Lecithinase activity of various yeast strains]

The activity of lecithinase was studied among 50 yeast strains belonging to the genera Rhodotorula Harrison, Cryptococcus Kütz, and Lipomyces Lodder et Kreger van Rij. The maximum activity of lecithinase is typical of epiphyte yeast strains belonging to the genus Rhodotorula and is not manifested by species of the henus Lipomyces which inhabit soil. Strains of the genus Cryptococcus cannot be distinctly differentiated into soil and epiphyte cultures, and occupy an intermediate position by the activity of lecithinase.     

Fractional makeup of the lipids of some yeast species]

The fractional composition of lipids was studied in 32 yeast strains belonging to the genera of Rhodotorula Harrison, Lipomyces Lodder et Kreger van Rij and Cryptococcus Kutz. The effect of C/N ratio in the growth medium on the content of various lipid fractions was studied. Lipids of the most studied cultures were found to contain di- and triglycerides, waxes, free fatty acids, sterines, their esters, and phospholipids. The fraction of monoglycerides was also detected in Rhodotorula and three species of Cryptococcus, but not in Lipomyces and Cr. laurentii. If C/N ratio equals 10, the predominant lipid component in Lipomyces is triglycerides, and in Rhodoturula and Cryptococcus phospholipids. The fraction of triglycerides prevailed in all cultures at C/N ratio of 100. The content of phospholipids decreased with an increase of C/N ratio in the medium from 10 to 100.     

Studies on Osmophillic Yeasts

Influences of concentrations of sodium chloride and pH values of soy mash on the changes of microflora during the ripening process were investigated. The proportions of various yeasts in the soy mash were proved to be changed with the above two environmental factors. And it was shown that growth sequence of yeasts in soy mash was controlled according to their pH sensitivities at the hypertonic condition. From young soy mash (3 days’ old), the following yeasts were isolated: salt-tolerant type.…Saccharomyces rouxii Boutrpux, Torulopsis famata (Harrison) Lodder et Kregervan Rij, Candida polymorpha Ohara et Nonomura, Pichia farinosa (Lindner) Hansen, and Trichosporon behrendii Lodder et Kreger-van Rij ; salt-sensitive type.…Candida tropicalis (de Beurm., Gougerot et Vaucher) Ota and Candida rugosa (Anderson) Diddens et Lodder.     

Ascospores in the type species of the genus Torulopsis

It has been found that the type species, T. colliculosa, of the form genus Torulopsis constitutes a perfect state forming ascospores. It is proposed that the same “Torulopsis Lodder et Kreger-Van Rij” based on a new type, be conserved against the earlier homonym “Torulopsis Berlese” which is based on the type T. rosea.     

The genusCandida berkhout

The aim of the study was to verify the accuracy of the taxonomic classification of rough variants of the speciesCandida guilliermondii on the basis of comprehensive study of phenetic manifestation and to determine differences in cell wall structure with special reference to polysaccharides (1) According to their phenotype, the test strainsCandida guilliermondii (Cast.) Langeron et Guerra andCandida guilliermondii var.membranaefaciens Lodder et Kreger-Van Rij belong to the speciesCandida guilliermondii, whileCandida guilliermondii var.nitratophila Diddens et Lodder is phenotypically closer toCandida pelliculosa. (2) Observation of native and hydrolysed cell walls in the electron microscope showed no differences between the test strains. (3) The results of X-ray phase analysis of cell walls differentiatedCandida guilliermondii var.nitratophila from the other two, however. (4) Electron microscopy photomicrographs and diffractograms of cell walls indicated that, after 2% HCl extraction at 100 C, the cell walls contain chitin, which is isolated by further extraction with 30% HCl. After 3% NaOH hydrolysis the chitin diffractogram is not clear.     

YEASTS CAUSING SPOILAGE IN ACETIC ACID PRESERVES

SUMMARY: Forty-seven cultures of yeasts, isolated from 47 packs of spoiled acetic acid preserves including 11 varieties and originating from nineteen manufacturers, have been identified according to the system of Lodder & Kreger-van Rij. Forty-three cultures had the characteristics of Saccharomyces acidifaciens and four those of Pichia membranaefaciens .     

Yeasts in greenhouse environment

Summary The examination of a total of 98 yeast cultures collected from the buds, the open flowers and the host animals of 8 different species of plants and from the related soils of the vessels in a greenhouse, has demonstrated the presence of 13 different yeasts, including 3 sporogenous and 10 asporogenous species. The more frequent species were: Torulopsis bacillaris (Kr. et Krumbh.) Lodder (frequency 37.5%) and Candida reukaufii (Grüss) Diddens et Lodder (37.5%), on the open flowers. Rhodotorula mucilaginosa (Jörg.) Harrison (37.5%), and Rhodotorula glutinis (Fres.) Harrison var. rubescens (Saito) Lodder (25%), on the bud flowers. Torulopsis bacillaris (Kr. et Krumbh.) Lodder (50%) on the animals. Saccharomyces ellipsoideus Hansen (37.5%) and Pichia fermentans Lodder (37.5%), in the soils of the related vessels.The yeast like form Aureobasidium pullulans (De Bary) Arnaud, has 50% of frequency on the bud flowers and 12.5% on the open flowers.     

Babjevia gen. nov. — a new genus of the Lipomycetaceae

The species described asLipomyces anomalus Babjeva & Gorin shows significant genetic and phenotypic divergence from the type speciesLipomyces starkeyi Lodder & Kreger-van Rij in terms of rRNA base sequence substitution and ascosporal and septal ultrastructure. The species is consequently reclassified in the new, unispecific genusBabjevia, asBabjevia anomala.     

The genus Saccharomyces (Meyen) Reess

The speciesSaccharomyces heterogenicus Osterwalder,Saccharomyces steineri Lodder et Kreger-van Rij,Saccharomyces pastorianus Hansen,Saccharomyces bayanus Saccardo andSaccharomyces willianus Saccardo were compared. It was found that the biochemical characters used for the definition of these species were variable and the strains of the given species were therefore evaluated together. With reference to the present accepted criteria of species specificity, grouping on the basis of coefficients of similarity was not conclusive. One of the characters (the fermentation and assimilation of galactose) was therefore dispensed with, while a new characteristic (determination) of amylolytic activity was added. It was found that the speciesSaccharomyces pastorianus, Saccharomyces bayanus andSaccharomyces willianus were so similar that they could be grouped in one species.Saccharomyces heterogenicus retained its species specific characteristics, whileSaccharomyces steineri formed a transition between this species and the other three. The coefficients of similarity, S, calculated by the methods of Jaccard and of Sokal and Michener, were compared and some of the more problematical questions of the numerical method are discussed.     

Endomycopsis platypodis sp.n. (Ascomycetes): an auxiliary ambrosia fungus ofPlatypus cylindrus Fab. (Col. Platypodidae)

A new species of mycelium-forming yeast,Endomycopsis platypodis Baker et van Rij is described. It occurs as an auxiliary ambrosia fungus of the wood-boring ambrosia beetlePlatypus cylindrus Fab. (Col. Platypodidae) and is the first fungus to become established in new tunnels where it forms a sparse irregular lining. Later a palisade-formingSporothrix becomes the dominant fungus in a mixed ambrosial flora. E. platypodis, which is apparently homothallic, assimilates nitrate and weakly ferments glucose. The asci typically contain 4 hat-shaped ascospores. Assimilation reactions and morphology are described and the affinities of the new species are discussed.     

The yeast genus Yarrowia gen. nov.

The ascigerous teleomorph of Candida lipolytica (Harrison) Diddens et Lodder, previously classified as Endomycopsis lipolytica Wickerham et al. and as Saccharomycopsis lipolytica (Wickerham et al.) Yarrow, has been assigned to the new genus Yarrowia. Yarrowia lipolytica (Wickerham et al.) comb. nov. is the type species for the genus.The remaining species of Saccharomycopsis are revised.     

Considerazioni Intorno ad „Endomycopsis Fibuliger (Lindner) Dekker“

Riassunto Da uve di paesi subtropicali (Brasile) sono stati isolati più ceppi diEndomycopsis. Il loro studio comparativo ha suggerito di riconvalidareEnd. lindneri Saito passata daLodder &Kreger van Rij in sinonimia conE. fibuliger, e di istituire una nuova varietà di quest' ultima specie:E. fibuliger, var.energica n. var.

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Summary From grape must of a subtropical country (Brasil) some strains ofEndomycopsis had been isolated. Their comparative study was suggestive to confirm again the speciesE. lindneri Saito. Moreover, the same studies permitted us to establish a new variety:E. fibuliger v.energica, n. var.

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Resumo Foram isoladas algumas culturas deEndomycopsis de mosto de uvas cultivadas no Estado de S. Paulo, Brasil.Os estudo comparativos dessas cepas sugeriram considerar como valida a especieE. lindneri Saito, queLodder &Kreger van Rij dao como sinonimo deE. fibuliger.Foi sugerido tambem instituir uma nova variedade, aE. fibuliger var.energica.

     

Identification of Zygowillopsis californica strains of various origin by polymerase chain reaction with universal primers]

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 (Kl?cker) Naumov et al. Universal primers L45 and N21 are recommended for identification of the Z. californica yeasts.     

The yeastKluyveromyces africanus nov. spec. and its phylogenetic significance

Summary A new budding yeast species isolated from soil is described. Its outstanding features are, firstly, the formation of asci containing up to sixteen long oval to reniform ascospores and, secondly, a fermentative as well as oxidative metabolism. The assimilation of nitrate is absent and no pseudomycelium is formed. The taxonomic position of the yeast is discussed and it is pointed out that, due to its exceptional ascospore number (1–16), it cannot be classified in any of the existing fermentative genera of theEndomycetaceae (in sensu Lodder et Kreger-van Rij). The reniform shape of its ascospores indicates, however, its close relationship with the multispored genusKluyveromyces, on the one hand, and the newly proposed one to four-spored genusDekkeromyces on the other. The species is provisionally classified as aKluyveromyces species,Kluyveromyces africanus nov. spec., until further information regarding its sexual characteristics becomes available. By virtue of its more or less intermediate ascospore number, it establishes the direct derivation of the genusDekkeromyces fromDipodascus uninucleatus via the multispored yeast genusKluyveromyces.     

Filtering mechanism of the honey bee proventriculus

ABSTRACT. The fine structure and function of a honey bee's ( Apis mellifera Linn.) proventriculus were studied by scanning electron microscopy and video-recording. Our observations revealed that the proventriculus is used to engulf pollen and other particles which contaminate the nectar carried into the crop. The four lips are closed and opened, pulled backwards and straightened by the external circular muscles and internal longitudinal muscles. Combs of filiform-hairs (70 μm in length) located on the margins of the lips 'catch' and filter particles from the fluid. By repeated filtering, opening and closing actions of the hairs and lips, particles are filtered and collected in pouches between the ventricular folds to form boluses and are eventually passed into the midgut. In the present experiment, particle sizes ranging from 0.5 to 100 μm in diameter, including dandelion pollen ( Taraxacum officinale Web.), Torula yeast ( Candida utilis Lodder et Kreger-Van Rij), bee disease spores of Nosema apis Zander and Bacillus larvae White, and man-made particles can be filtered by the hairs. Small particles (0.23 μm in diameter) filter through the hair and return back to the fluid. Large particles (100–200 μm in diameter) are caught between the stylets of the mouthparts and are not ingested. These observations suggest that the particle size plays an important role in determining what can be taken by the mouthparts and the proventriculus and what can later be utilized as a food source by the bee. The role of the proventriculus in disease transmission is also discussed.     

Phenotypic and genotypic identification of yeasts from cheese

Eighty-five yeast strains isolated from different cheeses of Austria, Denmark, France, Germany, and Italy were identified using physiological methods and genotypically using random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) analysis. Good congruence was found between the phenotypic and genotypic data for 39 of the isolates. However, 26 isolates of Geotrichum could only be identified to the species level using the genotypic methods and 7 isolates were correctly identified to the genus level only using phenotypic identification methods. The phenotypic identification did not agree with the genotypic data for 14 yeast isolates. Using ubiquinone analysis, yeast cell wall sugars and the diazonium blue B test 5 incorrectly identified isolates with phenotypic methods could be identified genotypically. In addition the 7 isolates identified only to the genus level by the phenotypic methods and the 26 Geotrichum strains were identified to the species level using the polyphasic molecular approach mentioned above. Eleven strains remained unidentified. The 76 identified yeast isolates were assigned to 39 species, the most frequent assignments were made to Debaryomyces hansenii, Geotrichum candidum, Issatchenkia orientalis, Kluyveromyces lactis, K. marxianus, Saccharomyces cerevisiae, Yarrowia lipolytica, andCandida catenulata. It is proposed that Debaryomyces hansenii (Zopf) Lodder et Kreger-van Rij and Debaryomyces fabryi Ota should be reinstated. The RAPD-PCR data reinforced the view that the species Galactomyces geotrichum is heterogeneous with all of the Geotrichum isolates from cheese products being assigned G. geotrichum group A sensu M.T. Smith. It is suggested that the name Geotrichum candidum be conserved for this rather common species.     

Ultrastructure ofDebaryomyces hansenii

Summary The ultrastructure of the extreme halotolerant yeastDebaryomyces hansenii (Zopf) van Rij was similar whether the organism was grown under normal physiological conditions or at high concentrations of NaCl (12, 20 per cent w/v). A multitude of channels often seen in association with plasma membrane and/or vacuoles occur in the cytoplasm. The vacuoles contain lipid storage material. A decrease in mitochondrial size was observed with increasing salt concentration. The ultrastructure has been discussed with respect to halotolerance.