Metabolic fingerprinting to elucidate the biodegradation of phosphonoacetic acid and its impact on Penicillium metabolism

The application of metabolomic analysis to the study of fungal cell physiology provides a valuable means of elucidating the metabolic diversity of fungi. This study aims to identify metabolites that distinguish the metabolism of moulds based on the phosphorus source used in the culture medium, either inorganic phosphate (Pi) or phosphonoacetic acid (PA). A targeted metabolomics approach, using LC–MS combined with chemometric tools, facilitated the identification of metabolic differences between three fungal strains of the Penicillium genus: Penicillium commune, Penicillium crustosum S2, and Penicillium funiculosum S4. The availability of PA in the medium enables P. commune to synthesize compounds that stimulate cellular responses to unfavorable environmental conditions, while activating pathways involving precursors of secondary metabolites. Comparative analysis of cell-free extracts from P. commune and P. funiculosum S4 cultured on Pi-containing medium revealed increased levels of metabolites, including tyrosine, tryptophan, glutathione, and ethyl-3-hydroxybutyrate, in both fungal extracts. Furthermore, analysis of the cell-free extracts obtained from biomass grown on a medium containing PA showed similarities between P. commune and P. crustosum S2, as well as between the two wild strains. From these results, it can be concluded that the metabolic strategies of P. commune and P. funiculosum S4 are similar when Pi is the sole phosphorus source, whereas the use of phosphonate reveals common characteristics between the P. commune strain and P. crustosum S2. These observations allowed the identification of fungal biomarkers and provided insights into the mechanisms of metabolic response to changing environmental conditions.