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

Figure 10

Etymology.

Named in honor of Josep Guarro for his contributions to our knowledge of microfungi.

Type.

Spain, Catalonia, Alt Camp, Alcover, Brugent River , sediments, Mar. 2019, D. Torres & J. Gené (holotype CBS H-24782, cultures ex-type CBS 148238 = FMR 17747 ) .

Subgeneric classification.

Subgenus Penicillium Aspergilloides , Penicillium section Gracilenta , series Penicillium Estinogena .

Description.

Mycelium superficial and immersed, composed of septate, smooth-walled, hyaline hyphae, 2.5-3.5 μm wide. Conidiophores predominantly symmetrically biverticillate, occasionally with subterminal branches; stipes smooth- to rough-walled, 88-215 × 3-4 μm; metulae appressed, 2-4 per stipe, vesiculate, 5-10 × 2-4.5 μm (vesicle up to 5.5 μm wide); phialides 3-6 per metula, ampulliform, 6-9 × 1.5-3 μm; conidia smooth-walled, globose, 2-2.5 × 2-2.5 μm.

Culture characteristics (7 d at 25 °C).

Colonies on CYA, 38-40 mm diam., slightly raised at center, radially sulcate, velvety, brownish gray (6C2) and white (1A1) towards periphery, margins fimbriate, sporulation moderate, conidial masses greenish gray (28C2); reverse dark brown (6F6) and light brown (6D6) at periphery, becoming entirely brown after 14 d; soluble pigment absent. On MEA, 41-43 mm diam., slightly raised, granular, yellowish green (29B7) and white (1A1) towards periphery, margins slightly fimbriate, sporulation moderate, conidial masses grayish green (28D2); reverse yellowish brown (5E6) at center to grayish yellow at periphery; soluble pigment absent. On YES, 49-51 mm diam., raised at center, radially sulcate, velvety, brownish gray (5C2) and white (1A1) at periphery, margins entire, sporulation sparse, conidial masses greenish gray (28D2); reverse dark green (30F5) and yellowish brown (5D5) towards periphery; soluble pigment absent. On OA, 24-26 mm diam., elevated at center, velvety, white (1A1) at center and dull green (25E3) towards periphery, margins regular, sporulation moderate, conidial masses dull green (25D4); reverse brown (6E4) and yellowish gray (4B2) at periphery; soluble pigment absent. On DG18, 22-25 mm diam., flattened, granular, grayish green (30C3) at center, and dull green (29D49) towards periphery, margins fimbriate, sporulation moderate, conidial masses greenish gray (27D2); reverse grayish green (30E5) and white (1A1) at periphery, soluble pigment absent. On CREA, 22-25 mm diam., flattened, floccose, yellowish green (29B7) and white (1A1) at periphery, margins irregular, sporulation moderate, conidial masses grayish green (27B3-D3); reverse dark gray (1F1); soluble pigment absent, no acid production.

Colony diameter on CYA after 7d (mm).

5 °C no growth, 15 °C 17-19, 20 °C 26-28, 30 °C 34-36, 35 °C 4-5, 37 °C no growth, 40 °C no growth.

Distribution.

Spain.

Notes.

Penicillium guarroi is the second species included in section Gracilenta series Estinogena (Fig. 7 ). This species shows morphological attributes of the series based on its type P. estinogenum , namely that both have symmetrically appressed biverticillate conidiophores with rough-walled stipes ( Houbraken et al. 2020). However, P. guarroi mainly differs from P. estinogenum by producing strictly smooth-walled globose conidia, which are ellipsoidal to ovate and with smooth to finely roughened walls in the latter ( Abe 1956; Houbraken et al. 2020). In addition to their phylogenetic distance, other members of section Gracilenta (i.e., series Gracilenta and Macrosclerotiorum ) can be differentiated morphologically by the production of monoverticillate conidiophores and the lack of growth at 37 °C, with the exception of P. apimei and P. aquaticum , which are able to grow at this temperature ( Barbosa et al. 2018; Houbraken et al. 2020). Penicillium guarroi was unable to grow at 37 °C, but it shows a maximum temperature for growth at 35 °C (4-5 mm), like other members in the section (i.e., P. macrosclerotiorum , P. angustiporcatum , P. gracilentum and P. estinogenum ).

Figures

Figure 7. Phylogenetic tree of Penicillium section Gracilenta 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 P. abidjanum CBS 246.67. The name in red is the new species described in this study. T = Ex-type strain.

Figure 10. Morphological characters of Penicillium guarroi sp. nov. (ex-type FMR 17747). A colonies from left to right (top row) CYA, MEA, YES, and OA; (bottom row) CYA reverse, MEA reverse, DG 18, and CREA B-E conidiophores on MEA F conidia. Scale Bars: 25 μm (B), 10 μm (C-F).