Phenotyping of Rhodotorula tolerance to heavy metal contamination for bioremediation applications

Phenotyping of Rhodotorula tolerance to heavy metal contamination for bioremediation applications at  Fungal Genetics Conference, Pacific Grove, CA, Asilomar Conference Grounds

Abstract: 

Rhodotorula is an extremotolerant generalist yeast that has been isolated from a wide range of locations, from food spoilage, soils, plants, dishwashers, to more extreme conditions such as the International Space Station (ISS). Rhodotorula has also been isolated from marine and terrestrial environments contaminated with various heavy metals. The ability of Rhodotorula to tolerate these environments may be associated with the production of carotenoids, protective pathways for oxidative stress, and the ability to form biofilms. These capabilities make Rhodotorula a potential candidate for bioremediation applications that can be naturally or engineered to detoxify or bioaccumulate contaminants from its environment. Despite this potential, there is limited work on linking Rhodotorula’s distinct tolerance to metals with genetic features. To fill this research gap, we aim to phenotype our collection of over 300 genome sequenced Rhodotorula strains to test their sensitivity to heavy metals. Using UCR’s ExFAB biofoundry, we have applied automated workflows to replicate colonies, capture time-lapse of solid media growth, estimate pigmentation intensity and growth rates with newly developed software. The growth rates determined from the time series will permit research aims to (I) assess strain IC50s to heavy metals copper, iron, zinc, mercury, chromium, and cadmium, (II) identify strains with novel morphologies or tolerances, and (III) attempt to correlate genetic alleles or features associated with variance in tolerance.