0000000000522860
AUTHOR
Inge Schönig
Fermentation of gluconic acid by lactic acid bacteria isolated from wine
Insgesamt 116 verschiedene, uberwiegend aus Wein isolierte Stamme von Milchsaure-bakterien der GattungenLactobacillus, Leuconostoc, Pediococcus undStreptococcus wurden auf die Fahigkeit zur Verwertung von Gluconsaure untersucht. Bis auf einzelne Ausnahmen wurde Gluconsaure von denLactobacillus-Arten, die den UntergattungenStreptobacterium undBetabacterium angehorten, und der Mehrzahl derLeuconostoc-Stamme vergoren. VonPediococcus wurde Gluconsaure nicht abgebaut. Bei wachsenden Kulturen und ruhenden Zellen vonLactobacillus brevis, Lactobacillus casei undLeuconostoc oenos waren die Endprodukte des Gluconsaureabbaus Milchsaure, Essigsaure, Athanol und CO2. Milchsaure entsteht aus Gluconsaure …
Investigation of a Killer Strain of Zygosaccharomyces Bailii
Summary: The yeast Zygosaccharomyces bailii strain 412 was found to liberate a killer toxin (KT412) lethal to sensitive strains of Saccharomyces cerevisiae and Candida glabrata. Culture supernatants of the killer strain were concentrated by ultrafiltration and the extracellular protein was purified by gel filtration and ion-exchange chromatography. Gel filtration and SDS-PAGE of the electrophoretically homogeneous killer protein indicated an apparent molecular mass of 10 kDa. The killer toxin KT412 is probably not glycosylated since it did not show any detectable carbohydrate structures. KT412 was bound to sensitive but not to resistant yeast cells. The mannan, and not the glucan, fraction …
In vitro and in vivo sulfate reduction in the gut contents of the termite Mastotermes darwiniensis and the rose-chafer Pachnoda marginata.
Sulfate-reducing bacteria (SRB) from termites have been assigned to the genus Desulfovibrio. Desulfovibrio intestinalis lives in the gut of the Australian termite Mastotermes darwiniensis. For the first time we were able to enrich and identify a sulfate-reducing bacterium from the gut of the rose-chafer Pachnoda marginata, which showed the highest 16S rDNA sequence identity (93%) to Desulfovibrio intestinalis and Desulfovibrio strain STL1. Compared to Mastotermes darwiniensis (1x10(7) cells of SRB per ml gut contents), sulfate-reducing bacteria occurred in higher numbers in the gut contents of Pachnoda marginata reaching cell titers of up to 2x10(8) cells per ml gut contents. In vitro sulfa…
Aerobic and facultatively anaerobic cellulolytic bacteria from the gut of the termite Zootermopsis angusticollis.
Aims: To demonstrate the occurrence of cellulolytic bacteria in the termite Zootermopsis angusticollis. Methods and Results: Applying aerobic cultivation conditions we isolated 119 cellulolytic strains from the gut of Z. angusticollis, which were assigned to 23 groups of aerobic, facultatively anaerobic or microaerophilic cellulolytic bacteria. 16S rDNA restriction fragment pattern and partial 16S rDNA sequence analysis, as well as numerical taxonomy, were used for the assignment of the isolates. The Gram-positive bacteria of the actinomycetes branch could be assigned to the order Actinomycetales including the genera Cellulomonas/Oerskovia, Microbacterium and Kocuria. The Gram-positive bact…
Fast protocols for the 5S rDNA and ITS-2 based identification ofOenococcus oeni
To identify specific marker sequences for the rapid identification of Oenococcus oeni, we sequenced the 23S-5S internal transcribed spacer (ITS-2) region and the 5S rDNA of five different O. oeni strains and three phylogenetically related lactic acid bacteria (LAB). Comparative analysis revealed 100% identity among the ITS-2 region of the O. oeni strains and remarkable differences in length and sequence compared to related LAB. These results enabled us to develop a primer set for a rapid PCR-identification of O. oeni within three hours. Moreover, the comparison of the 5S rDNA sequences and the highly conserved secondary structure provided the template for the design of three fluorescence-la…
Cell cycle studies on the mode of action of yeast K28 killer toxin.
The virally encoded K28 killer toxin of Saccharomyces cerevisiae kills sensitive cells by a receptor-mediated process. DNA synthesis is rapidly inhibited, cell viability is lost more slowly and cells eventually arrest, apparently in the S phase of the cell cycle with a medium-sized bud, a single nucleus in the mother cell and a pre-replicated (1n) DNA content. Cytoplasmic microtubules appear normal, and no spindle is detectable. Arrest of a sensitive haploid yeast strain by alpha-factor at START gave complete protection for at least 4 h against a toxin concentration that killed non-arrested cells at the rate of one log each 2.5 h. Cells released from alpha-factor arrest were killed by toxin…