Penicillium terrae Thitla, Monkai, Lumyong & Hongsanan, 2025

Penicillium terrae Thitla, Monkai, Lumyong & Hongsanan sp. nov.

Etymology.

The specific epithet terrae refers to the soil substrate, from which this species was isolated.

Holotype.

Thailand • Chiang Mai Province, Mae Taeng District, Papae , on soil in the forest dump-sites, 20 June 2024, T. Thitla & J. Monkai; VR 040 ( SZU 25-005 About SZU , holotype); ex-type living culture, MBSZU 24-008 , dried culture permanently preserved in a metabolically inactive state, SZU 25-005 About SZU .

Colony diam.

(in mm) 7 days, 25 ° C: CREA 8–11 , CYA 13–18, CYAS 7–9, CZ 11–15, DG 18 12–16, MEA 15–19, MEAbl 16–19, OA 13–19, PDA 12–15 and YES 9–13. 7 days, 30 ° C: CYA 10–15. 7 days, 37 ° C: CYA no growth.

Culture characteristics.

Colonies at 25 ° C for 7 days on CREA thin colonies; acid production absent (Fig. 5 A View Figure 5 ). Colonies on CYA circular, convex, wrinkled texture, entire margin; white mycelia; soluble pigment absent; reverse yellowish-brown (Fig. 5 B View Figure 5 ). Colonies on CYAS barely growing, circular, raised, wrinkled texture, undulate margin; white mycelia; soluble pigment absent; reverse white (Fig. 5 C View Figure 5 ). On CZ thin colonies, circular, flat, entire margin; white mycelia; soluble pigment absent; reverse white (Fig. 5 D View Figure 5 ). On DG 18 circular, flat, wrinkled at the centre, margin smooth and entire; grey mycelia at the centre, white mycelia at the margin; soluble pigment absent; reverse greenish-grey to light yellow (Fig. 5 E View Figure 5 ). Colonies on MEA circular, flat, smooth texture, entire margin; light grey mycelia; soluble pigment absent; reverse light yellow to white (Fig. 5 F View Figure 5 ). On MEAbl circular, flat, wrinkled at the centre, margin smooth and entire; light grey at the centre, white at the margin; soluble pigment absent; reverse yellowish-brown (Fig. 5 G View Figure 5 ). On OA circular, flat, smooth textured, entire margin; light brown mycelia at the centre, white mycelia at the margin; soluble pigment absent; reverse white (Fig. 5 H View Figure 5 ). Colonies on PDA circular, flat, wrinkled texture, entire margin; white mycelia; soluble pigment absent; reverse white to light yellow (Fig. 5 I View Figure 5 ). Colonies on YES circular, convex, wrinkled texture, entire margin; white mycelia; soluble pigment absent; reverse light brown (Fig. 5 J View Figure 5 ). Sporulation abundantly produces on all media.

Micromorphology.

Conidiophores mononematous, growing out at right angles from hyphae, unbranched, smooth, hyaline, 3–14 × 1–3 µm (Fig. 5 K – P View Figure 5 ). Phialides solitary, terminal, ampulliform, smooth, hyaline, 5–12 × 1–4 µm (Fig. 5 K – P View Figure 5 ). Conidia globose to subglobose, 2–4 µm diam., smooth, hyaline (Fig. 5 K – N, Q View Figure 5 ). Sclerotia not observed. Sexual morph absent.

Additional strain examined.

Thailand • Chiang Mai Province, Mae Taeng District, Papae , on soil in the forest dump-sites, 20 June 2024, T. Thitla & J. Monkai; CMUVR 039 ; living culture, MBSZU 24-007 , dried culture permanently preserved in a metabolically inactive state, CMUVR 039 .

Habitat and distribution.

Soil; only known from Chiang Mai Province, Thailand.

Notes.

Penicillium section Exilicaulis was first established by Pitt (1980), with P. restrictum as the type species. This section was initially proposed to accommodate Penicillium species characterised by monoverticillate conidiophores and non-vesiculated stipes. Subsequently, phylogenetic studies expanded the section to include species with bi-verticillate conidiophores and those with conidiophores bearing solitary phialides ( Houbraken and Samson 2011; Visagie et al. 2016 a, b; da Silva et al. 2023). Species of the sect. Exilicaulis have been isolated from diverse environments, including soil, marine ecosystems, air, plants and insects ( Ansari et al. 2023). Currently, this section comprises over 60 species across six series: Alutacea, Citreonigra, Corylophila, Erubescentia , Lapidosa and Restricta ( Ansari et al. 2023; Visagie et al. 2024 a).

Penicillium terrae is classified within section Exilicaulis , series Erubescentia . Phylogenetically, this species is closely related to P. laeve and P. ovatum (Fig. 2 View Figure 2 ). However, P. laeve and P. ovatum were unable to grow on CREA and CYAS media, while P. terrae can grow on these media. Regarding growth rates, P. laeve exhibited slower growth than P. terrae , including CYA (8–9 mm), DG 18 (5–7 mm), OA (7–8 mm) and YES (8–9 mm) at 25 ° C, as well as CYA at 30 ° C (4–5 mm) ( Visagie et al. 2016 a). Similarly, P. ovatum also demonstrated slower growth compared to P. terrae on CYA (10–11 mm), DG 18 (9–11 mm), MEA (7–8 mm) and OA (10–11 mm) at 25 ° C ( Visagie et al. 2016 a). Micromorphologically, the phialides of P. laeve (4–6 µm × 2–3 µm) and P. ovatum (4.5–7 µm × 2–3 µm) were shorter than P. terrae ( Visagie et al. 2016 a). In terms of conidia, P. terrae produced globose to subglobose conidia with 2–4 µm, while P. leave produced globose conidia measuring 2.5–3 µm diam. and P. ovatum produced ellipsoidal conidia with 2–3 × 1.5–2 µm ( Visagie et al. 2016 a). Furthermore, a pairwise nucleotide comparison between P. terrae and P. laeve showed differences of 0.86 % (5 / 581 bp, including gaps) in ITS, 2.87 % (13 / 453 bp, including gaps) in TUB, 2.62 % (13 / 497 bp, including gaps) in CAM and 1.39 % (13 / 938 bp, including gaps) in RPB 2. Similarly, the comparison between P. terrae and P. ovatum revealed nucleotide differences of 2.64 % (15 / 569 bp, including gaps) in ITS, 14.41 % (65 / 451 bp, including gaps) in TUB, 17.74 % (91 / 513 bp, including gaps) in CAM and 12.37 % (116 / 938 bp, including gaps) in RPB 2.