摘要
乙醇酸氧化酶(GO)是植物光呼吸途径中的一种关键酶,可以催化乙醇酸生产乙醛酸。从新鲜菠菜叶中提取总RNA,利用RT-PCR技术获得编码GO基因的cDNA片断。通过基因重组将GO基因克隆到载体pAO815中,构建了胞内表达载体pAO815/GO,重组质粒经电转整合至甲醇营养酵母GS115染色体。在混合碳源为10g/L山梨醇和0.5g/L甲醇的培养条件下,细胞的GO酶活达到474 IU/g(DCW)。利用该重组毕赤酵母作为催化剂生产乙醛酸,结果表明:在乙醇酸浓度为0.25 mol/L,重组酵母湿茵体为10g/L,黄素单核苷酸(FMN)浓度为0.01 mmol/L,pH8.0,20℃,反应18h后乙醛酸的产率达到51.8%。
Glycolate oxidase （GO） is a key-enzyme in the photorespiration of plants, which can catalyze glycolic acid into glyoxylic acid. A cDNA coding for glycolate oxidase was isolated from fresh spinach leaves by RT-PCR. The GO gene was cloned into the pAO815 under the control of AOX1 promoter and integrated into the genome of methylotrophic yeast Pichia pastoris GSll5. The GO activity of cells could reach up to 474 IU/g （DCW） in batch culture on mixed substrates of 1% sorbitol and 0.05 % methanol. Recombinant Pichia pastoris cells were used as bio-catalyst in the bio-producfion process of glyoxylic acid. Results showed that yield of glyoxylic acid reached 51.8% under the conditions of 0.25 mol/L glycolic acid, 0.01 mmol/L flavin mononuleotide, pH 8.0, temperature 20℃ and reaction time 18 h.
出处
《工业微生物》
CAS
CSCD
2009年第3期45-50,共6页
Industrial Microbiology
关键词
乙醇酸氧化酶
重组毕赤酵母
乙醛酸
glycolate oxidase
recombinant Pichia pastoris
glyoxylic acid
