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Enabled by comparative genomics, yeasts have increasingly developed into a powerful model system for molecular evolution. Here we survey several areas in which yeast studies have made important contributions, including regulatory evolution, gene duplication and divergence, evolution of gene order and evolution of complexity. In each area we highlight key studies and findings based on techniques ranging from statistical analysis of large datasets to direct laboratory measurements of fitness. Future work will combine traditional evolutionary genetics analysis and experimental evolution with tools from systems biology to yield mechanistic insight into complex phenotypes. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

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The main goal of the present study is to provide an insight on the role played by non-volatile molecules on the different in-mouth attributes, particularly astringency. For achieving such goal, the main in-mouth sensory attributes of 34 oaked Spanish red wines were measured by a trained panel. The wine content in 30 sensory-active molecules was analysed by different HPLC based methodologies together with classical enological parameters and two proanthocyanidin indexes. Fourteen compounds (aconitic acids, polymeric proanthocyanidins, caftaric, caffeic and coutaric acids and seven quercetins) were found to be at concentrations above reported taste thresholds and to have a reasonably high range of occurrence. Two highly statistically significant models for astringency were built with those compounds. Even if the models could not be fully validated by sensory addition experiments, the research has demonstrated that wine astringency is driven by polymeric proanthocyanidins and by certain phenolic acids, the rate trans/cis-aconitic acid and flavonol profiles. The research has highlighted the existence of extremely complex interactions between non-volatile compounds on the in-mouth sensory perception. Particularly remarkable is the lack of additivity and potential antagonism found between the pairs cis/trans-aconitic acids, between aconitic and caffeic acids and between quercetin-3-O-galactoside and quercetin-3-O-glucoside. Also remarkable was the sweetness × astringent interaction and the matrix-dependence of the sensory responses elicited by flavonols. These results suggest the need for new paradigms and experimental procedures for fully decoding the real sensory relevance of individual non-volatile compounds in the overall wine flavour.  相似文献   

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Insights into the role of quorum sensing in food spoilage   总被引:1,自引:0,他引:1  
Food spoilage is a consequence of the degrading enzymatic activity of some food-associated bacteria. Several proteolytic, lipolytic, chitinolytic, and pectinolytic activities associated with the deterioration of goods are regulated by quorum sensing, suggesting a potential role of such cell-to-cell communication in food spoilage. Here we review quorum sensing signaling molecules and methods of their detection and quantification, and we provide insights into the role of quorum sensing in food spoilage and address potential quorum sensing inhibitors that might be used as biopreservatives.  相似文献   

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分子识别在分离科学中的应用   总被引:1,自引:0,他引:1  
分子识别引导着所有生理过程中大分子间的选择性相互作用。分子识别材料由原来的天然化合物逐步向仿生聚合物等人工受体化合物发展。分子识别应用于亲和色谱、固相萃取、膜分离技术极大地促进了分离效率的提高和一些复杂物质的拆分。目前,分子识别进一步被用于临床药物分析、模拟酶催化以及化学仿生传感器,为定性分离和设计提供更多的信息,也为加速分子发现提供潜能。  相似文献   

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Milk and dairy products are important sources of proteins, fats and vitamins. Although Brazil is the fourth largest milk producer in the world, mastitis, metritis, enteritis and respiratory diseases are still important in this industry. A number of antibiotics are employed for treatment and prophylaxis for these diseases, including cephalosporins, lincosamides, aminoglycosides, penicillins, tetracyclines and macrolides. Vaccination offers an important opportunity to reduce the demand for antibiotics. In this review, we present insights into milk production, antibiotic use in the Brazilian dairy industry, the consequences of these activities and perspectives for the control and surveillance of antibiotic resistance.  相似文献   

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首先综述了新型的识别分子,包括分子印迹聚合物、适配体以及受体;同时对各种识别分子在传感器中的应用分别进行了讨论;最后对传感器技术在小分子生物毒素检测中现存的问题和未来的发展方向进行了总结和展望。   相似文献   

10.
Insights into the sorption properties of cutin and cutan biopolymers   总被引:1,自引:0,他引:1  
Plant cuticles have been reported as highly efficient sorbents for organic compounds. The objective of this study was to elucidate the sorption and desorption behavior of polar and nonpolar organic compounds with the major structural components of the plant cuticle: the biopolymers cutin and cutan. The sorption affinity values of the studied compounds followed the order: phenanthrene > atrazine > chlorotoluron > carbamazepine. A higher sorption affinity of phenanthrene and atrazine to cutin was probably due to the higher level of amorphous paraffinic carbon in this biopolymer. Phenanthrene exhibited reversible sorption behavior and a high ratio of organic-carbon-normalized distribution coefficient (Koc) to carbon-normalized octanol-water partitioning coefficients (Kowc) with both biopolymers. This suggests that both biopolymers provide phenanthrene with a partition medium for hydrophobic interactions with the flexible long alkyl-chain moieties of the biopolymers. The low Koc/Kowc ratios obtained for the polar sorbates suggest that the polar sites in the biopolymers are not accessible for sorption interactions. Atrazine and carbamazepine exhibited sorption-desorption hysteresis with both sorbents, indicating that both sorbates interact with cutin and cutan via both hydrophobic and specific interactions. In general, the sorptive properties of the studied biopolymers were similar, signifying that the active sorption sites are similar even though the biopolymers exhibit different properties.  相似文献   

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The effect of repeated annealing treatment (RANN) and continuous annealing treatment (CANN) on the structure, physicochemical properties and digestibility of wheat B-starch were studied. Annealing degraded the starch molecules, disrupted amylopectin and amylose structures, and decreased the molecular weight and the long chain of amylopectin. Meanwhile, the double helix structure and the crystalline and amorphous region were broken, the starch and water molecules were rearranged after RANN and CANN. As a result, annealing increased the crystallinity, gelatinisation temperature, resistant starch and slowly digestible starch content, while decreased the solubility, swelling power and pasting viscosity. The different changes of structural and physicochemical properties for normal and waxy B-starch upon annealing treatment were because of the different amylose contents and amylopectin chain mobility. The RANN exhibited greater advantages than CANN in the modification of the structural, physicochemical, and digestible properties of normal B-starch; while CANN significantly affected properties of waxy B-starch.  相似文献   

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Bifidobacteria represent important human commensals because of their perceived contribution to the maintenance of a balanced gastro intestinal tract (GIT). In recent years bifidobacteria have drawn much scientific attention because of their use as live bacteria in numerous food preparations with various health-related claims. For such reasons these bacteria constitute a growing area of interest with respect to genomics, molecular biology and genetics. This review will discuss the current knowledge on the molecular players that allow bifidobacteria to contend with heat-, osmotic-, bile-and acidic stress. Here, we describe the principal molecular chaperones involved in such stresses, as well as their use as phylogenetic markers for gaining insight into the evolutionary history of high G+C Gram positive bacteria.  相似文献   

13.
The process of skin aging is a combination of an extrinsic and intrinsic aspect, and knowing the molecular changes underlying both is a prerequisite to being able to effectively counter it. However, despite its importance for a deeper understanding of skin aging as a whole, the process of intrinsic skin aging in particular has barely been investigated. In this study, the molecular changes of intrinsic skin aging were analyzed by applying 'Serial Analysis of Gene Expression' (SAGE(TM)) to skin biopsies of young and aged donors. The analysis resulted in several hundred differentially expressed genes with varying statistical significance. Of these, several genes were identified that either have never been described in skin aging before (e.g. APP) or have no identified function, e.g. EST sequences. This is the first time that intrinsic skin aging has been analyzed in such a comprehensive manner, offering a new and partially unexpected set of target genes that have to be analyzed in more detail in terms of their contribution to the skin aging process.  相似文献   

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以合成的雌酮分子印迹聚合物为微柱填料,建立了分子印迹聚合物富集雌酮原位显色反应的方法,并对影响测定结果的显色剂用量、填料量、上样流速和上样时间等主要实验参数进行了优化,在印迹材料填料量为0.030g,上样流速为1.0mL·min-1,1.00μg·L-1雌酮-甲醇标准溶液富集10.0mL条件下,再加入稀氢氧化钾-乙醇溶液1.0mL条件下,显色剂15.00g·L-1间二硝基苯溶液1.0mL,在暗处反应1h,最低检出限可达10.00μg·L-1。为了验证所建立的方法的实用性,本研究对湖水样品中的痕量雌酮残留进行了检测分析。通过对检测为空白的样品进行浓度为10.00,50.00,100.00μg·L-1的添加,以所建立的分析方法进行检测,结果均有比较明显的颜色反应,从而说明所建立的检测方法的可行性。  相似文献   

15.
The identification of mechanisms associated with phenolic neuroprotection is delayed due to a lack of information regarding the ability of phenolic compounds to enter the central nervous system (CNS). The aim of this work was to evaluate the transmembrane transport of catechin and epicatechin across blood-brain barrier (BBB). Two BBB cell lines, RBE-4 cells (immortalized cell line of rat capillary cerebral endothelial cells) and hCMEC/D3 (immortalized human cerebral microvessel endothelial cell line), were used. HPLC-DAD/MS was used to detect these compounds and their metabolites in the studied samples. The metabolites of the tested flavan-3-ols were synthesized to be used as standards. Catechin and epicatechin could cross both cells in a time-dependent manner. This transport was stereoselective (epicatechin ? catechin), involving one or more stereoselective entities. Additionally, these cells were capable of metabolizing these compounds, particularly by conjugation with glucuronic acid, since this metabolite was detected in the basolateral media. Several studies suggest that blood levels of catechin and epicatechin are far below the levels used in this study and that these compounds appeared mainly as methyl, sulfate and glucuronide metabolites. Nevertheless, the information obtained by this study is valuable for the new insights about flavan-3-ols transport. In conclusion: (i) catechin and epicatechin are capable of crossing the BBB; (ii) a stereoselective process was involved in the passage of these compounds across BBB cells; (iii) these endothelial cells have enzymes capable of metabolizing these compounds.  相似文献   

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Abstract

Significant efforts have been made to address the hidden hunger challenges due to iron, zinc, iodine, and vitamin A since the beginning of the 21st century. Prioritizing the vitamin A deficiency (VAD) disorders, many countries are looking for viable alternative strategies such as biofortification. One of the leading causes of VAD is the poor bioconversion of β-carotene into retinoids. This review is focused on the opportunities of bacterial biosynthesis of retinoids, in particular, through the gut microbiota. The proposed hypothesis starts with the premise that an animal can able to store and timely convert carotenoids into retinoids in the liver and intestinal tissues. This theory is experimental with many scientific insights. The syntrophic metabolism, potential crosstalk of bile acids, lipocalins and lipopolysaccharides of gut microbiota are reported to contribute significantly to the retinoid biosynthesis. The gut bacteria respond to these kinds of factors by genetic restructuring driven mainly by events like horizontal gene transfer. A phylogenetic analysis of β-carotene 15, 15′-mono (di) oxygenase enzymes among a selected group of prokaryotes and eukaryotes was carried out to validate the hypotheses. Shedding light on the probiotic strategies through non-genetically modified organism such as gut bacteria capable of synthesizing vitamin A would address the VAD disorders.  相似文献   

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In this review, we present a summary of the research work performed so far using high accuracy quantum chemical methods on polyphenolic antioxidant compounds. We have reviewed the different groups of polyphenols, which mostly belong to the Mediterranean food culture, i.e. phenolic acids, flavonoids and stilbenes. The three main proposed mechanisms through which the antioxidants may play their protective role, which is the H atom transfer, the single electron transfer and the metals chelation, have been analysed and discussed in details. This work represents a further important contribution to the elucidation of the beneficial effects on health of these substances.  相似文献   

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在供给侧改革和糖业二次创业的新形势下,针对广西蔗糖产业如何转变生产方式和转型升级,特别是如何进一步加快推进广西甘蔗生产全程机械化,笔者深入开展调查研究,从6个方面进行探索和思考,并提出了新形势下加快推进广西甘蔗生产实现全程机械化的战略措施,即"必须树立甘蔗生产全程机械化的现代经营理念";"必须加快推进甘蔗生产经营规模化";"必须创新农机农艺融合的技术模式";"必须加大甘蔗生产全程机械化的示范和推广力度";"必须加快推进甘蔗机械装备现代化和产业化";"必须进一步加大政策引导和扶持力度"。上述战略措施的提出,对于促进广西蔗糖产业可持续发展和增强蔗糖产业国际竞争力具有重要的指导意义和战略意义。  相似文献   

19.
Abstract: For years, high‐pressure processing has been viewed as useful for pasteurizing food while maintaining the quality of fresh food. However, even at moderate pressure, this process is not without effects on food, especially on meat products. These effects are especially important because pressure greater than 400 MPa is generally necessary to achieve efficient microbial inactivation. In this review, recent advances in the understanding of the impacts of high pressure on the overall quality of raw and processed meat are discussed. Many factors, including meat product formulation and processing parameters, can influence the efficiency of high pressure in pasteurizing meat products. It appears that new strategies are applied either (i) to improve the microbial inactivation that results from high pressure while minimizing the adverse effects of high pressure on meat quality or (ii) to take advantage of changes in meat attributes under high pressure. Most of the time, multiple preservation factors or techniques are combined to produce safe, stable, and high‐quality food products. Among the new applications of high‐pressure techniques for meat and meat‐derivative products are their use in combination with temperature manipulation to texturize and pasteurize new meat products simultaneously.  相似文献   

20.
The presence of glutelin plays an important role in the textural properties of reconstituted rice, but available information is limited. Herein, a comprehensive assessment of the effects of multi-scale structure and intramolecular interactions of glutelin on the textural properties of reconstituted rice was performed. The results demonstrated that the hardness, adhesiveness, and chewiness of reconstituted rice were improved as the added ratio of glutelin increased and the internal structure changed by forming compact flake-like, fibrous branches, more α-helix and β-sheet structure, and enhanced intermolecular interactions. Furthermore, extrusion promoted the generation of special aroma substances by the Maillard reaction. Correlation analysis revealed that the hardness, adhesiveness, and chewiness of reconstituted rice were significant positive correlation with Tp, ∆H, β-turn, random coil, and free SH content, and negative correlation with α-helix of glutelin. These observations provide better insights into strategies for producing reconstituted rice by extrusion.  相似文献   

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