SCREENING OF IRON- AND ZINC-ENRICHED YEAST STRAIN AND OPTIMIZATION OF CULTIVATION CONDITIONS

Abstract Saccharomyces cerevisiae LN-17 was selected from 26 kinds of primary yeast strains that belong to different genera and species. The iron- and zinc-enriched capability of strain LN-17 was higher than the others. The highest iron and zinc contents of the strain were obtained when the strain grew up under the following conditions: The strain was incubated (5%, v/v) in 50 mL wort medium (pH 6.0) with 100 mg/L Fe ion and 120 mg/L Zn ion. The medium was loaded into a 250-mL Erlenmeyer flask and shaken in a rotary shaker (200 rpm) at 30°C for 60 h. Ferrous sulfate and zinc sulfate were chosen as the source of Fe and Zn. The Fe and Zn contents of the dry cells were determined by atomic absorption spectrum analysis. Under the optimized cultivation conditions, the Fe and Zn contents reached 7.854 mg/g dry cells and 4.976 mg/g dry cells. Keywords: biomasscultivation conditionsironyeastzinc ACKNOWLEDGMENTS This work was supported by the Natural Science Foundation of Fushun city (20071219). Notes Note. Data with different superscripts have significant differences, as evaluated using multiple comparisons, p < 0.01. Note. Significant differences were evaluated using Student's t-test, indicated by *p < 0.05; **p < 0.01. The results of YEPD medium were used as control. Note. CK: S. cerevisiae LN-17 was cultured without adding Zn or Fe salts. Significant differences were evaluated using Student's t-test, indicated by *p < 0.05; **p < 0.01. Note. Significant differences were evaluated using Student's t-test, indicated by *p < 0.05; **p < 0.01.