In search of Zrt1 gene expression changes in Saccharomyces cerevisiae under different concentrations of zinc in medium

The S. cerevisiae is a unique microorganism in toxic metals biosorption. The extracellular uptake of zinc in S. cerevisiae mediated by the high-affinity Zrt1 protein as zinc transporter. The aim of current study was to examination of Zrt1 gene expression level in the presence of zinc metal, in S. cerevisiae as an industrially important yeast strain.

Yeast isolates, obtained from alcohol factory’s effluent were filtered and grown in YPD (yeast extract-peptone-dextrose) medium as a specific medium for yeast growth. The PCR method and DNA sequencing was employed to identify S. cerevisiae yeasts strains. Then, growth rate of this yeast in present of different concentration of Zn2+, was examined at 24-hour intervals (0, 24, 48, and 72 h), using spectrophotometry. The qRT-PCR technique was carried out to quantified expression level of Zrt1 in yeast cells under these conditions. Also, the protein-protein interaction (PPI) network of Zrt1 and its closely interacting genes, obtained from STRING database were analyzed using Network Analyzer (plugged in Cytoscape v3.7.0) to identify the most potentially effective genes.

In optimum conditions of 25 µg/ml of zinc after 24 h incubation, S. cerevisiae showed the maximum growth rate and expression level of Zrt1 as Zn transporter. Also, bioinformatics analyses identified Zrt1 as crucial gene in cell signaling pathway for zinc absorption by S. cerevisiae.

our study demonstrated that S. cerevisiae, obtained from industrial effluents, can be used to produce Zn-enriched biomass.