Microbial electrosynthesis of acetate from CO2 under hypersaline conditions

Microbial electrosynthesis of acetate from CO2 in three-chamber cells with gas diffusion biocathode under moderate saline conditions

“…This resulted in a maximum acetate-specific production of 58.4 kg MWh À1 , 24% higher than that obtained with 5 g L À1 NaCl (46.8 kg MWh À1 ). Despite the higher applied current (0.25 vs 0.156 mA cm À2 ), the cell voltage was similar to that reported by Zhang et al [21] in two-chamber cells at 35 g L À1 salinity, suggesting that the addition of more than 10 g L À1 NaCl might not improve the efficiency of the cells significantly.…”

“…Acetobacterium has been widely indicated as one of the key species in the core microbiome of acetogenic MES cells, and responsible of acetate production from CO 2 and (bio) electrochemically produced H 2 through the Wood-Ljungdahl Pathway [44]. It has been reported to dominate the cathodic community of MES cells operated at up to 60 g L À1 salinity [21], demonstrating resilience to halophilic conditions. The hydrogenproducing Desulfovibrio sp., a syntrophic partner of Acetobacterium, was detected in both the H-type and the three-chamber cells at relative abundances between 1% and 3%, along with the other members of the MES core microbiomes (Christensenellaceae, Lentimicrobiaceae, and Synergistaceae) [4].…”

“…However, acetate production was low (in the mg order) and unstable, with current densities mostly below 0.15 mA cm À2 . Zhang et al [21] achieved a stable acetate production of 3.5 g m À2 d À1 at 35 g L À1 (3.5%) salinity after lowering the hardness of the catholyte by decreasing the Mg and Ca concentrations. The production rate was further increased to 9 g m À2 d À1 by implementing a three-chamber cell to avoid chloride oxidation at the anode.…”

Enhancing photocatalytic CO2 reduction with TiO2-based materials: Strategies, mechanisms, challenges, and perspectives

“…Recent excessive consumption of fossil fuels has resulted in substantial dioxide (CO 2 ) emissions, leading to obvious climate warming and ecological and environmental challenges [ 1 , 2 ]. Controlling the ever-increasing CO 2 emissions has become an urgent problem.…”

Enrichment of halotolerant hydrogen-oxidizing bacteria and production of high-value-added chemical hydroxyectoine using a hybrid biological–inorganic system

“…In other variants of bioelectrochemical systems, such as microbial fuel cells and microbial electrosynthesis systems, it has been suggested that the use of halotolerant bacteria allows the system to operate under higher ionic conditions, thereby reducing internal resistance and improving performance. Halophilic CO 2 -fixing microbial communities have been used as biocatalysts in microbial electrosynthesis to produce acetate (Alqahtani et al, 2019(Alqahtani et al, , 2021Kiran et al, 2023;Zhang et al, 2023), exhibiting an improvement in efficiency with high-ionic-strength electrolytes. Furthermore, halotolerant bacteria are known to accumulate compatible solutes, such as ectoine, hydroxyectoine, glycine betaine, and proline betaine, to counteract osmotic stresses.…”