Zhu Yunfei, Zheng Gaofan, Xin Xiujuan, Ma Junying, Ju Jianhua, An Faliang
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.
CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
Bioresour Bioprocess. 2022 Oct 22;9(1):111. doi: 10.1186/s40643-022-00599-z.
Ilamycins E/E are novel cyclic heptapeptides from Streptomyces atratus SCSIO ZH16, which have the MIC value of 9.8 nM against Mycobacterium tuberculosis H37Rv. However, the lower fermentative titer of ilamycins E/E cut off further development for novel anti-TB lead drugs. In order to break the obstacle, the combinatorial strategy of medium optimization, fermentative parameters optimization, exogenous addition of metal ions, precursors, and surfactants was developed to promoted the production of ilamycins E/E. Addition of 1 mM ZnCl at 0 h, 1 g/L tyrosine at 96 h, and 2 g/L shikimic acid at 48 h increased the production of ilamycins E/E from 13.51 to 762.50 ± 23.15, 721.39 ± 19.13, and 693.83 ± 16.86 mg/L, respectively. qRT-PCR results showed that the transcription levels of key genes in Embden-Meyerhof-Parnas pathway, hexose phosphate shunt pathway, and shikimic acid pathway were upregulated. In addition, the production of ilamycins E/E reached 790.34 mg/L in a 5-L bioreactor by combinatorial strategy. Combinatorial strategies were used for improving ilamycins E/E production in S. atratus ΔilaR and provided a sufficient basis on further clinic development.
伊拉霉素E/E是从阿特拉链霉菌SCSIO ZH16中分离得到的新型环七肽，其对结核分枝杆菌H37Rv的最低抑菌浓度（MIC）值为9.8 nM。然而，伊拉霉素E/E较低的发酵效价阻碍了其作为新型抗结核先导药物的进一步开发。为了突破这一障碍，开发了培养基优化、发酵参数优化、外源添加金属离子、前体和表面活性剂的组合策略，以促进伊拉霉素E/E的生产。在0 h添加1 mM ZnCl₂、在96 h添加1 g/L酪氨酸以及在48 h添加2 g/L莽草酸，分别使伊拉霉素E/E的产量从13.51 mg/L提高到762.50±23.15 mg/L、721.39±19.13 mg/L和693.83±16.86 mg/L。定量逆转录聚合酶链反应（qRT-PCR）结果表明，糖酵解途径、磷酸己糖支路途径和莽草酸途径中关键基因的转录水平上调。此外，通过组合策略，在5-L生物反应器中伊拉霉素E/E的产量达到了790.34 mg/L。组合策略用于提高阿特拉链霉菌ΔilaR中伊拉霉素E/E的产量，为其进一步的临床开发提供了充分的依据。
