Effect of Skin Contact Before and During Alcoholic Fermentation on the Chemical and Sensory Profile of South African Chenin Blanc White Wines

The volatile and phenolic composition of Chenin blanc wines made with different skin contact treatmentswas studied. One batch of grapes was used to make a dry white wine according to two different treatments,namely pre-fermentative skin contact and complete fermentation on the skins. A white wine fermentedwithout any skin contact was used as control. Fermentation on the skins and skin contact beforefermentation led to significantly lower levels of terpenes, esters, acids and thiols, and the highest significantlevels of alcohols and phenolic compounds. However, this effect was less pronounced in wines with skincontact before fermentation. Sensory analysis of all the experimental wines was also performed. The resultsshowed a significant shift from the sensory attributes of fresh and tropical fruits of the control Cheninblanc wines towards riper fruit notes in the skin contact treatments. This observation was correlated withthe length of the skin contact period. Possible reasons to explain the results observed in this study arediscussed

Antimicrobial treatment improves mycobacterial survival in nonpermissive growth conditions

Antimicrobials targeting cell wall biosynthesis are generally considered inactive against nonreplicating bacteria. Paradoxically, we found that under nonpermissive growth conditions, exposure of Mycobacterium bovis BCG bacilli to such antimicrobials enhanced their survival. We identified a transcriptional regulator, RaaS (for regulator of antimicrobial-assisted survival), encoded by bcg1279 (rv1219c) as being responsible for the observed phenomenon. Induction of this transcriptional regulator resulted in reduced expression of specific ATP-dependent efflux pumps and promoted long-term survival of mycobacteria, while its deletion accelerated bacterial death under nonpermissive growth conditions in vitro and during macrophage or mouse infection. These findings have implications for the design of antimicrobial drug combination therapies for persistent infectious diseases, such as tuberculosis

Effect of skin contact before and during alcoholic fermentation on the chemical and sensory profile of South African Chenin Blanc white wines

CITATION: Aleixandre-Tudo, J. L., et al. 2015. Effect of Skin Contact Before and During Alcoholic Fermentation on the Chemical and Sensory Profile of South African Chenin Blanc White Wines. South African Journal for Enology and Viticulture, 36(3):366-377, doi:10.21548/36-3-969.The original publication is available at http://www.journals.ac.za/index.php/sajevThe volatile and phenolic composition of Chenin blanc wines made with different skin contact treatments was studied. One batch of grapes was used to make a dry white wine according to two different treatments, namely pre-fermentative skin contact and complete fermentation on the skins. A white wine fermented without any skin contact was used as control. Fermentation on the skins and skin contact before fermentation led to significantly lower levels of terpenes, esters, acids and thiols, and the highest significant levels of alcohols and phenolic compounds. However, this effect was less pronounced in wines with skin contact before fermentation. Sensory analysis of all the experimental wines was also performed. The results showed a significant shift from the sensory attributes of fresh and tropical fruits of the control Chenin blanc wines towards riper fruit notes in the skin contact treatments. This observation was correlated with the length of the skin contact period. Possible reasons to explain the results observed in this study are discussed.http://www.journals.ac.za/index.php/sajev/article/view/969Publisher's versio

Oleoyl coenzyme A regulates interaction of transcriptional regulator RaaS (Rv1219c) with DNA in mycobacteria

We have recently shown that RaaS (regulator of antimicrobial-assisted survival), encoded by Rv1219c in Mycobacterium tuberculosis and by bcg_1279c in Mycobacterium bovis bacillus Calmette-Guérin, plays an important role in mycobacterial survival in prolonged stationary phase and during murine infection. Here, we demonstrate that long chain acyl-CoA derivatives (oleoyl-CoA and, to lesser extent, palmitoyl-CoA) modulate RaaS binding to DNA and expression of the downstream genes that encode ATP-dependent efflux pumps. Moreover, exogenously added oleic acid influences RaaS-mediated mycobacterial improvement of survival and expression of the RaaS regulon. Our data suggest that long chain acyl-CoA derivatives serve as biological indicators of the bacterial metabolic state. Dysregulation of efflux pumps can be used to eliminate non-growing mycobacteria

Re Rites of Passage : Asian Canada in Motion

" (re)Rites of Passage: Asian Canada in Motion is a special anthology published as part of the Toronto Reel Asian Film International Film Festival’s 25th anniversary celebrations, and a follow-up to Reel Asian: Asian Canada on Screen (published in 2007 for Reel Asian’s 10th anniversary). Drawing inspiration from the vibrant and kinetic histories of independent publishing in Asian diaspora, the anthology features a range of critical responses from Asian Canadian media artists on the contributions, maturations and evolving sensibilities of Asian Canadian film and media creation. " -- Publisher's website

Tri-, Tetra-, and Hexanuclear Copper(II) Phosphonates Containing N-Donor Chelating Ligands: Synthesis, Structure, Magnetic Properties, and Nuclease Activity

Reaction of Cu(ClO4)2 3 6H2O with cyclopentyl phosphonic acid and 2,20-bipyridine (bpy) in presence of triethylamine afforded a trinuclear compound [Cu3(C5H9PO3)2(bpy)3(MeOH)(H2O)](ClO4)2 (2). The latter dimerizes to a hexanuclear derivative [Cu6(C5H9PO3)4(bpy)6(MeOH)4](ClO4)4 (1) under prolonged reaction conditions. Reaction of CuCl2 with cyclopentyl phosphonic acid and 2,20-bipyridylamine (bpya) affords a tetranuclear derivative [Cu4(C5H9PO3)2( μ-Cl)2(bpya)4](Cl)2, (MeOH)2 (3). Reaction of the latter with NaClO4 also affords a trinuclear compound [Cu3(C5H9PO3)2( μ-Cl)(bpya)3(H2O)](ClO4) (4). Double and single-bridged hexanuclear species, [{Cu3(C5H9PO3)2(bpy)3(bpp)}(MeOH)2(H2O)(CH2Cl2)(ClO4)2]2 (5), [{Cu3(i- PrPO3)2(bpy)3(4.40-bpy)(H2O)}(H2O)2(ClO4)2]2 (6), [{Cu3(C5H9PO3)2(bpya)3(4.40-bpy)(H2O)}(MeOH)(H2O)(ClO4)2]2 (7), and [Cu6(t-BuPO3)4(phen)6(4,40-bpy)(MeOH)4](CH2Cl2)(H2O)(ClO4)4 (8) (phen = 1,10-phenanthroline) were obtained by the reaction of an in situ generated trinuclear complex with appropriate bridging ligands 4,40-bipyridine (4,40-bpy) or 1,3-bis(4- pyridyl)propane (bpp). ESI-MS studies of these complexes reveal that 2-4 retain their structures in solution. Molecular structures of 2-8 were determined by X-ray crystallography. All the compounds reveal a capping coordination mode by tridentate phosphonate [RPO3]2- ligands. Detailed magnetic studies on 2 and 4-8 reveal intramolecular antiferromagnetic interactions between Cu(II) S = 1/2 spins. 2 and 4 are excellent artificial nucleases and can convert supercoiled plasmid DNA (pBR322) into its nicked form without the aid of an external oxidant

Spectrophotometric Analysis of Phenolic Compounds in Grapes and Wines

[EN] Phenolic compounds are of crucial importance for red wine color and mouthfeel attributes. A large number of enzymatic and chemical reactions involving phenolic compounds take place during winemaking and aging. Despite the large number of published analytical methods for phenolic analyses, the values obtained may vary considerably. In addition, the existing scientific knowledge needs to be updated, but also critically evaluated and simplified for newcomers and wine industry partners. The most used and widely cited spectrophotometric methods for grape and wine phenolic analysis were identified through a bibliometric search using the Science Citation Index-Expanded (SCIE) database accessed through the Web of Science (WOS) platform from Thompson Reuters. The selection of spectrophotometry was based on its ease of use as a routine analytical technique. On the basis of the number of citations, as well as the advantages and disadvantages reported, the modified Somers assay appears as a multistep, simple, and robust procedure that provides a good estimation of the state of the anthocyanins equilibria. Precipitation methods for total tannin levels have also been identified as preferred protocols for these types of compounds. Good reported correlations between methods (methylcellulose-precipitable vs bovine serum albumin) and between these and perceived red wine. astringency, in combination with the adaptation to high-throughput format, make them suitable for routine analysis. The bovine serum albumin tannin assay also allows for the estimation of the anthocyanins content with the measurement of small and large polymeric pigments. Finally, the measurement of wine color using the CIELab space approach is also suggested as the protocol of choice as it provides good insight into the wine's color properties.Aleixandre-Tudó, JL.; Buica, A.; Nieuwoudt, H.; Aleixandre Benavent, JL.; Du Toit, W. (2017). Spectrophotometric Analysis of Phenolic Compounds in Grapes and Wines. Journal of Agricultural and Food Chemistry. 65(20):4009-4026. https://doi.org/10.1021/acs.jafc.7b01724S40094026652