Abstract:
Rhodotorula toruloides is a potential workhorse for production of various value-added chemicals including terpenoids, oleo-chemicals, and enzymes from low-cost feedstocks. However, the limited genetic toolbox is hindering its metabolic engineering. In the present study, four type I and one novel type II peroxisomal targeting signal (PTS1/PTS2) were characterized and employed for limonene production for the first time in R. toruloides. The implant of the biosynthesis pathway into the peroxisome led to 111.5 mg/L limonene in a shake flask culture. The limonene titer was further boosted to 1.05 g/L upon dual-metabolic regulation in the cytoplasm and peroxisome, which included employing the acetoacetyl-CoA synthase NphT7, adding an additional copy of native ATP-dependent citrate lyase, etc. The final yield was 0.053 g/g glucose, which was the highest ever reported. The newly characterized PTSs should contribute to the expansion of genetic toolboxes forR. toruloides. The results demonstrated that R. toruloides could be explored for efficient production of terpenoids.
摘要:
Rhodotorulatoruloides是生产各种增值化学品的潜在主力,包括萜类化合物,油脂化学品,和来自低成本原料的酶。然而,有限的遗传工具箱阻碍了它的代谢工程。在本研究中,表征了四种I型和一种新型II型过氧化物酶体靶向信号(PTS1/PTS2),并首次在R.toruloides中用于柠檬烯生产。将生物合成途径植入过氧化物酶体导致摇瓶培养中111.5mg/L柠檬烯。在细胞质和过氧化物酶体的双重代谢调节后,柠檬烯的滴度进一步提高到1.05g/L,其中包括采用乙酰乙酰辅酶A合酶NphT7,添加一个额外的天然ATP依赖性柠檬酸裂解酶,等。最终产量为0.053g/g葡萄糖,这是有史以来最高的报道。新表征的PTS应有助于R的遗传工具箱的扩展。Toruloides.结果表明,可以探索高效生产萜类化合物。