During succinic acid (SA) biosynthesis, increasing the utilization of CO2 is beneficial for reducing greenhouse gas emissions and lowering production costs. In this study, amine-modified cellulose sponges (AMCS) were prepared, which could decrease more than 80% of CO2 emissions in water by adsorption and chemical reaction. An external fibrous bed bioreactor was filled with AMCS, and the repeated-batch pressurized fermentation was supplied with CO2 micronano bubbles (MNBs) without any carbonates or bicarbonates. In this process, Escherichia coli Suc260-CsgA could form stable biofilms on AMCS, which exhibited significantly enhanced resistance to free radicals. Compared with free-cell batch fermentation under atmospheric pressure, the average productivity of SA and yield were increased by 77.36 and 8.11%. The carbonic anhydrase activity of the biofilm was over 68% higher than that in free-cell fermentation mode, while the actual CO2 utilization increased 2.88-fold. The results indicated that the microbial carbon sequestration was enhanced and the anabolic metabolism of SA was accelerated by the combination of the biofilm, AMCS, and MNBs.
Pan et al. (Wed,) studied this question.