Enzymatic activity toward poly(L-lactic acid) implants

Tissue reactions toward biodegradable poly(L-lactic acid) implants were monitored by studying the activity pattern of seven enzymes as a function of time: alkaline phosphatase, acid phosphatase, -naphthyl acetyl esterase, -glucuronidase, ATP-ase, NADH-reductase, and lactate dehydrogenase. Cell types were identified by their specific enzyme patterns, their morphology and location. Special attention was paid to the enzyme patterns of macrophages, fibroblasts and polymorphonuclear granulocytes (PMNs), being involved in foreign body reactions or inflammatory responses. One day after implantation, an influx of neutrophilic and eosinophilic granulocytes was observed, coinciding with activity of alkaline phosphatase (PMN's) and -glucuronidase (eosinophils). From day 3 on, macrophages containing ATP-ase, acid phosphatase and esterase could be observed. From day 7 on, lactate dehydrogenase, the enzyme normally involved in the conversion of lactic acid, and its coenzyme NADH-reductase were observed in macrophages and fibroblasts. These two enzymes demonstrated more activity than expected on basis of wound-healing reactions upon implantation of a nonbiodegradable, inert biomaterial (as, e.g., Teflon). It is concluded that the biodegradable poly (L-lactic acid) used in these implantation studies is tissue compatible, and evokes a foreign body reaction with minor macrophage and giant cell activity, as observed during this 3-week implantation period. Most enzyme patterns were simply due to a wound-healing reaction. The slightly increased levels of LDH and NADH suggest the release of lactic acid from the implant, and thus confirms the biodegradable nature of this polymer

Correlating wine quality indicators to chemical and sensory measurements.

Twenty-seven commercial Californian Cabernet Sauvignon wines of different quality categories were analyzed with sensory and chemical methods. Correlations between five quality proxies-points awarded during a wine competition, wine expert scores, retail price, vintage, and wine region-were correlated to sensory attributes, volatile compounds, and elemental composition. Wine quality is a multi-faceted construct, incorporating many different layers. Depending on the quality proxy studied, significant correlations between quality and attributes, volatiles and elements were found, some of them previously reported in the literature

<i>Saccharomyces cerevisiae</i> in the production of whisk(e)y

Whisk(e)y is a major global distilled spirit beverage. Whiskies are produced from cereal starches that are saccharified, fermented and distilled prior to spirit maturation. The strain of Saccharomyces cerevisiae employed in whisky fermentations is crucially important not only in terms of ethanol yields, but also for production of minor yeast metabolites which collectively contribute to development of spirit flavour and aroma characteristics. Distillers must therefore pay very careful attention to the strain of yeast exploited to ensure consistency of fermentation performance and spirit congener profiles. In the Scotch whisky industry, initiatives to address sustainability issues facing the industry (for example, reduced energy and water usage) have resulted in a growing awareness regarding criteria for selecting new distilling yeasts with improved efficiency. For example, there is now a desire for Scotch whisky distilling yeasts to perform under more challenging conditions such as high gravity wort fermentations. This article highlights the important roles of S. cerevisiae strains in whisky production (with particular emphasis on Scotch) and describes key fermentation performance attributes sought in distiller’s yeast, such as high alcohol yields, stress tolerance and desirable congener profiles. We hope that the information herein will be useful for whisky producers and yeast suppliers in selecting new distilling strains of S. cerevisiae, and for the scientific community to stimulate further research in this area

Lactic Acid Bacteria and Yeast Inocula Modulate the Volatile Profile of Spanish-Style Green Table Olive Fermentations

In this work, Manzanilla Spanish-style green table olive fermentations were inoculated with Lactobacillus pentosus LPG1, Lactobacillus pentosus Lp13, Lactobacillus plantarum Lpl15, the yeast Wickerhanomyces anomalus Y12 and a mixed culture of all them. After fermentation (65 days), their volatile profiles in brines were determined by gas chromatography-mass spectrometry analysis. A total of 131 volatile compounds were found, but only 71 showed statistical differences between at least, two fermentation processes. The major chemical groups were alcohols (32), ketones (14), aldehydes (nine), and volatile phenols (nine). Results showed that inoculation with Lactobacillus strains, especially L. pentosus Lp13, reduced the formation of volatile compounds. On the contrary, inoculation with W. anomalus Y12 increased their concentrations with respect to the spontaneous process, mainly of 1-butanol, 2-phenylethyl acetate, ethanol, and 2-methyl-1-butanol. Furthermore, biplot and biclustering analyses segregated fermentations inoculated with Lp13 and Y12 from the rest of the processes. The use of sequential lactic acid bacteria and yeasts inocula, or their mixture, in Spanish-style green table olive fermentation could be advisable practice for producing differentiated and high-quality products with improved aromatic profile.Gobierno de España-OliFilm-AGL-2013-48300-

Co-Existence of Inoculated Yeast and Lactic Acid Bacteria and Their Impact on the Aroma Profile and Sensory Traits of Tempranillo Red Wine

This study investigates the effects of simultaneous inoculation of a selected Saccharomyces cerevisiae yeast strain with two different commercial strains of wine bacteria Oenococcus oeni at the beginning of the alcoholic fermentation on the kinetics of malolactic fermentation (MLF), wine chemical composition, and organoleptic characteristics in comparison with spontaneous MLF in Tempranillo grape must from Castilla-La Mancha (Spain). Evolution of MLF was assessed by the periodic analysis of L-malic acid through the enzymatic method, and most common physiochemical parameters and sensory traits were evaluated using a standardized sensory analysis. The samples were analyzed by GC/MS in SCAN mode using a Trace GC gas chromatograph and a DSQII quadrupole mass analyzer. Co-inoculation reduced the overall fermentation time by up to 2 weeks leading to a lower increase in volatile acidity. The fermentation-derived wine volatiles profile was distinct between the co-inoculated wines and spontaneous MLF and was influenced by the selected wine bacteria used in co-inoculation. Co-inoculation allows MLF to develop under reductive conditions and results in wines with very few lactic and buttery flavors, which is related to the impact of specific compounds like 2,3-butanedione. This compound has been also confirmed as being dependent on the wine bacteria use

Starch plus sunflower oil addition to the diet of dry dairy cows results in a trans-11 to trans-10 shift of biohydrogenation

Trans fatty acids (FA), exhibit different biological properties. Among them, cis-9,trans-11 conjugated linoleic acid has some interesting putative health properties, whereas trans-10,cis-12 conjugated linoleic acid has negative effects on cow milk fat production and would negatively affect human health. In high-yielding dairy cows, a shift from trans-11 to trans-10 pathway of biohydrogenation (BH) can occur in the rumen of cows receiving high-concentrate diets, especially when the diet is supplemented with unsaturated fat sources. To study this shift, 4 rumen-fistulated nonlactating Holstein cows were assigned to a 4 × 4 Latin square design with 4 different diets during 4 periods. Cows received 12 kg of dry matter per day of 4 diets based on corn silage during 4 successive periods: a control diet (22% starch, <3% crude fat on DM basis), a high-starch diet supplemented with wheat plus barley (35% starch, <3% crude fat), a sunflower oil diet supplemented with 5% of sunflower oil (20% starch, 7.6% crude fat), and a high-starch plus sunflower oil diet (33% starch, 7.3% crude fat). Five hours after feeding, proportions of trans-11 BH isomers greatly increased in the rumen content with the addition of sunflower oil, without change in ruminal pH compared with the control diet. Addition of starch to the control diet had no effect on BH pathways but decreased ruminal pH. The addition of a large amount of starch in association with sunflower oil increased trans-10 FA at the expense of trans-11 FA in the rumen content, revealing a trans-11 to trans-10 shift. Interestingly, with this latter diet, ruminal pH did not change compared with a single addition of starch. This trans-11 to trans-10 shift occurred progressively, after a decrease in the proportion of trans-11 FA in the rumen, suggesting that this shift could result from a dysbiosis in the rumen in favor of trans-10-producing bacteria at the expense of those producing trans-11 or a modification of bacterial activities

Role of physiological ClC-1 Cl- ion channel regulation for the excitability and function of working skeletal muscle.

Electrical membrane properties of skeletal muscle fibers have been thoroughly studied over the last five to six decades. This has shown that muscle fibers from a wide range of species, including fish, amphibians, reptiles, birds, and mammals, are all characterized by high resting membrane permeability for Cl(-) ions. Thus, in resting human muscle, ClC-1 Cl(-) ion channels account for ∼80% of the membrane conductance, and because active Cl(-) transport is limited in muscle fibers, the equilibrium potential for Cl(-) lies close to the resting membrane potential. These conditions-high membrane conductance and passive distribution-enable ClC-1 to conduct membrane current that inhibits muscle excitability. This depressing effect of ClC-1 current on muscle excitability has mostly been associated with skeletal muscle hyperexcitability in myotonia congenita, which arises from loss-of-function mutations in the CLCN1 gene. However, given that ClC-1 must be drastically inhibited (∼80%) before myotonia develops, more recent studies have explored whether acute and more subtle ClC-1 regulation contributes to controlling the excitability of working muscle. Methods were developed to measure ClC-1 function with subsecond temporal resolution in action potential firing muscle fibers. These and other techniques have revealed that ClC-1 function is controlled by multiple cellular signals during muscle activity. Thus, onset of muscle activity triggers ClC-1 inhibition via protein kinase C, intracellular acidosis, and lactate ions. This inhibition is important for preserving excitability of working muscle in the face of activity-induced elevation of extracellular K(+) and accumulating inactivation of voltage-gated sodium channels. Furthermore, during prolonged activity, a marked ClC-1 activation can develop that compromises muscle excitability. Data from ClC-1 expression systems suggest that this ClC-1 activation may arise from loss of regulation by adenosine nucleotides and/or oxidation. The present review summarizes the current knowledge of the physiological factors that control ClC-1 function in active muscle