Characterization and Distribution of Selenite Reduction Products in Cultures of the Marine Yeast Rhodotorula mucilaginosa-13B

Selenite reduction by fungi is a widespread and ecologically significant phenomenon, but previous studies of fungal isolates have not fully characterized the reduction products. We investigated selenite reduction and the distribution of Se in cultures of the marine yeast Rhodotorula mucilaginosa-13B. Strain 13B reduced a substantial amount of selenite to form amorphous elemental selenium particles. Minor volatilization was also observed. Under the aerobic experimental conditions, intact 13B cultures were required for substantial distribution to the solid and volatile phases. This is the first study to report comprehensive microscopic image data and spectroscopic analyses confirming the accumulation of amorphous Se⁰ particles external and internal to cells of a Rhodotorula strain.