Production of single-cell protein by Alcaligenes aerobic fermentation with industrial waste acetic acid

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.