Scytalidium rodionovae S. Q. Tong & Zhi. Y. Zhang, 2025

12. Scytalidium rodionovae S. Q. Tong & Zhi. Y. Zhang sp. nov.

Type.

RUSSIA • Moscow, isolated from a rotting rope in the 1970s, living culture 3 C .

Etymology.

It was initially isolated by Rodionova et al.

Description and illustration.

Pavlov et al. (2018).

Notes.

Scytalidium rodionovae is phylogenetically closely related to S. album , S. assmuthi , S. aurantiacum , S. circinatum , S. terrigenum , and S. tongrenense (Figs 1 View Figure 1 , 2 View Figure 2 ). The distinctions between S. rodionovae and S. album , S. assmuthi , and S. aurantiacum are detailed in the respective notes for S. album , S. assmuthi , and S. aurantiacum . Scytalidium rodionovae is distinguished from S. circinatum , S. terrigenum , and S. tongrenense by its known sexual morph, hyaline, ovoid, and septate chlamydospore-like cells ( Sigler and Wang 1990; Jeong et al. 2025). Additionally, based on a pairwise comparison of ITS and LSU, S. rodionovae (ex-type 3 C) differs from S. circinatum (ex-type CBS 654.89 ) by 4 % (23 / 571 bp, four gaps) in the ITS and 1.1 % (7 / 628 bp, no gap) in the LSU; from S. terrigenum (ex-type KNUF- 23-236) by 7.8 % (44 / 559 bp, six gaps) in the ITS and 3.2 % (42 / 1299 bp, two gaps) in the LSU; from S. tongrenense (ex-type CGMCC 3.28994 ) by 9.7 % (53 / 548 bp, 11 gaps) in the ITS and 3.7 % (34 / 909 bp, one gap) in the LSU.

Rodionova et al. (1974) identified strain 3 C as Geotrichum candidum based only on morphological characters. Pavlov et al. (2018) integrated morphological characteristics and phylogenetic analyses based on molecular data derived from 3 C to reclassify G. candidum into Scytalidium , naming it S. candidum . However, they overlooked the fact that 3 C does not belong to G. candidum . Here, we propose the new species Scytalidium rodionovae to accommodate the species for which 3 C is the ex-type. To date, the genome sequencing of strain 3 C has been completed ( Polev et al. 2014). Studies have shown that this strain secretes a variety of enzymes capable of efficiently degrading cellulose, exhibits broad pH adaptability, and holds potential application value in lignocellulosic biomass conversion and green industrial processes ( Lapin et al. 2002; Borisova et al. 2015).