Engineering Corynebacterium glutamicum to produce the biogasoline isopentenol from plant biomass hydrolysates
Engineering Corynebacterium glutamicum to produce the biogasoline isopentenol from plant biomass hydrolysates
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DOI：
10.1186/s13068-019-1381-3
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发表时间：
2019-02-27
影响因子：
6.3
通讯作者：
Mukhopadhyay, Aindrila
中科院分区：
文献类型：
--
作者：
Sasaki, Yusuke;Eng, Thomas;Mukhopadhyay, Aindrila
背景许多用于快速发现和开发代谢途径的微生物对终产物和工艺试剂具有敏感性。异戊烯醇（3-甲基-3-丁烯-1-醇），一种新的乙酰胆碱候选物，具有已建立的异源基因途径，但对几种微生物宿主有毒。用于植物生物质预处理的试剂，如离子液体，也抑制许多宿主菌株的生长。我们探索了使用谷氨酸棒杆菌作为替代宿主来解决这些限制。谷氨酸菌ATCC 13032对最终产物异戊烯醇以及三类离子液体都具有耐受性。在C.谷氨酸。异源途径蛋白质的靶向蛋白质组学研究表明，3-羟基-3-甲基戊二酰辅酶A还原酶蛋白HmgR是该合成途径中潜在的限速酶。通过组合三种方法将异戊烯醇滴度从不可检测提高到1.25g/L：培养基优化;来自Silicibacter pomeroyi的NADH依赖性HmgR同源物的替代;以及C.结论我们描述了在革兰氏阳性工业微生物C.谷氨酸杆菌，用于生产乙酰胆碱候选物异戊烯醇。我们确定了关键的遗传因素，利用异戊烯醇途径，在C。谷氨酸。进一步的培养基和培养优化使得能够从高粱生物质水解产物生产异戊烯醇。
BackgroundMany microbes used for the rapid discovery and development of metabolic pathways have sensitivities to final products and process reagents. Isopentenol (3-methyl-3-buten-1-ol), a biogasoline candidate, has an established heterologous gene pathway but is toxic to several microbial hosts. Reagents used in the pretreatment of plant biomass, such as ionic liquids, also inhibit growth of many host strains. We explored the use of Corynebacterium glutamicum as an alternative host to address these constraints.ResultsWe found C. glutamicum ATCC 13032 to be tolerant to both the final product, isopentenol, as well to three classes of ionic liquids. A heterologous mevalonate-based isopentenol pathway was engineered in C. glutamicum. Targeted proteomics for the heterologous pathway proteins indicated that the 3-hydroxy-3-methylglutaryl-coenzyme A reductase protein, HmgR, is a potential rate-limiting enzyme in this synthetic pathway. Isopentenol titers were improved from undetectable to 1.25g/L by combining three approaches: media optimization; substitution of an NADH-dependent HmgR homolog from Silicibacter pomeroyi; and development of a C. glutamicum poxB ldhA host chassis.ConclusionsWe describe the successful expression of a heterologous mevalonate-based pathway in the Gram-positive industrial microorganism, C. glutamicum, for the production of the biogasoline candidate, isopentenol. We identified critical genetic factors to harness the isopentenol pathway in C. glutamicum. Further media and cultivation optimization enabled isopentenol production from sorghum biomass hydrolysates.