The antimicrobial peptide oranicin P16 isolated from Trichosporon asahii ICVY021, found in camel milk's, inhibits Kocuria rhizophila

Abstract Six Trichosporon asahii strains designated ICVY021, ICVY022, ICVY023, ICVY024, ICVY025 and ICVY026 were isolated from camel milk and studied for their inhibitory activities against a large number of fungi and bacteria as target organisms. Only strain ICVY021 was able to inhibit Kocuria rhizophila CIP 53.45, through production of an extracellular heat-stable, proteinaceous antibacterial peptide, with partial amino acid sequences of PPFPK and CTHV(L/I)(K/Q) or TCHV(L/I)(K/Q), determined using LC/MS/MS. This peptide, named oranicin P16, was thought to impede the cell-division mechanism. The anti- K. rhizophila activity was confirmed, in situ, using skim milk as a food matrix. T. asahii ICVY021 did not show any hemolytic activity or any cytotoxicity effect against eukaryotic Caco-2 cells. T. asahii ICVY021 was sensitive to azoles antifungal compounds, but not to 5-fluorocytosine and anidulafungin.