摘要
为改造甲醇利用型酵母Pichiapastoris来生产腺苷甲硫氨酸 (SAM ,S adenosyl L methionine) ,我们将一个带有SAM合成酶基因的胞内表达质粒转化入Pichiapastoris菌株GS115 ,经过G418抗性筛选得到一株有两个基因拷贝的转化子。该菌在含有甲醇和甲硫氨酸的培养基中生长 5d后 ,其细胞内的SAM的产量比原始菌株提高了 30余倍。对该菌生产SAM的培养基中的碳源与氮源进行了优化 ,结果显示碳源的控制对该菌SAM产量的影响很大。在试管水平 ,该菌在含有 0 .75 %的L methionine并且碳源和有机氮源经过一定程度优化的培养基中 ,生长 6d后SAM产量达到 1.5 8g L。
To utilize Pichia pastoris to produce S-adenosyl-L-methionine (SAM), an intracellular expression vector harboring S. cerevisiae SAM2 was transformed into GS115. A recombinant strain having 2 copies of expression cassette was obtained through G418 resistance screening. This strain had higher SAM synthetase activity and higher SAM production capacity than the original strain, when cultured in medium containing methanol and methionine. The carbon source and nitrogen source of medium was optimized. The results showed SAM production by this strain was closely related to carbon metabolism. With supplementation of 0.2% glycerol every day from the beginning of 3rd day, this strain produced 1.58g/L SAM when cultured in a medium containing 0.75% L-methionine and optimized carbon and nitrogen source after 6 days.
出处
《生物工程学报》
CAS
CSCD
北大核心
2002年第3期295-299,共5页
Chinese Journal of Biotechnology
关键词
腺苷甲硫氨酸高产菌
重组
SAM合成酶
S-adenosyl-L-methionine high production strain, recombinant, SAM synthetase, Pichia pastoris
