The metabolically engineered plant pathogen Ustilago maydis MB215 Δcyp3 P_etefria1 has been cultivated to produce more than 80 g/L itaconate in 16 L scale pH and temperature controlled fermentation, in fed-batch mode with two successive feedings. The effect of pH as well as successive rounds of feeding has been quantified via elemental balances. Volumetric itaconic acid productivity gradually decreased with successive glucose feedings with increasing itaconic titers, with nearly constant product yield. Extracellular pH was decreased from 6 down to 3.5 and the fermentation was characterized in specific uptake, production, and growth rates. Notable is that the biomass composition changes significantly from growth phase to itaconic acid production phase, carbon content increases from 42% to around 62%. Despite the gradual decrease in itaconic acid levels with decreasing pH (nearly 50% decrease in itaconic acid at pH 3.5, compared to pH 6), significant itaconate production is still observed at pH 4 (around 63 g/L). Biomass yield remained nearly constant until pH 4. Taken together, these results strongly illustrate the potential of engineered Ustilago maydis in itaconate production at commercial levels.

代谢工程植物病原体Ustilago maydis MB215 Δ cyp3 P _etef ria1已经培养为在 16 L 规模 pH 和温度控制发酵中生产超过 80 g/L 衣康酸盐，在补料分批模式下连续两次补料。pH 值的影响以及连续几轮喂食已通过元素平衡进行量化。随着衣康酸滴度的增加，随着连续葡萄糖进料，体积衣康酸生产力逐渐降低，产品产量几乎恒定。细胞外 pH 值从 6 降至 3.5，发酵的特征在于比吸收、生产和生长速率。值得注意的是，生物质组成从生长期到衣康酸生产阶段发生了显着变化，碳含量从 42% 增加到 62% 左右。尽管衣康酸水平随着 pH 值的降低而逐渐降低（在 pH 值 3.5 时衣康酸含量降低近 50%，与 pH 6) 相比，在 pH 4（约 63 g/L）下仍观察到显着的衣康酸产量。在 pH 值为 4 之前，生物质产量几乎保持不变。总而言之，这些结果有力地说明了工程改造的潜力Ustilago maydis在衣康酸盐的商业水平生产中。