Antonie van Leeuwenhoek 56: 283-288, 1989. 9 1989 Kluwer Academic Publishers. Printed in the Netherlands. Zygozyma suomiensis, sp. nov. a new species from Finland (Lipomycetaceae), M A U D Y Th. SMITH 1, J.P. VAN D E R WALT2, Y. YAMADA 3 & W l L M A H. BATENBURG-VAN D E R V E G T E 1 1Centraalbureau voor Schimmelcultures, Yeast Division and Delft University of Technology, Department of Microbiology and Enzyrnology, 2628 BC Delft, The Netherlands; 2Division of Food Science and Technology, Councilfor Scientific and Industrial Research, Pretoria0001, South Africa; 3Laboratory of Applied Microbiology, Department of Agricultural Chemistry, Shizuoka University, Shizuoka 422, Japan Received 19 January 1989; accepted 27 February 1989 Key words: Zygozyma suomiensis, Lipomycetaceae, yeasts, taxonomy Abstract. A new species of the genus Zygozyma, Z. suomiensis, is described, based on the study of a single strain, derived from a bovine skin lesion. Introduction The yeast genus Zygozyma Van der Walt et al. (1987) was introduced to accommodate a single undescribed ascosporogenous species, Z. oligophaga. Forming mucoid colonies on solid media and producing allantoid to cymbiform ascospores in saccate asci, this taxon was considered to be related to both Lipomyces Lodder & Kreger-van Rij and DipodascopsisBatra & Millner. It is distinguished from the former genus by the formation of allantoid, smooth ascospores, and from the latter by the absence of septate hyphae. The taxon can also be differentiated on the basis of its coenzyme Q system, which is CoQ8 in Zygozyma and CoQ9 in both Lipomyces and Dipodascopsis. In the present communication a second species is described, based on the study of a single strain isolated from a bovine skin lesion by E. Tunnela in Turku (Finland) in 1985. Materials and methods The morphological and physiological characters were determined by the conventional techniques described by Van der Walt & Yarrow (1984). Utilization 284 of carbon sources was examined at 25 ~C on a Tissue Culture Rollordrum (New Brunswick), rotating at 40 rph. Results were scored after 3, 7 and 14 days. If complete utilization of carbon source occurred only after 7 days, it was scored as delayed (D). The formation of starch-like compounds was also examined on Aschner's medium at pH 4.5 and pH 6.0. The utilization of nitrogen sources was examined by the conventional auxanographic technique. The ubiquinone isoprenologues were determined by the methods of Yamada & Kondo (1972, 1973). Material for observations by transmission electron microscopy (TEM) was prepared according the methods as previously described (Smith & Batenburg-van der Vegte 1986). The extraction and purification of the nDNA and the determination of the base composition were performed as described by Golubev et al. (1989). The reported mol% G + C reflects the mean and standard deviation of three determinations. Description Zygozyma suomiensis M.Th. Smith, Van der Walt et Yamada sp. nov. ( Lipomycetaceae) In extracto malti post triduum 25~C cellulae globosae, ellipsoideae vel ovoideae, 2.0 - 2.5 x 1.5 - 5.0/zm, incapsulatae, singulae vel binae, gemmantes holoblastice multilateraliter. Crescentia exigua. Post hebdomades 4 temperatura ambeunte sedimentum. In agaro malti post triduum formae et dimensiones cellularum eaedum sunt atque in extracto malti. Post triduum 25~ cultura aquosa mucosescens vel glutinosescens, partim cremea, impellucida, glabra, nitida, margine integro; post hebdomades 4 temperatura ambeunte brunneolo-cremea, mucosa, glabra, nitida, margine integro. In agaro farina Zeae maydis confecta post dies 10 25~ hyphae et pseudohyphae nullae. Asci adsunt post hebdomades 6 temperatura 15~ Asci saccati, 5 . 0 11.0 • 4 . 5 - 7.0/zm, quadri- vel multispori, persistentes, oriundi ex evaginationibus abstrictis inflatis cellularum singularium. Ascosporae allantoideae vel oblongae et intrinque obtusae, 2 . 0 - 4.5 x 1 . 0 - 2.0/zm. Fermentatio et crescentia in variis substratis carbonis et nitrogeni et reliqui characteres in tabula I monstrantur. Typus CBS 7251, isolatus ex pelle laesa bovis, exsiccatus in CBS Baarn, et vivus in collectione zymotica Delphis Batavorum praeservatur. Growth in malt extract After 3 days at 25~ the cells are globose, ellipsoid or ovoid, 2 . 0 - 5.0 x 1 . 5 - 5.0~m, encapsulated, budding multilaterally, occurring singly or in 285 Fig. 1. Ascus with numerous ascospores. (Light microscopy bright field, 1750x) Fig. 2. Germinating ascospores in an ascus (arrow). (Light microscopy bright field, 1750x) Fig. 3. Ascus with four ascospores (oblong with obtuse ends). (Light microscopy bright field, 1750x); Fig. 4. Transmission electron micrograph of an ascus with 3 ascospores. 13000x. 286 pairs. Growth in scant. After 4 weeks at ambient temperature a sediment is present. Growth on malt agar After 3 days at 25~ the cells have the same form and dimensions as in malt extract. The streak culture is viscous to mucoid, partly hyaline, partly creamish-opaque, smooth, glistening, with an entire margin. After 4 weeks at Table 1. Physiological characteristics of Zygozyma suomiensis sp. nov. F e r m e n t a t i o n not observed G r o w t h on carbon sources D-glucose D-Galactose L-Sorbose D-Glucosamine D-Ribose D-Xylose L-Arabinose D-Arabinose L-Rhamnose Sucrose Maltose ct-ct-Trehalose ct-Me-D-glucoside Cellobiose + + + D + + + D Salicin Arbutin Melibiose Lactose Raffinose Melezitose Inulin Soluble starch Glycerol m-Erythritol Ribitol Xylitol L-Arabinitol D-Giucitol D D D + + + + + Cadaverine Creatine Creatinine Imidazol + + D-Mannitol Galactitoi m-Inositol D-Glucono- 1,5-1actone 2-Keto-D-gluconate 5-Keto-D-gluconate D-Gluconate D-Galacturonate DL-Lactate Succinate Citrate Methanol Ethanol Phloroglucinol G r o w t h on nitrogen sources Nitrate Nitrite Ethylamine L-Lysine + + A d d i t i o n a l characteristics G r o w t h in vitamin-free m e d i u m G r o w t h at 30 ~ C G r o w t h at 35~ G r o w t h in presence of 0.1% actidione G r o w t h in 50% (m/m) glucose yeast extract agar F o r m a t i o n of amyloid material Hydrolysis of urea M a j o r ubiquinone Mol % G + C of n D N A + + + (pH dependant) Q8 45.1 ___ 0.2% D D + D D D D + 287 ambient temperature the culture is mucoid, brownish-cream, smooth, shiny, with an entire margin. Dalmau plate cultures on corn meal agar After 10 days at 25 ~C neither septate hyphae nor pseudohyphae are formed. Formation of asci and ascospores Asci with ascospores were observed after 6 weeks of incubation on Difco malt (5%)-agar (3%) medium at 15~C. Asci arise from abstricted inflating evaginations of single cells or individual cells in aggregations. The mature asci are saccate, 5.0 - 11.0 • 4.5 - 7.0/xm, persistent and contain four to numerous (up to 12) ascospores (Fig. 1). The ascospores are allantoid to oblong with obtuse ends (Fig. 3), 2 . 0 - 4.5 • 1 . 0 - 2.0/zm, glabrous by both light microscopy and TEM (Fig. 4). Upon germination the ascospores become swollen within the ascus (Fig. 2). Physiological characterization Fermentation and growth on various carbon compounds, growth on nitrogen sources and some additional properties are summarized in Table 1. Type strain CBS 7251 isolated from a bovine skin lesion, deposited living, in the Yeast Collection of the Centraalbureau voor Schimmelcultures Delft, and dried, in Baarn. D i s c u s s i o n Since the strain studied is distinguished by: hyaline, encapsulated, multilaterally budding cells, mucoid to glutinous colonies, saccate, four- to multispored asci arising from the abstricted, enlarging, evaginations of single cells, elongated to allantoid, palely pigmented, glabrous ascospores, the production of amyloid material, and the Coenzyme Q8 system, it possesses the definitive characters of the genus Zygozyma. It, nevertheless, differs from the type species, Z. oligophaga, by 15 physiological characters, and by 3.4% in its G + C content. The epithet suomiensis refers to Suomi (Finland), from where the type strain derives. - - - - - - 288 References Golubev WI, Smith MTh, Poot G A & Kock JLF (1989) Species delineation in the genus Nadsonia Sydow. Antonie van Leeuwenhoek 55:369-382 Smith MTh & Batenburg-van der Vegte WH (1986) Additional information on the ultrastructure in the genus Sporothrix. J. Gen. Appl. Microbiol. 32:549-552 Walt JP van der, Arx JA von, Ferreira NP & Richards PDG (1987) Zygozyma gen. nov., a new genus of the Lipomycetaceae. System. Appl. Microbiol. 9:115-120 Walt JP van der & Yarrow D (1984) Methods for the isolation maintenance, classification and identification of yeasts. In: Kreger-van Rij NJW (Ed) The Yeasts, a Taxonomic Study. 3rd edn. (pp 45-104) Elsevier Science Publ. Amsterdam Yamada Y & Kondo K (1972) Taxonomic significance of coenzyme Q system in yeasts and yeast-like fungi (1). In: Kockov~i-Kratochvflov~i A & Min~trik E (Eds) Yeasts, Models in Science and Technics: Proc. 1st Special. Int. Symp. on Yeasts, Smolenice, June 1--4, 1971 (pp 363-373) Slovak Academy of Sciences, Bratislava Yamada Y & Kondo K (1973) Coenzyme Q system in the classification of the yeast genera Rhodotorula and Cryptococcus, and the yeast-like genera Sporobolomyces and Rhodosporidiurn. J. Gen. Appl. Microbiol. 19:59-77