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Guehomyces Fell & Scorzetti (2004)
Chapter 143
Guehomyces Fell & Scorzetti (2004) Jack W. Fell and Eveline Gue´ho-Kellermann
DIAGNOSIS OF THE GENUS Asexual reproduction: Budding cells are ovoid to cylindrical and may be enteroblastic. Extensive hyphal growth disarticulates to form arthroconidia. Sexual reproduction: Unknown. Physiology/biochemistry: Tests for urea hydrolysis and the diazonium blue B reaction are positive. Sugars are not fermented. Coenzyme Q-9 is the predominant ubiquinone. Phylogenetic placement: Order Cystofilobasidiales, class Tremellomycetes (Fig. 143.1).
TYPE SPECIES Guehomyces pullulans (Lindner) Fell & Scorzetti
SPECIES ACCEPTED 1. Guehomyces pullulans (Lindner) Fell & Scorzetti (2004)
SYSTEMATIC DISCUSSION OF THE SPECIES 143.1. Guehomyces pullulans (Lindner) Fell & Scorzetti (2004) Synonyms: Oidium pullulans Lindner (1895) Oospora pullulans (Lindner) Lindau (1907) Oosporidium fuscans Stautz (1931)1 Monilia pullulans (Lindner) Langeron & Talice (1932) Trichosporon fuscans (Stautz) Buchwald (1939) Trichosporon pullulans (Lindner) Diddens & Lodder (1942) Basidiotrichosporon pullulans (Lindner) Kocková-Kratochvílová, Slavikova & Zemek (1977b)
are prevalent that become ovoid, or spheroid to ellipsoid and measure 9 3 9 20 μm. Growth in glucose yeast extract peptone broth: After 3 days at 20 C, budding cells are ovoid to cylindrical, seldom globose, 3.5 7 3 5.3 21 μm, single or in pairs. A dull or moist, smooth or rough, creeping pellicle is usually formed, or islets and an incomplete ring may form. The sediment is scarce or absent. Dalmau plate culture on corn meal agar: True hyphae and arthroconidia are abundant; pseudohyphae are sparse to abundant with spherical or ovoid to elongate blastoconidia, which arise singly, in pairs, short chains or as wreaths (Fig. 143.2).
Fermentation: Absent. Growth (in Liquid Media at 20 C)
1
Synonymy determined from nuclear DNA DNA reassociation (Guého et al. 1992a).
Growth on Sabouraud's glucose agar: After 10 days at 20 22 C, the colonies are flat and soft with a fringed margin. Initially the colonies are smooth and cream-colored; later they have a whitish, velutinous covering that becomes tan to an orange-like color. Colonies are 19 22 mm in diameter. There is a faint odor. Initial budding is enteroblastic; in older cultures disarticulating hyphae
The Yeasts, a Taxonomic Study © 2011 Elsevier B.V. All rights reserved.
Glucose Inulin Sucrose Raffinose Melibiose Galactose Lactose Trehalose Maltose
1 2 1 1 1 1 1 1 1
D-Ribose Methanol Ethanol Glycerol Erythritol Ribitol Galactitol D-Mannitol D-Glucitol
v 2 1 v 1 1 2 1 1
1773
1774 Melezitose Methyl-α-D-glucoside Soluble starch Cellobiose Salicin L-Sorbose L-Rhamnose D-Xylose L-Arabinose D-Arabinose
PART | VC myo-Inositol
v 1 1 1 v v v 1 1 v
Descriptions of Anamorphic Basidiomycetous Genera and Species
1 2 1 1 1 2 2 n 1 v
DL-Lactate
Succinate Citrate D-Gluconate D-Glucosamine N-Acetyl-D-glucosamine Hexadecane Nitrate Vitamin-free
Additional Growth Tests and Other Characteristics Xylitol 2-Keto-D-gluconate 5-Keto-D-gluconate D-Glucuronate Nitrite Cadaverine L-Lysine Creatine
1 1 1 1 1 v v 2
Ethylamine 10% NaCl/5% glucose 50% Glucose medium Starch formation DBB Growth at 21 C Growth at 25 C Growth at 30 C
v 1 1 1 1 1 v 2
Mrakia gelida CBS 5272T / AF189831 97
Mrakia frigida CBS 5270T / AF075463 Mrakia psychrophila AS 2.1921T / EU224266
100
Mrakiella cryoconiti CBS 10834T / AJ866978 Mrakiella cryoconiti CBS 10835 / AJ866979 Mrakiella aquatica CBS 5443T / AF075470 Guehomyces pullulans CBS 2532T / AF105394
100
Tausonia pamirica CBS 8428T / EF118825 Udeniomyces megalosporus CBS 7236T / AF075510 Udeniomyces puniceus CBS 5689T / AF075519
100
100
Udeniomyces pyricola CBS 6754T / AF075507
100
100
Udeniomyces pannonicus JCM 11145T / AB077382 Itersonilia perplexans CBS 363.85 / AJ235274
100
Mrakia curviuscula CBS 9136T / EF118826 Cryptococcus huempii CBS 8186T / AF189844 Cystofilobasidium capitatum CBS 6358T / AF075465 Cystofilobasidium ferigula CBS 6954 / AF444709 100
Cystofilobasidium bisporidii CBS 6347/ AF075464 Cystofilobasidium macerans CBS 2206T / AF189848 Cystofilobasidium infirmominiatum CBS 323T / AF075505 Xanthophyllomyces dendrorhous CBS 7918T / AF075496
100
Phaffia rhodozyma CBS 5905T / AF189871 Xanthophyllomyces dendrorhous CBS 9090 / AF444721
Cryptococcus fuscescens CBS 7189T / AF075472 Cryptococcus aerius CBS 155T / AF075486 Cryptococcus terricola CBS 6435T / AF181545 10 changes FIGURE 143.1 Phylogenetic relationship of Guehomyces within the Cystofilobasidiales. Neighbor joining tree based on D1/D2 LSU rRNA gene sequence analysis. Numbers on the branches represent bootstrap values from 1000 replicates in a full heuristic search.
Chapter | 143
Guehomyces Fell & Scorzetti (2004)
FIGURE 143.2 Guehomyces pullulans CBS 2532 grown on corn meal agar for 3 weeks at 20 C. The hyphae disarticulate into arthroconidia. Blastoconidia are also present on the hyphae. Bar 5 10 μm. CoQ: 9 (Guého et al. 1992b, Yamada et al. 1982). Mol% G 1 C: 56.6 57.3, CBS 2532, CBS 2535, CBS 2540, CBS 2542, IP 110 (WG 64132), IP 114 (WG 6459) (Tm: Guého et al. 1992b, Hara et al. 1989), 58.9 59.0 CBS 2540, CBS 2542 (BD: Guého et al. 1984). Gene sequence accession numbers, type strain: D1/D2 LSU rRNA 5 AF105394. Cell carbohydrates: CBS 2532T has glucose, mannose, xylose and moderate glucosamine in whole cell hydrolysates (Weijman 1979). Origin of the strains studied: The type strain (CBS 2532) was isolated as Oospora pullulans from an air sample obtained from a hop field in Germany (Lindner 1895). The Oospora fuscans type strain (CBS 2535) was isolated from exudates of a chestnut (Castenea) tree in Germany (Stautz 1931). Other strains (CBS website) were collected from sap of a maple (Acer) tree in The Netherlands (CBS 2542), frozen beef in Brisbane, Australia (CBS 2540), butter in Denmark (CBS 2541) and arctic soil (IP110 and IP 114). Type strain: CBS 2532. Systematics: The presence of extensive true hyphae with arthroconidia is a typical characteristic of the genus Trichosporon and, as a consequence, Diddens and Lodder (1942) assigned the species to that genus. Phenotypically, Guehomyces pullulans can be distinguished from species of Trichosporon by the utilization of nitrates. Guého et al. (1992b), who investigated the D2 LSU rRNA sequence, reported that the species was phylogenetically distinct from Trichosporon. Additional comparative sequence analysis of the D1/D2 and ITS rRNA regions (Fell et al. 1998, Scorzetti et al. 2002) placed the species among the Cystofilobasidiales, which prompted the creation of the genus Guehomyces and the transfer of T. pullulans to that genus (Fell and Scorzetti 2004). Ecology: The species has diverse habitats. Sources include soil (Slavikova et al. 2002), plants (Kvasikov et al. 1975b, Middelhoven 2003, Stautz 1931), pigeon feces (Gallo et al. 1989) and a nasal infection in a cat (Greene et al. 1985). The CBS website lists strains from sawdust in Sweden, frozen beef in Australia, butter in Denmark, brewery beer pipe in The Netherlands and sap of birch tree in
1775 Finland, a maple tree in The Netherlands and a chestnut tree in Germany. Biotechnology: Guehomyces pullulans has been studied for enzymatic activities that can be applied to the degradation of industrial waste products. Romer et al. (2002) reported that G. pullulans inhabits sediments, which are heavily polluted with discharges from oil refineries. The species may play a role in degradation of pollutants as demonstrated by the ability to hydroxylate dibenzofuran, which is a xenobiotic that is not easily transformed. The species also has the ability to transform recalcitrant lignin by-products associated with beechwood pulping (Slavikova et al. 2002). Similarly, G. pullulans' enzymatic activities have been examined in conjunction with the hydrolysis of lactose in milk. Production of novel beta-galactosidases was found at temperatures as low as 0 C (Nakagawa et al. 2006). Agriculture and food: Guehomyces pullulans has been investigated as a biocontrol agent to limit fungal postharvest decay in pears (Yao et al. 2004). The species is associated with decay of tomatoes (Wade et al. 2003). Clinical importance: Guehomyces pullulans (as T. pullulans) has been reported as an opportunistic pathogen with high morbidity and mortality in immunocompromised patents with neutropenia, particularly in association with chronic granulomatous disease (Lestini and Church 2006, Moylett et al. 2003) and catheter-related infections in cancer patients (Krcméry et al. 1999). Such infections are known to occur with members of the genera Trichosporon and Cryptococcus. However, human disease-related associations with G. pullulans seem unlikely. G. pullulans is a low-temperature organism with a maximum temperature of approximately 25 C, growth is not present at 30 C, and consequently there would seem to be little potential for the species to grow at the temperature of the human body (37 C). Consequently, Holland et al. (2004b) challenged a report of Moylett et al. (2003) on the grounds that the strain was inaccurately identified with a commercial identification kit. In response, Moylett et al. (2004) sequenced the ITS region and found that the strain was closely allied to Cryptococcus adeliensis. The authors noted that previous reports of disease associations of G. pullulans may have been misidentified strains of Cryptococcus spp. Commercial kits do not reliably identify clinical isolates (Dooley et al. 1994). Consequently, questionable reports continue to appear that present G. pullulans as a pathogen. These identification errors can be avoided by testing nitrate assimilation and capacity to grow at 37 C, or through the use of molecular methods such as sequencing or PCR primers and probes.
COMMENTS ON THE GENUS Guehomyces appears to be closely related to Tausonia. The latter genus was described (Bab'eva 1998) in a Russian journal that is not widely available. Consequently, the authors (Fell and Scorzetti 2004) were unaware of the Tausonia description. The two species Guehomyces pullulans and Tausonia pamirica are distinct (Fig. 143.1) and the genera can be distinguished by the presence of chlamydospore-like structures and clamp connections in Tausonia. The clamp connections suggest the presence of a sexual cycle in Tausonia, which has not been observed in Guehomyces. If the two genera are found to be synonymous, Tausonia has priority owing to the earlier date of publication.
Guehomyces Fell & Scorzetti (2004) Jack W. Fell and Eveline Gue´ho-Kellermann
DIAGNOSIS OF THE GENUS Asexual reproduction: Budding cells are ovoid to cylindrical and may be enteroblastic. Extensive hyphal growth disarticulates to form arthroconidia. Sexual reproduction: Unknown. Physiology/biochemistry: Tests for urea hydrolysis and the diazonium blue B reaction are positive. Sugars are not fermented. Coenzyme Q-9 is the predominant ubiquinone. Phylogenetic placement: Order Cystofilobasidiales, class Tremellomycetes (Fig. 143.1).
TYPE SPECIES Guehomyces pullulans (Lindner) Fell & Scorzetti
SPECIES ACCEPTED 1. Guehomyces pullulans (Lindner) Fell & Scorzetti (2004)
SYSTEMATIC DISCUSSION OF THE SPECIES 143.1. Guehomyces pullulans (Lindner) Fell & Scorzetti (2004) Synonyms: Oidium pullulans Lindner (1895) Oospora pullulans (Lindner) Lindau (1907) Oosporidium fuscans Stautz (1931)1 Monilia pullulans (Lindner) Langeron & Talice (1932) Trichosporon fuscans (Stautz) Buchwald (1939) Trichosporon pullulans (Lindner) Diddens & Lodder (1942) Basidiotrichosporon pullulans (Lindner) Kocková-Kratochvílová, Slavikova & Zemek (1977b)
are prevalent that become ovoid, or spheroid to ellipsoid and measure 9 3 9 20 μm. Growth in glucose yeast extract peptone broth: After 3 days at 20 C, budding cells are ovoid to cylindrical, seldom globose, 3.5 7 3 5.3 21 μm, single or in pairs. A dull or moist, smooth or rough, creeping pellicle is usually formed, or islets and an incomplete ring may form. The sediment is scarce or absent. Dalmau plate culture on corn meal agar: True hyphae and arthroconidia are abundant; pseudohyphae are sparse to abundant with spherical or ovoid to elongate blastoconidia, which arise singly, in pairs, short chains or as wreaths (Fig. 143.2).
Fermentation: Absent. Growth (in Liquid Media at 20 C)
1
Synonymy determined from nuclear DNA DNA reassociation (Guého et al. 1992a).
Growth on Sabouraud's glucose agar: After 10 days at 20 22 C, the colonies are flat and soft with a fringed margin. Initially the colonies are smooth and cream-colored; later they have a whitish, velutinous covering that becomes tan to an orange-like color. Colonies are 19 22 mm in diameter. There is a faint odor. Initial budding is enteroblastic; in older cultures disarticulating hyphae
The Yeasts, a Taxonomic Study © 2011 Elsevier B.V. All rights reserved.
Glucose Inulin Sucrose Raffinose Melibiose Galactose Lactose Trehalose Maltose
1 2 1 1 1 1 1 1 1
D-Ribose Methanol Ethanol Glycerol Erythritol Ribitol Galactitol D-Mannitol D-Glucitol
v 2 1 v 1 1 2 1 1
1773
1774 Melezitose Methyl-α-D-glucoside Soluble starch Cellobiose Salicin L-Sorbose L-Rhamnose D-Xylose L-Arabinose D-Arabinose
PART | VC myo-Inositol
v 1 1 1 v v v 1 1 v
Descriptions of Anamorphic Basidiomycetous Genera and Species
1 2 1 1 1 2 2 n 1 v
DL-Lactate
Succinate Citrate D-Gluconate D-Glucosamine N-Acetyl-D-glucosamine Hexadecane Nitrate Vitamin-free
Additional Growth Tests and Other Characteristics Xylitol 2-Keto-D-gluconate 5-Keto-D-gluconate D-Glucuronate Nitrite Cadaverine L-Lysine Creatine
1 1 1 1 1 v v 2
Ethylamine 10% NaCl/5% glucose 50% Glucose medium Starch formation DBB Growth at 21 C Growth at 25 C Growth at 30 C
v 1 1 1 1 1 v 2
Mrakia gelida CBS 5272T / AF189831 97
Mrakia frigida CBS 5270T / AF075463 Mrakia psychrophila AS 2.1921T / EU224266
100
Mrakiella cryoconiti CBS 10834T / AJ866978 Mrakiella cryoconiti CBS 10835 / AJ866979 Mrakiella aquatica CBS 5443T / AF075470 Guehomyces pullulans CBS 2532T / AF105394
100
Tausonia pamirica CBS 8428T / EF118825 Udeniomyces megalosporus CBS 7236T / AF075510 Udeniomyces puniceus CBS 5689T / AF075519
100
100
Udeniomyces pyricola CBS 6754T / AF075507
100
100
Udeniomyces pannonicus JCM 11145T / AB077382 Itersonilia perplexans CBS 363.85 / AJ235274
100
Mrakia curviuscula CBS 9136T / EF118826 Cryptococcus huempii CBS 8186T / AF189844 Cystofilobasidium capitatum CBS 6358T / AF075465 Cystofilobasidium ferigula CBS 6954 / AF444709 100
Cystofilobasidium bisporidii CBS 6347/ AF075464 Cystofilobasidium macerans CBS 2206T / AF189848 Cystofilobasidium infirmominiatum CBS 323T / AF075505 Xanthophyllomyces dendrorhous CBS 7918T / AF075496
100
Phaffia rhodozyma CBS 5905T / AF189871 Xanthophyllomyces dendrorhous CBS 9090 / AF444721
Cryptococcus fuscescens CBS 7189T / AF075472 Cryptococcus aerius CBS 155T / AF075486 Cryptococcus terricola CBS 6435T / AF181545 10 changes FIGURE 143.1 Phylogenetic relationship of Guehomyces within the Cystofilobasidiales. Neighbor joining tree based on D1/D2 LSU rRNA gene sequence analysis. Numbers on the branches represent bootstrap values from 1000 replicates in a full heuristic search.
Chapter | 143
Guehomyces Fell & Scorzetti (2004)
FIGURE 143.2 Guehomyces pullulans CBS 2532 grown on corn meal agar for 3 weeks at 20 C. The hyphae disarticulate into arthroconidia. Blastoconidia are also present on the hyphae. Bar 5 10 μm. CoQ: 9 (Guého et al. 1992b, Yamada et al. 1982). Mol% G 1 C: 56.6 57.3, CBS 2532, CBS 2535, CBS 2540, CBS 2542, IP 110 (WG 64132), IP 114 (WG 6459) (Tm: Guého et al. 1992b, Hara et al. 1989), 58.9 59.0 CBS 2540, CBS 2542 (BD: Guého et al. 1984). Gene sequence accession numbers, type strain: D1/D2 LSU rRNA 5 AF105394. Cell carbohydrates: CBS 2532T has glucose, mannose, xylose and moderate glucosamine in whole cell hydrolysates (Weijman 1979). Origin of the strains studied: The type strain (CBS 2532) was isolated as Oospora pullulans from an air sample obtained from a hop field in Germany (Lindner 1895). The Oospora fuscans type strain (CBS 2535) was isolated from exudates of a chestnut (Castenea) tree in Germany (Stautz 1931). Other strains (CBS website) were collected from sap of a maple (Acer) tree in The Netherlands (CBS 2542), frozen beef in Brisbane, Australia (CBS 2540), butter in Denmark (CBS 2541) and arctic soil (IP110 and IP 114). Type strain: CBS 2532. Systematics: The presence of extensive true hyphae with arthroconidia is a typical characteristic of the genus Trichosporon and, as a consequence, Diddens and Lodder (1942) assigned the species to that genus. Phenotypically, Guehomyces pullulans can be distinguished from species of Trichosporon by the utilization of nitrates. Guého et al. (1992b), who investigated the D2 LSU rRNA sequence, reported that the species was phylogenetically distinct from Trichosporon. Additional comparative sequence analysis of the D1/D2 and ITS rRNA regions (Fell et al. 1998, Scorzetti et al. 2002) placed the species among the Cystofilobasidiales, which prompted the creation of the genus Guehomyces and the transfer of T. pullulans to that genus (Fell and Scorzetti 2004). Ecology: The species has diverse habitats. Sources include soil (Slavikova et al. 2002), plants (Kvasikov et al. 1975b, Middelhoven 2003, Stautz 1931), pigeon feces (Gallo et al. 1989) and a nasal infection in a cat (Greene et al. 1985). The CBS website lists strains from sawdust in Sweden, frozen beef in Australia, butter in Denmark, brewery beer pipe in The Netherlands and sap of birch tree in
1775 Finland, a maple tree in The Netherlands and a chestnut tree in Germany. Biotechnology: Guehomyces pullulans has been studied for enzymatic activities that can be applied to the degradation of industrial waste products. Romer et al. (2002) reported that G. pullulans inhabits sediments, which are heavily polluted with discharges from oil refineries. The species may play a role in degradation of pollutants as demonstrated by the ability to hydroxylate dibenzofuran, which is a xenobiotic that is not easily transformed. The species also has the ability to transform recalcitrant lignin by-products associated with beechwood pulping (Slavikova et al. 2002). Similarly, G. pullulans' enzymatic activities have been examined in conjunction with the hydrolysis of lactose in milk. Production of novel beta-galactosidases was found at temperatures as low as 0 C (Nakagawa et al. 2006). Agriculture and food: Guehomyces pullulans has been investigated as a biocontrol agent to limit fungal postharvest decay in pears (Yao et al. 2004). The species is associated with decay of tomatoes (Wade et al. 2003). Clinical importance: Guehomyces pullulans (as T. pullulans) has been reported as an opportunistic pathogen with high morbidity and mortality in immunocompromised patents with neutropenia, particularly in association with chronic granulomatous disease (Lestini and Church 2006, Moylett et al. 2003) and catheter-related infections in cancer patients (Krcméry et al. 1999). Such infections are known to occur with members of the genera Trichosporon and Cryptococcus. However, human disease-related associations with G. pullulans seem unlikely. G. pullulans is a low-temperature organism with a maximum temperature of approximately 25 C, growth is not present at 30 C, and consequently there would seem to be little potential for the species to grow at the temperature of the human body (37 C). Consequently, Holland et al. (2004b) challenged a report of Moylett et al. (2003) on the grounds that the strain was inaccurately identified with a commercial identification kit. In response, Moylett et al. (2004) sequenced the ITS region and found that the strain was closely allied to Cryptococcus adeliensis. The authors noted that previous reports of disease associations of G. pullulans may have been misidentified strains of Cryptococcus spp. Commercial kits do not reliably identify clinical isolates (Dooley et al. 1994). Consequently, questionable reports continue to appear that present G. pullulans as a pathogen. These identification errors can be avoided by testing nitrate assimilation and capacity to grow at 37 C, or through the use of molecular methods such as sequencing or PCR primers and probes.
COMMENTS ON THE GENUS Guehomyces appears to be closely related to Tausonia. The latter genus was described (Bab'eva 1998) in a Russian journal that is not widely available. Consequently, the authors (Fell and Scorzetti 2004) were unaware of the Tausonia description. The two species Guehomyces pullulans and Tausonia pamirica are distinct (Fig. 143.1) and the genera can be distinguished by the presence of chlamydospore-like structures and clamp connections in Tausonia. The clamp connections suggest the presence of a sexual cycle in Tausonia, which has not been observed in Guehomyces. If the two genera are found to be synonymous, Tausonia has priority owing to the earlier date of publication.