Biotechnological production of high specific activity L-35 S-cysteine and L-35 S-methionine by using a diploid yeast Saccharomyces cerevisiae
作者:N. Gajendiran、N. Jayachandran、B. S. Rao、V. K. P. Unny、S. Thyagarajan
DOI:10.1002/jlcr.2580340612
日期:1994.6
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 Na2 35 SO4 (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, Na2 35 SO4, with a specific activity of 1350 Ci/mmole.
采用野生型二倍体面包酵母菌株——酿酒酵母合成了高比活性的L-35 S-半胱氨酸和L-35 S-蛋氨酸。酵母细胞在硫贫化的合成培养基中生长,其中补充Na2 35 SO4 (50 mCi/ml)作为唯一的硫源。合并水平平均为60%。对培养细胞的蛋白质水解产物进行纸色谱和柱色谱分离,得到单独的L-35 S-氨基酸。半胱氨酸和蛋氨酸的放射化学收率分别为6-7%和18-20%。产品放射化学纯度>95%。采用该方法获得的产物的最高比活度为1100 Ci/mmole,起始原料Na2 35 SO4,比活度为1350 Ci/mmole。