Effect of a Killer Toxin of Yeast on Eucaryotic Systems

The Saccharomyces cerevisiae killer toxin KT 28, which inhibits sensitive yeasts, was shown to have no effect on several pathogenic fungi or on the protozoan Trichomonas vaginalis. At concentrations of about 0.1 mg/ml, a partial inhibition of the skin pathogenic fungi Trichophyton rubrum and Microsporum canis was observed at pH 6.5. No pharmacological activity was detected in various tests with several animal organs.

Termite Gut Symbiotic Archaezoa Are Becoming Living Metabolic Fossils

ABSTRACT Over the course of several million years, the eukaryotic gut symbionts of lower termites have become adapted to a cellulolytic environment. Up to now it has been believed that they produce nutriments using their own cellulolytic enzymes for the benefit of their termite host. However, we have now isolated two endoglucanases with similar apparent molecular masses of approximately 36 kDa from the not yet culturable symbiotic Archaezoa living in the hindgut of the most primitive Australian termite, Mastotermes darwiniensis . The N-terminal sequences of these cellulases exhibited significant homology to cellulases of termite origin, which belong to glycosyl hydrolase family 9. The corre…

Pyroglutamic Acid: A Novel Compound in Wines

Wine contains a complex mixture of nearly 1,000 compounds, which include sugars, acids, alcohols, ketones, aldehydes, esters, amino acids, amines, phenol carbonic acids, flavonoids, anthocyanidins and cathechins. Many of these compounds have an influence on the aroma and bouquet of wine. Identification of wine-related compounds is by far not complete. Recently, pyroglutamic acid has been detected as a so far overlooked novel compound in wine samples, which is described below.

Properties of Halococcus salifodinae, an Isolate from Permian Rock Salt Deposits, Compared with Halococci from Surface Waters

Halococcus salifodinae BIpT DSM 8989T, an extremely halophilic archaeal isolate from an Austrian salt deposit (Bad Ischl), whose origin was dated to the Permian period, was described in 1994. Subsequently, several strains of the species have been isolated, some from similar but geographically separated salt deposits. Hcc. salifodinae may be regarded as one of the most ancient culturable species which existed already about 250 million years ago. Since its habitat probably did not change during this long period, its properties were presumably not subjected to the needs of mutational adaptation. Hcc. salifodinae and other isolates from ancient deposits would be suitable candidates for testing …

Degradation of diols and formation of ethylene glycol by different yeast species

Die mikrobielle Bildung von Ethylenglykol sowie der Abbau von Diolen durch Hefestamme verschiedener Gattungen wurde im synthetischen Medium und in Traubensaft untersucht. Diole (aber nicht Diethylenglykol) wurden von Arlen wieHansenula, Candida, Pichia undRhodotorula abgebaut. Von 40 uberpruften Hefen produzierten einzelne Stamme vonZygosaccharomyces bailii, Torulopsis ernobii undKluyveromyces veronae unter aeroben Bedingungen 70 bis 210 mg/l Ethylenglykol bei Zusatz von 400 mg/l Ethanolamin zum synthetischen Medium. Ohne Ethanolamin erzeugtenZ. bailii undT. ernobii im synthetischen Medium oder Traubensaft zwischen 7 bis 30 mg/l Ethylenglykol. Die Bildung von Ethylenglykol war bei aeroben K…

Immunochemical analysis of the carbohydrate moiety of yeast killer toxin K28

Killer toxin K28, a 16 kd protein secreted by the wine yeast Saccharomyces cerevisiae strain 28, was reversibly bound by a column of Concanavalin A-Sepharose, confirming its glycoprotein nature. HPLC analysis of acid hydrolyzates of K28 toxin as well as Western-blots of beta-eliminated and/or endo H-treated killer toxin preparations probed with polyclonal alpha-toxin antibodies revealed that the carbohydrate moiety of K28 consists of D-mannose only, which is O-glycosidically linked via Ser/Thr residues to the protein part. The change in gel mobility of K28 after beta-elimination was caused by a decrease in molecular mass of about 1,800, corresponding to a carbohydrate moiety of 10 mannose r…

Mikrobielle Synthese von Biopolymeren aus nachwachsenden Rohstoffen

Isolation of Desulfovibrio intestinalis sp. nov. from the hindgut' of the lower termite Mastotermes darwiniensis.

A Gram-negative, anaerobic sulfate-reducing bacterium was isolated from hindgut contents of the lower termite Mastotermes darwiniensis Froggatt (strain KMS2). Strain KMS2 is motile by a single polar flagellum. The isolate possesses desulfoviridin and catalase activity. The G+C content of its DNA is in the range of 54.5-55.5 mol% (strain KMS2). It respires hydrogen and different low molecular weight organic compounds in the presence of sulfate, thiosulfate, and sulfite, and also oxygen. The isolated strain ferments pyruvate. Fastest growth with a doubling time of 12.5 h was obtained at 37°C and not at 28°C, the temperature at which the termites were grown. The isolate showed a 16S rDNA seque…

Regulatory O 2 tensions for the synthesis of fermentation products in Escherichia coli and relation to aerobic respiration

In an oxystat, the synthesis of the fermentation products formate, acetate, ethanol, lactate, and succinate of Escherichia coli was studied as a function of the O2 tension (pO2) in the medium. The pO2 values that gave rise to half-maximal synthesis of the products (pO0. 5) were 0.2-0.4 mbar for ethanol, acetate, and succinate, and 1 mbar for formate. The pO0.5 for the expression of the adhE gene encoding alcohol dehydrogenase was approximately 0.8 mbar. Thus, the pO2 for the onset of fermentation was distinctly lower than that for anaerobic respiration (pO0.5/= 5 mbar), which was determined earlier. An essential role for quinol oxidase bd in microaerobic growth was demonstrated. A mutant de…

Hochleistungsfl�ssigchromatographische Bestimmung von organischen S�uren, Zuckern, Glycerin und Alkohol im Wein an einer Kationenaustauschers�ule

Mit der HPLC ist es moglich, die wichtigsten Bestandteile von Wein (Ethanol, Glycerin, Glucose, Fructose, Tartrat, Malat, Lactat, Succinat, Acetat und Citrat) in einem Lauf innerhalb von 25 min zu trennen und quantitativ zu bestimmen. Als stationare Phase dient der Kationenaustauscher HPX 87 H und als mobile Phase verdunnte Schwefelsaure. Die Untersuchungsergebnisse an einigen Weinen werden dargestellt. Es besteht eine gute Ubereinstimmung zwischen den Analysenergebnissen der HPLC und herkommlichen Methoden.[/p]

Manganese-dependent growth of Oenococci

Abstract Oenococci are usually grown in complex media supplemented with tomato juice. The manganese concentration of tomato juice is about 10 µM, which shows a growth-stimulating effect. Unexpectedly, we found that high concentrations of manganese (34 mM) could replace tomato juice. At this concentration, far exceeding the concentration in growth media, several Oenococcus oeni strains yielded the same cell density as in the presence of tomato juice. The observed significant differences in the manganese dependence should also have an impact on the growth of oenococci in must and wine, where they are used as starter cultures for the removal of malic acid.

Influence of epigallocatechin gallate and phenolic compounds from green tea on the growth of Oenococcus oeni

Aims:  To investigate the effect of phenolic compounds on the growth of Oenococcus oeni. Methods and Results:  Oenococci are usually grown in media often supplemented with complex additives such as tomato juice. In order to improve our knowledge about the growth requirements of oenococci, we added several juices and leaf extracts such as green tea to the culture media and screened them for growth-stimulating substances to substitute complex supplements such as juices by more defined components. We found that also green tea could cause a growth stimulation of Oenococcus oeni strain B2. Conclusions:  Further experiments showed that the stimulating effect was as a result of the phenolic compou…