State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
J Biotechnol. 2018 Sep 10;281:81-86. doi: 10.1016/j.jbiotec.2018.06.341. Epub 2018 Jun 18.
Lignin is one of the major components of lignocellulose biomass and chemically degrades into phenolic aldehydes including 4-hydroxybenzaldehyde, vanillin, and syringaldehyde. No lipid accumulation from the phenolic aldehydes by oleaginous microbes had been succeeded. Compared with vanillin and syringaldehyde, T. cutaneum ACCC 20271 have better tolerance to 4-hydroxybenzaldehyde. 4-Hydroxybenzaldehyde was found to be able as the substrate for lipid accumulation, while vanillin and syringaldehyde were only converted to less toxic phenolic alcohols and acids without observable lipid accumulation, perhaps due to the space shelling of methoxyl group(s) in the structures. A long term fed batch fermentation of 4-hydroxybenzaldehyde accumulated 0.85 g L of lipid, equivalent to 0.039 g lipid per gram of 4-hydroxybenzaldehyde substrate, approximately 3.7 folds greater than the control without 4-hydroxybenzaldehyde addition. The fatty acid composition well met the need for biodiesel synthesis. The preliminary pathway from 4-hydroxybenzaldehyde to lipid was predicted. This study took the first experimental trial on utilizing phenolic aldehydes as the sole carbon sources for microbial lipid accumulation by T. cutaneum ACCC 20271.
木质素是木质纤维素生物质的主要成分之一，化学上可降解为包括 4-羟基苯甲醛、香草醛和丁香醛在内的酚醛类物质。但油脂微生物尚未成功利用这些酚醛类物质积累油脂。与香草醛和丁香醛相比，T. cutaneum ACCC 20271 对 4-羟基苯甲醛具有更好的耐受性。研究发现，4-羟基苯甲醛可以作为积累脂质的底物，而香草醛和丁香醛则仅转化为毒性较低的酚醇和酸，没有观察到明显的脂质积累，这可能是由于结构中甲氧基（多个）的空间位阻所致。在 4-羟基苯甲醛的长期分批发酵中，积累了 0.85 g/L 的脂质，相当于每克 4-羟基苯甲醛底物积累 0.039 g 脂质，比不添加 4-羟基苯甲醛的对照组高约 3.7 倍。脂肪酸组成完全满足生物柴油合成的需要。预测了从 4-羟基苯甲醛到脂质的初步途径。本研究首次通过 T. cutaneum ACCC 20271 实验验证了利用酚醛类物质作为微生物积累脂质的唯一碳源的可行性。
