关键词: 木质纤维素, 有机酸, 生物基材料, 绿色生物制造, 合成生物学

Abstract:

The development of environmentally benign, biodegradable materials is considered an important way to address “white pollution”. Importantly, organic acid is one of the crucial monomers for preparing biodegradable materials. In recent years, the synthesis of organic acids through green and efficient methods has attracted much attention. As the most promising carbon source recognized for renewability and affordability, lignocellulose is considered a promising carbon source for the biochemical industry. Converting lignocellulose into organic acid is critical to preparing biodegradable materials and achieving carbon neutrality, which meets the requirements of the green and sustainable development strategy. Hence, researchers are focusing their investigations on the lignocellulose biorefinery. To date, innovations in synthetic biology have significantly advanced organic acid manufacturing. For example, the yield of succinic acid has exceeded 150 g/L, which facilitates the formation and development of the bio-based biodegradable materials industry. In this paper, various lignocellulose pretreatment technologies were reviewed, including physical, chemical, biological, physicochemical, and other emerging pretreatment methods. To realize the goal of efficient utilization of lignocellulose, the refining processes of lignocellulose were also reviewed, including detoxification of inhibitors, reductive catalytic fractionation, consolidated bioprocessing, and other methods. After the pretreatment and refining process, lignocellulose is transformed to sugars and aromatic compounds, which can be utilized for producing various organic acid compounds, such as succinic acid, 3-hydroxypropionic acid, cis,cis-muconic acid, 2,5-furandicarboxylic acid, 2-pyrone-4,6-dicarboxylic acid. Next, using the optimization of production of these organic acid compounds as examples, several synthetic biology strategies were summarized, including constructing biosynthetic pathways, optimizing regulatory elements, enlarging the substrates spectrum, and other strategies for improving cell production capacity. Finally, the development trends of the biodegradable materials industry are summarized and prospected. The development of emerging pretreatment and consolidated bioprocessing to facilitate the efficiency of lignocellulose utilization were discussed. Improving the robustness of microbial cell factories and designing the systematic lignocellulose conversion pathways could further optimize the performances of organic acid synthesis. The insights given in this review could facilitate further development on the industrial production of biodegradable materials, towards addressing the global energy crisis and “white pollution”.

Key words: lignocellulose, organic acids, bio-based materials, green biomanufacturing, synthetic biology