Omics-based analyses revealed metabolic responses of Clostridium acetobutylicum to lignocellulose-derived inhibitors furfural, formic acid and phenol stress for butanol fermentation
Omics-based analyses revealed metabolic responses of Clostridium acetobutylicum to lignocellulose-derived inhibitors furfural, formic acid and phenol stress for butanol fermentation
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基于组学的分析揭示了丁醇发酵过程中丙酮丁醇梭菌对木质纤维素衍生抑制剂糠醛、甲酸和苯酚应激的代谢反应
DOI：
10.1186/s13068-019-1440-9
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发表时间：
2019-04-27
影响因子：
6.3
通讯作者：
Liu, Bin
中科院分区：
文献类型：
--
作者：
Liu, Huanhuan;Zhang, Jing;Liu, Bin
丙酮丁醇梭菌（Clostridium acetobutylicum）是一种将木质纤维素水解物转化为丙酮-丁醇-乙醇（acetone-butanol-ethanol，ABE）的模式厌氧发酵菌。然而，普遍存在于木质纤维素水解物中的主要抑制剂（酸、呋喃和酚）严格限制了转化效率。因此，必须了解木质纤维素水解物抑制剂的潜在机制，以确定破坏高效生物燃料生产的关键工业瓶颈。最近开发的细胞内代谢物和蛋白质定量的组学策略，现在允许菌株代谢的深入映射，从而能够解决的潜在mechanism.ResultsThe主要抑制剂的毒性木质纤维素水解产物对C。系统研究了丙酮丁醇和ABE的合成，并利用代谢组学和蛋白质组学分析了细胞内代谢的变化。在相同剂量下，主要木质纤维素水解物抑制剂的毒性大小顺序为甲酸>苯酚>糠醛。基于加权基因共表达网络分析（WGCNA）的代谢组学分析表明，三种抑制剂均能触发C.丙酮丁醇基于肽质谱（MS）的蛋白质组学分析支持了上述结果，并提供了更全面的结论。在3种抑制剂胁迫下，参与糖酵解、还原性三羧酸（TCA）循环、丙酮丁醇合成和氧化还原代谢的代谢产物和关键酶/蛋白均低于对照组。此外，抑制剂胁迫诱导的蛋白质表达显著上调，其中蛋白质参与了植物的再生、氧化TCA循环和氧化应激的巯基过氧化物酶（TPX），表明抑制剂胁迫诱导了植物的应激反应和代谢调节。此外，这3种抑制剂还表现出与脂肪酸合成、ATP合成、核酸代谢、烟酸代谢、细胞壁合成、孢子合成和鞭毛合成等相关的应激特异性。丙酮丁醇与木质纤维素解构过程中释放的细胞毒性抑制剂的反应。这一见解使我们能够充分改善菌株，以适应具有挑战性的培养环境，这将证明对C的工业功效至关重要。丙酮丁醇
BackgroundClostridium acetobutylicum is a model fermentative anaerobe for consolidated bioprocessing of lignocellulose hydrolysates into acetone-butanol-ethanol (ABE). However, the main inhibitors (acids, furans and phenols) ubiquitous in lignocellulose hydrolysates strictly limit the conversion efficiency. Thus, it is essential to understand the underlying mechanisms of lignocellulose hydrolysate inhibitors to identify key industrial bottlenecks that undermine efficient biofuel production. The recently developed omics strategy for intracellular metabolites and protein quantification now allow for the in-depth mapping of strain metabolism and thereby enable the resolution of the underlying mechanisms.ResultsThe toxicity of the main inhibitors in lignocellulose hydrolysates against C. acetobutylicum and ABE production was systematically investigated, and the changes in intracellular metabolism were analyzed by metabolomics and proteomics. The toxicity of the main lignocellulose hydrolysate inhibitors at the same dose was ranked as follows: formic acid>phenol>furfural. Metabolomic analysis based on weighted gene coexpression network analysis (WGCNA) revealed that the three inhibitors triggered the stringent response of C. acetobutylicum. Proteomic analysis based on peptide mass spectrometry (MS) supported the above results and provided more comprehensive conclusions. Under the stress of three inhibitors, the metabolites and key enzymes/proteins involved in glycolysis, reductive tricarboxylic acid (TCA) cycle, acetone-butanol synthesis and redox metabolism were lower than those in the control group. Moreover, proteins involved in gluconeogenesis, the oxidative TCA cycle, thiol peroxidase (TPX) for oxidative stress were significantly upregulated, indicating that inhibitor stress induced the stress response and metabolic regulation. In addition, the three inhibitors also showed stress specificity related to fatty acid synthesis, ATP synthesis, nucleic acid metabolism, nicotinic acid metabolism, cell wall synthesis, spore synthesis and flagellum synthesis and so on.ConclusionsIntegrated omics platforms provide insight into the cellular responses of C. acetobutylicum to cytotoxic inhibitors released during the deconstruction of lignocellulose. This insight allows us to fully improve the strain to adapt to a challenging culture environment, which will prove critical to the industrial efficacy of C. acetobutylicum.