Ergothioneine yield of Rhodotorula species positively correlated with hydrogen peroxide tolerance.

Ergothioneine (EGT) is a natural sulfur-containing amino acid with potent antioxidant and cytoprotective activities. In this study, the oxidation tolerance of 23 different Rhodotorula strains were screened with hydrogen peroxide (H 2 O 2) as the inhibitory condition. By measuring their carotenoid and EGT production and correlation analysis with H 2 O 2 tolerance, the results showed that the carotenoid synthesis capacity has no effect on H 2 O 2 tolerance, in contrast to a strong positive correlation between EGT yield and H 2 O 2 tolerance of Rhodotorula species. In addition, a high EGT-producing strain R. mucilaginosa DL-X01 was screened with the yield of 38.48 ± 2.71 mg/L in a shaking flask fermentation. To the best of our knowledge, this is the highest EGT yield ever reported in non-recombinant strains. Growth kinetic data showed that DL-X01 had a longer lag phase in the presence of exogenous oxidant, but a shorter generation time and higher specific growth rate after entering the exponential phase. The results of this study provided a potential simple and rapid method for screening high EGT-producing strains, which could promote the efficient production of EGT by microorganisms and further development of the red yeast in the food and biotechnology industries. • Carotenoid content had no effect on H 2 O 2 tolerance of Rhodotorula species. • EGT yield of Rhodotorula species positively correlated with H 2 O 2 tolerance. • Rhodotorula mucilaginosa DL-X01 has excellent ergothioneine production capacity. [ABSTRACT FROM AUTHOR]