Studies on Breeding of Selenium-Enriched Yeasts

Abstract:

36 yeast strains were subjected to analysis of Selenium-resistance,and a Selenium-resistant and Selenium-enriched Candida tropicalis strain named 1254,was obtained,whose Se content and biomass were 5.48 mg/l and 4.1 g/l,respectively. The strain 1254 was subjected to genetic breeding via N-methy-N-nitro-N- Nitrosoguanidine(NTG) and UV irradiation mutagenesis successively,to screen high Selenium-resistant and ethionie-resistant mutants. As a result,A mutant 1254-6-1 was obtained,and the biomass,total selenium content,organic selenium content and conversion rate of organic selenium increased to 7.60 g/l,5 626.00 μg/g,4 879.99 μg/g,86.74%,much higher than that of the parent strain. Especially,the content of methionine and cystine were increased by 135% and 194.10%.