Unveiling the pharmacological potential of Penicillium citrinum PB1 isolated from almonds: a comprehensive...

This study investigates the isolation and characterization of the fungal strain PB1, obtained from dried almonds. Based on morphological features and molecular identification, the strain was identified as Penicillium citrinum. The fungal extract was prepared from a 21-day-old culture using ethyl acetate as the extraction solvent. This crude extract showed potent antimicrobial activity against the tested pathogenic microorganisms, with MIC values of 7.5 and 15 µg/mL against S. aureus ATCC 43,306 and B. cereus ATCC 14,579, respectively. The extract also demonstrated promising anti-inflammatory, antidiabetic, and antiproliferative properties, with IC₅₀ values of 33.27, 3.32, and 124.16 µg/mL, respectively. Antimicrobial agent production was optimized using the one-factor-at-a-time method. Optimization of growth parameters yielded notable activity against several strains, mainly E. coli, K. pneumoniae, and B. cereus, with inhibition zones of 19, 23, and 34 mm, respectively. Gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) were used to identify the compounds produced by the fungal strain. Fourteen diverse metabolites were detected: 3-methylbutanoic acid (1), ethylene glycol (2), 2,3-butanediol (3), lactic acid (4), propanoic acid (5), pentasiloxane (6), silanol, trimethyl-, phosphate (7), 2,3-dihydroxy-3-methylpropanoic acid (8), D-(-)-fructofuranose, pentakis (9), D-psicofuranose, pentakis (10), erigeside B (11), D-galactonic acid (12), bufa-20,22-dienolide (13), and uridine (14). These findings highlight the potential of P. citrinum PB1 as a source of bioactive natural products with potent pharmacological activity.

The online version contains supplementary material available at https://doi.org/10.1007/s13205-026-05066-6.