Simultaneous intensification of direct acetate cleavage and CO2 reduction to generate methane by bioaugmentation and increased electron transfer

Abstract

Detailed analysis of multiple methane production pathways was conducted.• Maximum H 2 production was promoted by ∼3 and 4 times with bioaugmentation and CMs.• Acetoclastic methanogenesis was beneficial from both bioaugmentation and CMs.• Various CH 4 generation pathways were stimulated by CMs except for DIET-dependent CO 2 .

Methane production by acetate dismutation stimulated by Shewanella oneidensis and carbon materials: An alternative to classical CO2 reduction

“…More importantly, conductive materials further facilitated the completion of this process. It was also observed that conductive materials increased the proportion of acetoclastic methanogenesis in anaerobic granular sludge [49]. Overall, the two methods, inhibitor and natural abundance stable isotope fractionation, reached perfectly consistent conclusions.…”

Effect of Antibiotics on the Microbial Efficiency of Anaerobic Digestion of Wastewater: A Review

“…However, in H 2 upgrading/ammonia inhibited AD system, methane production is mainly from hydrogenotrophic methanogenesis pathway. For acetoclastic methanogenesis, methanogens oxidize carboxyl groups to CO 2 and generate reducing forces to reduce methyl carbon to methane ( Welte and Deppenmeier, 2014 ; Xiao et al, 2019b , 2020a ). At present, only Methanosarcina and Methanosaeta have been found to produce methane by acetoclastic methanogenesis ( Holmes and Smith, 2016 ; Li et al, 2018 ; Xiao et al, 2019a ).…”

“…Methanogens are a class of exclusive anaerobic archaea that are widely distributed and can survive in lakes, marshes, sludges, wetlands, rice paddy soils, inside organisms, and even extreme environments ( Xiao et al, 2017 , 2019b , c ; Conrad, 2020 ). The blocking of the methanogenic reaction leads to the accumulation of organic acids, and the upstream acidification reaction will be slowed down by product inhibition.…”

“…Finally, these products are converted into methane and carbon dioxide by methanogens. Anaerobic digestion is widely used in the treatment of sewage sludges to reduce sludges volume and to produce methane ( Mehariya et al, 2018 ; Xiao et al, 2019b ).…”

Methylobacter accounts for strong aerobic methane oxidation in the Yellow River Delta with characteristics of a methane sink during the dry season

“…The gas sample (200 lL) was taken from the headspace using a sterilized syringe with a two-way valve. Methane and CO 2 were analyzed by gas chromatography (GC; Agilent 7820A, USA) equipped with a flame ionization detector (FID) and a thermal conductivity detector (TCD) as previously described (Xiao et al, 2019b). The column temperature was 80°C, and the low detection limits for methane and CO 2 were approximately 0.0008 mM and 0.04 mM, respectively.…”