Determination of phenol biodegradation pathways in three psychrotolerant yeasts, Candida subhashii A011, Candida oregonensis B021 and Schizoblastosporion starkeyi-henricii L012, isolated from Rucianka peatland.

In this study, three psychrotolerant phenol-degrading yeast strains Candida subhashii (strain A011), Candida oregonenis (strain B021) and Schizoblastosporion starkeyi-henricii (strain L012) isolated from Rucianka peatland were examined to determine which alternative metabolic pathway for phenol biodegradation is used by these microorganisms. All yeast strains were cultivated in minimal salt medium supplemented with phenol at 500, 750 and 1000 mg l-1 concentration with two ways of conducting phenol biodegradation experiments: with and without the starving step of yeast cells. For studied yeast strains, no catechol 2,3-dioxygenase activities were detected by enzymatic assay and no products of catechol meta-cleavage in yeast cultures supernatants (GC-MS analysis), were detected. The detection of catechol 1,2-dioxygenase activity and the presence of cis,cis-muconic acid in the analyzed samples revealed that all studied psychrotolerant yeast strains were able to metabolize phenol via the ortho-cleavage pathway. Therefore, they may be tested in terms of their use to develop biotechnology for the production of cis,cis-muconic acid, a substrate used in the production of plastics (PET) and other valuable goods.

Dihydroisocoumarins produced by Diaporthe cf. heveae LGMF1631 inhibiting citrus pathogens.

Citrus black spot (CBS) and post-bloom fruit drop (PFD), caused by Phyllosticta citricarpa and Colletotrichum abscissum, respectively, are two important citrus diseases worldwide. CBS depreciates the market value and prevents exportation of citrus fruits to Europe. PFD under favorable climatic conditions can cause the abscission of flowers, thereby reducing citrus production by 80%. An ecofriendly alternative to control plant diseases is the use of endophytic microorganisms, or secondary metabolites produced by them. Strain LGMF1631, close related to Diaporthe cf. heveae 1, was isolated from the medicinal plant Stryphnodendron adstringens and showed significant antimicrobial activity, in a previous study. In view of the potential presented by strain LGMF1631, and the absence of chemical data for secondary metabolites produced by D. cf. heveae, we decided to characterize the compounds produced by strain LGMF1631. Based on ITS, TEF1, and TUB phylogenetic analysis, strain LGMF1631 was confirmed to belong to D. cf. heveae 1. Chemical assessment of the fungal strain LGMF1631 revealed one new seco-dihydroisocoumarin [cladosporin B (1)] along with six other related, already known dihydroisocoumarin derivatives and one monoterpene [(-)-(1S,2R,3S,4R)-p-menthane-1,2,3-triol (8)]. Among the isolated metabolites, compound 5 drastically reduced the growth of both phytopathogens in vitro and completely inhibited the development of CBS and PFD in citrus fruits and flowers. In addition, compound 5 did not show toxicity against human cancer cell lines or citrus leaves, at concentrations higher than used for the inhibition of the phytopathogens, suggesting the potential use of (-)-(3R,4R)-cis-4-hydroxy-5-methylmellein (5) to control citrus diseases.

Soil fungal biodiversity and pathogen identification of rotten disease in Aconitum carmichaelii (Fuzi) roots.

Aconitum carmichaelii, commonly known as Fuzi, is a typical traditional Chinese medicine (TCM) herb that has been grown for more than one thousand years in China. Although root rot disease has been seriously threatening this crop in recent years, few studies have investigated root rot disease in Fuzi, and no pathogens have been identified. In this study, fungal libraries from rhizosphere soils were constructed by internal transcribed spacer (ITS) sequencing using the HiSeq 2500 high-throughput platform. A total of 948,843 tags were obtained from 17 soil samples, and these corresponded to 195,583,495 nt. At 97% identity, the libraries yielded 12,266 operational taxonomic units (OTUs), of which 97.5% could be annotated. In sick soils, Athelia, Mucor and Mortierella were the dominant fungi, comprising 10.3%, 10.1% and 7.7% of the fungal community, respectively. These fungi showed 2.6-, 1.53- to 6.31- and 1.38- to 2.65-fold higher enrichment in sick soils compared with healthy soils, and their high densities reduced the fungal richness in the areas surrounding the rotted Fuzi roots. An abundance analysis suggested that A. rolfsii and Mucor racemosus, as the dominant pathogens, might play important roles in the invading Fuzi tissue, and Phoma adonidicola could be another pathogenic fungus of root rot. In contrast, Mortierella chlamydospora, Penicillium simplicissimum, Epicoccum nigrum, Cyberlindnera saturnus and Rhodotorula ingeniosa might antagonize root rot pathogens in sick soils. In addition, A. rolfsii was further verified as a main pathogen of Fuzi root rot disease through hypha purification, morphological observation, molecular identification and an infection test. These results provide theoretical guidance for the prevention and treatment of Fuzi root rot disease.

Identification of Ophiocordyceps sinensis and Its Artificially Cultured Ophiocordyceps Mycelia by Ultra-Performance Liquid Chromatography/Orbitrap Fusion Mass Spectrometry and Chemometrics.

Since the cost of Ophiocordyceps sinensis, an important fungal drug used in Chinese medicine, has increased dramatically, and the counterfeits may have adverse health effects, a rapid and precise marker using the peptide mass spectrometry identification system could significantly enhance the regulatory capacity. In this study, we determined the marker peptides in the digested mixtures of fungal proteins in wild O. sinensis fruiting bodies and various commercially available mycelium fermented powders using ultra-performance liquid chromatography/Orbitrap Fusion mass spectrometry coupled with chemometrics. The results indicated the following marker peptides: TLLEAIDSIEPPK (m/z 713.39) was identified in the wild O. sinensis fruiting body, AVLSDAITLVR (m/z 579.34) was detected in the fermented O. sinensis mycelium powder, FAELLEK (m/z 849.47) was found in the fermented Ophiocordyceps mycelium powder, LESVVTSFTK (m/z 555.80) was discovered in the artificial Ophiocordyceps mycelium powder, and VPSSAVLR (m/z 414.75) was observed in O. mortierella mycelium powder. In order to verify the specificity and applicability of the method, the five marker peptides were synthesized and tested on all samples. All in all, to the best of our knowledge, this is the first time that mass spectrometry has been employed to detect the marker peptides of O.sinensis and its related products.

Assessing the biodegradation of polycyclic aromatic hydrocarbons and laccase production by new fungus Trematophoma sp. UTMC 5003.

Environmental pollution caused by petroleum compounds has become a global concern. The aim of this study was to evaluate the indigenous fungal isolates in Iran for biodegradation of crude oil pollutants. In order to isolate fungal strains, the soil samples were enriched in minimal salts medium (MSM) with 1% crude oil and then the crude oil degradation was measured by total petroleum hydrocarbon (TPH) assay. The degradation of hydrocarbons compounds was also analysed by FT-IR and HPLC, and the activity of peroxidase enzyme and biosurfactant production were also measured. We isolated 40 fungal strains and selected the isolate G-05 with 70% degradation ability of petroleum hydrocarbons as a premium isolate after 15 days. Residual crude oil analysis with FT-IR spectrophotometry and HPLC showed that G-05 is able to degrade 90 and 100% of aliphatic compounds and some polycyclic aromatic hydrocarbons (PAH), respectively. Evaluation of enzymatic activity showed that this isolate can produce 4 U L-1 of Laccase enzyme for oil removal; it is capable of producing biosurfactant and reducing the surface tension of the medium to 25.95 ± 0.1 m Nm-1. This strain was identified as a member of Trematophoma genus and the obtained results showed that this strain is a highly potent strain in bioremediation of soils contaminated by crude oil.

Ogataea kolombanensis sp. nov., Ogataea histrianica sp. nov. and Ogataea deakii sp. nov., three novel yeast species from plant sources.

Nine methanol-assimilating yeast strains isolated from olive oil sediments in Slovenia, extra virgin olive oil from Italy and rotten wood collected in Hungary were found to form three genetically separated groups, distinct from the currently recognized yeast species. Sequence analysis from genes of the small subunit (SSU) rRNA, internal transcribed spacer region/5.8S rRNA, large subunit (LSU) rRNA D1/D2 domains and translational elongation factor-1α (EF-1α) revealed that the three closely related groups represent three different undescribed yeast species. Sequence analysis of the LSU rRNA gene D1/D2 domains placed the novel species in the Ogataea clade. The three novel species are designated as Ogataea kolombanensis sp. nov. (type strain: ZIM 2322(T) = CBS 12778(T) = NRRL Y-63657(T)), Ogataea histrianica sp. nov. (type strain: ZIM 2463(T) = CBS 12779(T) = NRRL Y-63658(T)) and Ogataea deakii sp. nov. (type strain: NCAIM Y.01896(T) = CBS 12735(T) = NRRL Y-63656(T)).

Sporopachydermia cereana fungaemia in refractory leukaemia presenting as breakthrough infection during micafungin therapy.

The Sporopachydermia cereana species lives in decaying stems of cactus and is exceptionally rare as a human pathogen. A 57-year-old man with therapy-refractory acute promyelocytic leukaemia developed severe neutropaenia. After about 3 weeks of micafungin used as prophylaxis, he developed high fever, multiple pulmonary nodular infiltrates and a painful leg lesion. Blood culture yielded a yeast which was not identified by the Vitek 2 system. On ITS1-5.8S-ITS2 gene sequencing, the isolate was identified as S. cereana. Antifungal sensitivity by the Etest showed that the minimum inhibitory concentration for fluconazole was 0.75 µg/mL, and for anidulafungin, it was >32 µg/mL. He responded to liposomal amphotericin B but later died of Escherichia coli septicaemia. There were no cactus plants in the vicinity, suggesting that S. cereana might have alternative habitats.

Yamadazyma terventina sp. nov., a yeast species of the Yamadazyma clade from Italian olive oils.

During an investigation of olive oil microbiota, three yeast strains were found to be divergent from currently classified yeast species according to the sequences of the D1/D2 domain of the gene encoding the rRNA large subunit (LSU) and the internal transcribed spacer region including the gene for 5.8S rRNA. Phylogenetic analysis revealed that these strains, designated CBS 12509, CBS 12510(T) and CBS 12511, represent a novel anascosporogenous species described herein as Yamadazyma terventina sp. nov; the type strain is DAPES 1924(T) (= CBS 12510(T) = NCAIM Y.02028(T)). This novel species was placed in the Yamadazyma clade, with Yamadazyma scolyti, Candida conglobata and Candida aaseri as closest relatives. Y. terventina differs from the above-mentioned species in the ability to strongly assimilate dl-lactate and weakly assimilate ethanol.

[Blastoschizomyces capitatus fungemia: three case reports and review of the literature]. / Blastoschizomyces capitatus'un Etken Oldugu Fungemi: Üç Olgu Sunumu ve Literatürün Gözden Geçirilmesi.

Blastoschizomyces capitatus is a rare fungal pathogen that may lead to fatal infections especially in immunosuppressive individuals. In this report, three cases of B.capitatus were presented. The patients were under treatment for acute myeloid leukemia and their blood cultures yielded B.capitatus. The patients clinical conditions deteriorated and they died despite amphotericin B treatment. The isolates were identified by conventional mycological methods and API 20C AUX (Bio-Mérieux, France) system. Antifungal susceptibility test of the strains was performed with Sensititre Yeast One Panel (Trek Diagnostic Systems, USA) and minimum inhibitory concentration (MIC) ranges for amphotericin B, caspofungin, fluconazole, itraconazole, voriconazole, posaconazole, and flucytosine were found as 0.5-1; > 16; 8-16; 0.5; 0.25; 0.5-1 and 0.06-0.25 µg/ml, respectively. Isolated strains were genotyped with RAPD-PCR (Random Amplified Polymorphic DNA-Polymerase Chain Reaction) using Cnd-3, Cnd-4, OPE-03, OPE-18 primers. The strains isolated from the first two cases were found to be genotypically identical, while the strain isolated from the third case was different. Genotypically identical isolates belonged to two patients who were admitted to the hospital with approximately 18 months interval. The other strain with a unique genotype, was isolated from a patient who was admitted to the hospital about two years later than the other two patients. In conclusion, B.capitatus should be considered as an important opportunistic pathogen especially in patients with hematologic malignancies. The data of this study demonstrated that the lowest MIC values for B.capitatus strains were with voriconazole.

Potential utilization of sorghum field waste for fuel ethanol production employing Pachysolen tannophilus and Saccharomyces cerevisiae.

In this study, we demonstrate that the sorghum field waste, sorghum stover could be used to produce fuel grade ethanol. The alkaline treatment of 2% NaOH for 8h removed 64% of lignin from sorghum stover. Maximum of 68 and 56 g/L of ethanol yield were obtained by Saccharomyces cerevisiae (MTCC 173) and Pachysolen tannophilus (MTCC 1077) from sorghum stover under optimized condition, respectively. pH and temperature were optimized for the better growth of S. cerevisiae and P. tannophilus. A total of 51% and 48% more ethanol yield was obtained at initial sugar concentration of 200 g/L than 150 g/L by P. tannophilus and S. cerevisiae, respectively. Respiratory deficiency and ethanol tolerance of the organisms were studied. This investigation showed that sorghum field waste could be effectively used for the production of fuel ethanol to avoid conflicts between human food use and industrial use of crops.

Wickerhamomyces ochangensis sp. nov., an ascomycetous yeast isolated from the soil of a potato field.

A novel ascomycetous yeast, designated strain N7a-Y2(T), was isolated from soil collected in a potato field in Ochang, Korea, and its taxonomic position was studied. A neighbour-joining tree based on the D1/D2 domain of large-subunit rRNA gene sequences revealed that the isolate was a member of the Wickerhamomyces clade and that it was closely related to Wickerhamomyces bisporus, Candida quercuum, Candida ulmi and Wickerhamomyces alni. Strain N7a-Y2(T) formed Saturn-shaped ascospores in unconjugated and persistent asci. D1/D2 domain 26S rRNA gene sequence divergences of 11.0-21.1 % between strain N7a-Y2(T) and other members of the Wickerhamomyces clade indicate that the strain represents a novel species of the genus Wickerhamomyces, for which the name Wickerhamomyces ochangensis sp. nov. is proposed. The type strain is N7a-Y2(T) ( = KCTC 17870(T)  = CBS 11843(T)).

[Characteristics of three species of genus Debaryomyces Lodder & Kreger-van Rij].

A taxonomic state of the collection strains of three marketable species of genus Debaryomyses has been specified. Sources of their isolation have been analyzed and a list of econiches where the yeast occur has been supplemented. The properties have been found which are recommended to be used as additional for differentiation of D. hansenii, D. polymorphus, D. pseudopolymorphus species (that was the ability to assimilate nitrites, growth in the medium with 24 % of NaCl, synthesis of riboflavin, availability of jelatinase activity).

Metschnikowia strains isolated from botrytized grapes antagonize fungal and bacterial growth by iron depletion.

Noble-rotted grapes are colonized by complex microbial populations. I isolated pigment-producing Metschnikowia strains from noble-rotted grapes that had antagonistic activity against filamentous fungi, yeasts, and bacteria. A red-maroon pigment was formed from a diffusible colorless precursor released by the cells into the medium. The conversion of the precursor required iron and could occur both in the cells (red colonies) and in the medium (red halos around colonies). The intensity of pigmentation was correlated with the intensity of the antimicrobial activity. Mutants that did not form pigment also lacked antifungal activity. Within the pigmented halos, conidia of the sensitive fungi did not germinate, and their hyphae did not grow and frequently lysed at the tips. Supplementation of the medium with iron reduced the size of the halos and the inhibition zones, while it increased the pigment accumulation by the colonies. The iron-binding agent tropolone had a similar effect, so I hypothesize that pigmented Metschnikowia isolates inhibit the growth of the sensitive microorganisms by pigment formation, which depletes the free iron in the medium. As the pigment is a large nondiffusible complex produced in the presence of both low and high concentrations of ferric ions, the proposed mechanism is different from the mechanisms operating in microbes that release siderophores into the environment for iron acquisition.

Application of waste activated bleaching earth containing rapeseed oil on riboflavin production in the culture of Ashbya gossypii.

Waste activated bleaching earth (ABE) that contained 40% rapeseed oil and was discharged by an oil refinery plant, was used for riboflavin production in a culture of Ashbya gossypii. When 125 g/L waste ABE that contained 50 g/L rapeseed oil was added into the culture, the riboflavin concentration was 1.12 g/L, which was almost 1.6-fold as high as that of pure rapeseed oil. However, in waste ABE concentration higher than 125 g/L, the produced riboflavin concentration decreased, which was due to the difficulty in mixing due to the presence of a high amount of solid material in the culture. The surface of the waste ABE was smooth without a hitch, because of being covered with rapeseed oil. However, after the culture, the surface of the waste ABE seemed like that of new one, and the oil content was nearly zero grams per liter. The waste ABE, oily clay, and its black color gradually fade and yellow little by little, and finally the waste ABE changed to yellow powder. Of the riboflavin produced during the culture, 70% was adsorbed in the oil free waste ABE. With diluted alkali solution, extraction only two times yielded 90% recovery of riboflavin adsorbed in the waste ABE. The waste ABE containing waste vegetable oil was suitable for raw material for production of the value-added useful bioproducts, which might be a good model for reuse of the waste resource.

Dipodascus starmeri sp. nov., a new species of yeast occurring in cactus necroses.

In a previous publication describing the geographic distribution of yeasts associated with cactus necroses (W. T. Starmer, M.-A. Lachance, H. J. Phaff, and W. B. Heed, Evol. Biol. 24:253-296, 1990), 127 isolates were identified as strains of Candida ingens van der Walt et van Kerken on the basis of morphology and certain phenotypic characteristics. Here we show by using DNA hybridization and additional phenotypic properties that these strains were misidentified and that they represent a minimum of three separate species that can be differentiated from C. ingens and from each other by utilization of 2-propanol or acetone, sensitivity to digitonin, utilization of L-lysine as a sole nitrogen source, vitamin dependence, NaCl tolerance, lipolytic activity, and habitat. One of the new species is haploid and heterothallic, and its teleomorph represents the genus Dipodascus. We describe Dipodascus starmeri sp. nov. The phylogenetic relationship of D. starmeri with other members of the genus Dipodascus and its anamorph, the genus Geotrichum, was estimated from ribosomal DNA nucleotide sequence divergence. The type strain, a heterothallic haploid isolate, is UCD-FST 72-316 (= CBS 780.96 = ATCC 200546 = NRRL Y-17816). The complementary mating type is UCD-FST 81-513.3 (= CBS 781.96 = ATCC 200547 = NRRL Y-17817).