Penicillium sicoris Torres-Garcia, Gene and Dania Garcia, 2022

Torres-Garcia, Daniel, Gene, Josepa & Garcia, Dania, 2022, New and interesting species of Penicillium (Eurotiomycetes, Aspergillaceae) in freshwater sediments from Spain, MycoKeys 86, pp. 103-145 : 103

Penicillium sicoris Torres-Garcia, Gene and Dania Garcia sp. nov.

Figure 13

Etymology.

Referring to the Segre River where the fungus was found.

Type.

Spain, Catalonia, La Noguera, Camarassa, Segre river , from sediments, Dec. 2019, D. Torres & J. Gené (holotype CBS H-24784, cultures ex-type CBS 148241 = FMR 18076 ) .

Subgeneric classification.

Subgenus Penicillium Penicillium , Penicillium section Paradoxa , series Penicillium Atramentosa .

Description.

Mycelium superficial and immersed, composed of septate, smooth-walled, hyaline hyphae, 3-5 μm wide. Conidiophores biverticillate or terverticilliate, occasionally irregularly branched with phialides growing directly from branches and divaricate; stipes smooth-walled, 25-215 × 3-4.5 μm; metulae divergent, 2-3 per branch, vesiculate, 7-20 × 2.5-4 μm (vesicle up to 5.5 μm wide); phialides 1-6 per metula, ampulliform, 4-7.5 × 2.5-4 μm; conidia smooth-walled, usually globose to subglobose, some broadly ellipsoidal, 2-4.5 × 2-3.5 μm.

Culture characteristics (7 d at 25 °C).

Colonies on CYA, 32-34 mm diam., raised at center, radially sulcate, velvety, brownish violet (11D8) at center, pale orange (5A3) and white (1A1) towards periphery, margins entire, sporulation abundant, conidial masses grayish green (28B3); reverse light orange (6A5) to orange (6B7) at center and grayish yellow (4B4) towards periphery; soluble pigment absent. On MEA, 28-30 mm diam., flat, velvety, grayish green (30D6) at center, bluish green (25C8), and white (1A1) at periphery, margins entire, sporulation abundant, conidial masses grayish turquoise (24C3-C4); reverse pea green (29D5), yellowish white (4A2); soluble pigment absent. On YES, 39-43 mm diam., raised at center, radially sulcate, velvety, orange gray (5B2) at center and white (1A1) towards periphery, margins entire, sporulation sparse, conidial masses grayish green (28C3); reverse grayish yellow (4B4) and pale yellow (4A3) at periphery; soluble pigment absent. On OA, 23-24 mm diam., slightly elevated at center, floccose, grayish green (26E6), opaline green (25C6) and brownish gray (5C2) towards periphery, margins slightly fimbriate, sporulation abundant, conidial masses dull green (27D3); reverse pea green (29D5) at center and brownish gray (5C2) towards periphery; soluble pigment absent. On DG18, 13-16 mm diam., slightly raised at center, velvety, olive (3D3) at center, grayish turquoise (24B3) and white (1A1) towards periphery, margins entire, sporulation abundant, conidial masses grayish turquoise (24B3); reverse, grayish green (1C4) and white (1A1) at periphery; soluble pigment absent. On CREA, 21-27 mm diam., slightly elevated at center, velutinous, apple green (29C7), margins regular, sporulation abundant, conidial masses grayish green (26B3-C3); reverse colorless; soluble pigment absent, acid production absent.

Colony diameter on CYA after 7d (mm).

5 °C 3-4, 15 °C 25-26, 20 °C 30-31, 30 °C 29-31, 35 °C no growth, 37 °C no growth, 40 °C no growth.

Distribution.

Spain.

Notes.

Penicillium sicoris is closely related to P. mexicanum in series Atramentosa (Fig. 3 ). Phenotypically, species of this series share a moderately fast colony growth and brown reverse on CYA and YES, and good growth on CREA without acid production ( Houbraken et al. 2020). However, our species differs in having an orange to grayish yellow reverse on CYA. In addition, P. sicoris also differs from its counterpart in several micromorphological features: i.e., its conidiophores are bi- or terverticillate, whereas in P. mexicanum they are ter- or quaterverticillate, stipes are shorter (25-215 vs. 65-370 μm), phialides shorter (4-7.5 vs. 7-10 μm) and metulae longer (7-20 vs. 8.5-15.5 μm) than those of P. mexicanum , and its conidia are predominantly globose to subglobose, whereas in P. mexicanum they are broadly ellipsoidal to ellipsoidal ( Visagie et al. 2014c). Moreover, P. mexicanum has a more restrictive growth on CREA than P. sicoris (5-8 vs. 21-27 mm diam. after 7 d).

Figures

Figure 3. Phylogenetic tree of Penicillium section Paradoxa based on ML analysis obtained by RAxML inferred from the combined tub 2, cmdA, ITS, and rpb 2 loci. Branch lengths are proportional to phylogenetic distance. Bootstrap support values / Bayesian posterior probability scores above 70 % / 0.95 are indicated on the nodes. Bold branches indicate bs / pp values 100 / 1. The tree is rooted to Penicillium species belonging to Penicillium section Turbata (P. madriti CBS 347.61, P. caprifimosum CBS 142990, P. bovifimosum CBS 102825 and P. turbatum CBS 383.48). The name in red is the new species described in this study. T = Ex-type strain.

Figure 13. Morphological characters of Penicillium sicoris sp. nov. (ex-type FMR 18076). A colonies from left to right (top row) CYA, MEA, YES, and OA; (bottom row) CYA reverse, MEA reverse, DG 18, and CREA B-G conidiophores on MEA H conidia. Scale Bars: 25 μm (B), 10 μm (C-H).