Phylum:Ascomycota >> Class: Ascomycetes >>  Order: Eurotiales 
 BCRC Number NO BCRC Number!  
 Scientific Name: Thermoascus taitungiacus

Thermoascus taitungiacus K. Y. Chen & Z. C. Chen, Mycotaxon 60:225-240. 1996.

 Description: Coloniae in agaro " YpSs ", crescola totus catillus ad 40℃ post six dies. et aerius et de-cumbens hyphae, abundans agamicus structura cum maxime efficiens aerius hyphae ac pauci granulae disseminatus. Collor albesco ad Naples Yellow (Ridgway, 1912); reversum armemacus flaius cum aurantiacus flavus granulae. Ascocarpae non ostiolatae, dispersae vel confluentes, subglobosae vel irregulares, 330-600 μm diam, flavae, aurantiacae vel brunneolae. Asci glabri, hyalini, globosi vel subglobosi, octospori, (8.5) 10-13 × 10-15 μm. Ascosporae galbanae, ovoideae vel ellipsoideae, glo-bosae vel subglobosae, 4.5-5.6 × 6.3-7.5 μm, crassitunicatae, spinulosae. Anam: Paecilomyces taitungiacus K. Y. Chen & Z.C. Chen sp. nov. Conidiophora recta, hyalina, septata, glabra, phialides hyalina, cylindrica vel ampullacea (2.8) 3.4-5.6 × 18-32 μm, singulares vel irregulariter 2-3 verticillatae. Conidia laevia, flavida, elliptica, (3-5 × 5-8 μm), vel subglobosa (2.5-6 μm diam). Holotypus: Colonia exsiccata ex K-Y Chen 8709-2 (TAI-Mycology), ver sohim in " An-tong" Taitung, Taiwan, 5.IX. 1987. Etymology: taitungiacus, referring to Taitung, the locality where this new species was iso-lated in Taiwan. Colonies on YpSs, growing all plate at 40℃ in 6 days, both aerial and prostrate hyphae abundant, asexual reproductive structures mostly coming from aerial hyphae, mycelial granules scattered. White at first becoming Naples Yellow, reverse Apricot Yellow with or-ange yellow granules. At 35℃, colonies with abundant granules, covered by sparse, erect aerial hyphae; the color Naples Yellow-Mustard Yellow, Cadmium Yellow, then turning to Light Orange Yellow, reverse Cadmium Yellow with Orange Rufous granules. Ascomata nonostiolate, scattered or confluent, forming a crust-like layer, covered by aerial hyphae and conidia, subglobose, or irregular m shape, 330-600 μm in diam., white at first, then yellow, light orange yellow, orange, orange brown. Asci smooth, hyaline, globose or subglobose mostly with 8 ascospores ( sometimes with 4-6 ascospores) (8.5) 10-13 × 10-15 μm evanescent at maturity. Ascospores yellowish green, oval to elliptical, rarely globose to subglobose, 4.5-5.6 × 6.3-7.5 μm, thick-walled, predominantly echinulate under LM, but irregularly verrucose under SEM. Conidiophores erect, arising from prostrate and trailing aerial hyphae, hyaline, septate, smooth walled, consisting of an irregularly arranged branch system, and with the apex of each branch bearing 1-3 phialides. Phialides usually cylindrical or slightly flask-like, (2.8) 3.4-5.6 × 18-32 μm, with a long conidium-bearing neck, up to 8 μm long , single as side branches or appearing irregularly 2 or 3 at the end of branches. Conidia in long chains at the tip of phialides, smooth, pale yellow, cylindrical at first (2.2.-3.4 × 4.0-7.0 μm), then ellipti-cal (3.0-5.5 × 5-8.0 μm) or subglobose (2.5-6.0 μm in diam.) at maturity.

Taiwan: Taitung, Among. low land, weed soils, 5 IX, 1987. K-Y Chen 8709-2 (Holotype, TAI-Mycology).

 Habitat: weed soils.



Chen, KY and Chen, ZC. 1996; Stolk, AC. 1965; Udea, S and Udagawa, SI. 1983.


K. Y. Chen

 Note: Thermoascus aurantiacus was first isolated by Miehe (1907), followed by Apinis (1967). It was isolated from alluvial grassland soils. Tansey(1973) also isolated it from alligator nest-ing material. They had similar anamorph-aleurioconidia (a single, thick-walled, terminal conidium); while no conidia were observed from those isolated by Awao & Otsuka (1973); Minoura, et al.(1973); Stolk (1965) and Chen & Chen (1988). Cooney & Emerson's isolate of T. aurantiacus is most likely identical with T. crustaceus (Stolk, 1965). Upadhay, et al. (1984) reported a new variety, T. aurantiacus var. levisporus, which had an anamorph similar to that of T. aurantiacus. The anamorph of T. crustaceus ( Stolk, 1965) (=Dactylomyces crustaceus Apinis & Chesters, 1967) and T. aegyptiacus (Udea & Udagawa, 1983) were confirmed to be the Paecilomyces, while T. thermophilus produced a Polypaecilum anamorph. All species of Thermoascus had ellipsoidal and nearly smooth ascospores under LM. Under SEM, however the ascospores appeared very minutely verrucose in T. aurantiacus , finely echinulate in T. crustacens, and verruculose in T. thermophilus and T. aegyptiacus. The ascospores of T. taitungiacus were not only predominantly echinulate under LM, but also irregularly verrucose under SEM. It showed close affinity to T. crustaceus in having a Paecilomyces anamorph. Two kinds of conidia were observed in the new species, one cylindrical or elliptical and the other globose to subglobose. The latter usually developed at maturity. Temperature tests: It is a philic(thermophilic) fungus. The optimum temperature for mycelial growth was between 30 ℃ and 40 ℃. The most abundant production of conidia was observed at 40℃, followed at 30℃ and 35℃, but ascocarp production was abundant between 30℃ and 35℃ and very sparse at 40℃. Several species of Thermoascus are thermophilic, including T. aurantiacus (Miehe, 1907); T. aurantiacus var. levisporus Upadhyay, Farmelo, Goetz & Melan (1984); T. crustaceus (Stolk, 1965); T. thermophilus (Sopp) von Arx (1970) and T. aegypliacus Ueda & Udagawa (1983). The taxonomy of these fungi is based mainly on the morphology of their anamorph and teleomorph. The genus Thermoascus was established by Miehe in 1907.