Metabolic engineering of the type I methanotroph Methylomonas sp. DH-1 for production of succinate from methane
Metabolic engineering of the type I methanotroph Methylomonas sp. DH-1 for production of succinate from methane
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DOI：
10.1016/j.ymben.2019.03.013
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发表时间：
2019-07-01
影响因子：
8.4
通讯作者：
Lee, Eun Yeol
中科院分区：
文献类型：
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作者：
Diep Thi Ngoc Nguyen;Lee, Ok Kyung;Lee, Eun Yeol
利用甲烷的甲烷氧化菌是一种非常有吸引力的甲烷生物转化系统。Methylomonasp. DH-1是从啤酒厂污泥中分离得到的一株Ⅰ型甲烷氧化菌，具有良好的工业生物催化剂应用前景。琥珀酸盐被认为是农业、食品和制药行业的顶级基础化学品之一。在这项研究中，甲基单胞菌DH-1的工程积累琥珀酸作为所需的产品。TCA循环和将碳通量转移到乙酸盐或甲酸盐的酶被修饰或删除以提高琥珀酸盐生产率。通过删除TCA循环中的琥珀酸脱氢酶（sdh），与野生型相比，琥珀酸产量显著增加了约10倍。此外，通过整合来自E.杆菌MG 1655菌株。丙酮酸甲酸裂解酶（pfl）和乙酸激酶-磷酸转乙酰酶（ack-pta）基因被破坏，以进一步集中碳通量的TCA循环。然而，这些竞争途径的额外中断并不积极影响细胞生长或琥珀酸生产。将琥珀酸产量最高的突变株DS-GL在补料分批生物反应器中培养，获得了较高的细胞生长和琥珀酸产量（类似于195 mg/L琥珀酸，0.0789 g琥珀酸/g甲烷产率）。在这项研究中，我们展示了一个新的平台，微生物转化甲烷琥珀酸利用甲烷营养菌。
Methane-utilizing methanotrophs are fascinating systems for methane bioconversion. Methylomonas sp. DH-1, a novel type I methanotroph isolated from brewery sludge, has been evaluated as a promising candidate for an industrial bio-catalyst. Succinate has been considered one of the top building block chemicals for the agricultural, food, and pharmaceutical industries. In this study, Methylomonas sp. DH-1 was engineered to accumulate succinate as a desired product. The TCA cycle and enzymes diverting carbon flux to acetate or formate were modified or deleted to improve succinate productivity. By deleting succinate dehydrogenase (sdh) in the TCA cycle, succinate production increased dramatically similar to 10 times compared to that of the wild type. In addition, the maximum succinate titer of similar to 134 mg/L (DS-GL) was achieved by integrating glyoxylate shunt enzymes from the E. coli. MG1655 strain. Pyruvate formate lyase (pfl) and acetate kinase-phosphotransacetylase (ack-pta) genes were disrupted to further concentrate carbon flux to the TCA cycle. However, these additional disruptions of competitive pathways did not affect cell growth or succinate production positively. The mutant strain DS-GL, which showed the best succinate production, was grown in a fed-batch bioreactor, and higher cell growth and succinate production (similar to 195 mg/L succinate with 0.0789 g-succinate/g-methane yield) were achieved. In this study, we demonstrated a novel platform for microbial conversion of methane to succinate using methanotroph.