1. Killer toxin from several food-derived Debaryomyces hansenii strains effective against pathogenic Candida yeasts.
- Author
-
Banjara, Nabaraj, Nickerson, Kenneth W., Suhr, Mallory J., and Hallen-Adams, Heather E.
- Subjects
- *
DEBARYOMYCES hansenii , *MYCOTOXINS , *FOOD microbiology , *YEAST , *MYCOSES , *PROBIOTICS - Abstract
Candida yeasts are the dominant fungi in the healthy human microbiome, but are well-known for causing disease following a variety of perturbations. Evaluation of fungal populations from the healthy human gut revealed a significant negative correlation between the foodborne yeast, Debaryomyces hansenii , and Candida species. D. hansenii is reported to produce killer toxins (mycocins) effective against other yeast species. In order to better understand this phenomenon, a collection of 42 D. hansenii isolates was obtained from 22 cheeses and evaluated for killer activity against Candida albicans and Candida tropicalis over a range of temperatures and pH values. Twenty three strains demonstrated killer activity against both C. albicans and C. tropicalis , which was pH- and temperature-dependent, with no killer activity observed for any strain at pH 6.5 or higher, or at ≥ 35 °C (physiological conditions in the human gastrointestinal tract). A cell-free mycocin preparation showed transient killer activity against C. albicans at 35 °C and a cheese sample containing a killer D. hansenii strain demonstrated sustained killer activity against both C. albicans and C. tropicalis . Together, these observations raise the possibility that D. hansenii could influence Candida populations in the gut. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF