Cai Chenggu, Xu Zhaoxian, Li Jie, Zhou Huarong, Jin Mingjie
Department of Bioengineering, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, China.
Biotechnol Bioeng. 2022 Nov;119(11):3162-3177. doi: 10.1002/bit.28215. Epub 2022 Sep 3.
Bioconversion is being regarded as a promising way for lignin valorization because it enables funneling diverse lignin components into single compounds, overcoming the heterogeneity of lignin. Although numerous lignin-derived aromatic monomers have been funneled to target compounds in previous studies, the bioconversion of low-molecular-weight lignin (LMW-lignin) fragments, for example, lignin-derived dimers, has been rarely systematically studied, impeding further conversion of lignin. In this study, coculture systems were designed and developed to funnel multiple lignin-derived dimers to cis, cis-muconate and gallate by combining lignin-derived dimers cleavage bacterium Sphingobium sp. and monomers conversion bacterium Rhodococcus opacus. With the developed coculture systems, β-O-4 type dimer guaiacylglycerol-β-guaiacyl ether, 4-O-5 type dimer 4,4'-dihydroxydiphenyl ether, β-5 type dimer balanophonin, β-β type dimer pinoresinol, β-1 type dimer 1,2-bis(4-hydroxy-3-methoxyphehyl)-1,3-propanediol and 5-5 type dimer 5,5'-dehydrodivanillate were converted to cis, cis-muconate. Additionally, the developed coculture systems also showed potential in conversion of lignin-derived dimers to gallate. The application of alkali lignin for cis, cis-muconate production further demonstrated the effectiveness of the designed coculture systems. Overall, the developed coculture systems are beneficial to lignin biological valorization, and also provide references for the valorization of other bio-resources.
生物转化被视为一种有前景的木质素增值方法，因为它能够将多种木质素成分转化为单一化合物，克服了木质素的异质性。尽管在先前的研究中，许多木质素衍生的芳香单体已被转化为目标化合物，但低分子量木质素（LMW-木质素）片段（例如木质素衍生的二聚体）的生物转化很少得到系统研究，这阻碍了木质素的进一步转化。在本研究中，通过将木质素衍生的二聚体裂解细菌鞘氨醇单胞菌属（Sphingobium sp.）和单体转化细菌不透明红球菌（Rhodococcus opacus）相结合，设计并开发了共培养系统，以将多种木质素衍生的二聚体转化为顺，顺-粘康酸和没食子酸。利用所开发的共培养系统，β-O-4型二聚体愈创木基甘油-β-愈创木基醚、4-O-5型二聚体4,4'-二羟基二苯醚、β-5型二聚体巴拉诺芬宁、β-β型二聚体松脂醇、β-1型二聚体1,2-双（4-羟基-3-甲氧基苯基）-1,3-丙二醇和5-5型二聚体5,5'-脱氢二香草酸被转化为顺，顺-粘康酸。此外，所开发的共培养系统在将木质素衍生的二聚体转化为没食子酸方面也显示出潜力。碱木质素用于生产顺，顺-粘康酸进一步证明了所设计的共培养系统的有效性。总体而言，所开发的共培养系统有利于木质素的生物增值，也为其他生物资源的增值提供了参考。
