[The ability of saprotrophic bacteria isolated from natural habitats to lyse yeasts]. / Drozhzheliticheskie svoistva saprotrofnykh bakterii iz prirodnykh mestoobitanii.

More than 600 bacterial strains isolated from different horizons of steppe biogeocenoses and zoogenous loci (diplopod intestines and feces) were tested for the ability to lyse yeast cell walls. About half of the strains that were isolated from biotopes with active degradation of plant debris (steppe litters and diplopod intestines and feces) were found to possess yeast-lytic activity. Most of the yeast-lytic strains belonged to the genera Streptomyces, Promicromonospora, Oerskovia, and Agromyces. The yeast-lytic activity of actinobacteria from the genera Agromyces, Mycobacterium, and Micrococcus has not previously been reported.

[Alkalitolerant yeasts from natural biotopes]. / Alkalotolerantnye drozhzhi iz prirodnykh biotopov.

Using a solid nutrient medium containing alkaline buffer (pH 10) and an antibiotic, alkalitolerant yeasts were isolated from samples of soda-rich saline soils (solonchaks) of Armenia (Arazdayan) and the Transbaikal Region (the Kungur Steppe). The species diversity of the yeast populations of the tested soda-rich soils was relatively insignificant. They only contained alkalitolerant representatives of asporogenic capsulated yeasts belonging to the species Cryptococcus laurentii, C. albidus, Rhodotorula glutinis, R. mucilaginosa, and Sporobolomyces roseus. C. laurentii representatives clearly dominated the isolates obtained, their number exceeding that of the other species by 2-3 orders of magnitude. All of the isolates grew on acidic wort agar, suggesting that they did not include obligate alkaliphiles.

[Mrakia curviuscula sp. Nov.--a new species of psychrophilic yeasts from forest substrates]. / Mrakia curviuscula sp. Nov.--novyi vid psikhrofil'nykh drozhzhei iz lesnykh substratov.

Seven strains with similar characteristics from the laboratory collection of yeasts isolated from forest substrates collected in the central part of European Russia corresponded to none of the known yeast species. Based on the study of their life cycle, physiological characteristics, and the nucleotide composition of DNA and taking into account the data of PCR analysis with universal primers, the strains were ascribed to a new psychrophilic yeast species, Mrakia curviuscula sp. nov.

[Molecular-genetic analysis of the yeast Komagataea (williopsis) pratensis populations from Caucasian and Tien Shan regions]. / Molekuliarno-geneticheskii analiz populiatsii drozhzhei Komagataea (williopsis) pratensis Kavkaza i Tian'-Shania.

The analysis of sixteen Komagataea (Williopsis) pratensis from the Caucasian and Tien Shan soils by the PCR, blot hybridization, and isoenzyme electrophoresis techniques showed that fifteen of them do belong to the species K. pratensis. The isolates from the two geographic areas differed in some physiological characteristics and in the PCR product profiles obtained with the microsatellite primers (CAC)5 and (GACA)4.

[Identification of Zygowillopsis californica strains of various origin by polymerase chain reaction with universal primers]. / Identifikatsiia shtammov Zygowillopsis californica raznogo proiskhozhdenia na osnove polimeraznoi tsepnoi reaktsii s uiversal'nymi praimerami.

After reevaluation of the taxonomic position of 27 yeast collection strains of different origin by UP-PCR followed by dot-hybridization, only 22 strains were assigned to the biological species Zygowilliopsis californica (Lodder) Kudriavzev. Four strains were identified as Williopsis suaveolens (Klöcker) Naumov et al. Universal primers L45 and N21 are recommended for identification of the Z. californica yeasts.

[A new yeast species Candida anutae sp.nov. from the fruiting bodies of agaricus]. / Novyi vid drozhzhei Candida anutae sp.nov. iz plodovykh tel agarikovykh gribov.

Among the yeasts isolated from the fruiting bodies of different species of agarics picked in forests near Moscow and Turku (Finland) in 1995-1998, populations of an earlier unknown species, morphologically similar to Metschnikowia lunata but differing from it by physiological characteristics and the absence of asci with spores, were constantly found. Description of the new species is given within the genus Candida Berkhout.

[Discrimination of the soil yeast species Williopsis saturnus and Williopsis suaveolens by the polymerase chain reaction using nonspecific primers]. / Differentsiatsiia pochvennykh drozhzhei Williopsis saturnus i Willi opsis suaveolens metodom polimeraznoi tsepnoi reaktsii s nespetsifichnymi praimerami.

Thirty-five yeast strains of the genus Williopsis, analyzed by the polymerase chain reaction with the universal primer N21, were found to belong to two sibling species, W. saturnus and W. suaveolens. Such affiliation of the strains studied agrees well with the results of genetic and physiological investigations.

[A new species of psychrophilic basidiomycetes yeast Leucosporidium fasciculatum sp. Nov]. / Novyi vid psikhrofil'nykh bazidiomitsetovykh drozhzhei Leucosporidium fasciculatum sp. Nov.

A psychrophilic yeast with a basidiomycetous developmental cycle and properties corresponding to the genus Leucosporidium Fell et al. was isolated from the fruiting body of the edible spring mushroom Gyromitra esculenta Pers. picked near Moscow. However, the isolate differed from all Leucosporidium species described to date in a number of characteristics. The results of the study of the developmental cycle and of the cultural, morphological, physiological, and biochemical properties of the new isolate, strain KBP Y-3696, allow it to be assigned to a new species of the genus Leucosporidium.

[Phenylalanine ammonia-lyase of pigmented yeasts]. / O fenilalanin-ammiak-liaze pigmentnykh drozhzhei.

116 pigmented yeast cultures were tested for the presence of L-phenylalanine-ammonia lyase transforming L-phenylalanine into trans-cinnamic acid. The enzyme was found in 54 strains. Most of these strains belonged to the genera Rhodotorula and Sporobolomyces. Toluene, along with acetone, was successfully used to increase cellular permeability of the yeast cultures while determining the activity of phenylalanine-ammonia lyase.

[Optimization of the medium for the yeast synthesis of biotin]. / Optimizatsiia sredydlia obrazovaniia biotina drozhzhami.

In order to increase the yield of biotin produced by the culture Sporobolomyces pararoseus, the medium containing sucrose, asparagine, MgSO4 (NH4)2SO4, KH2PO4, vitamin complex and trace elements was optimized. With the aid of a fractional factor experiment (2(5-1)) and a complete factor experiment (2(4)), the proportion of constituents was chosen in such a way as to double biotin yield, i.e. to increase it to 55.25 micrograms/l. An enrichment of the medium with yeast autolysate, casein hydrolysate and peptone in the presence of adenine increased biotin yield to 105.7 micrograms/l and cell productivity from 6.1 to 8.0 micrograms/l dry biomass.

[Microbial cenosis in the initial stage of spruce needle decomposition]. / Mikrobnoe soobshchestvo v nachal'noi stadii razlozheniia khvoia eli.

The formation of saprophytic microbial cenosis at the primary stage of decomposition of spruce needles was studied by the method of scanning electron microscopy with parallel inoculations into growth media. The composition of the cenosis was found to differ depending on whether the needles were decomposed on the surface of the forest floor or on the soil without any flooring. The characteristics of the formation of the saprophytic microbial cenosis are described. The cenosis is formed from individual species of the soil microbial complex and from some representatives of the epiphytic microbial cenosis which change here becoming saprophytes instead of biotrophs. Yeasts and yeast-like organisms predominate at the primary stage of decomposition of spruce needles.

[Extracellular polysaccharides and the taxonomy of yeasts of the genus Lipomyces]. / Vnekletochnye polisakharidy i taksonomiia drozhzhei roda Lipomyces.

Variations in the composition of extracellular polysaccharides in Lipomyces spp. are discussed in terms of the species differentiation within the genus. Extracellular polymers of certain mycelial lower ascomycetes (Dipodascopsis uninucleata, Dipodascus spp., Endomyces magnusii) were found to be similar, this suggesting a relationship between these organisms.

[Isolated water in desiccated microorganisms]. / Ob izolirovannoi vode v vysushennykh mikroorganizmakh.

The presence of isolated mobile water in dehydrated eukaryotic microorganisms established earlier by NMR has been confirmed by direct chemical registration of this water in the yeast Cryptococcus albidus. This water constitutes several per cent of the dry biomass weight. Apparently, its preservation should be attributed to changes in the permeability of intracellular membranes upon dehydration. The water is released by the cells when they are heated to 150--200 degrees C and the cellular structures containing water are destroyed.

[Growth of epiphytic and soil yeasts on wheat seedlings]. / Razvitie épifitnykh i pochvennykh drozhzhei na prorostkakh pshenitsy.

Colonization of wheat seedlings by epiphytic (Rhodotorula glutinis) and soil (Lipomyces starkeyi) yeasts was studied by scanning electron microscopy. Epiphytic yeast cells dominated on the plant surface. Soil yeast cells were randomly distributed among both the zones of a seedling and the particles of an inorganic substrate. It has been found that epiphytic yeast strains can readily grow on the surface of a plant.