Search results for "Malic acid"
showing 10 items of 41 documents
A novel culture medium for Oenococcus oeni malolactic starter production
2015
Malolactic fermentation is essential in wine quality. One of the strategies used to control this fermentation involves the inoculation of selected lactic acid bacteria, mainly Oenococcus oeni. Laboratory media usually produce large amounts of biomass, but with little or no adaptability to wine. We propose a culture medium to grow and pre-adapt O. oeni cells, and the steps to scale-up production. To achieve this objective, 27 different media were tested. All contained grape must and wine, and nutritional supplements in order to benefit bacterial growth. Those media contained different ethanol levels, pH values, and grape must concentrations. The optimized culture medium named Oenococcus Prod…
Formation of l(-)malate by Saccharomyces cerevisiae during fermentation
1988
When grown in a synthetic medium most of the 51 strains of the genera Saccharomyces, Saccharomycodes, Zygosaccharomyces and Schizosaccharomyces investigated formed l-malate during fermentation. The quantity varied between 0.1 and 2.6 g malate per liter. Two strains of Saccharomyces cerevisiae synthesized malate at a rate of about 1.5 g/l. Malate was liberated during the growth phase and not metabolized during the stationary phase. Optimum malate formation was observed at a sugar concentration of about 20% (w/v), at pH 5 and at suboptimal nitrogen concentrations of less than 300 mg N/liter. Of the amino acids aspartate and glutamate were most favourable. If ammonium salts were used as the ni…
�pfels�urestoffwechsel bei Saccharomyces
1973
1. Aus Saccharomyces cerevisiae St. 79 konnte durch Protamin-und Ammoniumsulfatfallung sowie durch Chromatographie an DEAE-Cellulose ein Malatenzym [l-Malat: NAD(P) Oxidoreduktase, decarboxylierend, E.C. 1.1.1.38 oder 40] angereichert und von Malat-Dehydrogenase (l-Malat: NAD Oxidoreduktase, E.C. 1.1.1.37) weitgehend abgetrennt werden. 2. Neben Mn++-Ionen benotigt das Malatenzym der Hefe NAD oder NADP, bei einem optimalen pH-Wert von 7,5. Es ist spezifisch fur l-Malat, d-Malat wird nicht umgesetzt. Die Enzympraparate decarboxylierten Oxalessigsaure bei Abwesenheit von NAD. 3. Die Km Werte von Malatenzym sind fur l-Malat 5 · 10-2 M, fur NAD 5 · 10-4 M und fur Mangan 1,4 · 10-4 M. 4. Ein Zusa…
Untersuchungen �ber die L-�pfels�ure-abbauenden Enzyme von Schizosaccharomyces acidodevoratus
1970
Der Abbau von L-Apfelsaure wird bei Schizosaccharomyces acidodevoratus von einer Malat-Dehydrogenase (EC 1.1.1.37) und einer Oxalacetat-Decarboxylase (EC 4.1.1.3) katalysiert. Stoffwechselprodukt ist Brenztraubensaure. Eine Pyruvat-Decarboxylase (EC 4.1.1.1) und Alkohol-Dehydrogenase (EC 1.1.1.1) wandeln die Brenztraubensaure in Alkohol und CO2 um. In einer Nebenreaktion entsteht Acetoin. Lactat-Dehydrogenase (EC 1.1.1.27) ist nicht nachweisbar.
Effect of Ti(IY) on some indicators of physiological activity inCapsicum annuum, L.
1994
SummaryPaprika pepper (Capsicum annuum, L., cv. Negral) plants grown in a greenhouse were supplied Ti(IV) ascorbate through the roots or through leaves. Biomass production, peroxidase (donor: H2O, oxidoreductase; EC 1.11.1.7) activity, and malic acid, starch and chlorophyll concentrations were determined in different plant organs. It was observed that Ti increased the concentration of some of the metabolites studied and promoted both peroxidase activity and biomass production. The profitable effect of the Ti treatments could occur because they enhance the availability of other nutrients. This effect could be due to the low redox potential of the Ti+3/Ti+4 system that catalyzes the activity …
Über den Abbau von L-Äpfelsäure durch Hefen verschiedener Gattungen mit Malatenzym
1974
Summary (1) The aerobic assimilation of malic acid is not a character of certain yeast genera or species as was shown by testing more than 300 different strains. Single strains of the following-species were found to grow on malic acid as the only carbon source: Candida pulcherrima, C. utilis, C. mycoderma, Torulopsis famata, Pichia membranaefaciens, P. wickerhamii, Hansenula capsulata, Trigonopsis variabilis , and Zygosaccharomyces chevalieri . (2) During fermentation C. pulcherrima and T. famata decompose up to 40% and C. utilis up to 80% of the L-malic acid that is present in the medium. (3) L-Malic acid is decomposed to CO 2 and the corresponding amounts of ethanol or pyruvate by cell fr…
Zum Abbau von 14C-markierter �pfels�ure durch Bacterium gracile
1962
Der Apfelsaureabbau durch B. gracile wird mit Hilfe 14C-markierter Sauren quantitativ untersucht. Die nach dem Abbau wiedergefundene Aktivitat in Restapfelsaure, Milchsaure und Kohlendioxyd betragt zusammen 96–97% der Aktivitat der eingesetzten dl-Apfelsaure-[1,4-14C2]. Die molaren Verhaltnisse von abgebauter Apfelsaure zu Milchsaure und Kohlendioxyd sind 1:1:0,9. Ein Weiterabbau der Apfelsaure uber Milchsaure hinaus ist zu verneinen, da in diesem Fall mehr Kohlendioxyd entstehen muste als dem Verhaltnis 1:1:1 entsprache. D-Apfelsaure und Fumarsaure werden von den Bakterien ebenfalls dissimiliert, Milchsaure wird nicht angegriffen. Citronensaure-[1,5-14C2] wird sehr langsam abgebaut; als ei…
Malic-Enzym-Synthese und pH-Adaptation bei L-�pfels�ure abbauenden Bakterien
1968
Es wird die Malic-Enzym-Synthese bei sechs verschiedenen Arten L-Apfelsaure abbauender Bakterien untersucht. Die homofermentativen Arten bilden unter den gepruften Bedingungen ausschlieslich ein adaptives Malic-Enzym, wahrend die Synthese bei den heterofermentativen in Abhangigkeit vom Zuchtungsmilieu adaptiv oder konstitutiv erfolgen kann. Beim konstitutiven Malic-Enzym ist der sonst positive Glucose-Effekt auf Aktivitat und Induktion nicht festzustellen, wie Versuche mit Enzymlosungen ergeben haben. Die pH-Maxima der Apfelsaureabbau-Aktivitat der intakten Bakterien verschieben sich bei Gewohnung der Zellen an hohere H+-Ionen-Konzentrationen im kunstlichen und naturlichen Milieu zu tiefer …
Characterization of Sicilian Olive Genotypes by Multivariate Analysis of Leaf and Fruit Chemical and Morphological Properties
2013
Leaf and fruit size and shape were measured and mannitol, glucose, sucrose and malic acid were quantified in leaf, bark and fruit of 25 Sicilian olive genotypes. Multivariate analysis was used to individuate groups with similar chemical composition and morphological traits suggesting potential for stress tolerance and/or oil yield and quality. Mannitol content varied greatly among genotypes and was the most abundant carbohydrate in leaf and bark, whereas glucose was the most abundant in fruit. Sucrose and malic acid were generally low indicating a marginal role in olive tissues. Mannitol and glucose were directly related in both leaf and fruit tissues. Genotypes also differed for carbohydra…
Effectiveness of a recent topical sialogogue in the management of drug-induced xerostomia
2011
Objectives: Use of certain drugs is the most common aetiology of xerostomia. Systemic sialogogues provide a longer effect than topic ones, but also induce relevant side effects. Topical sialogogues, as malic acid, allow a safe use as they induce no systemic side-effects or pharmacological interactions, being especially interesting in cases of mild hyposalivation and oral dryness, mainly the chronic use of xerostomizing drugs. The aim of this study was to evaluate the clinical effect of 1% malic acid in patients affected by xerostomia due to antihypertensives or antidepressants. Study Design: 10 patients with drug-induced xerostomia were prospectively evaluated before and after using malic a…