脆壁克鲁维酵母(Kluyveromycesfragilis)LFS 8611合成的β D 半乳糖苷酶具有较高的催化半乳糖基转移反应活力.脆壁克鲁维酵母(K.fragilis)LFS 8611细胞生长和β D 半乳糖苷酶的合成同步.该菌株生长和产酶的最适碳源为半乳糖,乳糖次之;...脆壁克鲁维酵母(Kluyveromycesfragilis)LFS 8611合成的β D 半乳糖苷酶具有较高的催化半乳糖基转移反应活力.脆壁克鲁维酵母(K.fragilis)LFS 8611细胞生长和β D 半乳糖苷酶的合成同步.该菌株生长和产酶的最适碳源为半乳糖,乳糖次之;最适氮源为蛋白胨F403;最适培养条件为:发酵培养基的初始pH值为7.0,摇床的转速为200r/min.培养基中碳源和氮源质量浓度对菌体生物量和β D 半乳糖苷酶活力有重要影响,以12mg/mL乳糖为碳源,16mg/mL蛋白胨(F403)为氮源,在最适培养条件下培养32h后,菌体生物量和β D 半乳糖苷酶活力分别为7.56g/L和18.83U/mL.展开更多
The genomic library of Kluyveromyces fragilis was constructed in E.coli TG1,and 5β-galactosidase gene(LAC4)clones have been obtained from the library by complementation of theKluyveromyces lactis lac4-8 mutation.The ...The genomic library of Kluyveromyces fragilis was constructed in E.coli TG1,and 5β-galactosidase gene(LAC4)clones have been obtained from the library by complementation of theKluyveromyces lactis lac4-8 mutation.The studies on the structure and the function of the LAC4 gene revealedthat(i)the gene can also complement E.coli lacZ mutation;(ii)the physical map of the K.fragilis LAC4gene was very similar to that of K.lactis;(iii)the β-galactosidase levels expressed by the clone strains weremuch higher than that expressed by the original strain;(iv)the variation of the β-galactosidase level of differ-ent clone strains induced by lactose or galactose was related to the retained degree of the 5’ flanking region ofLAC4 gene,suggesting that there migth he a lactose specific transcription activating element in the region.展开更多
文摘脆壁克鲁维酵母(Kluyveromycesfragilis)LFS 8611合成的β D 半乳糖苷酶具有较高的催化半乳糖基转移反应活力.脆壁克鲁维酵母(K.fragilis)LFS 8611细胞生长和β D 半乳糖苷酶的合成同步.该菌株生长和产酶的最适碳源为半乳糖,乳糖次之;最适氮源为蛋白胨F403;最适培养条件为:发酵培养基的初始pH值为7.0,摇床的转速为200r/min.培养基中碳源和氮源质量浓度对菌体生物量和β D 半乳糖苷酶活力有重要影响,以12mg/mL乳糖为碳源,16mg/mL蛋白胨(F403)为氮源,在最适培养条件下培养32h后,菌体生物量和β D 半乳糖苷酶活力分别为7.56g/L和18.83U/mL.
文摘The genomic library of Kluyveromyces fragilis was constructed in E.coli TG1,and 5β-galactosidase gene(LAC4)clones have been obtained from the library by complementation of theKluyveromyces lactis lac4-8 mutation.The studies on the structure and the function of the LAC4 gene revealedthat(i)the gene can also complement E.coli lacZ mutation;(ii)the physical map of the K.fragilis LAC4gene was very similar to that of K.lactis;(iii)the β-galactosidase levels expressed by the clone strains weremuch higher than that expressed by the original strain;(iv)the variation of the β-galactosidase level of differ-ent clone strains induced by lactose or galactose was related to the retained degree of the 5’ flanking region ofLAC4 gene,suggesting that there migth he a lactose specific transcription activating element in the region.
