Enhanced itaconic acid production in Aspergillus niger using genetic modification and medium optimization.
Enhanced itaconic acid production in Aspergillus niger using genetic modification and medium optimization.
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DOI：
10.1186/1472-6750-12-57
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发表时间：
2012-08-27
影响因子：
3.5
通讯作者：
Punt P
中科院分区：
文献类型：
--
作者：
Li A;Pfelzer N;Zuijderwijk R;Punt P
黑曲霉因其对衣康酸前体柠檬酸具有极高的积累能力和对各种生长环境的耐受性而被选为衣康酸生产的宿主。土曲霉CAD基因的表达开启了黑曲霉对衣康酸的代谢途径。为了提高生产水平，我们继续对其基因组进行了修改，并优化了培养基数。根据以往的转录学研究结果和其他研究小组的研究结果，两个基因：编码甘油醛−3-脱氢酶(Gpd)的gpda和编码黄红蛋白结构域(Hbd)的hbd1在黑曲霉中过表达。此外，还设计了以黄曲霉为参照的新的培养基料。为了分析大量的培养物，我们开发了一种方法，用于在96孔微滴度平板中同时筛选真菌转化子和各种培养基。Hbd1转化子(HBD 2.2/2.5)不能提高衣康酸的滴度，而GPDA转化子(GPD 4.3)则降低衣康酸的产量。使用20种不同的介质，发现铜对衣康酸的生产有积极的影响。在微量平板筛选中观察到的效果在控制分批发酵中得到了证实。在所测试的培养条件下，GPDA和hbd1转化子的性能不利于衣康酸的生产。培养基优化表明，铜与衣康酸产量的提高呈正相关。有趣的是，衣康酸的最佳条件与生产柠檬酸和草酸的最佳条件明显不同。
Aspergillus niger was selected as a host for producing itaconic acid due to its versatile and tolerant character in various growth environments, and its extremely high capacity of accumulating the precursor of itaconic acid: citric acid. Expressing the CAD gene from Aspergillus terreus opened the metabolic pathway towards itaconic acid in A. niger. In order to increase the production level, we continued by modifying its genome and optimizing cultivation media. Based on the results of previous transcriptomics studies and research from other groups, two genes : gpdA encoding the glyceraldehyde −3-dehydrogenase (GPD) and hbd1 encoding a flavohemoglobin domain (HBD) were overexpressed in A. niger. Besides, new media were designed based on a reference medium for A. terreus. To analyze large numbers of cultures, we developed an approach for screening both fungal transformants and various media in 96-well micro-titer plates. The hbd1 transformants (HBD 2.2/2.5) did not improve itaconic acid titer while the gpdA transformant (GPD 4.3) decreased the itaconic acid production. Using 20 different media, copper was discovered to have a positive influence on itaconic acid production. Effects observed in the micro-titer plate screening were confirmed in controlled batch fermentation. The performance of gpdA and hbd1 transformants was found not to be beneficial for itaconic acid production using the tested cultivation conditions. Medium optimization showed that, copper was positively correlated with improved itaconic acid production. Interestingly, the optimal conditions for itaconic acid clearly differ from conditions optimal for citric- and oxalic acid production.
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影响因子：
2.4
作者：
Alberto, F.;Navarro, D.;Record, E.
通讯作者：
Record, E.
影响因子：
5.6
作者：
Guilherme, A. A.;Pinto, G. A. S.;Rodrigues, S.
通讯作者：
Rodrigues, S.
影响因子：
4.4
作者：
Haq, IU;Ali, S;Iqbal, J
通讯作者：
Iqbal, J
影响因子：
5.4
作者：
Poulsen, BR;Nohr, J;Ruijter, GJG
通讯作者：
Ruijter, GJG
DOI：
10.1099/00221287-78-2-217
发表时间：
1973-01-01
期刊：
JOURNAL OF GENERAL MICROBIOLOGY
影响因子：
--
作者：
STARKEY, RL
通讯作者：
STARKEY, RL