Nuovi blastomiceti isolati da mosti del chianti e zone limitrofe

Zusammenfassung Beim Identifizieren von 531 Hefekulturen, die im Herbst 1936 aus Traubenmost des klassischen Chiantigebietes und seiner Umgebung isoliert wurden, fand der Autor folgende neue Arten und Varietäten: Sacch. italicus repräsentiert, soweit heute bekannt, die einzige Spezies der dritten Gruppe nach der Hansen schen Klassifikation der Gattung Saccharomyces. Sacch. ellipsoideus var. major unterscheidet sich von Sacch. ellipsoideus-Typ durch die konstant größeren Zellen und Sporen. Sacch. oviformis var. bisporus zeigt zum Unterschied vom Sacch. oviformis-Typ, außer anderen leichten Abweichungen, Asken mit fast immer zwei, aber nie mehr als zwei Sporen. Zygosaccharomyces florentinus ist ein gutes Beispiel für Übergänge zwischen den Gattungen Torulaspora und Zygosaccharomyces, da sich die seltenen Asken hauptsächlich parthenogenetisch bilden und nur selten das Ergebnis einer Kopulation sind. Zygopichia chiantigiana ermangelt der Fähigkeit zur Alkoholgärung und hat bei der Weinbereitung keine Bedeutung.     

Intorno ad un lievito osmofilo sistematicamente prossimo a Sacch. Elegans Lodder et Kreger-van Rij

Riassunto Viene descritto un lievito osmofilo, isolato da mosto d'uva naturale, tassonomicamente vicino aSacch. elegans Lodder etKreger-van Rij.Questo lievito viene riguardato comeSacch. elegans var.intermedia nov. var. (pro tempore).

---

Summary Here is described an osmophilic yeast isolated from natural grape must which is taxonomically similar toSacch. elegans Lodder etKreger-van Rij.This yeast is regarded asSacch. elegans var.intermedia nov. var. (pro tempore).

---

Resumo Nêste trabalho descrive-se uma levedura osmofila isolada de môsto de uva natural taxonomicamente proxima aSacch. elegans Lodder etKreger-van Rij.Esta levedura è considerada então, comoSacch. elegans, var.intermedia nov. var. (pro tempore).

     

Yeasts of the Miami,Florida, Area

The examination of a total of 301 yeast cultures collected from 22 water samples in the Miami River has demonstrated the presence of 18 different yeasts, including 6 sporogenous and 12 asporogenous species.The more frequent species were Sacch. carlsbergensis (100%), Cand. tropicalis (31%), Pichia fermentans (22%) Torulopsis glabrata (18%) and Cryptococcus albidus (18%).Comparison of Miami River studies with earlier collections made in Key Biscayne soil as well as in Biscayne Bay reveals the occurrence of common species in all three habitats.     

New data on the distribution of certain psychrophilic yeasts in Moscow oblast

Several rare species and varieties of psychrophilic yeasts were isolated from the Sphagnum mosses and paludal vascular plants of Moscow oblast. Based on their 26S rDNA D1/D2 nucleotide sequences, they were assigned to the species Sterigmatosporidium polymorphum, Rhodotorula psychrophenolica, and Aureobasidium pullulans var. subglaciale. Thus, a new habitat of S. polymorphum was found and yeasts known previously only for the Alpine environments and the Arctic region have been isolated in the central regions of Russia for the first time.     

Heat Resistance Studies on Yeast spp. Causing Spoilage in Soft Drinks

A test method to investigate the heat resistance of yeasts has been developed. The method was used to study the heat resistance of 120 yeast strains, representative of the fungal flora in soft drinks and certain acid food products: 35 asporogenous yeast strains ( Brettanomyces, Candida, Kloeckera, Rhodotorula and Torulopsis ) and 85 ascomycetous strains ( Debaryomyces, Hansenula, Kluyveromyces, Lodderomyces, Pichia, Saccharomyces and Saccharomycopsis ) were tested. Generally, asporogenous yeasts were found to be less heat resistant than ascomycetous types. The genus Saccharomyces showed the highest heat resistance, especially strains of the species Sacch. cerevisiae and Sacch. chevalieri . For an evaluation of the practical implications of these results additional studies on environmental factors influencing the heat resistance of ascomycetous yeast species are required.     

Isolation and identification of killer yeasts from Agave sap (aguamiel) and pulque

Wild killer yeasts have been identified as inhibitory to strains used as starters in the production of alcoholic beverages such as beer and wine; therefore, killer or killer-resistant strains have been sought for use in alcoholic fermentations. In the current paper a total of 16 strains belonging to six species were isolated. From two samples of Agave sap (aguamiel) the following yeast strains were isolated: Candida lusitaneae (1), Kluyveromyces marxianus var. bulgaricus (2), and Saccharomyces cerevisiae (capensis) (1). Additionally, in seven samples of pulque (the fermented product), the species C. valida (six strains), S. cerevisiae (chevalieri) (4), S. cerevisiae (capensis) (1), and K. marxianus var. lactis (1) were found. The killer strains were C. valida and K. marxianus var. lactis from pulque and K. marxianus var. bulgaricus from aguamiel. One strain of S. cerevisiae (chevalieri) isolated from pulque which did not show killer activity was, on the other hand, resistant to other killer strains and it had a remarkable ethanol tolerance, suggesting that this strain could be used for alcohol production.     

Isolation of yeasts from bovine milk in Belgium

A total of 436 milk samples from non-infected and 80 from infected quarters were investigated: 24.5% of the samples collected from non-infected and 55% of those collected from infected quarters were positive. Normal milk yielded not less than 16 different species and among them many potentially pathogenic yeast species such as C. parapsilosis, C. guilliermondii, C. tropicalis, C. glabrata and T. asahii, all five able to grow at 40 ° C. In contrast, the yeasts isolated from infected quarters were from 3 species: C. kefyr, C. catenulata and C. lambica, which were also among the yeasts species recovered from normal milk. Among the three species, only one i.e. Candida kefyr is able to grow above 40 ° C and from there can be considered as potentially pathogenic, even if bacterial association is necessary to cause mastitis.     

Yeasts from U.S.A. soils

Summary Investigations of yeasts from 38 U.S.A. soils samples show the occurrence of 22 different species (16 sporogenous and 6 asporogenous).The most widespread species were Pichia fermentans and Hansenula anomala. The other isolated species were Saccharomyces ellipsoideus, Torulaspora delbrueckii, Pichia membranefaciens, Saccharomyces smittii, Saccharomyces carlsbergensis, Saccharomyces uvarum, Torulaspora rosei, Zygosaccharomyces rouxii, Zygosaccharomyces n. sp., Hansenula saturnus, Hansenula californica, Hansenula n. sp., Hansenula suaveolens, Debaryomyces n. sp., Torulopsis glabrata, Torulopsis n. sp. Candida tropicalis, Candida robusta, Rhodotorula glutinis, Trichosporon cutaneum and Trichosporon cutaneum var. multisporus.     

Occurrence of Verticillium fungicola var. fungicola on Agaricus bitorquis Mushroom Crops in Spain

Diseased fruit bodies of Agaricus bitorquis, with similar symptoms to those caused by dry bubble on Agaricus bisporus, were observed in some Spanish crops during summer 1999. Isolates of Verticillium fungicola from A. bitorquis and A. bisporus were submitted to different temperatures and to prochloraz–Mn sensitivity tests. All the isolates collected from A. bitorquis and A. bisporus were identified as V. fungicola var. fungicola. Artificial infections of A. bisporus and A. bitorquis with V. fungicola var. fungicola are also described in the present study. The appearance of natural infections of V. fungicola var. fungicola in A. bitorquis crops could well be due to the growing temperatures used in Spain, which are considerably below those used in other countries.     

Yeasts and moulds contaminants of food ice cubes and their survival in different drinks

Aims

To evaluate the levels of unicellular and filamentous fungi in ice cubes produced at different levels and to determine their survival in alcoholic beverages and soft drinks.

Methods and Results

Sixty samples of ice cubes collected from home level (HL) productions, bars and pubs (BP) and industrial manufacturing plants (MP) were investigated for the presence and cell density of yeasts and moulds. Moulds were detected in almost all samples, while yeasts developed from the majority of HL and MP samples. Representative colonies of microfungi were subjected to phenotypic and genotypic characterization. The identification was carried out by restriction fragment length polymorphism (RFLP) analysis of the region spanning the internal transcribed spacers (ITS1 and ITS2) and the 5·8S rRNA gene. The process of yeast identification was concluded by sequencing the D1/D2 region of the 26S rRNA gene. The fungal biodiversity associated with food ice was represented by nine yeast and nine mould species. Strains belonging to Candida parapsilosis and Cryptococcus curvatus, both opportunistic human pathogens, and Penicillium glabrum, an ubiquitous mould in the ice samples analysed, were selected to evaluate the effectiveness of the ice cubes to transfer pathogenic microfungi to consumers, after addition to alcoholic beverages and soft drinks. All strains retained their viability.

Conclusions

The survival test indicated that the most common mode of consumption of ice cubes, through its direct addition to drinks and beverages, did not reduce the viability of microfungi.

Significance and Impact of the Study

This study evidenced the presence of microfungi in food ice and ascertained their survival in soft drinks and alcoholic beverages.     

Molecular and physiological diversity among Verticillium fungicola var. fungicola

The genetic and physiological variability of Verticillium fungicola var. aleophilum responsible for Agaricus bisporus dry bubble disease in North America is well documented but little is known about the var. fungicola affecting European crops. Variability was assessed within this variety and compared with that reported for the var. aleophilum. Eighteen isolates of V. fungicola var. fungicola and four var. aleophilum isolates were analysed for DNA polymorphism, mycelial growth, response to biochemicals produced by A. bisporus, fungicide resistance, and pathogenicity assessed by direct inoculation on sporophore or casing contamination. RAPD and AFLP markers delineated three French isolates from a homogeneous group containing the other var. fungicola isolates, but no correlation could be drawn between DNA polymorphism and the various traits studied. The var. fungicola isolates were more susceptible than the var. aleophilum isolates to the antibiosis effect of A. bisporus. Only mycelial growth rate at 23 °C could explain the variability in aggressiveness among the European isolates. The putative effect of the post-incubation temperature on contamination during mushroom cultivation was discussed. This work emphasized that, like the American var. aleophilum, the var. fungicola in Europe is genetically homogeneous, but physiological diversity exists, especially in France where it could be related to less standardized cultural practices.     

Fungi isolated from Antarctic material

Summary Fungi isolated from samples of soil, penguin, skua and petrel dung and bird feathers in the Victoria Land, Antarctica, from Inexpressible Island to Cape King, were studied. All material was collected in December 1987–January 1988. Fungi occurred prevalently in bird dung and in soil, especially when mosses were present. The main species isolated were: the keratinophilic Chrysosporium verrucosum and Geomyces pannorum var. pannorum, Phoma herbarum and Thelebolus microsporus. A variety of filamentous fungi and yeasts were also encountered in soil, dung and bird feathers samples in different localities: Acremonium strictum, Cladosporium herbarum, Scolecobasidium salinum, Mortierella antarctica, Paecilomyces farinosus, Phialophora fastigiata, the thermophilic Scytalidium thermophile and Thermomyces lanuginosus, Verticillium sp., Mycelia sterilia and Cryptococcus albidus and Torulaspora delbrueckii. Most of the fungal isolates appeared to be cold-tolerant. Results from this study are discussed in conjuction with data from previous Antarctic studies in this area.     

Efficient succinic acid production from high-sugar-content beverages by Actinobacillus succinogenes

This study presents the production of succinic acid (SA) by Actinobacillus succinogenes using high-sugar-content beverages (HSCBs) as feedstock. The aim of this study was the valorization of a by-product stream from the beverage industry for the production of an important building block chemical, such as SA. Three types of commercial beverages were investigated: fruit juices (pineapple and ace), syrups (almond), and soft drinks (cola and lemon). They contained mainly glucose, fructose, and sucrose at high concentration—between 50 and 1,000 g/L. The batch fermentation tests highlighted that A. succinogenes was able to grow on HSCBs supplemented with yeast extract, but also on the unsupplemented fruit juices. Indeed, the bacteria did not grow on the unsupplemented syrup and soft drinks because of the lack of indispensable nutrients. About 30–40 g/L of SA were obtained, depending on the type of HSCB, with yield ranging between 0.75 and 1.00 g_SA/g_S. The prehydrolysis step improved the fermentation performance: SA production was improved by 6–24%, depending on the HSCB, and sugar conversion was improved of about 30–50%.     

Yeasts associated with pollinating bees and flower nectar

A study of the yeast flora of 328 honey stomachs from 7 different pollinating bee species, and 342 flower nectar samples of 9 different flower species yielded 766 yeast isolates composed of 16 genera and 47 species. Most of the yeast species from both the sources belonged to the genusCandida, while the most frequently isolated yeasts wereDekkera intermedia from honey stomach andCandida blankii from flower nectar. Among the honey bees,Xylocopa sp., and among flowers,Citrus medica, yielded the highest number of yeast species. Nineteen species of yeasts belonging to 9 genera were common to both the sources.     

A study on the inhibition of rat myocardium glutathione peroxidase and glutathione reductase by moniliformin

The yeasts of patients with oral cancer has been studied before and during Xr-therapy. Gram and PAS smears revealed an increase of yeast-like structures, during treatment, from 56% to 66% of the cases. Before radiotherapy oral yeasts were isolated from 56% of the patients with cancer represented by Candida albicans (30%); C. tropicalis (12%); C. glabrata and C. krusei (4%), besides six other different species (2%). During radiotherapy yeasts were isolated in 72% of the cases, as follow: C. albicans (36%); C. tropicalis (16%); Rhodotorula rubra (6%); C. kefyr; C. krusei and Pichia farinosa (4%), besides other nine species (2%). C. albicans serotype A represented 93% of the isolated samples, before treatment and 88,8% during Xr-therapy.     

Candida shehatae — Genetic diversity and phylogenetic relationships with other xylose-fermenting yeasts

The xylose-fermenting yeasts Candida shehatae and Pichia stipitis were compared from extent of nuclear DNA complementarity and ribosomal RNA sequence similarity. Low levels of DNA relatedness confirmed that the two taxa are distinct biological species, but the similarity of rRNA sequences suggests that they only recently diverged. C. shehatae is comprised of three genetically divergent (ca. 50% DNA relatedness) subgroups that were accorded varietal status: C. shehatae var. shehatae, var. Lignosa and var. insectosa. Estimates of phylogenetic distance from rRNA sequence similarity show C. shehatae and P. stipitis to be more closely related to Pachysolen tannophilus than to Saccharomyces cerevisiae, and that all of these budding yeasts are well separated from Schizosaccharomyces pombe.     

A taxonomic study of soil yeasts

Summary Eighty-four samples of Minnesota soils were collected in the spring of the year. All samples yielded yeasts, and a total of 180 cultures were isolated of which 117 were studied taxonomically. Twenty-five cultures were black yeasts. Approximately one-third of the isolates were spore forming yeasts and members of the oxidative and film forming generaHansenula, Pichia, andDebaryomyces, of which a new species (D. mrakii) has been described. Not a single culture ofSaccharomyces was isolated. Perhaps later in the season when fruit was abundant members of this genus would have been present.The greatest number of imperfects belonged to the genusCandida (32 cultures), althoughPullularia (25 cultures),Rhodotorula (20 cultures), andTorulopsis (16 cultures) were well represented.The cultures ofPullularia darkened very slowly if at all, in the asbence of excess sugar. Under these circumstances they were very similar toT. pullulans.A single culture ofTrichisporon cerebriformis was isolated. The culture isolated formed both blastospores and arthrospores.I would like to express my appreciation to Dr.C. E. Skinner of Washington State College, for his help and guidance throughout this entire problem. I would also like to thank Dr.E. M. Mark, of the University of California, Berkeley, for the privilege of working under his direction, and in his laboratory during the study.     

Caffeinated soft drinks reduce bacterial prevalence in voice prosthetic biofilms

Laryngectomized patients use indwelling silicone rubber voice prostheses, placed in a surgically created fistula in between the trachea and the esophagus, for voice and speech rehabilitation. At the esophageal side, these voice prostheses rapidly become colonized by a thick biofilm consisting of a variety of oral and skin bacteria and yeasts, and on average, after 3–4 months a prosthesis has to be replaced. In this study, the influence of caffeinated soft drinks on biofilm formation on silicone rubber voice prostheses has been investigated in a modified Robbins device. Robbins devices were first inoculated with the total cultivable microflora from an explanted voice prosthesis for 3 d, after which the devices were perfused three times daily over a 12 day period with 650 ml of either phosphate buffered saline or carbonated mineral water (controls), caffeinated soft drinks (two types), or a decaffeinated and a sugar‐free version of one of the caffeinated soft drinks. At the end of a day, during the experimental period, the devices were filled with growth medium for 30 min. Both caffeinated soft drinks reduced bacterial prevalence in the biofilms to 1–5% of the control, while yeasts thrived in voice prosthetic biofilms exposed to caffeinated soft drinks. Neither the controls, nor the decaffeinated soft drink, nor the sugar‐free version of this showed these effects on bacterial prevalence.     

Relative contribution of nematodes (Caenorhabditis elegans) and bacteria towards the disruption of flushing patterns and losses in yield and quality of mushrooms (Agaricus bisporus)

Laboratory tests of bacteria isolated from the body surface, or from the gut, of a saprophagous rhabditid nematode Caenorhabditis elegans infesting mushrooms (Agaricus bisporus) showed that some bacteria enhanced nematode reproduction and that others inhibited it. As some bacteria were shown to inhibit mycelial growth of the mushroom, the effects of Acinetobacter calcoaceticus var. anitratus, Enterobacter cloacae and Serratia liquefaciens, either alone or in combination with C. elegans, on the flushing patterns, quality and yield of A. bisporus (strain Horst U3) were studied. Bacteria alone had little effect on flushing patterns whereas C. elegans delayed the onset of mushroom production and significantly disrupted the growth pattern of crops, with mushrooms appearing more regularly and not within obvious flushes. Inoculation with bacteria resulted in ‘browning’ of mushrooms that was even more pronounced in C. elegans treatments. Characteristic distortion of sporophores was observed only in the presence of C. elegans. Nematodes commonly colonised sporophores. Bacteria affected the size of nematode populations both on the sporophores and in the casing. Significant yield loss occurred; up to 10% when bacteria were inoculated, up to 27.8% when C. elegans was inoculated, and up to 35% with both bacteria and nematodes. Synergism between C. elegans and A. calcoaceticus var. anitratus was observed; the combination resulted in significantly greater reduction in mushroom yield than any other treatment. It is concluded that bacteria contribute to yield loss and quality deterioration in A. bisporus but that the effects are far greater in the presence of C. elegans.     

Yeasts and Yeast-Like Fungi Associated with Tree Bark: Diversity and Identification of Yeasts Producing Extracellular Endoxylanases

A total of 239 yeast strains was isolated from 52 tree bark samples of the Medaram and Srisailam forest areas of Andhra Pradesh, India. Based on analysis of D1/D2 domain sequence of 26S rRNA gene, 114 strains were identified as ascomycetous; 107 strains were identified as basidiomycetous yeasts; and 18 strains were identified as yeast-like fungi. Among the ascomycetous yeasts, 51% were identified as members of the genus Pichia, and the remaining 49% included species belonging to the genera Clavispora, Debaryomyces, Kluyveromyces, Hanseniaspora, Issatchenkia, Lodderomyces, Kodamaea, Metschnikowia, and Torulaspora. The predominant genera in the basidiomycetous yeasts were Cryptococcus (48.6%), Rhodotorula (29%), and Rhodosporidium (12.1%). The yeast-like fungi were represented by Aureobasidium pullulans (6.7%) and Lecythophora hoffmanii (0.8%). Of the 239 yeast strains tested for Xylanase, only five strains of Aureobasidium sp. produced xylanase on xylan-agar medium. Matrix-assisted laser desorption ionization-time of flight analysis and N-terminal amino-acid sequence of the xylanase of isolate YS67 showed high similarity with endo-1-4-β-xylanase (EC 3.2.1.8) of Aureobasidium pullulans var. melanigenum. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.