Zhang Baixi, Ni Lijuan, Tang Xiaoshu, Chen Xuemei, Hu Bo
School of Chemical Engineering, Xuzhou College of Industrial Technology, No. 1 Xiangwang Road, Xuzhou, Jiangsu 221140, P. R. China.
J Agric Food Chem. 2022 Jul 13;70(27):8377-8384. doi: 10.1021/acs.jafc.2c02242. Epub 2022 Jun 28.
-10, -12-Conjugated linoleic acid (10, 12-CLA) is an octadecadienoic acid with various biological benefits. Previously, linoleic acid isomerase from (PAI) was overexpressed in () to produce 10, 12-CLA. However, the 10, 12-CLA yield was restricted by the peroxisomal β-oxidation pathway. In this study, to minimize the degradation of 10, 12-CLA, four genetically modified strains of ( and ) were constructed and compared in terms of production stability and yield of 10, 12-CLA using safflower seed oil as substrates. The strain exhibited the best results, as revealed by the reduction of the 10, 12-CLA degradation rate from 58.5 to 18.6 mg/L/h. Additionally, the YLUpex10mP recombinant strain bearing six copies of o combined with deletion enhanced 10, 12-CLA production to 7.4 g/L and exhibited a CLA degradation rate of 19.7 mg/L/h, a 78% decrease from that of the control strain. Finally, in a bioreactor containing low-cost volatile fatty acids as partial carbon sources, the 10, 12-CLA content in the YLUpex10mP strain increased to 9.7 g/L, 1.3 times higher than in flasks. To our knowledge, this is the highest 10, 12-CLA yield through microbial synthesis reported to date.
-10，-12-共轭亚油酸（10,12-CLA）是一种具有多种生物学益处的十八碳二烯酸。此前，来自丙酸杆菌属（PAI）的亚油酸异构酶在酿酒酵母（Saccharomyces cerevisiae）中过表达以生产10,12-CLA。然而，10,12-CLA的产量受到过氧化物酶体β-氧化途径的限制。在本研究中，为了尽量减少10,12-CLA的降解，构建了四株转基因酿酒酵母菌株（YLUpex10、YLUpex10m、YLUpex10mP和YLUpex10mPex1），并以红花籽油为底物，对它们在10,12-CLA生产稳定性和产量方面进行了比较。YLUpex10mP菌株表现出最佳结果，10,12-CLA降解率从58.5降至18.6 mg/L/h。此外，携带六个o拷贝并缺失pex1的YLUpex10mP重组菌株将10,12-CLA产量提高到7.4 g/L，CLA降解率为19.7 mg/L/h，比对照菌株降低了78%。最后，在含有低成本挥发性脂肪酸作为部分碳源的生物反应器中，YLUpex10mP菌株中的10,12-CLA含量增加到9.7 g/L，比在摇瓶中高出1.3倍。据我们所知，这是迄今为止报道的通过微生物合成获得的最高10,12-CLA产量。
