Study on the effects and mechanisms of lactonic sophorolipid on the growth and biofilm formation of Candida albicans
Objective To investigate and discuss the inhibition effects and mechanisms of lactonic sophorolipid(LSL)on the growth and biofilm formation of Candida albicans(C.albicans).Methods Microdilution method and spread plate method were used to determine the minimal inhibitory concentration(MIC)and minimum fugicide concentration(MFC)values of LSL against C.albicans.The effects of LSL on the growth of C.albicans plankton cells were measured by absorptiometry method and the antifungal curves were drawn accordingly.Besides,the effect of LSL on the biofilm formation of C.albicans was determined by crystal violet staining.The changes of micromorphology and membrane permeability of LSL treated C.albicans cells were observed and detected by scanning electron microscope(SEM)and laser scanning confocal microscopy(CLSM),respectively.The contents of intracellular ATP and extracellular UV-absorbing substances were detected by the kits.Results The MIC and MFC values of LSL against C.albicans were determined at 6.00 mg/mL and 18.00 mg/mL respectively.The inhibition curves showed that the inhibitory effects of LSL on C.albicans plankton cells were significant,rapid and long-lasting.All LSL treatment groups could basically reach the maximum inhibitory rate within 2 hours and showed significant inhibition effects on the biofilm formation of C.albicans.Finally,the amount of C.albicans biofilm formation was reduced by 65.2％to 97.0％.Besides,both the growth inhibiting and biofilm formation destroying of LSL on C.albicans was positively correlated with the treatment dosages.The SEM and CLSM images revealed an obvious alteration in cell wall integrity and membrane permeability of LSL treated cells,and enhanced cellular damage and cell death when cells were co-cultured with LSL.Meanwhile,a serious loss of the intracellular ATP and a significant increase of the extracellular ultraviolet absorption substances were observed,further suggesting that LSL destroyed the integrity and permeability of the cell wall and membrane of C.albicans,resulting in the outflow of ATP,proteins,nucleic acids and other substances in the cells.Conclusion LSL can effectively inhibit the growth and biofilm formation of C.albicans,and possess the potential to be developed as an antimicrobial agent or adjuvant for the treatment of C.albicans related diseases.
NETL
NSTL
万方数据
