Morphological, Molecular and Metabolic Characterization of the Pigmented Fungus Subramaniula asteroids

J Fungi (Basel). 2022 Oct 29;8(11):1149. doi: 10.3390/jof8111149.

Abstract

Chaetomiaceae fungi are ascosporulating fungi whose importance as human pathogens has been frequently ignored. In the current study, a new isolate of the genus Subramaniula was described. The fungus was isolated from the soil of Wadi Om Nefa'a, Hurghada in the Red Sea Governorate, Egypt. Previously, Subramaniula were misidentified as Papulaspora spp. According to molecular analysis, the fungus was identified as Subramaniula asteroids OP484336. Remarkably, this species has been found among other fungi responsible for keratitis in humans and has been recorded for the first time in Egypt. Analysing the Subramaniula asteroids' metabolic profile was one of the objectives of the current study because little is known about this family's metabolome. The fungal extract's untargeted metabolic profiling was carried out by gas chromatography-mass spectroscopy (GC/MS), 1H and 1H-HSQC nuclear magnetic resonance (NMR) data, and their corresponding databases. In total, fifty-nine metabolites have been reported in the polar and non-polar extracts. The majority of polar metabolites are amino acids and carbohydrates. The non-polar extract's main components were 1-dodecanamine, N,N-dimethyl-, 1-tetradecanamine, N,N-dimethyl-, and 9-octadecenoic acid ethyl ester. The current study is the first to provide a metabolic profile of Subramaniula asteroids, which can be used in chemotaxonomical classification, antifungal drug development, and biological activity investigation of the studied species.

Keywords: GC/MS; NMR analysis; Subramaniula asteroids; chaetomiaceae; keratitis; metabolic profile.