Abstract:

As the development of industry, a large amount of CO₂ emissions has aggravated greenhouse effect of the world and environmental pollution. In addition, the growing global population will face the problem of insufficient supply of protein resources. A more efficient route for CO₂ fixation and conversion involves chemical reduction of CO₂ to synthesize methanol, followed by microbial conversion of methanol into multi-carbon products. Therefore, from both a feedstock and product perspective, this review suggests the use of a chemical-biological cascade process for CO₂ conversion to produce single-cell protein (SCP), which involves the chemical reduction of CO₂ to methanol, followed by the microbial production of SCP from methanol and ammonium using microbial cell factories. The SCP from CO₂ can be used in the feed and food industries. Firstly, the reaction processes, mechanisms, and catalyst design for the sustainable hydrogenation of CO₂ to methanol are introduced. Secondly, methanol-utilizing microorganisms found in the nature, their methanol metabolic pathways, and their application in converting methanol into SCP are summarized. Finally, the bottlenecks and potential solutions for the industrial-scale production of SCP via chemical-biological cascade conversion of CO₂ are prospected.

Key words: one-carbon chemical engineering, methanol, cascade conversion, single cell protein, microbial cell factory

摘要：

工业发展导致CO₂大量排放，加剧了全球温室效应和环境污染。此外，全球人口的不断增长将会导致蛋白质供应不足。通过化学催化CO₂还原合成甲醇等有机一碳化合物，进一步通过微生物将甲醇转化为多碳产物，是一条高效的CO₂固定和转化利用路线。因此，从原料和产品层面考虑，本文提出了利用化学-生物级联转化CO₂生产单细胞蛋白（single cell protein, SCP）的策略，即将CO₂通过化学转化生产甲醇，再进一步利用微生物细胞工厂代谢甲醇和无机铵生产SCP，SCP产品有望应用于饲料和食品工业。本文首先介绍了CO₂加氢可持续生产甲醇的反应过程及反应机制，总结了相关催化剂的研究进展。其次，介绍了自然界中发现的可利用甲醇的微生物及甲醇代谢途径，以及利用甲醇生产SCP的研究进展。最后，对CO₂化学-生物级联转化工业化制造SCP的瓶颈和解决方案进行了展望。

关键词: 一碳化工, 甲醇, 级联转化, 单细胞蛋白, 微生物细胞工厂