Penicillium tardochrysogenum Frisvad, Houbraken & Samson. Persoonia 29: 93. 2012.

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 tardochrysogenum Frisvad, Houbraken & Samson. Persoonia 29: 93. 2012.

Figure 15

Subgeneric classification.

Subgenus Penicillium Penicillium , Penicillium section Chrysogena , series Penicillium Chrysogena .

Description.

Mycelium superficial and immersed composed of septate, smooth-walled, hyaline hyphae, 2.5-5.5 μm wide. Conidiophores biverticillate, terverticillate or quaterverticillate; stipes smooth-walled, 40-200 × 2.5-4 μm; metulae appressed to slightly divergent, 2-4 per branch or stipe, vesiculate, 6-12.5 × 2-4 μm (vesicle up to 4.5 μm wide); phialides 3-6 per metulae, ampulliform, 5.5-7.5 × 1.5-2.5 μm; conidia smooth-walled, globose to subglobose, 2.5-3 × 2.5-3 μm.

Culture characteristics (7 d at 25 °C).

Colonies on CYA reaching 41-43 mm diam., slightly raised at center, floccose, radially sulcate, yellowish white (1A2) at center to orange white (6A2) and white (1A1) towards periphery, margins slightly lobate, sporulation sparse, conidial masses grayish green (28B3); reverse champagne (4B4) at center to red-haired (6C4) towards periphery; soluble pigment absent. On MEA, 38-39 mm diam., flattened, velvety, grayish green (26D2-E4), white (1A1) towards periphery, margins low and slightly fimbriate, sporulation abundant, conidial masses dull green (25D4); reverse colorless; soluble pigment absent. On YES, 56-57 mm diam., slightly raised at center, floccose, radially sulcate, yellowish white (4A2) at center to champagne (4B4) towards periphery, margins entire, sporulation sparse, conidial masses grayish green (27B3); reverse amber yellow (4B6) at center to maize (yellow) (4A5) towards periphery; soluble pigment absent. On OA, 35-37 mm diam., flattened, velvety, dark green (28F8) at center to greenish gray (28D4) and white (1A1) towards periphery, margins low and entire, sporulation abundant, conidial masses dull green (25D3); reverse honey yellow (4D6) at center and sand yellow (4B3) towards periphery; soluble pigment absent. On DG18, 30-32 mm diam., flattened, floccose, dark green (27F8) at center to pale orange (5A3) and white (1A1) towards periphery, margins low and entire, sporulation abundant, conidial masses grayish green (28C3) at the center; reverse wax yellow (3B5) at center to white (1A1) towards periphery; soluble pigment absent. On CREA, 24-25 mm diam., flattened, floccose, jade green (27E5) at center to yellowish green (30B8) towards periphery, margins slightly fimbriate, sporulation sparse, conidial masses grayish green (27C3-C4); reverse yellowish white (30B8), soluble pigment absent and acid production moderately strong.

Colony diameter on CYA after 7d (mm).

5 °C 3-4, 15 °C 23-24, 20 °C 27-28, 30 °C 31-33, 35 °C 16-19, 37 °C 8-9, 40 °C no growth.

Specimen examined.

Spain, Catalonia, Montsant Natural Park, Siurana’s Swamp, from sediments, Feb 2018, E. Carvalho & J. Gené (FMR 17137).

Distribution.

Antarctica and Spain.

Notes.

Although P. tardochrysogenum was introduced based only on the type specimen collected in the Antarctica, the species was later described as endemic of that continent since it was isolated at high densities on rocks from several Islands and Continental Antarctica ( Houbraken et al. 2012; Alves et al. 2019). The Spanish isolate from freshwater sediments represents the first report of this species in temperate regions. Of note, however, is that recently the species has also been reported from historical manuscripts preserved in Iraq ( Jasim et al. 2019), but only the ITS barcode was used for confirming the identity of isolates, a well-known gene marker unable to distinguish between closely related penicillia ( Houbraken et al. 2012; Visagie et al 2014a). Penicillium tardochrysogenum belongs to series Chrysogena and is closely related to P. allii-sativi , P. chrysogenum , P. rubens and P. vanluykii (Fig. 1 ), but it was distinguished from these species and other members of the series by more restricted and floccose colonies on MEA, the lack of sporulation on YES and the production of finely roughened conidia ( Houbraken et al. 2012). Despite the high sequence similarity of the markers analyzed with the ex-type strain of P. tardochrysogenum , our isolate showed some phenotypic variation regarding the protologue; i.e., faster growth rate after 7 d on MEA (38-39 vs. 18-24 mm), sporulation (sparse) on YES, smooth-walled conidia, and shorter stipes (40-200 × 2.5-4 vs. 150-400 × 2-3 µm) and metulae (6-12.5 × 2-4 vs. 10-13(-18) × 2.5-3.5 µm). These differences suggest that more specimens should be examined for a more accurate morphological characterization of this fungus.

Figures

Figure 1. Phylogenetic tree of Penicillium section Chrysogena based on ML analysis obtained by RAxML inferred from the combined tub 2, cmdA and ITS 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. turbatum CBS 237.60 and P. bovifimosum CBS 102825. The name in green is the strain of P. tardochrysogenum included in this study. T = Ex-type strain.

Figure 15. Morphological characters of Penicillium tardochrysogenum (FMR 17137). 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).