Vergleichende Untersuchungen von Mosten und Weinen aus gesunden und aus Botrytis-infizierten Traubenbeeren

II. Modellversuche zur Veränderung des Mostes durch Botrytis-Infektion und ihre Konsequenzen für die Nebenproduktbildung bei der GärungDie vorliegenden Untersuchungen sollten die Frage klären, ob die hohe Pyruvat- und Ketoglutaratbildung bei der Vergärung edelfauler Moste und die u. a. von ihr ausgehende hohe SO2-Bindung von Auslesen verursacht wird vom hohen Zukkergehalt, vom Aminosäure- bzw. Stickstoffmangel oder vom geringen ThiaminGehalt dieser Moste.Hierzu wurde Mostnormal belassen,einem Botrytis-Bewuchs unterworfen,kationenarm gemacht,um die erwartete Botrytis-Wirkung zu simulieren, insbesondere einen Aminosäure- und Thiamin-Mangel zu erzeugen. Die so hergestellten Varianten wurden jeweilsa) ohne Zusatz,b) nach Zusatz eines Aminosäurengemisches,c) nach Zusatz von Ammonium-Ionen vergoren.Alle diese Varianten wurden außerdem mit 0,5 mg Thiamin/l angereichert und danach vergoren. Die Analyse der S02-bindenden Hefe-Stoffwechselprodukte ergab bei den Botrytis-bewachsenen und den kationenverarmten Proben eine sehr starke Pyruvat- und Ketoglutaratbildung, wie sie auch schon von uns bei der Vergärung edelfauler Moste beobachtet worden war. Der Anstau dieser Metaboliten wird vom Stickstoffgehalt nicht beeinflußt. Allein von Thiamin wird er in jedem Falle auf eine normale Konzentration verringert.Dieses Ergebnis beweist, daß das hohe SO2 -Bedürfnis von Weinen aus Botrytisinfizierten Beeren zu einem wesentlichen Teil eine Folge des gestörten Stoffwechsels der Hefe bei der Vergärung dieser Moste ist. Ursache dieser Stoffwechselstörung ist die Thiamin-Verarmung des Beeren-Inhaltes durch Botrytis. Die Hefe in solchen Mosten kann infolge ihres Thiamin-Defizits die Thiamin-abhängige Decarboxylierung ihrer Metaboliten Pyruvat und Ketoglutarat nicht normal vollziehen. Beide SO2 -bindenden Hefestoffwechselprodukte stauen sich daher in hohen Konzentrationen an, die ein Mehrfaches dieser Werte bei normalen Jungweinen betragen können. 0,5 mg Thiamin/! normalisieren diese Stoffwechselstörung der Hefe und die von ihr ausgehende erhöhte SO2 -Bindung von Weinen aus edelfaulem Lesegut.   Comparative investigations on musts and wines from healthy and ,Botrytis-infestedgrape-berries. II. Pattern tests on changing of musts by Botrytis infestion and their consequences for the production of by-products of fermentationDuring the fermentation of "noble rotten" musts (musts from Botrytis-infested grapes) the production of pyruvic acid and ketoglutaric acid is significantly increased, which causes high SO2 binding. Investigations were performed to clarify whether this process is due to the high sugar concentration, a deficiency of amino acids or nitrogen, or to the low thiamine content of these musts.Therefore, samples of must were treated as follows:a) unadulterated,b) infested by Botrytis,c) treated with cation exchanger in order to simulate the presumed effect of Botrytisand, particularly, to cause a deficiency of amino acids and thiamine. These variants were fermenteda) without additives,b) after addition of an amino acid mixture,c) after addition of ammonium-ions.Besides, all these variants were fermented with a dose of 0,5 mg thiamine/l. The analysis of the so. binding metabolites showed a very high formation of pyruvic acid and ketoglutarlc acid in Botrytis-infested samples and in the cationdepleted ones, as already observed in fermented musts with "noble rot". The accumulation of these metabolites is independent of the nitrogen content. In any case, it is diminished to a normal concentration only by thiamine.The result proves that the high requirement of SO2, in wines made from Botrytisinfested grapes is essentially caused by the disturbed metabolism of yeasts during the fermentation of these musts. This disturbance is due to the thiamine depletion in grapes by Botrytis. Owing to this deficiency, the yeast in these musts cannot perform the normal decarboxylation of its metabolites pyruvic acid and ketoglutaric acid. Therefore, both SO2 binding metabolites build up to high concentrations which can amount to a multiple of the quantity found in normal young wines. A dose of 0,5 mg thiamine/1 normalizes the metabolism of the yeasts and, in consequence of this process, the increase in SO2 binding in wines made from Botrytis-infested material

Influence of phenolic acids on growth and inactivation of Oenococcus oeni and Lactobacillus hilgardii

Aims: To determine the effect of several wine-associated, phenolic acids on the growth and viability of strains of Oenococcus oeni and Lactobacillus hilgardii. Methods and Results: Growth was monitored in ethanol-containing medium supplemented with varying concentrations of hydroxybenzoic acids (p-hydroxybenzoic, protocatechuic, gallic, vanillic and syringic acids) and hydroxycinnamic acids (p-coumaric, caffeic and ferulic acids). Progressive inactivation was monitored in ethanolcontaining phosphate buffer supplemented in a similar manner to the growth experiments. Hydroxycinnamic acids proved to be more inhibitory to the growth of O. oeni than hydroxybenzoic acids. On the other hand, some acids showed a beneficial effect on growth of Lact. hilgardii. p-Coumaric acid showed the strongest inhibitory effect on growth and survival of both bacteria. Conclusions: Most phenolic acids had a negative effect on growth of O. oeni, for Lact. hilgardii this effect was only noted for p-coumaric acid. Generally, O. oeni was more sensitive to phenolic acid inactivation than Lact. hilgardii. Significance and Impact of the Study: Eight wine-derived, phenolic acids were compared for their effects on wine lactic acid bacteria. Results indicate that phenolic acids have the capacity to influence growth and survival parameters. The differences found between phenolic compounds could be related to their different chemical structures

Search for composite and exotic fermions at LEP 2

A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172 GeV and 161 GeV. The search for pair-produced new leptons establishes 95% confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio

Search for lightest neutralino and stau pair production in light gravitino scenarios with stau NLSP

Promptly decaying lightest neutralinos and long-lived staus are searched for in the context of light gravitino scenarios. It is assumed that the stau is the next to lightest supersymmetric particle (NLSP) and that the lightest neutralino is the next to NLSP (NNLSP). Data collected with the Delphi detector at centre-of-mass energies from 161 to 183 \GeV are analysed. No evidence of the production of these particles is found. Hence, lower mass limits for both kinds of particles are set at 95% C.L.. The mass of gaugino-like neutralinos is found to be greater than 71.5 GeV/c^2. In the search for long-lived stau, masses less than 70.0 to 77.5 \GeVcc are excluded for gravitino masses from 10 to 150 \eVcc . Combining this search with the searches for stable heavy leptons and Minimal Supersymmetric Standard Model staus a lower limit of 68.5 \GeVcc may be set for the stau mas

Procalcitonin for diagnosis of infection and guide to antibiotic decisions: past, present and future

There are a number of limitations to using conventional diagnostic markers for patients with clinical suspicion of infection. As a consequence, unnecessary and prolonged exposure to antimicrobial agents adversely affect patient outcomes, while inappropriate antibiotic therapy increases antibiotic resistance. A growing body of evidence supports the use of procalcitonin (PCT) to improve diagnosis of bacterial infections and to guide antibiotic therapy. For patients with upper and lower respiratory tract infection, post-operative infections and for severe sepsis patients in the intensive care unit, randomized-controlled trials have shown a benefit of using PCT algorithms to guide decisions about initiation and/or discontinuation of antibiotic therapy. For some other types of infections, observational studies have shown promising first results, but further intervention studies are needed before use of PCT in clinical routine can be recommended. The aim of this review is to summarize the current evidence for PCT in different infections and clinical settings, and discuss the reliability of this marker when used with validated diagnostic algorithms

Measurements of the leptonic branching fractions of the τ\tau

Data collected with the DELPHI detector from 1993 to 1995 combined with previous DELPHI results for data from 1991 and 1992 yield the branching fractions B({\tau \rightarrow \mbox{\rm e} \nu \bar{\nu}}) = (17.877 \pm 0.109_{stat} \pm 0.110_{sys} )\% and $B({\tau \rightarrow \mu \nu \bar{\nu}}) = (17.325 \pm 0.095_{stat} \pm 0.077_{sys} )\%$

Search for scalar fermions and long-lived scalar leptons at centre-of-mass energies of 130 GeV to 172 GeV

Data taken by DELPHI during the 1995 and 1996 LEP runs have been used to search for the supersymmetric partners of electron, muon and tau leptons and of top and bottom quarks. The observations are in agreement with standard model predictions. Limits are set on sfermion masses. Searches for long lived scalar leptons from low scale supersymmetry breaking models exclude stau masses below 55~GeV/c$^2$ at the 95\% confidence level, irrespective of the gravitino mass

Measurement of the Quark and Gluon Fragmentation Functions in Z0Z^0 Hadronic Decays

The fragmentation functions and multiplicities in $b\overline{b}$ and light quark events are compared. The measured transverse and longitudinal components of the fragmentation function allow the gluon fragmentation function to be evaluated

Investigation of the splitting of quark and gluon jets

The splitting processes in identified quark and gluon jets are investigated using longitudinal and transverse observables. The jets are selected from symmetric three-jet events measured in Z decays with the Delphi detector in 1991-1994. Gluon jets are identified using heavy quark anti-tagging. Scaling violations in identified gluon jets are observed for the first time. The scale energy dependence of the gluon fragmentation function is found to be about two times larger than for the corresponding quark jets, consistent with the QCD expectation TeX . The primary splitting of gluons and quarks into subjets agrees with fragmentation models and, for specific regions of the jet resolution TeX , with NLLA calculations. The maximum of the ratio of the primary subjet splittings in quark and gluon jets is TeX . Due to non-perturbative effects, the data are below the expectation at small TeX . The transition from the perturbative to the non-perturbative domain appears at smaller TeX for quark jets than for gluon jets. Combined with the observed behaviour of the higher rank splittings, this explains the relatively small multiplicity ratio between gluon and quark jets