Metabolic engineering of Clostridium tyrobutyricum for n-butanol production from sugarcane juice
Metabolic engineering of Clostridium tyrobutyricum for n-butanol production from sugarcane juice
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DOI：
10.1007/s00253-017-8200-1
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发表时间：
2017-02
影响因子：
5
通讯作者：
Jianzhi Zhang;Le Yu;Mengmeng Xu;Shangtian Yang;Q. Yan;Meng Lin;I. Tang
中科院分区：
文献类型：
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作者：
Jianzhi Zhang;Le Yu;Mengmeng Xu;Shangtian Yang;Q. Yan;Meng Lin;I. Tang
酪丁酸梭菌是一种很有前途的丁酸和正丁醇生产菌，但不能生长在蔗糖上。从乙酰丁基梭菌中克隆了参与蔗糖分解代谢途径的三个基因(scra、scrb和scrK)以及一个醛/醇脱氢酶基因，并将其导入C。酪丁酸菌(Δack)与醋酸激酶基因敲除。在分批发酵中，工程菌Ct(Δack)-pscrBAK以蔗糖和甘蔗汁为原料，生产丁醇14.8~18.8g/L，丁醇/总溶剂比高达∼0.94w/w。此外，在没有抗生素筛选压力的情况下，分批发酵丁醇产量稳定，丁醇产率为0.25g/g，产率为0.28g/L∙h，表明Ct(Δack)-pscrBAK具有遗传稳定性。此外，Ct(Δack)-pscrBAK对蔗糖的利用不受葡萄糖的抑制，而葡萄糖通常会对溶剂型梭状芽孢杆菌造成碳分解代谢抑制。因此，CT(Δack)-pscrBAK有利于从甘蔗汁和其他富含蔗糖的原料中生产生物丁醇。
Clostridium tyrobutyricumis a promising organism for butyrate andn-butanol production, but cannot grow on sucrose. Three genes (scrA,scrB, andscrK) involved in the sucrose catabolic pathway, along with an aldehyde/alcohol dehydrogenase gene, were cloned fromClostridium acetobutylicumand introduced intoC. tyrobutyricum(Δack) with acetate kinase knockout. In batch fermentation, the engineered strain Ct(Δack)-pscrBAK produced 14.8–18.8 g/L butanol, with a high butanol/total solvent ratio of ∼0.94 (w/w), from sucrose and sugarcane juice. Moreover, stable high butanol production with a high butanol yield of 0.25 g/g and productivity of 0.28 g/L∙h was obtained in batch fermentation without using antibiotics for selection pressure, suggesting that Ct(Δack)-pscrBAK is genetically stable. Furthermore, sucrose utilization by Ct(Δack)-pscrBAK was not inhibited by glucose, which would usually cause carbon catabolite repression on solventogenic clostridia. Ct(Δack)-pscrBAK is thus advantageous for use in biobutanol production from sugarcane juice and other sucrose-rich feedstocks.