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The genetic relatedness of yeasts in the Saccharomyces bayanus complex has been studied using the methods of molecular and classical genetics. A divergent population of S. bayanus has been found in New Zealand and Australia. The S. bayanus complex includes four genetic populations: S. bayanus var. bayanus, S. bayanus var. uvarum, S. eubayanus, and the New Zealand population. The strains of the New Zealand population differ significantly in the nucleotide sequences of the nuclear (FSY1, HIS3, MET2) and mitochondrial (FUN14, COX2) genes and form semi-sterile hybrids with other populations: the viability of ascospores is 6.2–23.3%. There is no complete interspecific postzygotic isolation among S. bayanus var. bayanus, S. bayanus var. uvarum, S. eubayanus, and the New Zealand populations: all hybrids showed regular meiotic segregation of the control auxotrophic markers. According to the results obtained, the four genetic populations belong to the same biological species with genomic divergence at the level of taxonomic varieties. [ABSTRACT FROM AUTHOR]

According to the modern classification of yeasts, the species Kluyveromyces lactis includes two taxonomic varieties: cultural dairy yeast K. lactis var. lactis and nonlactose-fermenting environmental strains of K. lactis var. drosophilarum. This subdivision of the species, which is based only on phenotypic and ecological criteria, is formal and does not reflect the existing heterogeneity of K. lactis. Using various molecular methods and genetic hybridization analysis, we studied the genetic relationship of 35 K. lactis strains isolated from dairy products and environmental sources in different regions of the world. The lactose-fermenting yeasts K. lactis, including dairy strains, clinical and soil isolates, had identical molecular karyotypes, did not differ in the nucleotide sequences of a number of molecular markers, and formed fertile hybrids with 84–99% ascospore viability. On the other hand, nonlactose-fermenting yeasts split into three genetically isolated populations: "krassilnikovii," "drosophilarum," and "phaseolosporus," which differed in molecular karyotypes, had unique SNP substitutions in the ACT1 gene, and formed semisterile hybrids: 6–34% ascospore viability. Despite profound chromosome length polymorphism, K. lactis var. lactis, "krassilnikovii," "drosophilarum," and "phaseolosporus" probably have the same haploid number of chromosomes equal to six. The largest range of chromosome sizes was observed in "krassilnikovii" (1000–2900 kb), and the smallest in "drosophilarum" (1600–2200 kb). The biogeography of the yeast K. lactis is noteworthy. Lactose-fermenting strains of K. lactis var. lactis have been isolated in various regions of the world. Genetic "drosophilarum" and "phaseolosporus" populations are typical of North America, while "krassilnikovii" is represented by European and Central Asian isolates. Comparative analysis of the ACT1 sequences should be applied for reliable delineation of all four genetic populations of K. lactis. [ABSTRACT FROM AUTHOR]

Based on strains of various ecological and geographical origins, we studied intraspecific polymorphism of the wild yeast Kluyveromyces dobzhanskii, the closest relative of the cultured dairy yeasts K. lactis and K. marxianus. Using microsatellite typing, phylogenetic analysis of the nucleotide sequences of the ITS1/ITS2 internal transcribed spacers and of the mitochondrial gene COX2, we found the species K. dobzhanskii to be of complex composition, consisting of at least three geographical populations: North American (including the type culture CBS 2104), European, and Far Eastern. Strains of different geographic origin were characterized by unique nucleotide substitutions in the ITS1/ITS2 region and in the mitochondrial COX2 gene. In European strains, a correlation was revealed between the (GTG)5 profiles and the source of isolation. The strains isolated from insects in Spain had unique patterns. [ABSTRACT FROM AUTHOR]

The distribution and properties of the pectinase-encoding PGU genes in different species of Saccharomyces yeasts was studied. Application of molecular karyotyping and Southern hybridization revealed that S. arboricola, S. cariocanus, S. cerevisiae, S. kudriavzevii, and S. paradoxus species had a single PGU gene located on chromosome X. The other three species had polymeric PGU genes of different chromosomal localization: S. mikatae and S. jurei (chromosomes X and VIII), S. bayanus (X, I, and XIV). This is the first report on comparative analysis of the nucleotide and amino acid sequences of the PGU genes was carried out in all eight species of the genus Saccharomyces. Species-specificity of the PGU genes was revealed, as well as their intraspecific polymorphism in S. kudriavzevii and S. paradoxus, associated with the geographical origin of the strains. The most divergent proteins were Pgu1a (S. arboricola) and Pgu1b, Pgu2b, Pgu3b (S. bayanus), for which the level of similarity to the Pgu proteins of other Saccharomyces species did not exceed 89%. The highest similarity (>95%) was noted for the Pgu proteins of S. cerevisiae, S. paradoxus, and S. cariocanus, as well as S. mikatae and S. jurei. Significant intraspecific polymorphism of endo-polygalacturonase secretion was observed in the studied Saccharomyces species, except for the species S. bayanus, all studied strains of which had a relatively high activity. The ability to secrete active endo-polygalacturonase is probably a specific feature of this species. [ABSTRACT FROM AUTHOR]

The ability to ferment lactose is a characteristic peculiarity of dairy Kluyveromyceslactis yeasts; the vast majority of other yeast species are not able to assimilate this disaccharide. Molecular polymorphism of LAC4 genes encoding β-galactosidase controlling lactose fermentation is not well studied, and the published data concern only a single strain (K. lactis var. lactis NRRL Y-1140) isolated from cream in the United States. We studied β-galactosidase genes in lactose-fermenting K. lactis strains isolated from dairy products and natural sources in different regions of the world using molecular karyotyping, Southern hybridization, and sequencing. It was established that the ability to ferment lactose in K. lactis var. lactis dairy yeasts is controlled by at least three polymeric LAC loci with different chromosomal localization: LAC1 (chromosome III), LAC2 (II), and LAC3 (IV). Most of the strains we studied had the LAC2 locus. A comparative analysis of β-galactosidases of the Kluyveromyces genus yeasts and these enzymes from other yeasts was conducted for the first time. Phylogenetic analysis detected significant differences between the LAC4 proteins of yeasts of the Kluyveromyces genus (K. lactis, K. marxianus, К. aestuarii, K. nonfermentans, K. wickerhamii), Scheffersomyces stipitis, Sugiyamaella lignohabitans, and Debaryomyces hansenii. A correlation between β-galactosidase sequences and ecological origin (dairy products and natural sources) of Kluyveromyces strains was found. The group of dairy strains is heterogeneous and includes K. lactis var. lactis and K. marxianus yeasts (99.80–100% similarity), which indicates a common origin of their LAC4 genes. Phylogenetic analysis of β-galactosidases indicates a close genetic relationship of dairy and hospital strains of K. lactis var. lactis and K. marxianus. Clinical isolates are able to ferment lactose and appear to originate from the dairy yeasts. [ABSTRACT FROM AUTHOR]

Molecular genetic study of 22 methanol-assimilating Komagataella strains maintained at the UCDFST collection (United States) was carried out. Multigene phylogenetic analysis revealed that strains previously assigned to "Pichia pastoris" based on the standard taxonomic tests actually belong to four different species: K. pastoris, K. phaffii, K. mondaviorum, and K. ulmi. Seven Komagataella species are practically indistinguishable by the standard morphological and physiological tests, and have similar D1/D2 sequences. Multigene phylogenetic analysis should be applied for reliable delineation of all seven Komagataella species. The biogeography of Komagataella yeasts is noteworthy. K. mondaviorum, K. kurtzmanii, K. phaffii, K. populi, and K. ulmi have been found only in North America, while K. pastoris and K. pseudopastoris are characteristic of Europe. [ABSTRACT FROM AUTHOR]

A molecular genetic study of pectinase PGU genes from 74 strains of the yeast Saccharomyces bayanus var. uvarum isolated from various fermentation processes and natural sources in different regions of Europe and the United States has been performed. Unlike the S. cerevisiae yeasts, each having a single PGU gene, the S. bayanus var. uvarum strains have three divergent genes, PGU1b, PGU2b, and PGU3b, which are located respectively on chromosomes X, I, and XIV. The high pectinolytic activity of these yeasts appears to be related to the presence of several PGU polymeric genes in their genomes. [ABSTRACT FROM AUTHOR]

A molecular genetic study of pectinase PGU genes from 74 strains of the yeast Saccharomyces bayanus var. uvarum isolated from various fermentation processes and natural sources in different regions of Europe and the United States has been performed. Unlike the S. cerevisiae yeasts, each having a single PGU gene, the S. bayanus var. uvarum strains have three divergent genes, PGU1b, PGU2b, and PGU3b, which are located respectively on chromosomes X, I, and XIV. The high pectinolytic activity of these yeasts appears to be related to the presence of several PGU polymeric genes in their genomes. [ABSTRACT FROM AUTHOR]

The paper completes a series of works about the unique Schlema-Alberoda deposit. The data on sources of vein and ore minerals and their relation to the processes of regressive alteration of rocks from the contact metamorphism zone are refined. The correlation between stages of mineral formation and their directed change are shown. A general scheme for the sequences in formation stages of the deposit's hydrothermal ores is oriented on a joint analysis of geological and mineralogical–geochemical evolution of potentially ore-bearing provinces. [ABSTRACT FROM AUTHOR]

Taking into account the accepted concept of the ancient whole genome duplication (WGD) in the yeast genus Saccharomyces, comparative analysis of the multiple α-glucosidases MAL and IMA of the genetic line Saccharomyces cerevisiae S288C and α-glucosidases of protoploid yeasts Kluyveromyces and Lachancea, which have not experienced genome duplication, was carried out. Only certain MAL and IMA isoforms of the latter two genera were shown to be in a close phylogenetic relationship to α-glucosidases MAL12, MAL32, and IMA1-IMA4 of S. cerevisiae S288C, while others were closer to the divergent IMA5. These results are consistent with the WGD concept, according to which the yeast Saccharomyces, Kluyveromyces, and Lachancea originated from the common protoploid ancestor and may therefore have common closely related α-glucosidases MAL and IMA. The identity of amino acid sequences of the IMA1-IMA4 isomaltoses of S. cerevisiae S288C to those of L. dasiensis, L. fantastica, L. fermentati, L. lanzarotensis, L. meyersii, L. quebecensis, and L. thermotolerans was 75−100%, while identity of the MAL maltoses of the same species was 75−99%. Importantly, the MAL and IMA α-glucosidases diverged independently in each genus, species, and even strain. [ABSTRACT FROM AUTHOR]

The paper reports on the search for the superfamily of divergent species-specific PGU genes in ascomycetous yeasts in the GenBank (http://www.ncbi.nlm.nih.gov/genbank/) and the Sanger Institute (http://www.sanger.ac.uk) databases. It has been demonstrated that the species within the Eremothecium, Galactomyces, Geotrichum, Kluyveromyces, and Lachancea genera contain divergent pectinase genes. Within these genera, we observed the following levels of similarity between the nucleotide sequences of the PGU genes: 64.5-98.2% in Kluyveromyces, 72.7-81.3% in Galactomyces/Geotrichum, and 69-87.9% in Eremothecium. Polymeric PGU genes capable of interspecies transfer were found in Galactomyces citri-aurantii, Geotrichum klebahnii, and Galactomyces candidus. The importance of PGU genes for the diagnosis and selection of yeasts is discussed. [ABSTRACT FROM AUTHOR]

Analysis of the literature and GenBank data showed that the genus Ogataea is heterogeneous and includes at least five non-described genera. Comprehensive phylogenetic analysis of the present genus Ogataea may be conducted only based on multigene analysis of all the known species. Possibilities of molecular species identification in biogeographical and ecological studies of yeasts are discussed. [ABSTRACT FROM AUTHOR]

Molecular genetic screening of Saccharomyces yeasts, isolated from natural sources in the regions of the world with a hot climate (Africa, South America, Southeast and Central Asia) was used for the search of thermotolerant S. cerevisiae strains. Based on physiological tests, four strains were selected that could grow at high temperatures (42 and 43°C) and had good fermentation activity: 7962-4B, 3529-7B, 52922-4-1-1A- 1C, and 87-2421.1-2A. Hybrids of monosporic culture of distiller’s race XII (XII7-2) with the thermotolerant strains were obtained. Unlike the strain XII7-2, which is unable to grow at above 39°C, all hybrids showed good growth at 42°C. Two of the six hybrids analyzed, H2-1 (87-2421.1-2A × XII7-2) and H3-2 (7962-4B × XII7-2), showed higher fermentation activity than the parental strains. According to the results obtained, inter-strain hybridization is an efficient method of obtaining S. cerevisiae strains, which combine thermotolerance with high efficiency of alcoholic fermentation. [ABSTRACT FROM AUTHOR]

Comparative molecular genetic study of Williopsis yeasts isolated in different world regions reveals some peculiarities of species content in Taiwan. Some Williopsis yeasts may represent novel species. In Taiwan, four of the five known Williopsis species are documented: W. saturnus, W. suaveolens, W. mrakii, and W. subsufficiens. The W. saturnus yeasts predominate in Taiwanese soils, while W. suaveolens is more frequently isolated in Europe. [ABSTRACT FROM AUTHOR]

Molecular karyotyping and Southern blot hybridization were used to investigate chromosomal polymorphism of the LAC genes controlling lactose fermentation in Kluyveromyces marxianus strains isolated from various dairy products and natural sources in Russia and CIS countries. Profound polymorphism of karyotype patterns and accumulation of LAC genes were observed in dairy K. marxianus strains. K. marxianus strains isolated from dairy products intensively fermented lactose at 37°C after one day of cultivation, while non-dairy strains exhibited delayed lactose fermentation or did not ferment it at all. Based on the fermentation tests, twelve K. marxianus strains were selected, which are of interest as potential probiotic microorganisms suitable for further molecular genetic studies and breeding. [ABSTRACT FROM AUTHOR]

The genomes of the recently discovered yeast Saccharomyces eubayanus and traditional S. cerevisiae are known to be found in the yeast S. pastorianus (syn. S. carlsbergensis), which are essential for brewing. The cryotolerant yeast S. bayanus var. uvarum is of great importance for production of some wines. Based on ascospore viability and meiotic recombination of the control parental markers in hybrids, we have shown that there is no complete interspecies post-zygotic isolation between the yeasts S. eubayanus, S. bayanus var. bayanus and S. bayanus var. uvarum. The genetic data presented indicate that all of the three taxa belong to the same species. [ABSTRACT FROM AUTHOR]

As a result of integrating geological, mineralogical, and geochemical data on the unique Schlema-Alberoda five-element uranium deposit situated in Federal Republic of Germany and explored in detail down to a depth of 2 km, it has been shown that its formation for more than 100 Ma has been caused by combination of internal and external factors. The latter comprise favorable metallogenic specialization of the region, injection of intrusive bodies bearing the necessary stock of energy, and periodic pulses of tectonic reactivation. The internal factors of self-development involve evolutionary processes, which occur in host rocks at the consecutive stages of prograde and retrograde metamorphism giving rise to alteration of rocks in consistence with physical and chemical laws at variable temperature and degree of system opening. [ABSTRACT FROM AUTHOR]

The review deals with natural diversity of sherry ('flor') Saccharomyces cerevisiae yeasts. Various properties of these yeasts are analyzed: life cycles, fermentation of sugars, sensitivity to methyl violet and killer toxins, and resistance to ethanol and sulfite. Special attention is paid to molecular identification and differentiation of sherry yeasts. The history of their nomenclature is considered, including the names of possible subpopulations: 'aceti,' 'beticus' ('cheresienses'), 'cordubensis,' 'gaditensis,' 'hispanica' ('prostoserdovii'), and 'oxidans.' [ABSTRACT FROM AUTHOR]

Using yeast genome databases and literature data, phylogenetic analysis of pectinase PGU genes from 112 Saccharomyces strains assigned to the biological species S. arboricola, S. bayanus (var. uvarum), S. cariocanus, S. cerevisiae, S. kudriavzevii, S. mikatae, S. paradoxus, and the hybrid taxon S. pastorianus (syn. S. carlsbergensis) was carried out. A superfamily of divergent PGU genes was found. Natural interspecies transfer of the PGU gene both from S. cerevisiae to S. bayanus and from S. paradoxus to S. cerevisiae may, however, occur. Within the Saccharomyces species, identity of the PGU nucleotide sequences was 98.8-100% for S. cerevisiae, 86.1-95.7% for S. bayanus (var. uvarum), 94-98.3% for S. kudriavzevii, and 96.8-100% for S. paradoxus/ S. cariocanus. For the first time, a family of polymeric PGU1b, PGU2b, PGU3b and PGU4b genes is documented for the yeast S. bayanus var. uvarum, a variety important for winemaking. [ABSTRACT FROM AUTHOR]

Pectinase (endo-polygalacturonase) is the key enzyme splitting plant pectin. The corresponding single gene PGU1 is documented for the yeast S. cerevisiae. On the basis of phylogenetic analysis of the PGU nucleotide sequence available in the GenBank, a family of divergent PGU genes is found in the species complex S. bayanus: S. bayanus var. uvarum, S. eubayanus, and hybrid taxon S. pastorianus. The PGU genes have different chromosome localization. [ABSTRACT FROM AUTHOR]

Genetic hybridization analysis revealed that industrially important species Komagataella kurtzmanii has reproductive postzygotic isolation from K. pastoris, K. phaffii, K. populi, K. pseudopastoris, and K. ulmi. Therefore, it represents a new biological species of the genus Komagataella. The genetic data are in perfect agreement with the molecular taxonomy of the genus Komagataella. [ABSTRACT FROM AUTHOR]

Experimental data on genetic molecular classification and identification of the yeast genus Zygowilliopsis are summarized. The genus is represented by at least five biological species and three varieties of Z. californica: var. californica, var. dimennae, and var. fukushimae. Biogeography, ecology and killer activity of Z. californica yeasts is considered. Heterogeneity of the taxonomic genus Barnettozyma Kurtzman et al. (2008) and the necessity for its revision are discussed. [ABSTRACT FROM AUTHOR]

Using induced complementary auxotrophic mutants and selective growth of prototrophic hybrids on minimal medium, hybridization of the type strain of Komagataella kurtzmanii VKPM Y-727 with the type strains of K. pastoris VKPM Y-3262, K. phaffii NRRL Y-7556, K. populi NRRL YB-455, K. pseudopastoris NRRL Y-27603, and K. ulmi NRRL YB-407 was demonstrated. The data obtained suggest that the genus Komagataella, established previously by phylogenetic analysis, corresponds well to the concept of genetic genus in ascomycetous fungi. According to this concept, a genetic genus is a group of hybridized species having a common mating type system. Application of the concept of genetic genus for different yeast genera is discussed. [ABSTRACT FROM AUTHOR]

The effect of isotope exchange reactions (deuterium/protium, D/H) on morphofunctional indices and the state of the antioxidant blood system in rats was studied under physiological conditions and during experimental chronic endotoxicosis of hepatorenal genesis. It was demonstrated that introduction of water with a decreased content of deuterium in the food rations of rats results in a decrease in its concentration in the blood plasma by 32-36% (to 98-106 ppm) and in lyophilized liver, kidney, and heart tissues by 13-17% (to 123-128 ppm). It was noted that it is accompanied by correction of metabolic processes, an increase in the functional activity of nonspecific protection system, and an increase in the body weight growth by the 42nd day in the group of animals that passed (for 14 days) the stage of preliminary adaptation with a change in the D/H ratio in the organism. [ABSTRACT FROM AUTHOR]

In some recent publications, the ability of selection strains of Saccharomyces cerevisiae to ferment inulin was attributed to inulinase activity. The review summarizes the literature data indicating that overproduction of invertase, an enzyme common to S. cerevisiae, may be responsible for this phenomenon. [ABSTRACT FROM AUTHOR]

A phenomenon of ascospore death was observed in a number of Schizosaccharomyces pombe interstrain hybrids. Meiotic recombination of the control parental auxotrophic markers was, however, observed in random ascospore analysis. Genetic and molecular biological data indicated existence of at least geographical divergence of the genomes in Sch. pombe populations. Classification of the genus, species, and varieties of these yeasts is discussed. [ABSTRACT FROM AUTHOR]

A three-link robot moving due to controlled dry friction forces that act on the central contact points of the robot with a horizontal rough surface is considered. A mathematical model of the mechanism is developed. Algorithms for the implementation of various types of motion are presented. Numerical simulation results and the comparison with analytical results are discussed. [ABSTRACT FROM AUTHOR]

Well-known yeasts Kluyveromyces lactis var. lactis, which are usually associated with dairy products, were discovered in nature: in woodland park soil under Impatiens glandulifera Royle plants. Reliable identification of the yeasts was carried out using physiological criteria (lactose and maltose utilization) and molecular markers (nucleotide sequence of the 5.8S-ITS rDNA fragment, pulsed-field gel electrophoresis, and Southern hybridization of chromosomal DNA with the LAC4 probe). Ecology of Kl. lactis var. lactis is discussed. [ABSTRACT FROM AUTHOR]

The paths of the movements of hydrothermal solutions are considered in the case of one of the world's largest uranium vein deposits, the Schlema-Alberoda, which was mined by the Soviet-German corporation Wismut JSC in the second half of the 20th century. Detailed geological exploration to a depth of 2 km was accompanied by specialized research, the results of which have remained practically unpublished due to confidentiality. The data obtained show that the region adjoining the largest fault was draining rather than ore-conducting. This circumstance specifies and supplements the current concept concerning the movement of hydrothermal fluids. [ABSTRACT FROM AUTHOR]

The molecular polymorphism of SUC genes that encode β-fructosidase has been investigated in the yeast genus Saccharomyces. We have determined the nucleotide sequences of subtelomeric SUC3, SUC5, SUC7, SUC8, SUC9, and SUC10 genes of S. cerevisiae and the SUCa gene of S. arboricola. Comparisons of the nucleotide sequences of all known SUC genes revealed the predominance of C → T transitions in the third codon position, which were silent. The amino acid sequences of β-fructosidases studied have identity of 88-100%. SUCa ( S. arboricola) and SUCb ( S. bayanus) proteins, which had amino acid identity with other SUC proteins of less than 92%, were the most divergent. It was determined that accumulation of the polymeric SUC genes takes place in industrial populations of S. cerevisiae, while the other Saccharomyces species ( S. arboricola, S. bayanus, S. cariocanus, S. kudriavzevii, S. mikatae, and S. paradoxus) each harbor only one SUC gene. Subtelomeric repeats of β-fructosidase SUC genes could appear in the genome of S. cerevisiae under the effect of selection in the course of their domestication. [ABSTRACT FROM AUTHOR]

The review deals with the early studies of Saccharomyces paradoxus (syn. S. cerevisiae var. tetrasporus) yeast. The data demonstrate strong evidence that, in contrast to the well-known cultivated Saccharomyces yeasts (baker, wine, spirits, and beer yeast), wild Saccharomyces yeasts are often found in natural habitats, such as exudate and leaf litter of trees, decaying wood, soil, and insect intestines. These yeasts form a potentially valuable gene pool for research and breeding programs. [ABSTRACT FROM AUTHOR]

The thermotolerant strain 1-IR was isolated as a contaminant microflora of the industrial strain 'Red' (the Netherlands) during the study of the baker's yeast Saccharomyces cerevisiae. The strain was assigned to the species Ogataea parapolymorpha by sequencing the 26S rDNA D1/D2 domain. The strain 1-IR was shown to be capable of efficient glucose and xylose fermentation at an elevated temperature of 45°C. In this respect, the strain 1-IR surpassed the thermotolerant yeasts O. polymorpha CBS 4732, NCYC 495, and O. parapolymorpha DL1. The prospects of using the O. parapolymorpha yeasts as producers of biofuel from lignocellulose wastes of agricultural and woodworking industries is discussed. [ABSTRACT FROM AUTHOR]

Reciprocal translocations between chromosomes XVI and VIII were revealed in eight Saccharomyces cerevisiae strains (mostly wine ones) using pulse-field electrophoresis of native chromosomal DNAs and their hybridizations with the CUP1 and GAL4 probes. New and reciprocal translocations of at least the gene CUP1 occur at the expense of crossing-over in the hybrids of such strains with the genetic lines of normal karyotype during meiosis. Relationship between these reciprocal translocations and the sulfite (NaSO) resistance gene SSU1-R is discussed. [ABSTRACT FROM AUTHOR]

Genomes of 36 Saccharomyces distillers' strains, mainly of domestic origin, were studied by PCR-RFLP analysis of rDNA 5.8S-ITS fragment, molecular karyotyping, and Southern hybridization. Molecular analysis revealed that all the strains belonged to the species S. cerevisiae. According to the karyotypic analysis, many of the strains were aneuploid. Accumulation of polymeric genes SUC and MAL was detected in S. cerevisiae distillers' strains. Accumulation of polymeric genes of sugar fermentation may be of adaptive importance and may result in increased fermentation activity of the strains. It was demonstrated that most strains fermenting maltose after one day of fermentation possessed several MAL genes. Thermotolerant strains with high fermentation activity were selected. [ABSTRACT FROM AUTHOR]

The review is dedicated to the molecular genetics of yeast α-glucosidases: the maltase and isomaltase isozymes. Comparative analysis of the genome sequence of the yeast Saccharomyces cerevisiae S288C using the isomaltase gene of Saccharomyces cerevisiae ATCC56960 revealed a new family of polymeric isomaltase genes IMA1-IMA5 located in the telomeric regions of chromosomes VII, XV, IX, X, and X, respectively. The isomaltase overexpression and substrate specificity are discussed. [ABSTRACT FROM AUTHOR]

Molecular genetic identification of 52 Kluyveromyces strains from VKM, mainly of dairy origin, was carried out. Restriction analysis of 5.8S-ITS rDNA fragments was used to differentiate between Kl. lactis var. lactis, Kl. lactis var. drosophilarum (European population of 'krassilnikovii'), and Kl. marxianus. Kl. lactis was shown to differ from Kl. marxianus in its ability to assimilate α-glucosides: maltose, melezitose, and α-methyl-glucoside. [ABSTRACT FROM AUTHOR]

The review considers various aspects of the biology of the yeast Saccharomyces bayanus, which is distantly related to the cultured yeast S. cerevisiae. The cryotolerant S. bayanus strains found in wine-making became the second most important yeast for basic and applied studies. Introduction of natural and experimental hybrids of S. cerevisiae × S. bayanus in a range of fermentation processes indicates the high breeding importance of S. bayanus. The biological species S. bayanus acts as a new gene pool for the scientific and breeding projects. [ABSTRACT FROM AUTHOR]

Molecular genetic analysis of melibiose-fermenting Saccharomyces strains isolated from fermentative processes and natural sources in different world regions was conducted to deduce the evolutionary diversity of Saccharomyces yeasts and find new α-galactosidase MEL genes. The species S. bayanus, S. mikatae, and S. paradoxus were shown to have a single copy of MEL and not accumulate polymeric genes, unlike some S. cerevisiae populations. The polymeric genes MELp1 and MELp2 were identified in S. paradoxus for the first time. Genes identical by 98.7% are located on the chromosomes X and VI, respectively. Phylogenetic analysis indicates that MEL genes of the Saccharomyces yeasts are species-specific. [ABSTRACT FROM AUTHOR]

Based on the results of genetic analysis and molecular karyotyping, a total of 11 strains involved in fermentation processes employed in various regions of Africa were identified as representatives of the species Saccharomyces cerevisiae. These stains exhibited a high degree of chromosomal polymorphism. The obtained fertile genetic lines of the studied African strains may be of considerable interest for evolutionary genetics and breeding of yeasts of the genus Saccharomyces. [ABSTRACT FROM AUTHOR]

Information concerning molecular reidentification of the species of the rejected genus Chlamydozyma is generalized. The yeasts Chl. pulcherrima Wickerham (1964) and Chl. reukaufii Wickerham (1964) are shown to be sibling species of Metschnikowia pulcherrima Pitt et Miller (1968) and M. reukaufii Pitt et Miller (1968), respectively. Restoration of the species M. zygota (Wickerham) Fell at Hunter (1968) is proposed. The parasexual cycle and the prospects of its application for investigation of the Metschnikowia yeasts are discussed. [ABSTRACT FROM AUTHOR]

Three different translocations involving chromosome IX have been detected in natural Saccharomyces cerevisiae strains using pulsed-field gel electrophoresis with intact chromosomal DNA and their hybridization with the SUC2 probe. Hybrids of these strains with genetic lines having normal molecular karyotype were shown to have back dislocation of at least marker SUC2 due to crossingover. The significance of the detected translocations is discussed. [ABSTRACT FROM AUTHOR]

Genetic relationships among forty-one strains of Saccharomyces bayanus var. uvarum isolated in different wine regions of Europe and four wild isolates were investigated by restriction analysis (RPLP) of mitochondrial DNA (mtDNA) with four restriction endonucleases, AluI, DdeI, HinfI and RsaI. No clear correlation between origin and source of isolation of S. bayanus var. uvarum strains and their mtDNA restriction profiles was found. On the whole, the mtDNA of S. bayanus var. uvarum is much less polymorphic than that of S. cerevisiae. This observation is in good agreement with results obtained by electrophoretic karyotyping. Unlike wine S. cerevisiae, strains of S. bayanus var. uvarum display a low level of chromosome length polymorphism. [ABSTRACT FROM AUTHOR]

Using molecular karyotyping and genetic hybridization analysis, two new polymeric β-fructosidase genes, SUC9 and SUC10, were identified in the yeast Saccharomyces cerevisiae, which are located on chromosome XIV and on the chromosome XVI/XIII doublet, respectively. The genes are responsible for fermentation of sucrose and raffinose. The SUC gene genotypes of strains VKM Y-1831 and DBVPG 1340 are SUC2 SUC9 and suc20 SUC10, respectively. suc20 is a silent sequence. The scientific and applied significance of SUC genes is discussed. [ABSTRACT FROM AUTHOR]

Using sequence analysis of internal transcribed spacers ITS1 and ITS2, RAPD-PCR, and pulsed-field gel electrophoresis of intact chromosomal DNA, we investigated the molecular and genetic peculiarities of the genomes of 40 Yarrowia lipolytica strains. All the strains showed nearly identical ITS-sequences. On the other hand, karyotypic analysis revealed significant differences in the chromosomal patterns of Y. lipolytica. The number and order of individual chromosomes vary from strain to strain. Chromosome-length polymorphism of the Y. lipopytica strains was pronounced and independent of their geographic origin and the source of isolation. Intraspecific polymorphism of Y. lipolytica chromosomes is discussed. [ABSTRACT FROM AUTHOR]

Molecular and genetic analyses revealed that the distillers race XII, which is an ancestor of Saccharomyces cerevisiae Peterhof and Gatchina genetic lines, has three polymeric β-fructosidase genes: SUC2, SUC5, and SUC8. The latter gene located on the X chromosome was identitied in this work for the first time. The presence of the single SUC2 gene in yeasts used in the international project on sequencing of the S. cerevisiae genome is discussed. [ABSTRACT FROM AUTHOR]

Using yeast genome databases and literature data, we have conducted a phylogenetic analysis of pectinase PGU genes from Saccharomyces strains assigned to the biological species S. arboricola, S. bayanus (var. uvarum), S. cariocanus, S. cerevisiae, S. kudriavzevii, S. mikatae, S. paradoxus, and hybrid taxon S. pastorianus (syn. S. carlsbergensis). Single PGU genes were observed in all Saccharomyces species, except S. bayanus. The superfamily of divergent PGU genes has been documented in S. bayanus var. uvarum for the first time. Chromosomal localization of new PGU1b, PGU2b, and PGU3b genes in the yeast S. bayanus var. uvarum has been determined by molecular karyotyping and Southern hybridization. [ABSTRACT FROM AUTHOR]

Genetic hybridization analysis was conducted with 16 natural Zygowilliopsis strains isolated in different geographical regions and maintained in collections under species names Z. californica, Hansenula dimennae, and Pichia populi. Genetic relatedness was determined on the basis of mating, viability of hybrid progeny, and meiotic recombination of markers. Four new biological species are recognized in the former monotypic genus Zygowilliopsis. Species Z. californica and Zygowiliopsis sp. 3 probably include divergent geographical populations. It is necessary to reconsider the species composition of the genus Zygowiliopsis and generic assignment of P. populi yeasts. Genetic and molecular identifications of the Zygowiliopsis species are in perfect agreement. [ABSTRACT FROM AUTHOR]

The molecular karyotyping analysis of 21 strains within the taxonomic complex Pichia membranifaciens allowed the sibling species P. membranifaciens and P. manshurica, as well as P. deserticola and P. punctispora, to be differentiated. Heterogeneity of the species P. membranifaciens at the variety level is discussed. [ABSTRACT FROM AUTHOR]