Antimicrobial Effect of Citric, Acetic, Lactic Acids and Sodium Nitrite against Escherichia Coli in Tryptic Soy Broth

Antimicrobial effect of organic acids against E. coli (EC1 and EC2) was studied in  tryptic soy broth (pH 5) adjusted to various concentrations 1, 2, 3, 4 or 6% of the citric,  acetic and lactic acid then incubated at 5, 20 and 37ºC during 96 hours. In the second study, the effect of sodium nitrite on the survival of E. coli cells was investigated at pHs (4.5 and 6).   ¶¶In the majority of the cases, the order of effectiveness of the organic acids was: citric >acetic > lactic¶.¶ At low temperature, 1 to 6% of lactic and acetic acid does not seem sufficient concentrations to influence cellular viability significantly. ¶ In contrast, addition of citric acid (3%) to TSB medium reduced E. coli from approximately 6.3 log CFU/ml to an undetectable number. Furthermore, antimicrobial effect of all organic acids increased with increasing the temperature of incubation. This study has confirmed that the lethal effect of sodium nitrite was much enhanced by low pH. Thus, the most bactericidal effect was obtained at pH = 4.5 and the concentrations NaNO2 (0.4 or 0.6). Key words: Escherichia coli, Antimicrobial effect, citric acid, acetic acid, lactic acid, sodium nitrite

Évolution de la teneur glucidique et protéique dans les tubercules de topinambour (Helianthus tuberosus L.)

Cette note concerne l'étude de la production de matière sèche, de glucides totaux et de protéine pendant les différents stades du développement des tubercules de topinambour. (Helianthus tuberosus L.). La matière sèche varie de 17 à 20% matière frafche, les glucides totaux de 8,85 à 14,5% matière frafche dont 75% de fructose (6,71 à 12,3% matière frafche) et les proMines de 9,20 à 12,85% du poids sec. La production moyenne de glucides totaux à l'hectare se situe en année normale à 6,5 Tlha (5,9-7,2); les tubercules perdent une fraction de leur glucides en hiver. Les sous-produits d'extraction des glucides contiennent des résidus sucrés et des acides aminés et constituent un aliment dont la valeur nutritive n'est pas négligeable en période hivernale.Carbohydrates and proteins evolution in the Jerusalem artichoke (HelianthUil tubero.UII L.) tubersThis note concerns a study of production of dry matter, total carbohydrate and protein at aIl stages of development of the tubers of the Jerusalem Artichoke (Helianthus tuberosus L.). Dry matter ranges from 17 to 20% fresh matter, overall carbohydrates from 8,85 to 14,5% fresh matter, of wich 75% is fructose (6,71 à 12,3% matière frafche) and protein from 9,20 to 12,85% dry matter. The average overall carbohydrate production per hectare amounts to 6,5 Tlha (5,9-7,2) in a normal year; the tubers lose a fraction oftheir carbohydrates in winter. The byproduct from extraction of carbohydrates contain residual carbohydrates and amino-acids and orovide a food of significant nutrition al value for the win ter season

Activité antifongique in vitro du phoséthyl-Al sur quelques souches de Verticillium albo-atrum Reinke & Berthold

La fongitoxicité du phosphonate, métabolite actif du phoséthyl-Al est modulée par la composition des milieux de culture. Sur le Cristomalt (milieu naturel) la toxicité du phosphonate vis-à-vis du Verticillium albo-atrum Reinke & Berthold. fonne à microsclérotes. est beaucoup plus grande que sur le Ribeiro (milieu synthétique). L'addition du phosphate au milieu de culture abaisse l'efficacité du phosphonate. Ce sont toujours les souches de Verticillium pathogènes sur la tomate, qui sont les plus sensibles au phoséthyl-Al.In vitro antifungal activity of fosetyl-Al on several strains of Verticillium albo-alrum Reinloe & BertholdToxicity of phosphonate, the active breakdown product of the fosethyl-Al, is modulated by culture media composition. On the Cristomalt ( natural medium), phosphonate toxicity against Verticillium albo-atrum Reinke & Berthold,-microsclerotial fonn, is higher than in synthetic media (Ribeiro). Phosphate is the main constituent of culture medium which modifies phosphonate fungitoxicity. Strains ofVerticillium, pathogenicon tomato, are al ways more sensitive" to fosethyl-Al

Ubiquitous [Na+]i/[K+]i-Sensitive Transcriptome in Mammalian Cells: Evidence for Ca2+i-Independent Excitation-Transcription Coupling

Stimulus-dependent elevation of intracellular Ca2+ ([Ca2+]i) affects the expression of numerous genes – a phenomenon known as excitation-transcription coupling. Recently, we found that increases in [Na+]i trigger c-Fos expression via a novel Ca2+i-independent pathway. In the present study, we identified ubiquitous and tissue-specific [Na+]i/[K+]i-sensitive transcriptomes by comparative analysis of differentially expressed genes in vascular smooth muscle cells from rat aorta (RVSMC), the human adenocarcinoma cell line HeLa, and human umbilical vein endothelial cells (HUVEC). To augment [Na+]i and reduce [K+]i, cells were treated for 3 hrs with the Na+,K+-ATPase inhibitor ouabain or placed for the same time in the K+-free medium. Employing Affymetrix-based technology, we detected changes in expression levels of 684, 737 and 1839 transcripts in HeLa, HUVEC and RVSMC, respectively, that were highly correlated between two treatments (p<0.0001; R2>0.62). Among these Na+i/K+i-sensitive genes, 80 transcripts were common for all three types of cells. To establish if changes in gene expression are dependent on increases in [Ca2+]i, we performed identical experiments in Ca2+-free media supplemented with extracellular and intracellular Ca2+ chelators. Surprisingly, this procedure elevated rather than decreased the number of ubiquitous and cell-type specific Na+i/K+i-sensitive genes. Among the ubiquitous Na+i/K+i-sensitive genes whose expression was regulated independently of the presence of Ca2+ chelators by more than 3-fold, we discovered several transcription factors (Fos, Jun, Hes1, Nfkbia), interleukin-6, protein phosphatase 1 regulatory subunit, dual specificity phosphatase (Dusp8), prostaglandin-endoperoxide synthase 2, cyclin L1, whereas expression of metallopeptidase Adamts1, adrenomedulin, Dups1, Dusp10 and Dusp16 was detected exclusively in Ca2+-depleted cells. Overall, our findings indicate that Ca2+i-independent mechanisms of excitation-transcription coupling are involved in transcriptomic alterations triggered by elevation of the [Na+]i/[K+]i ratio. There results likely have profound implications for normal and pathological regulation of mammalian cells, including sustained excitation of neuronal cells, intensive exercise and ischemia-triggered disorders

Regional microbial signatures positively correlate with differential wine phenotypes: evidence for a microbial aspect to terroir

Many crops display differential geographic phenotypes and sensorial signatures, encapsulated by the concept of terroir. The drivers behind these differences remain elusive, and the potential contribution of microbes has been ignored until recently. Significant genetic differentiation between microbial communities and populations from different geographic locations has been demonstrated, but crucially it has not been shown whether this correlates with differential agricultural phenotypes or not. Using wine as a model system, we utilize the regionally genetically differentiated population of Saccharomyces cerevisiae in New Zealand and objectively demonstrate that these populations differentially affect wine phenotype, which is driven by a complex mix of chemicals. These findings reveal the importance of microbial populations for the regional identity of wine, and potentially extend to other important agricultural commodities. Moreover, this suggests that long-term implementation of methods maintaining differential biodiversity may have tangible economic imperatives as well as being desirable in terms of employing agricultural practices that increase responsible environmental stewardship

Polygenic risk scores predict diabetes complications and their response to intensive blood pressure and glucose control

Aims/hypothesis: Type 2 diabetes increases the risk of cardiovascular and renal complications, but early risk prediction could lead to timely intervention and better outcomes. Genetic information can be used to enable early detection of risk. Methods: We developed a multi-polygenic risk score (multiPRS) that combines ten weighted PRSs (10 wPRS) composed of 598 SNPs associated with main risk factors and outcomes of type 2 diabetes, derived from summary statistics data of genome-wide association studies. The 10 wPRS, first principal component of ethnicity, sex, age at onset and diabetes duration were included into one logistic regression model to predict micro- and macrovascular outcomes in 4098 participants in the ADVANCE study and 17,604 individuals with type 2 diabetes in the UK Biobank study. Results: The model showed a similar predictive performance for cardiovascular and renal complications in different cohorts. It identified the top 30% of ADVANCE participants with a mean of 3.1-fold increased risk of major micro- and macrovascular events (p = 6.3 × 10−21 and p = 9.6 × 10−31, respectively) and a 4.4-fold (p = 6.8 × 10−33) higher risk of cardiovascular death. While in ADVANCE overall, combined intensive blood pressure and glucose control decreased cardiovascular death by 24%, the model identified a high-risk group in whom it decreased the mortality rate by 47%, and a low-risk group in whom it had no discernible effect. High-risk individuals had the greatest absolute risk reduction with a number needed to treat of 12 to prevent one cardiovascular death over 5 years. Conclusions/interpretation: This novel multiPRS model stratified individuals with type 2 diabetes according to risk of complications and helped to target earlier those who would receive greater benefit from intensive therapy. Graphical abstract: [Figure not available: see fulltext.

Anti-inflammatory evaluation of immature fruit and seed aqueous extracts from several populations of Tunisian Citrullus colocynthis Schrad

Plant extracts are some of the most attractive sources of new drugs and have shown promising results for the treatment of inflammation and immune-related diseases, including rheumatoid arthritis. Citrullus colocynthis Schrad. (Cucurbitaceae) endemic in Tunisia, is widely used in folk medicine to treat many inflammation disorders. The aim of this study is to quantify the alkaloid and the flavonoid levels of different populations of C. colocynthis fruit and seed aqueous extracts at immature state. After acute toxicity assay, these extracts were screened for anti-inflammatory activity using the carrageenaninduced paw edema assay in rats. Alkaloid and flavonoid levels vary among the population. The best anti-inflammatory activities were obtained with immature fruits from south Tunisia. Therefore, C. colocynthis Schrad. could be a potential useful product suitable for further evaluation for inflammatory diseases.Key words: Citrullus colocynthis Schrad., alkaloids, flavonoids, toxicity, anti-inflammatory, Tunisia