Fu J, Parker C B, Burke P, Schultz L D, Montgomery D L, Arnold B A, McGinnis K
Department of Vaccine Bioprocess R&D, Merck Research Laboratories, West Point, Pennsylvania 19486, USA.
Biotechnol Prog. 1996 Jan-Feb;12(1):145-8. doi: 10.1021/bp950060m.
The effect of host strain ploidy on the production of hepatitis B surface antigen (HBsAg) in Saccharomyces cerevisiae was evaluated at the pilot scale (75 L). We found that the accumulation of HBsAg normalized to cell protein was 2-fold higher for the diploid strain compared to its isogenic haploid. No detectable differences in many fermentation parameters were observed (e.g., rate of fermentation, growth rate, final cell yield). However, the enhancement of productivity in the diploid strain appeared to be associated with a slower rate of plasmid shedding (2 microns element) and, thus, a higher average copy number (2-fold at stationary phase) compared to those of the haploid strain.
在中试规模（75升）下评估了宿主菌株倍性对酿酒酵母中乙型肝炎表面抗原（HBsAg）产生的影响。我们发现，与同基因单倍体菌株相比，二倍体菌株中归一化至细胞蛋白的HBsAg积累量高2倍。在许多发酵参数方面未观察到可检测到的差异（例如，发酵速率、生长速率、最终细胞产量）。然而，二倍体菌株生产力的提高似乎与质粒脱落（2μm元件）速率较慢有关，因此，与单倍体菌株相比，其平均拷贝数更高（稳定期时高2倍）。
