Abstract:

The development of single-cell protein (SCP) technology is a crucial approach to addressing food security and supply issues. However, the traditional method of producing SCP using hydrogen to reduce carbon dioxide under aerobic conditions suffers from the critical problems of low mass transfer efficiency and explosive safety hazards. This study utilizes waste acetic acid generated from chemical plants as a carbon source to feed Alcaligenes and produce SCP under aerobic conditions. By reasonably controlling the feedstock and growth environment in the reactor, a maximum cell dry weight (CDW) of 15.2g/L is achieved, with an average CDW production rate of 3.7g/(L·d), and the protein content in the CDW reaches approximately 80%. The test of bacteria community compositions in the reactor shows that the Alcaligenes could be enriched during growth, reaching a proportion of up to 95%. Furtherly, the amino acid profile test reveals that the produced SCP is rich in various essential amino acids, which is comparable in value to high-quality fish meal protein. These study findings provide a new process for the high-value utilization of waste acetic acid in industrial production and the safe and efficient production of SCP technology.

Key words: waste acetic acid, Alcaligenes, fermentation, protein, reactors

摘要：

发展单细胞蛋白技术是解决粮食安全和供应问题的重要途径。然而普遍使用H₂在好氧条件下还原CO₂生产单细胞蛋白的方法存在传质效率低和容易爆炸的关键问题。本研究以化工厂产生的废乙酸为碳源，利用产碱杆菌（Alcaligenes）在好氧条件下异养发酵生产单细胞蛋白。通过对反应器中原料和生长环境的合理控制，在整个运行过程中，实现了最大细胞干重（cell dry weight，CDW）为15.2g/L，CDW平均生产速率为3.7g/(L·d)，且干细胞生物量中蛋白质含量高达80%左右（质量分数）。反应器内微生物群落分析表明，产碱杆菌能够在生长过程中进一步富集，最终占比高达95%，且进一步的菌体蛋白内的氨基酸测试表明，所生产的单细胞蛋白中富含多种人体必需氨基酸，其价值与优质的鱼粉蛋白相当。研究结果为工业产生的废乙酸的高值化利用和菌体蛋白技术的高效安全生产提供了一种新的方案。

关键词: 废乙酸, 产碱杆菌, 发酵, 蛋白质, 反应器