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1.
Int J Mol Sci ; 22(19)2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34638921

RESUMO

The mass production of graphene oxide (GO) unavoidably elevates the chance of human exposure, as well as the possibility of release into the environment with high stability, raising public concern as to its potential toxicological risks and the implications for humans and ecosystems. Therefore, a thorough assessment of GO toxicity, including its potential reliance on key physicochemical factors, which is lacking in the literature, is of high significance and importance. In this study, GO toxicity, and its dependence on oxidation level, elemental composition, and size, were comprehensively assessed. A newly established quantitative toxicogenomic-based toxicity testing approach, combined with conventional phenotypic bioassays, were employed. The toxicogenomic assay utilized a GFP-fused yeast reporter library covering key cellular toxicity pathways. The results reveal that, indeed, the elemental composition and size do exert impacts on GO toxicity, while the oxidation level exhibits no significant effects. The UV-treated GO, with significantly higher carbon-carbon groups and carboxyl groups, showed a higher toxicity level, especially in the protein and chemical stress categories. With the decrease in size, the toxicity level of the sonicated GOs tended to increase. It is proposed that the covering and subsequent internalization of GO sheets might be the main mode of action in yeast cells.


Assuntos
Poluentes Ambientais/toxicidade , Grafite/toxicidade , Nanoestruturas/toxicidade , Testes de Toxicidade/métodos , Toxicogenética/métodos , Células A549 , Análise por Conglomerados , Ensaio Cometa/métodos , Dano ao DNA , Poluentes Ambientais/química , Grafite/química , Humanos , Microscopia Eletrônica de Varredura/métodos , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Oxirredução/efeitos dos fármacos , Espectroscopia Fotoeletrônica/métodos , Proteoma/classificação , Proteoma/efeitos dos fármacos , Proteômica/métodos , Espécies Reativas de Oxigênio/metabolismo , Leveduras/citologia , Leveduras/efeitos dos fármacos , Leveduras/metabolismo
2.
Int J Mol Sci ; 22(18)2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34575923

RESUMO

Molecules involved in DNA damage response (DDR) are often overexpressed in cancer cells, resulting in poor responses to chemotherapy and radiotherapy. Although treatment efficacy can be improved with the concomitant use of DNA repair inhibitors, the accompanying side effects can compromise the quality of life of patients. Therefore, in this study, we identified a natural compound that could inhibit DDR, using the single-strand annealing yeast-cell analysis system, and explored its mechanisms of action and potential as a chemotherapy adjuvant in hepatocellular carcinoma (HCC) cell lines using comet assay, flow cytometry, Western blotting, immunofluorescence staining, and functional analyses. We developed a mouse model to verify the in vitro findings. We found that hydroxygenkwanin (HGK) inhibited the expression of RAD51 and progression of homologous recombination, thereby suppressing the ability of the HCC cell lines to repair DNA damage and enhancing their sensitivity to doxorubicin. HGK inhibited the phosphorylation of DNA damage checkpoint proteins, leading to apoptosis in the HCC cell lines. In the mouse xenograft model, HGK enhanced the sensitivity of liver cancer cells to doxorubicin without any physiological toxicity. Thus, HGK can inhibit DDR in liver cancer cells and mouse models, making it suitable for use as a chemotherapy adjuvant.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Dano ao DNA/efeitos dos fármacos , Flavonoides/farmacologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Reparo do DNA/efeitos dos fármacos , Modelos Animais de Doenças , Sinergismo Farmacológico , Medicamentos de Ervas Chinesas , Regulação da Expressão Gênica , Recombinação Homóloga/efeitos dos fármacos , Humanos , Camundongos , Rad51 Recombinase/genética , Rad51 Recombinase/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Leveduras/efeitos dos fármacos , Leveduras/genética , Leveduras/metabolismo
3.
Biomolecules ; 11(8)2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34439852

RESUMO

All proteins are subject to quality control processes during or soon after their synthesis, and these cellular quality control pathways play critical roles in maintaining homeostasis in the cell and in organism health. Protein quality control is particularly vital for those polypeptides that enter the endoplasmic reticulum (ER). Approximately one-quarter to one-third of all proteins synthesized in eukaryotic cells access the ER because they are destined for transport to the extracellular space, because they represent integral membrane proteins, or because they reside within one of the many compartments of the secretory pathway. However, proteins that mature inefficiently are subject to ER-associated degradation (ERAD), a multi-step pathway involving the chaperone-mediated selection, ubiquitination, and extraction (or "retrotranslocation") of protein substrates from the ER. Ultimately, these substrates are degraded by the cytosolic proteasome. Interestingly, there is an increasing number of native enzymes and metabolite and solute transporters that are also targeted for ERAD. While some of these proteins may transiently misfold, the ERAD pathway also provides a route to rapidly and quantitatively downregulate the levels and thus the activities of a variety of proteins that mature or reside in the ER.


Assuntos
Degradação Associada com o Retículo Endoplasmático , Retículo Endoplasmático/metabolismo , Animais , Mamíferos/metabolismo , Chaperonas Moleculares/metabolismo , Dobramento de Proteína , Transporte Proteico , Proteólise , Ubiquitina/metabolismo , Ubiquitinação , Leveduras/metabolismo
4.
Nutrients ; 13(7)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34371928

RESUMO

The "drunken monkey" hypothesis posits that attraction to ethanol derives from an evolutionary linkage among the sugars of ripe fruit, associated alcoholic fermentation by yeast, and ensuing consumption by human ancestors. First proposed in 2000, this concept has received increasing attention from the fields of animal sensory biology, primate foraging behavior, and molecular evolution. We undertook a review of English language citations subsequent to publication of the original paper and assessed research trends and future directions relative to natural dietary ethanol exposure in primates and other animals. Two major empirical themes emerge: attraction to and consumption of fermenting fruits (and nectar) by numerous vertebrates and invertebrates (e.g., Drosophila flies), and genomic evidence for natural selection consistent with sustained exposure to dietary ethanol in diverse taxa (including hominids and the genus Homo) over tens of millions of years. We also describe our current field studies in Uganda of ethanol content within fruits consumed by free-ranging chimpanzees, which suggest chronic low-level exposure to this psychoactive molecule in our closest living relatives.


Assuntos
Consumo de Bebidas Alcoólicas , Evolução Biológica , Exposição Dietética , Etanol/metabolismo , Fermentação , Frutas/microbiologia , Leveduras/metabolismo , Consumo de Bebidas Alcoólicas/efeitos adversos , Consumo de Bebidas Alcoólicas/metabolismo , Consumo de Bebidas Alcoólicas/psicologia , Alcoolismo/metabolismo , Alcoolismo/psicologia , Animais , Exposição Dietética/efeitos adversos , Etanol/efeitos adversos , Comportamento Alimentar , Frutas/metabolismo , Humanos , Pan troglodytes
5.
Food Microbiol ; 100: 103859, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34416959

RESUMO

Beta-glucosidase is an important enzyme for the hydrolysis of grape glycosides in the course of winemaking. Yeasts are the main producers of ß-glucosidase in winemaking, therefore play an important role in determining wine aroma and flavour. This article discusses common methods for ß-glucosidase evaluation, the ß-glucosidase activity of different Saccharomyces and non- Saccharomyces yeasts and the influences of winemaking conditions, such as glucose and ethanol concentration, low pH environment, fermentation temperature and SO2 level, on their activity. This review further highlights the roles of ß-glucosidase in promoting the release of free volatile compounds especially terpenes and the modification of wine phenolic composition during the winemaking process. Furthermore, this review proposes future research direction in this area and guides wine professionals in yeast selection to improve wine quality.


Assuntos
Proteínas Fúngicas/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Vinho/análise , Leveduras/enzimologia , beta-Glucosidase/metabolismo , Proteínas Fúngicas/genética , Odorantes/análise , Fenóis/química , Fenóis/metabolismo , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Vitis/química , Vitis/microbiologia , Compostos Orgânicos Voláteis/química , Vinho/microbiologia , Leveduras/genética , Leveduras/metabolismo , beta-Glucosidase/genética
6.
Cells ; 10(8)2021 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-34440717

RESUMO

Recent findings suggest that ribosomes, the translational machineries, can display a distinct composition depending on physio-pathological contexts. Thanks to outstanding technological breakthroughs, many studies have reported that variations of rRNA modifications, and more particularly the most abundant rRNA chemical modification, the rRNA 2'O-ribose methylation (2'Ome), intrinsically occur in many organisms. In the last 5 years, accumulating reports have illustrated that rRNA 2'Ome varies in human cell lines but also in living organisms (yeast, plant, zebrafish, mouse, human) during development and diseases. These rRNA 2'Ome variations occur either within a single cell line, organ, or patient's sample (i.e., intra-variability) or between at least two biological conditions (i.e., inter-variability). Thus, the ribosomes can tolerate the absence of 2'Ome at some specific positions. These observations question whether variations in rRNA 2'Ome could provide ribosomes with particular translational regulatory activities and functional specializations. Here, we compile recent studies supporting the heterogeneity of ribosome composition at rRNA 2'Ome level and provide an overview of the natural diversity in rRNA 2'Ome that has been reported up to now throughout the kingdom of life. Moreover, we discuss the little evidence that suggests that variations of rRNA 2'Ome can effectively impact the ribosome activity and contribute to the etiology of some human diseases.


Assuntos
Evolução Molecular , Processamento Pós-Transcricional do RNA , RNA Fúngico/metabolismo , RNA Ribossômico/metabolismo , Ribossomos/metabolismo , Leveduras/metabolismo , Animais , Linhagem Celular , Humanos , Metilação , Biossíntese de Proteínas , RNA Fúngico/genética , RNA Ribossômico/genética , Ribossomos/genética , Leveduras/genética
7.
Microb Cell Fact ; 20(1): 124, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193127

RESUMO

The manufacture of recombinant therapeutics is a fastest-developing section of therapeutic pharmaceuticals and presently plays a significant role in disease management. Yeasts are established eukaryotic host for heterologous protein production and offer distinctive benefits in synthesising pharmaceutical recombinants. Yeasts are proficient of vigorous growth on inexpensive media, easy for gene manipulations, and are capable of adding post translational changes of eukaryotes. Saccharomyces cerevisiae is model yeast that has been applied as a main host for the manufacture of pharmaceuticals and is the major tool box for genetic studies; nevertheless, numerous other yeasts comprising Pichia pastoris, Kluyveromyces lactis, Hansenula polymorpha, and Yarrowia lipolytica have attained huge attention as non-conventional partners intended for the industrial manufacture of heterologous proteins. Here we review the advances in yeast gene manipulation tools and techniques for heterologous pharmaceutical protein synthesis. Application of secretory pathway engineering, glycosylation engineering strategies and fermentation scale-up strategies in customizing yeast cells for the synthesis of therapeutic proteins has been meticulously described.


Assuntos
Produtos Biológicos/metabolismo , Engenharia Metabólica , Proteínas Recombinantes/biossíntese , Leveduras/genética , Sistemas CRISPR-Cas , Fermentação , Glicosilação , Regiões Promotoras Genéticas , Proteínas Recombinantes/metabolismo , Leveduras/crescimento & desenvolvimento , Leveduras/metabolismo
8.
Pol J Vet Sci ; 24(2): 167-173, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34250775

RESUMO

Koumiss has beneficial therapeutic effects on bacterial diseases. Four antibacterial com- pounds from yeasts (Kluyveromyces marxianus and Saccharomyces cerevisiae) in koumiss were evaluated for their antibacterial effects against three Gram-negative bacteria, three Gram-positive bacteria and five pathogenic Escherichia coli strains. The antibacterial compounds from yeasts in koumiss were extracted, and their main components were determined. The inhibition zones were analyzed, and their minimum inhibition concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined. Aqueous phases of Kluyveromyces marxianus and Saccharomyces cerevisiae at pH 2.0 and 8.0 produced larger inhibition zones than those in other phases, and then antibacterial compounds from K. marxianus (K2, pH=2.0; K8, pH=8.0) and S. cerevisiae (S2, pH=2.0; S8, pH=8.0) were obtained. Their main components were organic acids and killer toxins. K2 had more propanoic acid and S2 had more oxalic acid than others. The inhibition zones of K2, K8, S2 and S8 against three Gram-negative bacteria and three Gram-positive bacteria were 12.03-23.30 mm, their MICs were 0.01-0.13 g/mL, and MBCs were 0.03-0.50 g/mL. Meantime, the inhibition zones of K2, K8, S2 and S8 against five pathogenic E. coli were 16.10-25.26 mm, their MICs were 0.03-0.13 g/mL, and MBCs were 0.13-1.00 g/mL. These four antibacterial compounds from yeasts in koumiss had broad antibacterial spectrum. In addition, K2 and S2 were better than K8 and S8.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Kumis/microbiologia , Leveduras/metabolismo , Antibacterianos/química , Leveduras/química
9.
Int J Mol Sci ; 22(14)2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34299371

RESUMO

Wine can be defined as a complex microbial ecosystem, where different microorganisms interact in the function of different biotic and abiotic factors. During natural fermentation, the effect of unpredictable interactions between microorganisms and environmental factors leads to the establishment of a complex and stable microbiota that will define the kinetics of the process and the final product. Controlled multistarter fermentation represents a microbial approach to achieve the dual purpose of having a less risky process and a distinctive final product. Indeed, the interactions evolved between microbial consortium members strongly modulate the final sensorial properties of the wine. Therefore, in well-managed mixed fermentations, the knowledge of molecular mechanisms on the basis of yeast interactions, in a well-defined ecological niche, becomes fundamental to control the winemaking process, representing a tool to achieve such objectives. In the present work, the recent development on the molecular and metabolic interactions between non-Saccharomyces and Saccharomyces yeasts in wine fermentation was reviewed. A particular focus will be reserved on molecular studies regarding the role of nutrients, the production of the main byproducts and volatile compounds, ethanol reduction, and antagonistic actions for biological control in mixed fermentations.


Assuntos
Fermentação/fisiologia , Vinho/microbiologia , Leveduras/metabolismo , Etanol/metabolismo , Humanos , Microbiota/fisiologia , Nutrientes/metabolismo , Saccharomyces/metabolismo
10.
Biosci Biotechnol Biochem ; 85(8): 1890-1898, 2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34160605

RESUMO

Phylloplane yeast genera Pseudozyma and Cryptococcus secrete biodegradable plastic (BP)-degrading enzymes, termed cutinase-like enzymes (CLEs). Although CLEs contain highly conserved catalytic sites, the whole protein exhibits ≤30% amino acid sequence homology with cutinase. In this study, we analyzed whether CLEs exhibit cutinase activity. Seventeen Cryptococcus magnus strains, which degrade BP at 15 °C, were isolated from leaves and identified the DNA sequence of the CLE in one of the strains. Cutin was prepared from tomato leaves and treated with CLEs from 3 Cryptococcus species (C. magnus, Cryptococcus flavus, and Cryptococcus laurentii) and Pseudozyma antarctia (PaE). A typical cutin monomer, 10,16-dihydroxyhexadecanoic acid, was detected in extracts of the reaction solution via gas chromatography-mass spectrometry, showing that cutin was indeed degraded by CLEs. In addition to the aforementioned monomer, separation analysis via thin-layer chromatography detected high-molecular-weight products resulting from the breakdown of cutin by PaE, indicating that PaE acts as an endo-type enzyme.


Assuntos
Biodegradação Ambiental , Hidrolases de Éster Carboxílico/metabolismo , Proteínas Fúngicas/metabolismo , Plásticos/metabolismo , Leveduras/metabolismo , Cromatografia em Camada Delgada , Cromatografia Gasosa-Espectrometria de Massas , Lipídeos de Membrana/metabolismo , Folhas de Planta/microbiologia
11.
Food Microbiol ; 99: 103839, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34119090

RESUMO

The use of non-Saccharomyces yeast together with S. cerevisiae in winemaking is a current trend. Apart from the organoleptic modulation of the wine, the composition of the resulting yeast lees is different and may thus impact malolactic fermentation (MLF). Yeasts of Saccharomyces cerevisiae, Torulaspora delbrueckii and Metschnikowia pulcherrima were inactivated and added to a synthetic wine. Three different strains of Oenococcus oeni were inoculated and MLF was monitored. Non-Saccharomyces lees, especially from some strains of T. delbrueckii, showed higher compatibility with some O. oeni strains, with a shorter MLF and a maintained bacterial cell viability. The supplementation of lees increased nitrogen compounds available by O. oeni. A lower mannoprotein consumption was related with longer MLF. Amino acid assimilation by O. oeni was strain specific. There may be many other compounds regulating these yeast lees-O. oeni interactions apart from the well-known mannoproteins and amino acids. This is the first study of MLF with different O. oeni strains in the presence of S. cerevisiae and non-Saccharomyces yeast lees to report a strain-specific interaction between them.


Assuntos
Malatos/metabolismo , Oenococcus/metabolismo , Vinho/microbiologia , Leveduras/metabolismo , Meios de Cultura/metabolismo , Fermentação , Filogenia , Leveduras/classificação , Leveduras/genética
12.
Food Microbiol ; 99: 103806, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34119099

RESUMO

The increasing interest in novel beer productions focused on non-Saccharomyces yeasts in order to pursue their potential in generating groundbreaking sensory profiles. Traditional fermented beverages represent an important source of yeast strains which could express interesting features during brewing. A total of 404 yeasts were isolated from fermented honey by-products and identified as Saccharomyces cerevisiae, Wickerhamomyces anomalus, Zygosaccharomyces bailii, Zygosaccharomyces rouxii and Hanseniaspora uvarum. Five H. uvarum strains were screened for their brewing capability. Interestingly, Hanseniaspora uvarum strains showed growth in presence of ethanol and hop and a more rapid growth than the control strain S. cerevisiae US-05. Even though all strains showed a very low fermentation power, their concentrations ranged between 7 and 8 Log cycles during fermentation. The statistical analyses showed significant differences among the strains and underlined the ability of YGA2 and YGA34 to grow rapidly in presence of ethanol and hop. The strain YGA34 showed the best technological properties and was selected for beer production. Its presence in mixed- and sequential-culture fermentations with US-05 did not influence attenuation and ethanol concentration but had a significant impact on glycerol and acetic acid concentrations, with a higher sensory complexity and intensity, representing promising co-starters during craft beer production.


Assuntos
Cerveja/microbiologia , Hanseniaspora/metabolismo , Mel/microbiologia , Ácido Acético/análise , Ácido Acético/metabolismo , Cerveja/análise , Etanol/metabolismo , Fermentação , Microbiologia de Alimentos , Hanseniaspora/crescimento & desenvolvimento , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo , Resíduos/análise , Leveduras/crescimento & desenvolvimento , Leveduras/metabolismo
13.
Food Microbiol ; 99: 103824, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34119109

RESUMO

Rapid yeast identification is of particular importance in monitoring wine fermentation and assessing strain application in winemaking. We used MALDI-TOF MS analysis supported by 26 S rRNA gene sequence analysis and Saccharomyces-specific PCR testing to differentiate reference and field strains recovered from organic wine production facilities in Waipara, New Zealand, in which Pinot Noir wine was produced by spontaneous fermentations in the vineyard and in the winery. Strains were isolated from each of four key stages of each ferment to evaluate changes in taxonomic diversity. MALDI-TOF MS analysis was confirmed as an excellent yeast identification method, with even closely related Saccharomyces species readily distinguished. A total of 13 indigenous species belonging to eight genera were identified from Pinot Noir ferments, with taxonomic diversity generally reducing as fermentation progressed. However, differences between the taxa recovered were observed between the vineyard and winery ferments, despite the grapes used being from the same batch. Furthermore, some consistent proteomic differences between strains of S. cerevisiae, Hanseniasporum uvarum, Candida californica, Pichia membranifaciens and Starmerella bacillaris correlated with the different fermentation systems used. The high speed, low cost, taxonomic resolution and ability to characterise subtle changes in phenotype that may result from variations in environmental conditions makes MALDI-TOF analysis an attractive tool for further and wider applications in the wine industry. Such applications may include monitoring wine fermentation to actively support the consistency of high-quality wine products, and potentially for the development of such products too.


Assuntos
Técnicas de Tipagem Micológica/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Vinho/microbiologia , Leveduras/isolamento & purificação , Leveduras/metabolismo , Fermentação , Frutas/microbiologia , Nova Zelândia , Vitis/microbiologia , Vinho/análise , Leveduras/química , Leveduras/classificação
14.
Genes (Basel) ; 12(5)2021 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-34066718

RESUMO

Mutations in DNA can be limited to one or a few nucleotides, or encompass larger deletions, insertions, duplications, inversions and translocations that span long stretches of DNA or even full chromosomes. These so-called structural variations (SVs) can alter the gene copy number, modify open reading frames, change regulatory sequences or chromatin structure and thus result in major phenotypic changes. As some of the best-known examples of SV are linked to severe genetic disorders, this type of mutation has traditionally been regarded as negative and of little importance for adaptive evolution. However, the advent of genomic technologies uncovered the ubiquity of SVs even in healthy organisms. Moreover, experimental evolution studies suggest that SV is an important driver of evolution and adaptation to new environments. Here, we provide an overview of the causes and consequences of SV and their role in adaptation, with specific emphasis on fungi since these have proven to be excellent models to study SV.


Assuntos
Evolução Molecular , Genoma Fúngico , Variação Estrutural do Genoma , Adaptação Fisiológica , Leveduras/genética , Leveduras/metabolismo
15.
Appl Microbiol Biotechnol ; 105(12): 4899-4918, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34097119

RESUMO

The second-generation (2G) fermentation environment for lignocellulose conversion presents unique challenges to the fermentative organism that do not necessarily exist in other industrial fermentations. While extreme osmotic, heat, and nutrient starvation stresses are observed in sugar- and starch-based fermentation environments, additional pre-treatment-derived inhibitor stress, potentially exacerbated by stresses such as pH and product tolerance, exist in the 2G environment. Furthermore, in a consolidated bioprocessing (CBP) context, the organism is also challenged to secrete enzymes that may themselves lead to unfolded protein response and other stresses. This review will discuss responses of the yeast Saccharomyces cerevisiae to 2G-specific stresses and stress modulation strategies that can be followed to improve yeasts for this application. We also explore published -omics data and discuss relevant rational engineering, reverse engineering, and adaptation strategies, with the view of identifying genes or alleles that will make positive contributions to the overall robustness of 2G industrial strains. KEYPOINTS: • Stress tolerance is a key driver to successful application of yeast strains in biorefineries. • A wealth of data regarding stress responses has been gained through omics studies. • Integration of this knowledge could inform engineering of fit for purpose strains.


Assuntos
Lignina , Saccharomyces cerevisiae , Fermentação , Lignina/metabolismo , Saccharomyces cerevisiae/metabolismo , Amido/metabolismo , Leveduras/metabolismo
16.
ACS Appl Mater Interfaces ; 13(24): 27983-27990, 2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34110765

RESUMO

Nanowire-based optical biosensors with high sensitivity are highly desired for the detection of biological microenvironments and analysis of cellular processes. However, the current nanowire biosensors are mostly fabricated with metal and semiconductor materials, which are not suitable for long-term use in biological environments due to their incompatible and nondegradable properties. Biosensors based on biofriendly materials (e.g., spider silk) often do not have high enough sensitivity due to high losses or micron sizes. Here, polylactic acid (PLA), a polymer with high optical transparency, good biocompatibility, biodegradability, and flexibility, is used to fabricate nanowires using a directly drawing method for the first time. Because of the strong evanescent wave and abundant carboxyl groups on the surface of nanowires, an ultralow concentration sensing of cytochrome c is achieved with a limit of detection of 1.38 × 10-17 M, which is much lower than other detection results using semiconductor/metal-based nanosensors (10-6 to 10-12 M). On this basis, a label-free and real-time monitoring of cell apoptosis is realized. In addition, by doping quantum dots, the functionalized PLA nanowires can also sense a change in pH. These results are suggestive of the potential for PLA nanowires applied in multifunctional biosensing and biodetection, pushing forward the photomedicine field.


Assuntos
Apoptose/fisiologia , Técnicas Biossensoriais/métodos , Citocromos c/análise , Nanofios/química , Poliésteres/química , Citocromos c/metabolismo , Concentração de Íons de Hidrogênio , Limite de Detecção , Pontos Quânticos/química , Leveduras/metabolismo
17.
Food Funct ; 12(13): 5685-5702, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34037049

RESUMO

Traditional fermented fish products are favored due to their unique flavors. The fermentation process of fish is accompanied by the formation of flavor substances through a complex metabolic reaction of microorganisms, especially lipolysis and lipid oxidation. However, it is difficult to precisely control the reaction of microorganisms during the fermentation process in modern industrial production, and fermented fish products have lost their traditional characteristic flavors. The purpose of this review is to summarize the different kinds of fermented fish, core microorganisms in it, and flavor formation mechanisms, providing guidance for industrial cultural starters. Future research on the flavor formation mechanism is necessary to confirm the relationship between flavor formation, lipid metabolism, and microorganisms to ensure stable flavor and safety, and to elucidate the mechanism directly toward industrial application.


Assuntos
Fermentação , Produtos Pesqueiros , Microbiologia de Alimentos/métodos , Metabolismo dos Lipídeos , Paladar , Animais , Bacillus/metabolismo , Reatores Biológicos , Peixes/metabolismo , Humanos , Lactobacillus/metabolismo , Lipólise , Micrococcus/metabolismo , Oxirredução , Leveduras/metabolismo
18.
Front Immunol ; 12: 681098, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34054871

RESUMO

Recombinant human factor H (hFH) has potential for treating diseases linked to aberrant complement regulation including C3 glomerulopathy (C3G) and dry age-related macular degeneration. Murine FH (mFH), produced in the same host, is useful for pre-clinical investigations in mouse models of disease. An abundance of FH in plasma suggests high doses, and hence microbial production, will be needed. Previously, Pichia pastoris produced useful but modest quantities of hFH. Herein, a similar strategy yielded miniscule quantities of mFH. Since FH has 40 disulfide bonds, we created a P. pastoris strain containing a methanol-inducible codon-modified gene for protein-disulfide isomerase (PDI) and transformed this with codon-modified DNA encoding mFH under the same promoter. What had been barely detectable yields of mFH became multiple 10s of mg/L. Our PDI-overexpressing strain also boosted hFH overproduction, by about tenfold. These enhancements exceeded PDI-related production gains reported for other proteins, all of which contain fewer disulfide-stabilized domains. We optimized fermentation conditions, purified recombinant mFH, enzymatically trimmed down its (non-human) N-glycans, characterised its functions in vitro and administered it to mice. In FH-knockout mice, our de-glycosylated recombinant mFH had a shorter half-life and induced more anti-mFH antibodies than mouse serum-derived, natively glycosylated, mFH. Even sequential daily injections of recombinant mFH failed to restore wild-type levels of FH and C3 in mouse plasma beyond 24 hours after the first injection. Nevertheless, mFH functionality appeared to persist in the glomerular basement membrane because C3-fragment deposition here, a hallmark of C3G, remained significantly reduced throughout and beyond the ten-day dosing regimen.


Assuntos
Complemento C3/imunologia , Complemento C3/metabolismo , Fator H do Complemento/biossíntese , Fator H do Complemento/deficiência , Isomerases de Dissulfetos de Proteínas/metabolismo , Proteínas Recombinantes/metabolismo , Animais , Expressão Gênica , Imunomodulação , Camundongos , Camundongos Knockout , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Leveduras/genética , Leveduras/metabolismo
19.
FEMS Microbiol Lett ; 368(9)2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-34021569

RESUMO

Kocuria isolates collected from the sake brewing process have inhabited the Narimasa Sake Brewery in Toyama, Japan. To investigate the effect of these actinobacterial isolates on the growth and metabolism of sake yeast, co-cultivation of sake yeast and Kocuria isolates was performed in a medium containing tryptone, glucose and yeast extract (TGY), and a solution containing koji (steamed rice covered with Aspergillus oryzae) and glucose. In the TGY medium, the ethanol concentration and the number of living cells of each microorganism were measured. In the koji solution, the concentrations of ethanol and organic acids (citric acid, lactic acid and succinic acid) were measured. The results showed that in TGY media, the growth of each Kocuria isolate in the co-culture of the two Kocuria isolates was similar to that in each monoculture. However, the growth of both Kocuria isolates was inhibited in the co-cultures of sake yeast and Kocuria isolates. On the other hand, the growth and ethanol productivity of sake yeast did not differ between its monoculture and co-cultures with Kocuria isolates. In the koji solution, Kocuria isolates TGY1120_3 and TGY1127_2 affected the concentrations of ethanol and lactic acid, respectively. Thus, Kocuria isolates affected the microbial metabolism, but the effects were not identical between the two isolates. This strongly suggests that bacteria inhabiting a sake brewery may influence the flavor and taste of sake products of the brewery.


Assuntos
Bebidas Alcoólicas/microbiologia , Meios de Cultura/química , Fermentação , Micrococcaceae/metabolismo , Leveduras/metabolismo , Etanol/análise , Etanol/metabolismo , Japão , Ácido Láctico/análise , Ácido Láctico/metabolismo , Micrococcaceae/crescimento & desenvolvimento , Oryza/microbiologia , Paladar , Leveduras/crescimento & desenvolvimento
20.
J Mol Biol ; 433(15): 167045, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-33971209

RESUMO

Being essential for oxidative protein folding in the mitochondrial intermembrane space, the mitochondrial disulfide relay relies on the electron transfer (ET) from the sulfhydryl oxidase Erv1 to cytochrome c (Cc). Using solution NMR spectroscopy, we demonstrate that while the yeast Cc-Erv1 system is functionally active, no observable binding of the protein partners takes place. The transient interaction between Erv1 and Cc can be rationalized by molecular modeling, suggesting that a large surface area of Erv1 can sustain a fast ET to Cc via a collision-type mechanism, without the need for a canonical protein complex formation. We suggest that, by preventing the direct ET to molecular oxygen (O2), the collision-type Cc-Erv1 interaction plays a role in protecting the organism against reactive oxygen species.


Assuntos
Citocromos c/química , Citocromos c/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/química , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/metabolismo , Leveduras/metabolismo , Cristalografia por Raios X , Transporte de Elétrons , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular , Oxirredução , Oxigênio/metabolismo , Ligação Proteica , Conformação Proteica , Leveduras/química
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