Metabolic engineering of Yarrowia lipolytica for itaconic acid production
Metabolic engineering of Yarrowia lipolytica for itaconic acid production
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DOI：
10.1016/j.ymben.2015.09.005
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发表时间：
2015-11-01
影响因子：
8.4
通讯作者：
Alper, Hal S.
中科院分区：
文献类型：
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作者：
Blazeck, John;Hill, Andrew;Alper, Hal S.
衣康酸是一种天然产生的有机酸，作为石油衍生产品的替代品具有多种应用。然而，由于当地生产商的限制，其作为生物替代品的工业可行性受到限制。在这种情况下，解脂耶氏酵母是一个很好的潜在候选人，因为它的先天能力，积累柠檬酸循环中间体和耐受性较低的pH值。在这里，我们证明了通过异源表达的解脂耶氏酵母中产生的伊曲酸的伊曲酸合成酶，导致初始滴度为33毫克/升的能力。通过代谢途径工程、酶定位和培养基优化策略对该菌株进行进一步优化，使得在生物反应器中能够生产4.6 g/L的衣康酸，这代表了比初始滴度提高140倍。此外，这些发酵条件不需要额外的营养补充，并且利用能够产生酸形式的衣康酸的低pH条件。总产量（0.058 g/g葡萄糖产量）和0.045 g/L/h的最大生产率仍为未来菌株改进提供了空间。然而，这项工作表明，解脂耶氏酵母有潜力作为一个工业相关的平台，用于生产衣康酸。(C)2015年国际代谢工程学会。爱思唯尔公司出版All rights reserved.
Itaconic acid is a naturally produced organic acid with diverse applications as a replacement for petroleum derived products. However, its industrial viability as a bio-replacement has been restricted due to limitations with native producers. In this light, Yarrowia lipolytica is an excellent potential candidate for itaconic acid production due to its innate capacity to accumulate citric acid cycle intermediates and tolerance to lower pH. Here, we demonstrate the capacity to produce itaconic acid in Y, lipolytica through heterologous expression of the itaconic acid synthesis enzyme, resulting in an initial titer of 33 mg/L. Further optimizations of this strain via metabolic pathway engineering, enzyme localization, and media optimization strategies enabled 4.6 g/L of itaconic acid to be produced in bioreactors, representing a 140-fold improvement over initial titer. Moreover, these fermentation conditions did not require additional nutrient supplementation and utilized a low pH condition that enabled the acid form of itaconic acid to be produced. Overall yields (0.058 g/g yield from glucose) and maximum productivity of 0.045 g/L/h still provide areas for future strain improvement. Nevertheless, this work demonstrates that Y lipolytica has the potential to serve as an industrially relevant platform for itaconic acid production. (C) 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.