Search results for "Lip"

Stabilization of an enzymatic extract from Penicillium camemberti containing lipoxygenase and hydroperoxide lyase activities

2008

International audience; The stabilization of an enzymatic extract, obtained from Penicillium camemberti containing lipoxygenase (LOX) and hydroperoxide lyase (HPL) activities, was investigated using selected additives. Although the addition of KCl (86%, w/w) to the enzymatic extract decreased slightly (7%) the LOX activity, it increased HPL activity by 2.25 fold; however, the addition of dextran resulted in the inactivation of both enzymatic activities. The stability of the solid lyophilized enzymatic extract was greater in the presence of KCl than that without it, with ∼100% residual activity after 8 and 4 weeks of storage at −80 °C, for LOX and HPL, respectively. The rate constants of ina…

Possible amphi-Atlantic dispersal of Scyllarus lobsters (Crustacea: Scyllaridae): molecular and larval evidence

2017

14 pages, 6 figures, 1 table

2021

Social insects are hosts of diverse parasites, but the influence of these parasites on phenotypic host traits is not yet well understood. Here, we tracked the survival of tapeworm-infected ant workers, their uninfected nest-mates and of ants from unparasitized colonies. Our multi-year study on the ant Temnothorax nylanderi, the intermediate host of the tapeworm Anomotaenia brevis, revealed a prolonged lifespan of infected workers compared with their uninfected peers. Intriguingly, their survival over 3 years did not differ from those of (uninfected) queens, whose lifespan can reach two decades. By contrast, uninfected workers from parasitized colonies suffered from increased mortality comp…

Natural colorants improved the physicochemical and sensorial properties of frozen Brazilian sausage (linguiça) with reduced nitrite

2020

Made available in DSpace on 2021-06-25T12:18:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01. Added 1 bitstream(s) on 2021-07-15T15:05:51Z : No. of bitstreams: 1 S0103-90162021000300902.pdf: 246305 bytes, checksum: 130e2a2703383287ec0721e788c1b83e (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) The use of natural colorants in meat products can keep its coloring attractive as well as meet the demand from consumers interested in products that are healthier. Nitrite is added as a preservative to these products and it is also a precursor of the generation of a specifically desired color in meat products. However, its use has been associated with the dev…

Ergosterol elicits oxidative burst in tobacco cells via phospholipase A2 and protein kinase C signal pathway

2004

Ergosterol, a typical fungal sterol, induced in tobacco (Nicotiana tabacum L. cv. Xanthi) suspension cells the synthesis of reactive oxygen species and alkalization of the external medium that are dependent on the mobilization of calcium from internal stores. We used specific inhibitors to elucidate the signal pathway triggered by ergosterol compared with cryptogein, a proteinaceous elicitor of Phytophthora cryptogea. HerbimycinA and genistein, inhibitors of tyrosine protein kinases, had no effect on the oxidative burst and pH changes induced by bothelicitors.Similarly,H-89,aninhibitorofproteinkinaseA,hadnoeffectontheinductionofthesedefensereactions.However,theresponse to both elicitors was…

Cytosolic calcium rises and related events in ergosterol-treated Nicotiana cells

2011

International audience; The typical fungal membrane component ergosterol was previously shown to trigger defence responses and protect plants against pathogens. Most of the elicitors mobilize the second messenger calcium, to trigger plant defences. We checked the involvement of calcium in response to ergosterol using Nicotiana plumbaginifolia and Nicotiana tabacum cv Xanthi cells expressing apoaequorin in the cytosol. First, it was verified if ergosterol was efficient in these cells inducing modifications of proton fluxes and increased expression of defence-related genes. Then, it was shown that ergosterol induced a rapid and transient biphasic increase of free [Ca2þ]cyt which intensity dep…

Co-inertia multivariate approach for the evaluation of anthropogenic impact on two commercial fish along Tyrrhenian coasts

2019

Abstract Aliphatic hydrocarbon levels were determined by the GC/MS technique in fish livers of Engraulis encrasicolus (Ee) and Trachurus trachurus (Tt), collected from a particular area of the Mediterranean Sea, called GSA 10, which is located exactly in Tyrrhenian Sea between Campania coast and North Sicily coast. The aim was to evaluate their potential use as specific bioindicators towards this class of contaminants. Both Tt and Ee are considered to be pollution monitoring bioindicators, due to their dominance in marine communities and economic fishing interest. Ee showed a higher tendency to bioaccumulate TAHs, due to the lower quantity of fatty acids in liver tissues with respect to Tt.…

Effect of acyl-CoA oxidase activity on the accumulation of gamma-decalactone by the yeast Yarrowia lipolytica: a factorial approach.

2007

International audience; beta-Oxidation is a cyclic pathway involved in the degradation of lipids. In yeast, it occurs in peroxisomes and the first step is catalyzed by an acyl-CoA oxidase (Aoxp). The yeast Yarrowia lipolytica possesses several genes (POX) coding for Aoxps. This study is based on the factorial analysis of results obtained with the many POX derivative strains that have been constructed previously. The effect of interactions between Aoxps on the acyl-CoA oxidase (Aox) activity was important even at the second order. We then investigated the effect of Aox activity on growth and lactone production. Aox activity was correlated with acidification of the medium by cells and with ce…

An air-lift biofilm reactor for the production of γ-decalactones by Yarrowia lipolytica

2014

Decalactones are interesting flavouring compounds that can be produced from ricinoleic acid. In this study, the production of lactones in biofilms using Yarrowia lipolytica is investigated. The hydrophobia of cells increased for increased aeration rates resulting in higher adhesion when the reactor wall was hydrophobic (plastic). To increase adhesion, sheets of methyl-polymethacrylate (PMMA) were added in the reactor and the production of lactones increased with the surface of plastic added, reaching 850 mg/L of 3-hydroxy-γ-decalactone for 60 cm2. In an Airlift bioreactor made of PMMA, biofilms were present at the top of the reactor for increased aeration. In the meantime, a metabolic shift…

Production of 3-hydroxy-γ-decalactone, the precursor of two decenolides with flavouring properties, by the yeast Yarrowia lipolytica

2009

3-Hydroxy-γ-decalactone is the precursor of dec-2 and dec-3-en-4-olides which are valuable aroma compounds not yet produced. To promote the accumulation of this lactone, the yeast Yarrowia lipolytica was placed in different environmental conditions aiming at altering β-oxidation fluxes. The concentration of substrate, pH, aeration and dissolved oxygen level were modified. We observed an important accumulation at low aeration (0.40 molar yields) and, to a lesser extent, at lower pH (0.15). As oxygen played a key-role, we evaluated its effect at fixed dissolved oxygen and at the pH which was the most favourable to the biotransformation (pH 4.5). At 5% and 30% dissolved oxygen, yields reached …