Production and optimization of novel Sphorolipids from Candida parapsilosis grown on potato peel and frying oil wastes and their adverse effect on Mucorales fungal strains

Abstract

Brief introduction: Mucormycosis disease, which has recently expanded with the Covid 19 pandemic in many countries, endangers patients' lives, and treatment with common drugs is fraught with unfavorable side effects. Aim and objectives: This study deals with the economic production of sophorolipids (SLs) from different eight fungal isolates strains utilizing potato peels waste (PPW) and frying oil waste (FOW). Then investigate their effect against mucormycetes fungi. Results: The screening of the isolates for SLs production revealed the highest yield (39 g/100 g substrate) with most efficiency was related to a yeast that have been identified genetically as Candida parapsilosis. Moreover, the characterizations studies of the produced SLs by FTIR, 1H NMR and LC–MS/MS proved the existence of both acidic and lactonic forms, while their surface activity was confirmed by the surface tension (ST) assessment. The SLs production was optimized utilizing Box-Behnken design resulting in the amelioration of yield by 30% (55.3 g/100 g substrate) and ST by 20.8% (38mN/m) with constant level of the critical micelle concentration (CMC) at 125 mg/L. The studies also revealed the high affinity toward soybean oil (E24 = 50%), in addition to maintaining the emulsions stability against broad range of pH (4–10) and temperature (10–100℃). Furthermore, the antifungal activity against Mucor racemosus, Rhizopus microsporus, and Syncephalastrum racemosum proved a high inhibition efficiency of the produced SLs. Conclusion: The findings demonstrated the potential application of the SLs produced economically from agricultural waste as an effective and safer alternative for the treatment of infection caused by black fungus.