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Varela J, Varela C. Microbiological strategies to produce beer and wine with reduced ethanol concentration. Curr Opin Biotechnol 2018; 56:88-96. [PMID: 30390603 DOI: 10.1016/j.copbio.2018.10.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 09/25/2018] [Accepted: 10/07/2018] [Indexed: 11/25/2022]
Abstract
Changes in consumer preferences, government policies and environmental conditions have driven research efforts towards producing alcoholic beverages with reduced alcohol content, namely wine and beer. While the strategies available to accomplish this goal vary for wine and beer, a common approach relies on the use of yeast strains which are less efficient at producing ethanol. Here we discuss current research on the isolation and/or generation of yeast strains able to produce beer or wine with reduced ethanol concentration. Particular consideration is given to the impact of 'low-ethanol' yeasts on volatile composition and sensory profile of beer and wine.
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Baran E, Godoy A, Merino E, Benigni L, Gonzalez J, Pierini N, Copparoni G, Farah A, Zubillaga M, Rivera A, Ferranti S, Bocanegra R, Lorenzin A, Barrena E, Varela C, Gatti L, Goñi S. P159 Usefulness of extended oral glucose tolerance test in patients with cystic fibrosis older than 16 years. J Cyst Fibros 2018. [DOI: 10.1016/s1569-1993(18)30454-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Varela C, Barker A, Tran T, Borneman A, Curtin C. Sensory profile and volatile aroma composition of reduced alcohol Merlot wines fermented with Metschnikowia pulcherrima and Saccharomyces uvarum. Int J Food Microbiol 2017; 252:1-9. [PMID: 28436828 DOI: 10.1016/j.ijfoodmicro.2017.04.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 04/11/2017] [Accepted: 04/11/2017] [Indexed: 12/23/2022]
Abstract
Strategies for production of wines containing lower alcohol concentrations are in strong demand, for reasons of quality, health, and taxation. Development and application of wine yeasts that are less efficient at transforming grape sugars into ethanol has the potential to allow winemakers the freedom to make lower alcohol wines from grapes harvested at optimal ripeness, without the need for post-fermentation processes aimed at removing ethanol. We have recently shown that two non-conventional wine yeast species Metschnikowia pulcherrima and Saccharomyces uvarum were both able to produce wine with reduced alcohol concentration. Both species produced laboratory-scale wines with markedly different volatile aroma compound composition relative to Saccharomyces cerevisiae. This work describes the volatile composition and sensory profiles of reduced-alcohol pilot-scale Merlot wines produced with M. pulcherrima and S. uvarum. Wines fermented with M. pulcherrima contained 1.0% v/v less ethanol than S. cerevisiae fermented wines, while those fermented with S. uvarum showed a 1.7% v/v reduction in ethanol. Compared to S. cerevisiae ferments, wines produced with M. pulcherrima showed higher concentrations of ethyl acetate, total esters, total higher alcohols and total sulfur compounds, while wines fermented with S. uvarum were characterised by the highest total concentration of higher alcohols. Sensorially, M. pulcherrima wines received relatively high scores for sensory descriptors such as red fruit and fruit flavour and overall exhibited a sensory profile similar to that of wine made with S. cerevisiae, whereas the main sensory descriptors associated with wines fermented with S. uvarum were barnyard and meat. This work demonstrates the successful application of M. pulcherrima AWRI3050 for the production of pilot-scale red wines with reduced alcohol concentration and highlights the need for rigorous evaluation of non-conventional yeasts with regard to their sensory impacts.
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Goold HD, Kroukamp H, Williams TC, Paulsen IT, Varela C, Pretorius IS. Yeast's balancing act between ethanol and glycerol production in low-alcohol wines. Microb Biotechnol 2017; 10:264-278. [PMID: 28083938 PMCID: PMC5328816 DOI: 10.1111/1751-7915.12488] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 11/17/2016] [Accepted: 11/23/2016] [Indexed: 01/06/2023] Open
Abstract
Alcohol is fundamental to the character of wine, yet too much can put a wine off‐balance. A wine is regarded to be well balanced if its alcoholic strength, acidity, sweetness, fruitiness and tannin structure complement each other so that no single component dominates on the palate. Balancing a wine's positive fruit flavours with the optimal absolute and relative concentration of alcohol can be surprisingly difficult. Over the past three decades, consumers have increasingly demanded wine with richer and riper fruit flavour profiles. In response, grape and wine producers have extended harvest times to increase grape maturity and enhance the degree of fruit flavours and colour intensity. However, a higher degree of grape maturity results in increased grape sugar concentration, which in turn results in wines with elevated alcohol concentration. On average, the alcohol strength of red wines from many warm wine‐producing regions globally rose by about 2% (v/v) during this period. Notwithstanding that many of these ‘full‐bodied, fruit‐forward’ wines are well balanced and sought after, there is also a significant consumer market segment that seeks lighter styles with less ethanol‐derived ‘hotness’ on the palate. Consumer‐focussed wine producers are developing and implementing several strategies in the vineyard and winery to reduce the alcohol concentration in wines produced from well‐ripened grapes. In this context, Saccharomyces cerevisiae wine yeasts have proven to be a pivotal strategy to reduce ethanol formation during the fermentation of grape musts with high sugar content (> 240 g l−1). One of the approaches has been to develop ‘low‐alcohol’ yeast strains which work by redirecting their carbon metabolism away from ethanol production to other metabolites, such as glycerol. This article reviews the current challenges of producing glycerol at the expense of ethanol. It also casts new light on yeast strain development programmes which, bolstered by synthetic genomics, could potentially overcome these challenges.
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De Haro J, Bleda S, Varela C, Cañibano C, Acin F. Meta-analysis and adjusted indirect comparison of direct oral anticoagulants in prevention of acute limb ischemia in patients with atrial fibrillation. Curr Med Res Opin 2016; 32:1167-73. [PMID: 26949899 DOI: 10.1185/03007995.2016.1163256] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Direct oral anticoagulants are being presented as alternatives to warfarin for preventing stroke in patients with atrial fibrillation. Yet direct comparative trials between these agents in prevention of acute limb ischemia (ALI) are unavailable so far. OBJECTIVE To conduct an adjusted indirect comparison meta-analysis between direct oral agents for prevention of acute limb ischemia in atrial fibrillation. METHODS We conducted a systematic literature review searching electronic databases (MEDLINE and Embase) and the Cochrane Library from January 1990 through November 2014. Two blinded investigators reviewed all potentially relevant articles in a parallel manner by using a priori defined criteria. To assess the long-term efficacy and safety of these agents, only randomized clinical trials (RCTs) with follow-up durations of >1 year were included. The primary efficacy outcome was the end point of acute limb ischemia and/or extremity embolism. RESULTS A total of 44,563 patients from three RCTs met criteria for inclusion. Patients randomized to direct oral anticoagulants had a non-significant decreased risk for acute limb ischemia (risk ratio [RR]: 0.57, 95% confidence interval [CI]: 0.26-1.2). In the analysis between agents, however, rivaroxaban significantly lowered the risk of ALI compared to warfarin (RR: 0.23, 95% CI: 0.064-0.82), apixaban (RR: 0.26, 95% CI: 0.081-0.83), and dabigatran (RR: 0.24, 95% CI: 0.077-0.83). CONCLUSIONS Significant differences in prevention of acute limb ischemia may exist between oral anticoagulant agents in patients with atrial fibrillation. Rivaroxaban lowers the risk of limb embolism versus warfarin, apixaban and dabigatran.
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Matos MJ, Vilar S, Kachler S, Vazquez-Rodriguez S, Varela C, Delogu G, Hripcsak G, Santana L, Uriarte E, Klotz KN, Borges F. Progress in the development of small molecules as new human A3 adenosine receptor ligands based on the 3-thiophenylcoumarin core. MEDCHEMCOMM 2016. [DOI: 10.1039/c5md00573f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
3-Thiophenylcoumarins are described as adenosine receptor ligands. Synthesis, in vitro pharmacological assays and docking studies were performed.
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Nataraj V, Varela C, Javid A, Singh A, Besra GS, Bhatt A. Mycolic acids: deciphering and targeting the Achilles' heel of the tubercle bacillus. Mol Microbiol 2015; 98:7-16. [PMID: 26135034 PMCID: PMC4949712 DOI: 10.1111/mmi.13101] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2015] [Indexed: 12/31/2022]
Abstract
Mycolic acids are unique long chain fatty acids found in the lipid-rich cell walls of mycobacteria including the tubercle bacillus Mycobacterium tuberculosis. Essential for viability and virulence, enzymes involved in the biosynthesis of mycolic acids represent novel targets for drug development. This is particularly relevant to the impact on global health given the rise of multidrug resistant and extensively drug resistant strains of M. tuberculosis. In this review, we discuss recent advances in our understanding of how mycolic acid are synthesised, especially the potential role of specialised fatty acid synthase complexes. Also, we examine the role of a recently reported mycolic acid transporter MmpL3 with reference to several reports of the targeting of this transporter by diverse compounds with anti-M. tuberculosis activity. Additionally, we consider recent findings that place mycolic acid biosynthesis in the context of the cell biology of the bacterium, viz its localisation and co-ordination with the bacterial cytoskeleton, and its role beyond maintaining cell envelope integrity.
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Contreras A, Hidalgo C, Schmidt S, Henschke PA, Curtin C, Varela C. The application of non-Saccharomyces yeast in fermentations with limited aeration as a strategy for the production of wine with reduced alcohol content. Int J Food Microbiol 2015; 205:7-15. [PMID: 25866906 DOI: 10.1016/j.ijfoodmicro.2015.03.027] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 03/10/2015] [Accepted: 03/24/2015] [Indexed: 10/23/2022]
Abstract
High alcohol concentrations reduce the complexity of wine sensory properties. In addition, health and economic drivers have the wine industry actively seeking technologies that facilitate the production of wines with lower alcohol content. One of the simplest approaches to achieve this aim would be the use of wine yeast strains which are less efficient at transforming grape sugars into ethanol, however commercially available wine yeasts produce very similar ethanol yields. Non-conventional yeast, in particular non-Saccharomyces species, have shown potential for producing wines with lower alcohol content. These yeasts are naturally present in the early stages of fermentation but in general are not capable of completing alcoholic fermentation. We have evaluated 48 non-Saccharomyces isolates to identify strains that, with limited aeration and in sequential inoculation regimes with S. cerevisiae, could be used for the production of wine with lower ethanol concentration. Two of these, Torulaspora delbrueckii AWRI1152 and Zygosaccharomyces bailii AWRI1578, enabled the production of wine with reduced ethanol concentration under limited aerobic conditions. Depending on the aeration regime T. delbrueckii AWRI1152 and Z. bailii AWRI1578 showed a reduction in ethanol concentration of 1.5% (v/v) and 2.0% (v/v) respectively, compared to the S. cerevisiae anaerobic control.
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Matos MJ, Varela C, Vilar S, Hripcsak G, Borges F, Santana L, Uriarte E, Fais A, Di Petrillo A, Pintus F, Era B. Design and discovery of tyrosinase inhibitors based on a coumarin scaffold. RSC Adv 2015. [DOI: 10.1039/c5ra14465e] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A novel series of 3-aryl and 3-heteroarylcoumarins displaying tyrosinase inhibitory activity.
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Bindon K, Holt H, Williamson PO, Varela C, Herderich M, Francis IL. Relationships between harvest time and wine composition in Vitis vinifera L. cv. Cabernet Sauvignon 2. Wine sensory properties and consumer preference. Food Chem 2014; 154:90-101. [DOI: 10.1016/j.foodchem.2013.12.099] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 12/21/2013] [Accepted: 12/29/2013] [Indexed: 11/17/2022]
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Varela C, Kumar S, Yang JY, Wilson MA. Anatomical substrates for direct interactions between hippocampus, medial prefrontal cortex, and the thalamic nucleus reuniens. Brain Struct Funct 2014; 219:911-29. [PMID: 23571778 PMCID: PMC4179252 DOI: 10.1007/s00429-013-0543-5] [Citation(s) in RCA: 180] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 03/13/2013] [Indexed: 12/18/2022]
Abstract
The reuniens nucleus in the midline thalamus projects to the medial prefrontal cortex (mPFC) and the hippocampus, and has been suggested to modulate interactions between these regions, such as spindle-ripple correlations during sleep and theta band coherence during exploratory behavior. Feedback from the hippocampus to the nucleus reuniens has received less attention but has the potential to influence thalamocortical networks as a function of hippocampal activation. We used the retrograde tracer cholera toxin B conjugated to two fluorophores to study thalamic projections to the dorsal and ventral hippocampus and to the prelimbic and infralimbic subregions of mPFC. We also examined the feedback connections from the hippocampus to reuniens. The goal was to evaluate the anatomical basis for direct coordination between reuniens, mPFC, and hippocampus by looking for double-labeled cells in reuniens and hippocampus. In confirmation of previous reports, the nucleus reuniens was the origin of most thalamic afferents to the dorsal hippocampus, whereas both reuniens and the lateral dorsal nucleus projected to ventral hippocampus. Feedback from hippocampus to reuniens originated primarily in the dorsal and ventral subiculum. Thalamic cells with collaterals to mPFC and hippocampus were found in reuniens, across its anteroposterior axis, and represented, on average, about 8 % of the labeled cells in reuniens. Hippocampal cells with collaterals to mPFC and reuniens were less common (~1 % of the labeled subicular cells), and located in the molecular layer of the subiculum. The results indicate that a subset of reuniens cells can directly coordinate activity in mPFC and hippocampus. Cells with collaterals in the hippocampus-reuniens-mPFC network may be important for the systems consolidation of memory traces and for theta synchronization during exploratory behavior.
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Arevalo G, Varela C, Gijon L, Rosas M, Arevalo F. Modifiable risk factors and lumbar disc herniation: Results of a case control study in 652 patients. Ann Phys Rehabil Med 2014. [DOI: 10.1016/j.rehab.2014.03.718] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Rosado C, Fierro C, Cossio F, Rodriguez A, Candas MA, Varela C, Miranda G, Plano AI, Martínez-Múgica C, Gomez de Segura L. GM-018 Survey to assess outpatient satisfaction as a quality measure tool in a Hospital Pharmacy. Eur J Hosp Pharm 2014. [DOI: 10.1136/ejhpharm-2013-000436.296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Kutyna DR, Cordente AG, Varela C. Genetic engineering of industrial Saccharomyces cerevisiae strains using a selection/counter-selection approach. Methods Mol Biol 2014; 1152:157-68. [PMID: 24744032 DOI: 10.1007/978-1-4939-0563-8_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Gene modification of laboratory yeast strains is currently a very straightforward task thanks to the availability of the entire yeast genome sequence and the high frequency with which yeast can incorporate exogenous DNA into its genome. Unfortunately, laboratory strains do not perform well in industrial settings, indicating the need for strategies to modify industrial strains to enable strain development for industrial applications. Here we describe approaches we have used to genetically modify industrial strains used in winemaking.
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Jolly NP, Varela C, Pretorius IS. Not your ordinary yeast: non-Saccharomycesyeasts in wine production uncovered. FEMS Yeast Res 2013; 14:215-37. [DOI: 10.1111/1567-1364.12111] [Citation(s) in RCA: 521] [Impact Index Per Article: 47.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 10/07/2013] [Indexed: 11/30/2022] Open
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Samuel JC, Ludzu EK, Cairns BA, Varela C, Charles AG. A patient with severe peritonitis. Malawi Med J 2013; 25:86-87. [PMID: 24358426 PMCID: PMC3859995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
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Bindon K, Varela C, Kennedy J, Holt H, Herderich M. Relationships between harvest time and wine composition in Vitis vinifera L. cv. Cabernet Sauvignon 1. Grape and wine chemistry. Food Chem 2013; 138:1696-705. [DOI: 10.1016/j.foodchem.2012.09.146] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 09/28/2012] [Accepted: 09/28/2012] [Indexed: 10/27/2022]
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Diaz-Garcia CM, Fuentes-Silva D, Sanchez-Soto C, Domínguez-Pérez D, García-Delgado N, Varela C, Mendoza-Hernández G, Rodriguez-Romero A, Castaneda O, Hiriart M. Toxins from Physalia physalis (Cnidaria) raise the intracellular Ca(2+) of beta-cells and promote insulin secretion. Curr Med Chem 2013; 19:5414-23. [PMID: 22830340 DOI: 10.2174/092986712803833308] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 07/04/2012] [Accepted: 07/19/2012] [Indexed: 11/22/2022]
Abstract
Physalia physalis is a marine cnidarian from which high molecular weight toxins with hemolytic and neurotoxic effects have been isolated. In the present work, two novel toxins, PpV9.4 and PpV19.3 were purified from P. physalis by bioactive guideline isolation. It involved two steps of column chromatography, gel filtration and RP-HPLC. The molecular weights were 550.7 and 4720.9 Da for PpV9.4 and PpV19.3, respectively. In the light of the Edman sequencing results, the structure of these toxins included the presence of modified amino acids. Both toxins increased the percentage of insulin secreting beta-cells and induced cytosolic Ca2+ elevation. To date, this is the first report of low molecular weight toxins increasing insulin secretion purified from cnidarians, by constituting a new approach to the study of beta-cells physiology.
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Gómez S, Varela C. A new species of AlteuthaBaird (Harpacticoida: Peltidiidae) from north-western Mexico. J NAT HIST 2013. [DOI: 10.1080/00222933.2012.747634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
Thalamic input to the neocortex is crucial for sensory perception and constitutes the basis of complex awake behavior. Connections within the neocortex play an important role in internally generated neural activity, which is considered critical for memory retrieval and for the generation of imagery in our dreams. Modulatory neurotransmitters, such as noradrenaline and acetylcholine, gate information transmission in the brain. Favero et al. (J Neurophysiol 108: 1010-1024, 2012) show that modulators differentially facilitate thalamocortical relative to intracortical transmission in the input layers of cortex.
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Cordente AG, Curtin CD, Varela C, Pretorius IS. Flavour-active wine yeasts. Appl Microbiol Biotechnol 2012; 96:601-18. [PMID: 22940803 PMCID: PMC3466427 DOI: 10.1007/s00253-012-4370-z] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 08/11/2012] [Accepted: 08/13/2012] [Indexed: 11/26/2022]
Abstract
The flavour of fermented beverages such as beer, cider, saké and wine owe much to the primary fermentation yeast used in their production, Saccharomyces cerevisiae. Where once the role of yeast in fermented beverage flavour was thought to be limited to a small number of volatile esters and higher alcohols, the discovery that wine yeast release highly potent sulfur compounds from non-volatile precursors found in grapes has driven researchers to look more closely at how choice of yeast can influence wine style. This review explores recent progress towards understanding the range of ‘flavour phenotypes’ that wine yeast exhibit, and how this knowledge has been used to develop novel flavour-active yeasts. In addition, emerging opportunities to augment these phenotypes by engineering yeast to produce so-called grape varietal compounds, such as monoterpenoids, will be discussed.
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Varela C, Rittmann D, Singh A, Krumbach K, Bhatt K, Eggeling L, Besra GS, Bhatt A. MmpL genes are associated with mycolic acid metabolism in mycobacteria and corynebacteria. ACTA ACUST UNITED AC 2012; 19:498-506. [PMID: 22520756 PMCID: PMC3370651 DOI: 10.1016/j.chembiol.2012.03.006] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 02/24/2012] [Accepted: 03/08/2012] [Indexed: 11/16/2022]
Abstract
Mycolic acids are vital components of the cell wall of the tubercle bacillus Mycobacterium tuberculosis and are required for viability and virulence. While mycolic acid biosynthesis is studied extensively, components involved in mycolate transport remain unidentified. We investigated the role of large membrane proteins encoded by mmpL genes in mycolic acid transport in mycobacteria and the related corynebacteria. MmpL3 was found to be essential in mycobacteria and conditional depletion of MmpL3 in Mycobacterium smegmatis resulted in loss of cell wall mycolylation, and of the cell wall-associated glycolipid, trehalose dimycolate. In parallel, an accumulation of trehalose monomycolate (TMM) was observed, suggesting that mycolic acids were transported as TMM. In contrast to mycobacteria, we found redundancy in the role of two mmpL genes, in Corynebacterium glutamicum; a complete loss of trehalose-associated and cell wall bound corynomycolates was observed in an NCgl0228-NCgl2769 double mutant, but not in individual single mutants. Our studies highlight the role of mmpL genes in mycolic acid metabolism and identify potential new targets for anti-TB drug development.
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Varela C, Torrea D, Schmidt SA, Ancin-Azpilicueta C, Henschke PA. Effect of oxygen and lipid supplementation on the volatile composition of chemically defined medium and Chardonnay wine fermented with Saccharomyces cerevisiae. Food Chem 2012; 135:2863-71. [PMID: 22980883 DOI: 10.1016/j.foodchem.2012.06.127] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 06/08/2012] [Accepted: 06/27/2012] [Indexed: 11/28/2022]
Abstract
Oxygen or lipids are required to complete stressful alcoholic fermentation. Lack of these nutrients can inhibit sugar uptake and growth, which leads to incomplete or 'stuck' fermentation. Oxygen or lipids supplementation not only restores yeast fermentative activity and also affects formation of yeast volatile metabolites. To clarify the effect of oxygen and lipid supplementation on the formation of flavour active metabolites during wine fermentation, we evaluated the addition of these two nutrients to chemically defined grape juice and filter clarified Chardonnay must. Lipid addition increased the concentration of esters, higher alcohols and volatile acids, whereas oxygen increased the concentration of higher alcohols and altered the proportion of acetate to ethyl esters and the proportion of branch-chain acids to medium-chain fatty acids. Combined addition of lipids and oxygen showed an additive effect on concentration of higher alcohols whereas oxygen suppressed the enhancing effect of lipids on formation of esters and volatile acids. Our results demonstrate the potential of lipid and oxygen supplementation for the manipulation of wine aroma in white wine fermentation.
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Susla O, Shin HS, Jung YS, Rim H, Speer T, Owala FO, Razawi M, Holy E, Ferdinand B, Danilo F, Luscher TF, Tanner FC, Markaki A, Kyriazis J, Petrakis I, Mavroeidi V, Perakis K, Fragkiadakis GA, Venyhaki M, Tzanakakis M, Vardaki E, Maraki K, Doskas T, Daphnis E, Bregman R, Vale B, Lemos C, Kawakami L, Silva MI, Zhu F, Kaysen G, Kotanko P, Abbas SR, Dou Y, Heymsfield S, Levin NW, Turkmen K, Kayikcioglu H, Guney I, Altintepe L, Ozbek O, Tonbul HZ, Kaysen GA, Kaysen GA, Usvyat LA, Thijssen S, Levin NW, Kotanko P, Mutluay R, Konca Degertekin C, Derici U, Yilmaz MI, Akkiyal F, Gultekin S, Gonen S, Deger SM, Arinsoy T, Sindel S, Hueso M, Torras J, Carrera M, Vidal A, Navarro E, Rivas I, Rama I, Bolanos N, Varela C, Martinez-Castelao A, Grinyo JM, Harving F, Svensson M, Schmidt EB, Jorgensen KA, Christensen JH, Park JH, Koo EH, Kim HK, Kim MS, Cho AJ, Lee JE, Jang HR, Huh W, Kim DJ, Kim YG, Oh HY, Zawiasa A, Nowak D, Nowicki M, Nathalie N, Griet G, Eva S, Raymond V, Ng KP, Stringer S, Jesky M, Dutton M, Ferro C, Cockwell P, Jia T, Gama Axelsson T, Lindholm B, Heimburger O, Barany P, Stenvinkel P, Qureshi AR, Quiroga B, Goicoechea M, Garcia de Vinuesa S, Verdalles U, Reque J, Panizo N, Arroyo D, Santos A, Macias N, Luno J, Honda H, Hirano T, Ueda M, Kojima S, Mashiba S, Hayase Y, Michihata T, Akizawa T, Gungor O, Sezis Demirci M, Kircelli F, Tatar E, Hur E, Sen S, Toz H, Basci A, Ok E, Sepe V, Albrizio P, Gnecchi M, Cervio E, Esposito P, Rampino T, Libetta C, Dal Canton A, Faria MS, Faria MS, Ribeiro S, Silva G, Nascimento H, Rocha-Pereira P, Miranda V, Vieira E, Santos R, Mendonca D, Quintanilha A, Costa E, Belo L, Santos-Silva A, Pruijm M, Pruijm M, Hofmann L, Heuvelin E, Forni V, Coristine A, Stuber M, Vogt B, Burnier M, Chiappini MG, Ammann T, Muzzi L, Grosso A, Sabry A, Bansal V, Hoppensteadt D, Jeske W, Fareed J. Nutrition, inflammation and oxidative stress - CKD 1-5. Nephrol Dial Transplant 2012. [DOI: 10.1093/ndt/gfs238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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