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Talaromyces leycettanus sp.nov.
T rans. Br. mycol. Soc. 55 ( 1), 45- 49 ( 19 71) Printed in Great Britain
TALAROMYCES LEYCETTANUS SP.NOV. By H. C. EVANS* University of Keele, Staffs·
AMELIA C. STOLK Centraalbureau voor Schimmelcultures, Baarn AN D
(W ith 2 Text-figur es) A d escription with drawings and te mp era ture relationships is presented of a new thermotolerant species named T. leycettanus sp. no v., conidia l state: Penicillium leyceitanum stat, nov. The ne w sp ecies is comp ared with th e closely rela ted species T. thermophilus Sto lk, sta t. conid . P. dupontii Griffo n & M aublanc. T he te rms th ermotoler a n t, thermophilic a nd th ermophilou s are di scu ssed.
In the course of a n investigati on of th e thermophilous fungal pop ulations of coa l tips in St affordshi re an unusual th ermotolera nt Penicillium species belonging to Talaromy ces was enco untered . It is considered to be sufficiently di fferen t from all previously describ ed species (R aper & Thorn, 1949; Benj amin, 1955 ; Kulik, 1968) to wa rr an t its description as a new species. Cultures and dried typ e material are d eposited at th e Centr aalbureau voor Schimmelculturcs, Baarn, the Ne the rla nds. Talaromyces leycettanus sp .nov . (Fig. I)
stat.conid . Penicillium leycettanum st. nov. Co lonial' in agaro PD A 40 °C celeriter cresc un t, temperatura mo de rata va lde restrict ae ; primum pallide ochraceae, dei nde ascomati bus maturantibus stramineae, reverso pallide vel obscure brunneo. Aspect us coloniae simi lis in agaro maltoso , praeci pue ochrac eus, velutin us; in ag a ro Cz apekii vix provenit. H yphae h yalinae, septatae, 1- 3 /hm d iam etro. Ascomata sphaerica, fla va, 50-225 /hm d iamet ro , pl erumque 75- 125 /hm , pariete tenui hyphis teneri s texto, invo luc ra ta mycelio tenui hyali ne vel flavido, hyphis I - I '5 /-tm, texto bas ali hypharum infla tarum irregularium bru nnea rum, 1'5-3 /hm diametro. Asci ca tenis incurvatis oriundi, globosi vel subglobosi, octospori, eva nescen tes, 6- g (-10) /hm dia metro . Ascosporae len ticul ares, duabus vel q uinq ue costis irregularibus, flavi dae, 3-4 x 2- 3 /hm. Conidiophora erecta, pl erum qu e e my celio su bmerso vel su perficia li, sed et ia m e hyphis acriis ascendentia, h ya lina vel flavid a, septata, vu lgo levia, longitudine va ria bili, 30- 400 x 1'5- 3'5 Itm . Penicilli biv erti cillati asy mme tr ici, nonnumqua m mo nov erticilla ti, duabus vel quattuor metu lis, sae pe uno vel duobus ramis. R a m i, me tu alae , phialid esque leves. R a m i 10- [5 x 2'5- 3'5 /hm; mcr ulae 8-[2 x 2-3 /hm, apice infl at o ad 4 /tm; phialid es cylind rica l', basi modice in flata, surs um atten uatae collo d istin ct o, ternis ad sen sis in me tu lis, 10-[8 x J '5- 2' 5 usn, Conidia levia, hyalina, ellipsoidea vel cylind rica , 3-5 x [ - I ' 7 (- 2) Itrn, long is ca tenis in tr icatis cohaerentia. Typus CBS 3g8 ·68 isola tus ex cu rnulo deiecto carbonari um, Staffordshire, Ang lio, ab H . C , E vans, M aio 1963,
* Present ad d ress : Co coa R esearch I n stit ute, Tafo, Ghana.
46
Transactions British Mycological Society
Colonies on potato dextrose agar (PDA) spreading rapidly at 40°C, attaining a diameter of 8'5-9 em in 7 days; consisting of a thin layer of small ascomata covered with scattered penicilli; central areas commonly
F
100 11 m
Fig. I. Talaromyces leycettanus, CBS 398.68: A, section through ascoma; B, initials of ascomata; C, asci, produced in helicoidal chains; D, ascospores; E, habit sketches of penicilli; F, different types of penicilli; G, conidia.
raised, consisting of a floccose to funiculose mycelium, bearing abundant penicilli. Margin regular in outline. Colonies initially Pale OchraceousBuff (Ridgway, 1912), but rapidly becoming greenish yellow with the
Talaromyces leycettanus. H. C. Evans and Amelia C. Stolk
47
development of numerous ascomata, approximating to Primrose Yellow (Ridgway, pI. 30); central areas brownish near Avellaneous (Ridgway, pI. 40) because of conidial development, No exudate, Reverse of colonies brown, approximating to Ochraceous-Tawny (Ridgway, pI. 15), because of the development of a brown diffusate, with the surrounding agar coloured in lighter tints of the same shade. Colonies on Czapek agar grow very poorly at 40°, attaining a diameter of I em in 7 days; consisting of a very thin, largely submerged vegetative mycelium, bearing only a few ascomata and penicilli, Colonies on malt agar are as on PDA. Vegetative hyphae hyaline, septate, smooth-walled, 1-3 p,m diam, occasionally producing swollen cells. Ascomata produced in abundance on a variety of agar media after several days incubation, usually maturing within 7-10 days, initially white but quickly becoming greenish yellow, soft in all stages of development; spherical, ranging in size from 50 to 225 p,m in diam, average 75-160 pm, They are initiated by an ascogonial coil. Wall consisting of a thin network of hyaline to light yellow branching hyphae 1-1'5 pm diam. With the development of brown irregular hyphae (1'5-3 pm diam) at the base, the ascomata may darken in colour. Asci numerous, produced in helical chains, evanescent, globose to subglo bose, mostly 8-spored 6-9 (10) p,m diam. Ascospores lenticular, ornated by two to five irregular ridges, appearing yellow or light orange in mass, 3-4 x 2-3 usn. Conidiophores arising primarily from submerged hyphae, but also borne as branches from aerial hyphae, variable in length, ranging from 80 to 400 p,m, generally smooth-walled, although yellow to brown deposits have occasionally been observed in or on the conidiophore wall, septate, hyaline, 1'5-3'5 psx: in diam. Penicilli typically biverticillate and asymmetric, occasionally monoverticillate, bearing three to five phialides at the apex of a short conidiophore. All elements of the penicillus are hyaline, smooth-walled, Rami, when present, 10-15 x 2'5-3'5 pm. Metulae two to four in the verticil, measuring 8-12 x 2-3 p,m, sometimes enlarged at the apex to 4 p,m in diam. Phialides occur in clusters of three to six and mayor may not be divergent; consisting of a slightly swollen base, tapering to a fairly long distinct neck, suggestive of the Penicillium janthinellum series, ranging in length from 10-18 p,m, average 10-14 p,m by 1'5-2'5Ilm in diam. Conidia hyaline to light brownish, ellipsoid to cylindrical, 3'5-5 x 1-1'7 (2) p,m, produced in long tangled chains. The species is represented by three strains: CBS 398.68, type strain; CBS 275.70 and CBS 276.70, all isolated from Leycett coal spoil tips in Staffordshire, the first two in May 1968, the third one in February 1969, The specific epithet refers to the area of isolation up till now the only source of this interesting fungus. The species has been consistently isolated from this area, both from the surface layers as well as from lower horizons. The areas ofisolation are populated by a rich growth of Betula verrucosa and various common wayside weeds. This species was originally thought to be a varient of Talaromyces thermophilus Stalk, conidial state Penicillium dupontii Griffon & Maublanc (Stolk, 1965), being separated on the basis of its ability to freely produce ascomata on agar media. However, the presence of other distinguishing
Transactions British Mycological Society characteristics led us to believe that it was distinct from all pre viously described species of Talaromyces. That these two species are closely related is evident when on e considers the almost identical ascospores. Furthermore, the phialides are of the sam e type. The species, howev er, can most readily be separated by the following features. ( I) Ascom atal morphology; ascomata of T. leyceitanus develop on a variety of agar media, whereas those of T. Thermophilus are formed only on sterilized oats and grass, etc . Ascomata of T. leycettanus are gr eenish yellow in colour, thin-walled, 50-225 pm in diam, those of T. thermophilus are grey, thick-walled, 400- 1200 pm diam. Asci of T . leycettanus are produced in helicoidal chains, wh ereas those of T. thermophilus occur in almost straight to slightly curved
90
300 50°
20
2
4
6
8
10
Time (days) Fig.
2.
Talaromy ces leycetlanus, CBS 398 .68: temperature-growth relationships .
chains. (2) Penicilli; thos e of P. leycettanus tend to be more complex and less divergent than those of P. dupontii. Conidia of P. leycettanus are brownish, those of P. dupontii are greyish green. (3) Temperature-growth relationships; T. leycettanus is classified as a thermotolerant (minimum 18°), and T. thermophilus as a true thermophile (minimum 28-30 °). (4) Cultural characteristics; on malt agar T. leycettanus produces creamish buff to yellow colonies, whilst those of T. thermophilus are grey with pink and greenish shades. The dark brown reverse of colonies on potato agar and Czapek agar is a notable feature of T. leycettanus. Temperature-growth relationships were determined by measuring the diameter of colony growth on PDA (Fig. 2). T en replicate plates were ino culated with a standard ino culum (4 mm plug) taken from actively growing colonies and incubated at th e designated temperature. Temperature gradients in the incubators were carefully controlled and minimized. Several workers (Brancato & Golding, 1953; Crisan, 1959) have agreed
Talaromyces leycettanus. H. C. Evans and Amelia C. Stalk
49
that, in studying the effect of temperature on the growth of a fungus colony, the diameter method is accurate if all other variables are held constant. According to the definition of Cooney & Emerson (1964) T. leycettanus falls into the category of a thermotolerant. However, the distinction between a thermophile and a thermotolerant according to this definition is often difficult. It may be better to assume the temperature requirements of a true thermophile as a minimum temperature for growth at or above 25° and preferably nearer 30° (Kuster & Locci, 1964; Craveri, Manachini & Craveri, 1964). Evans (1969) has used the general term thermophilous to describe all those species which appear on soil isolation plates incubated at 48° and above. According to this definition T. leycettanus should be considered as thermophilous. The appearance of T. leycettanus in coal spoil tips is probably stimulated by the presence of high surface temperatures (30-50°) which are a consequence of the internal combustion. This may tend to select those species able to thrive at elevated temperatures and which may be unable to compete with mesophilic species better adapted to soils with normal temperature ranges. REFERENCES
BENJAMIN, C. R. (1955). Ascocarps of Aspergillus and Penicillium. Mycologia 47, 669-687. BRANCATO, F. P. & GOLDING, N. S. (1953). The diameter of the mold colony as a reliable measure of growth. Mycologia 45, 848-864. COONEY, D. G. & EMERSON, R. (1964). Thermophilic fungi. San Francisco and London: W. H. Freeman and Co. CRAVERI, R., MANACHINI, P. L. & CRAVERI, A. (1964). Eumiceti termofili presenti nel suolo. Annali Microbiologica 17, 1-30. CRISAN, E. V. (1959). The isolation and identification of thermophilic fungi. M.S. Thesis, Purdue University, Lafayette, Indiana. EVANS, H. C. (1969). Studies on the ecology and taxonomy of thermophilous fungi. Ph.D. Thesis, Keele University, Staffordshire. KULIK, M. M. (1968). A compilation of descriptions of new Penicillium species. Agricultural Handbook no. 35 I. Agricultural Research Service, United States Department of Agriculture. KUSTER, E. & LOCCI, R. (1964). Studies on peat and peat micro-organisms. II. Occurrence of thermophilic fungi in peat. Archiv fiir Mikrobiologie 48, 3 I 9-324. RAPER, K. B. & TROM, C. (1949). A manual of the Penicillia. Baltimore: Williams and Wilkins Co. RIDGWAY, R. (1912). Color standards and color nomenclature. Washington, D.C.: Ridgway. STOLK, A. C. (1965). Thermophilic species of Talaromyces Benjamin and Thermoascus Miehe. Antonie van Leeuwenhoek 31, 262-276.
(Acceptedfor publication 28 July 1970)
MYC
56
TALAROMYCES LEYCETTANUS SP.NOV. By H. C. EVANS* University of Keele, Staffs·
AMELIA C. STOLK Centraalbureau voor Schimmelcultures, Baarn AN D
(W ith 2 Text-figur es) A d escription with drawings and te mp era ture relationships is presented of a new thermotolerant species named T. leycettanus sp. no v., conidia l state: Penicillium leyceitanum stat, nov. The ne w sp ecies is comp ared with th e closely rela ted species T. thermophilus Sto lk, sta t. conid . P. dupontii Griffo n & M aublanc. T he te rms th ermotoler a n t, thermophilic a nd th ermophilou s are di scu ssed.
In the course of a n investigati on of th e thermophilous fungal pop ulations of coa l tips in St affordshi re an unusual th ermotolera nt Penicillium species belonging to Talaromy ces was enco untered . It is considered to be sufficiently di fferen t from all previously describ ed species (R aper & Thorn, 1949; Benj amin, 1955 ; Kulik, 1968) to wa rr an t its description as a new species. Cultures and dried typ e material are d eposited at th e Centr aalbureau voor Schimmelculturcs, Baarn, the Ne the rla nds. Talaromyces leycettanus sp .nov . (Fig. I)
stat.conid . Penicillium leycettanum st. nov. Co lonial' in agaro PD A 40 °C celeriter cresc un t, temperatura mo de rata va lde restrict ae ; primum pallide ochraceae, dei nde ascomati bus maturantibus stramineae, reverso pallide vel obscure brunneo. Aspect us coloniae simi lis in agaro maltoso , praeci pue ochrac eus, velutin us; in ag a ro Cz apekii vix provenit. H yphae h yalinae, septatae, 1- 3 /hm d iam etro. Ascomata sphaerica, fla va, 50-225 /hm d iamet ro , pl erumque 75- 125 /hm , pariete tenui hyphis teneri s texto, invo luc ra ta mycelio tenui hyali ne vel flavido, hyphis I - I '5 /-tm, texto bas ali hypharum infla tarum irregularium bru nnea rum, 1'5-3 /hm diametro. Asci ca tenis incurvatis oriundi, globosi vel subglobosi, octospori, eva nescen tes, 6- g (-10) /hm dia metro . Ascosporae len ticul ares, duabus vel q uinq ue costis irregularibus, flavi dae, 3-4 x 2- 3 /hm. Conidiophora erecta, pl erum qu e e my celio su bmerso vel su perficia li, sed et ia m e hyphis acriis ascendentia, h ya lina vel flavid a, septata, vu lgo levia, longitudine va ria bili, 30- 400 x 1'5- 3'5 Itm . Penicilli biv erti cillati asy mme tr ici, nonnumqua m mo nov erticilla ti, duabus vel quattuor metu lis, sae pe uno vel duobus ramis. R a m i, me tu alae , phialid esque leves. R a m i 10- [5 x 2'5- 3'5 /hm; mcr ulae 8-[2 x 2-3 /hm, apice infl at o ad 4 /tm; phialid es cylind rica l', basi modice in flata, surs um atten uatae collo d istin ct o, ternis ad sen sis in me tu lis, 10-[8 x J '5- 2' 5 usn, Conidia levia, hyalina, ellipsoidea vel cylind rica , 3-5 x [ - I ' 7 (- 2) Itrn, long is ca tenis in tr icatis cohaerentia. Typus CBS 3g8 ·68 isola tus ex cu rnulo deiecto carbonari um, Staffordshire, Ang lio, ab H . C , E vans, M aio 1963,
* Present ad d ress : Co coa R esearch I n stit ute, Tafo, Ghana.
46
Transactions British Mycological Society
Colonies on potato dextrose agar (PDA) spreading rapidly at 40°C, attaining a diameter of 8'5-9 em in 7 days; consisting of a thin layer of small ascomata covered with scattered penicilli; central areas commonly
F
100 11 m
Fig. I. Talaromyces leycettanus, CBS 398.68: A, section through ascoma; B, initials of ascomata; C, asci, produced in helicoidal chains; D, ascospores; E, habit sketches of penicilli; F, different types of penicilli; G, conidia.
raised, consisting of a floccose to funiculose mycelium, bearing abundant penicilli. Margin regular in outline. Colonies initially Pale OchraceousBuff (Ridgway, 1912), but rapidly becoming greenish yellow with the
Talaromyces leycettanus. H. C. Evans and Amelia C. Stolk
47
development of numerous ascomata, approximating to Primrose Yellow (Ridgway, pI. 30); central areas brownish near Avellaneous (Ridgway, pI. 40) because of conidial development, No exudate, Reverse of colonies brown, approximating to Ochraceous-Tawny (Ridgway, pI. 15), because of the development of a brown diffusate, with the surrounding agar coloured in lighter tints of the same shade. Colonies on Czapek agar grow very poorly at 40°, attaining a diameter of I em in 7 days; consisting of a very thin, largely submerged vegetative mycelium, bearing only a few ascomata and penicilli, Colonies on malt agar are as on PDA. Vegetative hyphae hyaline, septate, smooth-walled, 1-3 p,m diam, occasionally producing swollen cells. Ascomata produced in abundance on a variety of agar media after several days incubation, usually maturing within 7-10 days, initially white but quickly becoming greenish yellow, soft in all stages of development; spherical, ranging in size from 50 to 225 p,m in diam, average 75-160 pm, They are initiated by an ascogonial coil. Wall consisting of a thin network of hyaline to light yellow branching hyphae 1-1'5 pm diam. With the development of brown irregular hyphae (1'5-3 pm diam) at the base, the ascomata may darken in colour. Asci numerous, produced in helical chains, evanescent, globose to subglo bose, mostly 8-spored 6-9 (10) p,m diam. Ascospores lenticular, ornated by two to five irregular ridges, appearing yellow or light orange in mass, 3-4 x 2-3 usn. Conidiophores arising primarily from submerged hyphae, but also borne as branches from aerial hyphae, variable in length, ranging from 80 to 400 p,m, generally smooth-walled, although yellow to brown deposits have occasionally been observed in or on the conidiophore wall, septate, hyaline, 1'5-3'5 psx: in diam. Penicilli typically biverticillate and asymmetric, occasionally monoverticillate, bearing three to five phialides at the apex of a short conidiophore. All elements of the penicillus are hyaline, smooth-walled, Rami, when present, 10-15 x 2'5-3'5 pm. Metulae two to four in the verticil, measuring 8-12 x 2-3 p,m, sometimes enlarged at the apex to 4 p,m in diam. Phialides occur in clusters of three to six and mayor may not be divergent; consisting of a slightly swollen base, tapering to a fairly long distinct neck, suggestive of the Penicillium janthinellum series, ranging in length from 10-18 p,m, average 10-14 p,m by 1'5-2'5Ilm in diam. Conidia hyaline to light brownish, ellipsoid to cylindrical, 3'5-5 x 1-1'7 (2) p,m, produced in long tangled chains. The species is represented by three strains: CBS 398.68, type strain; CBS 275.70 and CBS 276.70, all isolated from Leycett coal spoil tips in Staffordshire, the first two in May 1968, the third one in February 1969, The specific epithet refers to the area of isolation up till now the only source of this interesting fungus. The species has been consistently isolated from this area, both from the surface layers as well as from lower horizons. The areas ofisolation are populated by a rich growth of Betula verrucosa and various common wayside weeds. This species was originally thought to be a varient of Talaromyces thermophilus Stalk, conidial state Penicillium dupontii Griffon & Maublanc (Stolk, 1965), being separated on the basis of its ability to freely produce ascomata on agar media. However, the presence of other distinguishing
Transactions British Mycological Society characteristics led us to believe that it was distinct from all pre viously described species of Talaromyces. That these two species are closely related is evident when on e considers the almost identical ascospores. Furthermore, the phialides are of the sam e type. The species, howev er, can most readily be separated by the following features. ( I) Ascom atal morphology; ascomata of T. leyceitanus develop on a variety of agar media, whereas those of T. Thermophilus are formed only on sterilized oats and grass, etc . Ascomata of T. leycettanus are gr eenish yellow in colour, thin-walled, 50-225 pm in diam, those of T. thermophilus are grey, thick-walled, 400- 1200 pm diam. Asci of T . leycettanus are produced in helicoidal chains, wh ereas those of T. thermophilus occur in almost straight to slightly curved
90
300 50°
20
2
4
6
8
10
Time (days) Fig.
2.
Talaromy ces leycetlanus, CBS 398 .68: temperature-growth relationships .
chains. (2) Penicilli; thos e of P. leycettanus tend to be more complex and less divergent than those of P. dupontii. Conidia of P. leycettanus are brownish, those of P. dupontii are greyish green. (3) Temperature-growth relationships; T. leycettanus is classified as a thermotolerant (minimum 18°), and T. thermophilus as a true thermophile (minimum 28-30 °). (4) Cultural characteristics; on malt agar T. leycettanus produces creamish buff to yellow colonies, whilst those of T. thermophilus are grey with pink and greenish shades. The dark brown reverse of colonies on potato agar and Czapek agar is a notable feature of T. leycettanus. Temperature-growth relationships were determined by measuring the diameter of colony growth on PDA (Fig. 2). T en replicate plates were ino culated with a standard ino culum (4 mm plug) taken from actively growing colonies and incubated at th e designated temperature. Temperature gradients in the incubators were carefully controlled and minimized. Several workers (Brancato & Golding, 1953; Crisan, 1959) have agreed
Talaromyces leycettanus. H. C. Evans and Amelia C. Stalk
49
that, in studying the effect of temperature on the growth of a fungus colony, the diameter method is accurate if all other variables are held constant. According to the definition of Cooney & Emerson (1964) T. leycettanus falls into the category of a thermotolerant. However, the distinction between a thermophile and a thermotolerant according to this definition is often difficult. It may be better to assume the temperature requirements of a true thermophile as a minimum temperature for growth at or above 25° and preferably nearer 30° (Kuster & Locci, 1964; Craveri, Manachini & Craveri, 1964). Evans (1969) has used the general term thermophilous to describe all those species which appear on soil isolation plates incubated at 48° and above. According to this definition T. leycettanus should be considered as thermophilous. The appearance of T. leycettanus in coal spoil tips is probably stimulated by the presence of high surface temperatures (30-50°) which are a consequence of the internal combustion. This may tend to select those species able to thrive at elevated temperatures and which may be unable to compete with mesophilic species better adapted to soils with normal temperature ranges. REFERENCES
BENJAMIN, C. R. (1955). Ascocarps of Aspergillus and Penicillium. Mycologia 47, 669-687. BRANCATO, F. P. & GOLDING, N. S. (1953). The diameter of the mold colony as a reliable measure of growth. Mycologia 45, 848-864. COONEY, D. G. & EMERSON, R. (1964). Thermophilic fungi. San Francisco and London: W. H. Freeman and Co. CRAVERI, R., MANACHINI, P. L. & CRAVERI, A. (1964). Eumiceti termofili presenti nel suolo. Annali Microbiologica 17, 1-30. CRISAN, E. V. (1959). The isolation and identification of thermophilic fungi. M.S. Thesis, Purdue University, Lafayette, Indiana. EVANS, H. C. (1969). Studies on the ecology and taxonomy of thermophilous fungi. Ph.D. Thesis, Keele University, Staffordshire. KULIK, M. M. (1968). A compilation of descriptions of new Penicillium species. Agricultural Handbook no. 35 I. Agricultural Research Service, United States Department of Agriculture. KUSTER, E. & LOCCI, R. (1964). Studies on peat and peat micro-organisms. II. Occurrence of thermophilic fungi in peat. Archiv fiir Mikrobiologie 48, 3 I 9-324. RAPER, K. B. & TROM, C. (1949). A manual of the Penicillia. Baltimore: Williams and Wilkins Co. RIDGWAY, R. (1912). Color standards and color nomenclature. Washington, D.C.: Ridgway. STOLK, A. C. (1965). Thermophilic species of Talaromyces Benjamin and Thermoascus Miehe. Antonie van Leeuwenhoek 31, 262-276.
(Acceptedfor publication 28 July 1970)
MYC
56