoma as young adult men. Conclusions and Relevance: The incidence of invasive melanoma in the United States appeared to decrease in adolescents and young adults from 2006 to 2015, and this finding contrasted with increases in older populations. These incidence trends suggest that public health efforts may be favorably influencing melanoma incidence in the United States.


Assuntos
Melanoma/epidemiologia , Neoplasias Cutâneas/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Programa de SEER/estatística & dados numéricos , Fatores Sexuais , Estados Unidos/epidemiologia , Adulto Jovem
10.
Proc Math Phys Eng Sci ; 475(2229): 20190175, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31611714

RESUMO

In the presence of glycoproteins, bacterial and yeast biofilms are hypothesized to expand by sliding motility. This involves a sheet of cells spreading as a unit, facilitated by cell proliferation and weak adhesion to the substratum. In this paper, we derive an extensional flow model for biofilm expansion by sliding motility to test this hypothesis. We model the biofilm as a two-phase (living cells and an extracellular matrix) viscous fluid mixture, and model nutrient depletion and uptake from the substratum. Applying the thin-film approximation simplifies the model, and reduces it to one-dimensional axisymmetric form. Comparison with Saccharomyces cerevisiae mat formation experiments reveals good agreement between experimental expansion speed and numerical solutions to the model with O ( 1 ) parameters estimated from experiments. This confirms that sliding motility is a possible mechanism for yeast biofilm expansion. Having established the biological relevance of the model, we then demonstrate how the model parameters affect expansion speed, enabling us to predict biofilm expansion for different experimental conditions. Finally, we show that our model can explain the ridge formation observed in some biofilms. This is especially true if surface tension is low, as hypothesized for sliding motility.

11.
Mol Biol Cell ; 30(12): 1505-1522, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30969903

RESUMO

Centrosomes and spindle pole bodies (SPBs) are membraneless organelles whose duplication and assembly is necessary for bipolar mitotic spindle formation. The structural organization and functional roles of major proteins in these organelles can provide critical insights into cell division control. Spc42, a phosphoregulated protein with an N-terminal dimeric coiled-coil (DCC), assembles into a hexameric array at the budding yeast SPB core, where it functions as a scaffold for SPB assembly. Here, we present in vitro and in vivo data to elucidate the structural arrangement and biological roles of Spc42 elements. Crystal structures reveal details of two additional coiled-coils in Spc42: a central trimeric coiled-coil and a C-terminal antiparallel DCC. Contributions of the three Spc42 coiled-coils and adjacent undetermined regions to the formation of an ∼145 Šhexameric lattice in an in vitro lipid monolayer assay and to SPB duplication and assembly in vivo reveal structural and functional redundancy in Spc42 assembly. We propose an updated model that incorporates the inherent symmetry of these Spc42 elements into a lattice, and thereby establishes the observed sixfold symmetry. The implications of this model for the organization of the central SPB core layer are discussed.


Assuntos
Centrossomo/metabolismo , Proteínas do Citoesqueleto/química , Proteínas do Citoesqueleto/metabolismo , Fosfoproteínas/química , Fosfoproteínas/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Sequência Conservada , Lipídeos/química , Modelos Biológicos , Domínios Proteicos , Multimerização Proteica , Estabilidade Proteica , Estrutura Secundária de Proteína , Corpos Polares do Fuso/metabolismo , Relação Estrutura-Atividade
12.
J Cell Biol ; 218(5): 1478-1490, 2019 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-30862629

RESUMO

Bipolar spindle formation in yeast requires insertion of centrosomes (known as spindle pole bodies [SPBs]) into fenestrated regions of the nuclear envelope (NE). Using structured illumination microscopy and bimolecular fluorescence complementation, we map protein distribution at SPB fenestrae and interrogate protein-protein interactions with high spatial resolution. We find that the Sad1-UNC-84 (SUN) protein Mps3 forms a ring-like structure around the SPB, similar to toroids seen for components of the SPB insertion network (SPIN). Mps3 and the SPIN component Mps2 (a Klarsicht-ANC-1-Syne-1 domain [KASH]-like protein) form a novel noncanonical linker of nucleoskeleton and cytoskeleton (LINC) complex that is connected in both luminal and extraluminal domains at the site of SPB insertion. The LINC complex also controls the distribution of a soluble SPIN component Bbp1. Taken together, our work shows that Mps3 is a fifth SPIN component and suggests both direct and indirect roles for the LINC complex in NE remodeling.


Assuntos
Centrossomo/metabolismo , Citoesqueleto/metabolismo , Membrana Nuclear/metabolismo , Matriz Nuclear/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Corpos Polares do Fuso/metabolismo , Ciclo Celular , Matriz Nuclear/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/genética
13.
Genetics ; 211(4): 1269-1282, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30709848

RESUMO

Inner nuclear membrane (INM) protein composition regulates nuclear function, affecting processes such as gene expression, chromosome organization, nuclear shape, and stability. Mechanisms that drive changes in the INM proteome are poorly understood, in part because it is difficult to definitively assay INM composition rigorously and systematically. Using a split-GFP complementation system to detect INM access, we examined the distribution of all C-terminally tagged Saccharomyces cerevisiae membrane proteins in wild-type cells and in mutants affecting protein quality control pathways, such as INM-associated degradation (INMAD), ER-associated degradation, and vacuolar proteolysis. Deletion of the E3 ligase Asi1 had the most specific effect on the INM compared to mutants in vacuolar or ER-associated degradation pathways, consistent with a role for Asi1 in the INMAD pathway. Our data suggest that Asi1 not only removes mistargeted proteins at the INM, but also controls the levels and distribution of native INM components, such as the membrane nucleoporin Pom33 Interestingly, loss of Asi1 does not affect Pom33 protein levels but instead alters Pom33 distribution in the nuclear envelope through Pom33 ubiquitination, which drives INM redistribution. Taken together, our data demonstrate that the Asi1 E3 ligase has a novel function in INM protein regulation in addition to protein turnover.


Assuntos
Proteínas de Membrana/metabolismo , Membrana Nuclear/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Membrana/genética , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Transporte Proteico , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Ubiquitinação
14.
PLoS Comput Biol ; 14(12): e1006629, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30507938

RESUMO

Many microbes are studied by examining colony morphology via two-dimensional top-down images. The quantification of such images typically requires each pixel to be labelled as belonging to either the colony or background, producing a binary image. While this may be achieved manually for a single colony, this process is infeasible for large datasets containing thousands of images. The software Tool for Analysis of the Morphology of Microbial Colonies (TAMMiCol) has been developed to efficiently and automatically convert colony images to binary. TAMMiCol exploits the structure of the images to choose a thresholding tolerance and produce a binary image of the colony. The images produced are shown to compare favourably with images processed manually, while TAMMiCol is shown to outperform standard segmentation methods. Multiple images may be imported together for batch processing, while the binary data may be exported as a CSV or MATLAB MAT file for quantification, or analysed using statistics built into the software. Using the in-built statistics, it is found that images produced by TAMMiCol yield values close to those computed from binary images processed manually. Analysis of a new large dataset using TAMMiCol shows that colonies of Saccharomyces cerevisiae reach a maximum level of filamentous growth once the concentration of ammonium sulfate is reduced to 200 µM. TAMMiCol is accessed through a graphical user interface, making it easy to use for those without specialist knowledge of image processing, statistical methods or coding.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Microbiota , Software , Sulfato de Amônio/metabolismo , Bacillus subtilis/crescimento & desenvolvimento , Biofilmes/crescimento & desenvolvimento , Biologia Computacional , Meios de Cultura , Bases de Dados Factuais/estatística & dados numéricos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/fisiologia
15.
J Cutan Pathol ; 45(11): 864-868, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30054925

RESUMO

Talimogene laherparepvec (T-VEC) is a novel intralesional oncolytic genetically modified herpes simplex virus type 1 vector for the treatment of unresectable cutaneous, subcutaneous, and nodal melanoma. Although immunological therapies such as T-VEC offer therapeutic promise, they carry a risk of immune-related adverse events (irAEs), the full spectrum of which is incompletely understood. We report a 63-year-old previously healthy man with cutaneous melanoma of the right ankle and progressive right lower extremity in-transit metastases despite systemic therapy with immunomodulatory and molecularly targeted treatments. T-VEC treatment resulted in a complete pathologic response on scouting biopsies. Biopsy of the right lateral calf showed lobular and septal panniculitis with lymphoplasmacytic infiltrate and lipophages. Gomori methenamine silver (GMS) stain and acid-fast bacilli (AFB) stains were negative, and no polarizable foreign material was noted. T-VEC was discontinued due to complete pathologic response and, in part, concern for development of irAEs including this panniculitis and an early concomitant autoimmune colitis. This case highlights a previously unreported irAE with this novel treatment for advanced cases of melanoma.


Assuntos
Antineoplásicos/administração & dosagem , Melanoma/terapia , Terapia Viral Oncolítica/efeitos adversos , Paniculite/etiologia , Neoplasias Cutâneas/terapia , Herpesvirus Humano 1 , Humanos , Masculino , Pessoa de Meia-Idade , Melanoma Maligno Cutâneo
16.
Sci Rep ; 8(1): 5992, 2018 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-29662092

RESUMO

The emergence of diffusion-limited growth (DLG) within a microbial colony on a solid substrate is studied using a combination of mathematical modelling and experiments. Using an agent-based model of the interaction between microbial cells and a diffusing nutrient, it is shown that growth directed towards a nutrient source may be used as an indicator that DLG is influencing the colony morphology. A continuous reaction-diffusion model for microbial growth is employed to identify the parameter regime in which DLG is expected to arise. Comparisons between the model and experimental data are used to argue that the bacterium Bacillus subtilis can undergo DLG, while the yeast Saccharomyces cerevisiae cannot, and thus the non-uniform growth exhibited by this yeast must be caused by the pseudohyphal growth mode rather than limited nutrient availability. Experiments testing directly for DLG features in yeast colonies are used to confirm this hypothesis.


Assuntos
Bacillus subtilis/crescimento & desenvolvimento , Simulação por Computador , Modelos Biológicos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Algoritmos , Difusão
17.
J Theor Biol ; 448: 122-141, 2018 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-29630992

RESUMO

Previous experiments have shown that mature yeast mat biofilms develop a floral morphology, characterised by the formation of petal-like structures. In this work, we investigate the hypothesis that nutrient-limited growth is the mechanism by which these floral patterns form. To do this, we use a combination of experiments and mathematical analysis. In mat formation experiments of the yeast species Saccharomyces cerevisiae, we observe that mats expand radially at a roughly constant speed, and eventually undergo a transition from circular to floral morphology. To determine the extent to which nutrient-limited growth can explain these features, we adopt a previously proposed mathematical model for yeast growth. The model consists of a coupled system of reaction-diffusion equations for the yeast cell density and nutrient concentration, with a non-linear, degenerate diffusion term for cell spread. Using geometric singular perturbation theory and numerics, we show that the model admits travelling wave solutions in one dimension, which enables us to infer the diffusion ratio from experimental data. We then use a linear stability analysis to show that two-dimensional planar travelling wave solutions for feasible experimental parameters are linearly unstable to non-planar perturbations. This provides a potential mechanism by which petals can form, and allows us to predict the characteristic petal width. There is good agreement between these predictions, numerical solutions to the model, and experimental data. We therefore conclude that the non-linear cell diffusion mechanism provides a possible explanation for pattern formation in yeast mat biofilms, without the need to invoke other mechanisms such as flow of extracellular fluid, cell adhesion, or changes to cellular shape or behaviour.


Assuntos
Biofilmes/crescimento & desenvolvimento , Nutrientes/farmacologia , Saccharomyces cerevisiae/ultraestrutura , Difusão , Modelos Biológicos , Modelos Teóricos
18.
FEMS Microbiol Ecol ; 94(2)2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29394344

RESUMO

Commercially available active dried wine yeasts are regularly used by winemakers worldwide to achieve reliable fermentations and obtain quality wine. This practice has led to increased evidence of traces of commercial wine yeast in the vineyard, winery and uninoculated musts. The mechanism(s) that enables commercial wine yeast to persist in the winery environment and the influence to native microbial communities on this persistence is poorly understood. This study has investigated the ability of commercial wine yeasts to form biofilms and adhere to plastic. The results indicate that the biofilms formed by commercial yeasts consist of cells with a combination of different lifestyles (replicative and non-replicative) and growth modes including invasive growth, bud elongation, sporulation and a mat sectoring-like phenotype. Invasive growth was greatly enhanced on grape pulp regardless of strain, while adhesion on plastic varied between strains. The findings suggest a possible mechanism that allows commercial yeast to colonise and survive in the winery environment, which may have implications for the indigenous microbiota profile as well as the population profile in uninoculated fermentations if their dissemination is not controlled.


Assuntos
Biofilmes/crescimento & desenvolvimento , Adesão Celular/fisiologia , Plásticos/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo , Fazendas , Fermentação , Microbiota , Nova Zelândia , Saccharomyces cerevisiae/genética , Vitis/microbiologia , Vinho/microbiologia
19.
FEMS Yeast Res ; 18(3)2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29425293

RESUMO

A deficiency of nitrogenous nutrients in grape juice can cause stuck and sluggish alcoholic fermentation, which has long been a problem in winemaking. Nitrogen requirements vary between wine yeast strains, and the ability of yeast to assimilate nitrogen depends on the nature and concentration of nitrogen present in the medium. In this study, a wine yeast gene deletion collection (1844 deletants in the haploid AWRI1631 background) was screened to identify genes whose deletion resulted in a reduction in the time taken to utilise all sugars when grown in a chemically defined grape juice medium supplemented with limited nitrogen (75 mg L-1 as a free amino acid mixture). Through micro-scale and laboratory-scale fermentations, 15 deletants were identified that completed fermentation in a shorter time than the wildtype (c.a. 15%-59% time reduction). This group of genes was annotated to biological processes including protein modification, transport, metabolism and ubiquitination (UBC13, MMS2, UBP7, UBI4, BRO1, TPK2, EAR1, MRP17, MFA2 and MVB12), signalling (MFA2) and amino acid metabolism (AAT2). Deletion of MFA2, encoding mating factor-a, resulted in a 55% decrease in fermentation duration. Mfa2Δ was chosen for further investigation to understand how this gene deletion conferred fermentation efficiency in limited nitrogen conditions.


Assuntos
Fermentação/genética , Deleção de Genes , Genes Fúngicos , Nitrogênio/metabolismo , Saccharomyces cerevisiae/genética , Vinho/microbiologia , Aminoácidos/metabolismo , Meios de Cultura/química , Lipoproteínas/genética , Feromônios/genética , Saccharomyces cerevisiae/fisiologia , Proteínas de Saccharomyces cerevisiae/genética , Ubiquitinação , Vitis/microbiologia
20.
J Clin Oncol ; 36(17): 1714-1768, 2018 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-29442540

RESUMO

Purpose To increase awareness, outline strategies, and offer guidance on the recommended management of immune-related adverse events in patients treated with immune checkpoint inhibitor (ICPi) therapy. Methods A multidisciplinary, multi-organizational panel of experts in medical oncology, dermatology, gastroenterology, rheumatology, pulmonology, endocrinology, urology, neurology, hematology, emergency medicine, nursing, trialist, and advocacy was convened to develop the clinical practice guideline. Guideline development involved a systematic review of the literature and an informal consensus process. The systematic review focused on guidelines, systematic reviews and meta-analyses, randomized controlled trials, and case series published from 2000 through 2017. Results The systematic review identified 204 eligible publications. Much of the evidence consisted of systematic reviews of observational data, consensus guidelines, case series, and case reports. Due to the paucity of high-quality evidence on management of immune-related adverse events, recommendations are based on expert consensus. Recommendations Recommendations for specific organ system-based toxicity diagnosis and management are presented. While management varies according to organ system affected, in general, ICPi therapy should be continued with close monitoring for grade 1 toxicities, with the exception of some neurologic, hematologic, and cardiac toxicities. ICPi therapy may be suspended for most grade 2 toxicities, with consideration of resuming when symptoms revert to grade 1 or less. Corticosteroids may be administered. Grade 3 toxicities generally warrant suspension of ICPis and the initiation of high-dose corticosteroids (prednisone 1 to 2 mg/kg/d or methylprednisolone 1 to 2 mg/kg/d). Corticosteroids should be tapered over the course of at least 4 to 6 weeks. Some refractory cases may require infliximab or other immunosuppressive therapy. In general, permanent discontinuation of ICPis is recommended with grade 4 toxicities, with the exception of endocrinopathies that have been controlled by hormone replacement. Additional information is available at www.asco.org/supportive-care-guidelines and www.asco.org/guidelineswiki .


Assuntos
Antineoplásicos Imunológicos/administração & dosagem , Antineoplásicos Imunológicos/efeitos adversos , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Adulto , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/efeitos adversos , Antineoplásicos Imunológicos/imunologia , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Antígeno CTLA-4/antagonistas & inibidores , Antígeno CTLA-4/imunologia , Humanos , Guias de Prática Clínica como Assunto , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia
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