Biotechnological production of high specific activity L-35 S-cysteine and L-35 S-methionine by using a diploid yeast Saccharomyces cerevisiae
✍ Scribed by N. Gajendiran; N. Jayachandran; B. S. Rao; V. K. P. Unny; S. Thyagarajan
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- French
- Weight
- 254 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0022-2135
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✦ Synopsis
Abstract
High specific activity L‐^35^ S‐cysteine and L‐^35^ S‐methionine were synthesised by using a wild type diploid strain of baker's yeast—Saccharomyces cerevisiae. Yeast cells were grown in a sulphur depleted synthetic medium in which Na~2~ ^35^ SO~4~ (50 mCi/ml) was supplemented as the sole sulphur source. The level of incorporation was 60% on an average. The protein hydrolysate of the cultured cells was subjected to paper and column chromatographic separations to get the individual L‐^35^ S‐aminoacids. The radiochemical yields of cysteine and methionine were 6–7% and 18–20% respectively. The radiochemical purity of the products was >95%. The highest specific activity for the products obtained by employing this method was 1100 Ci/mmole from the starting material, Na~2~ ^35^ SO~4~, with a specific activity of 1350 Ci/mmole.