title: Anti-yeast activity of a food-grade dilution-stable microemulsion.
abstract: The anti-yeast activities of a food-grade dilution-stable microemulsion against Candida albicans and Saccharomyces cerevisiae have been studied. The weight ratio of the formulated microemulsion is glycerol monolaurate (GML)/propionic acid/Tween 80/sodium benzoate (SB)/water = 3:9:14:14:24. Results of anti-yeast activity on solid medium by agar diffusion method showed that the anti-yeast activity of the microemulsion at 4.8 mg/ml was comparable to that of natamycin at 0.1 mg/ml as positive control. Results of anti-yeast activity in liquid medium by broth dilution method showed that the growth of both C. albicans and S. cerevisiae was completely inhibited when the liquid medium containing 10(6) cfu/ml was treated with 1.2 mg/ml microemulsion, which was determined as minimum fungicidal concentration. The kinetics of killing results showed that the microemulsion killed over 90% yeast cells rapidly within 15 min and caused a complete loss of viability in 120 min. Among the components, SB and GML had a similar anti-yeast activity, followed by propionic acid, while Tween 80 exhibited no activity and could not enhance the anti-yeast activities of these components, and it was revealed that the anti-yeast activity of the microemulsion was attributed to a combination of propionic acid, GML, and SB. The anti-yeast activity of the microemulsion was in good agreement with the leakage of 260-nm absorbing materials and the observation of transmission electron microscopy, indicating that the microemulsion induced the disruption and dysfunction of the cell membrane.
authors.affiliation: Department of Food Science and Nutrition, Huajiachi Campus, Zhejiang University, Hangzhou, 310029, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Yaoqi
authors.initials: Y
authors.lastname: Xu
authors.forename: Lijiang
authors.initials: L
authors.lastname: Wu
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zheng
authors.forename: Songming
authors.initials: S
authors.lastname: Zhu
authors.forename: Fengqin
authors.initials: F
authors.lastname: Feng
authors.forename: Lirong
authors.initials: L
authors.lastname: Shen
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D002176:Candida albicans / Q000737:chemistry / Q000187:drug effects* / Q000254:growth & development; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D045703:Emulsifying Agents / Q000737:chemistry / Q000494:pharmacology*; D005503:Food Additives / Q000737:chemistry / Q000494:pharmacology*; D007700:Kinetics; D007848:Laurates / Q000737:chemistry / Q000494:pharmacology*; D050296:Microbial Viability / Q000187:drug effects; D050178:Monoglycerides / Q000737:chemistry / Q000494:pharmacology*; D011422:Propionates / Q000737:chemistry / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000187:drug effects* / Q000254:growth & development
chemical_list: D000935:Antifungal Agents; D003470:Culture Media; D045703:Emulsifying Agents; D005503:Food Additives; D007848:Laurates; D050178:Monoglycerides; D011422:Propionates; C020777:monolaurin; C029658:propionic acid