Carbon monoxide conversion by anaerobic bioreactor sludges

Abstract

Seven different anaerobic sludges from wastewater treatment reactors were screened for their ability to convert carbon monoxide (CO) at 30 and 55 degrees C. At 30 degrees C, CO was converted to methane and/or acetate by all tested sludges. Inhibition experiments, using 2-bromoethanesulfonic acid and vancomycine, showed that CO conversion to methane at 30 degrees C occurred via acetate, but not via H2. At 55 degrees C, four sludges originally cultivated at 30-35 degrees C and one sludge cultivated at 55 degrees C converted CO rapidly into hydrogen or into methane. In the latter case, inhibition experiments showed that methane was formed via hydrogen as the intermediate.

Bacterial glycerol oxidation coupled to sulfate reduction at neutral and acidic pH

“…The neutrophilic sludges were obtained from anaerobic bioreactors for biological sulfate reduction to produce sulfide for metal removal. One sludge originated from a chemical plant in Emmen, The Netherlands (Dar et al, 2007) and the other sludge from a zinc smelter in Budel, The Netherlands (Sipma et al, 2003). These sludges were termed Paques sludge and Budel sludge, respectively.…”

Electricity generation from carbon monoxide in a single chamber microbial fuel cell

“…Carboxydotrophic bacteria can use CO as their only carbon source [2][3][4], at low temperatures and pressures. Their ability to oxidize and metabolize CO is connected to the existence of the enzyme CO-dehydrogenase [3], often found in carboxydotrophic methanogens and acetogens [5], resulting pre-dominantly in methane and acetate production, respectively. Metabolic activity of carboxydotrophic mesophilic bacteria also results in the formation of H 2 , ethanol, butyrate, butanol, and acetate [3,6].…”

Carbon monoxide conversion by thermophilic sulfate-reducing bacteria in pure culture and in co-culture with Carboxydothermus hydrogenoformans

“…The authors speculated that a main part of the CO was converted by homoacetogens, preventing CO toxicity for SO 4 -reducing bacteria. Several anaerobic bioreactor sludges at 55°C were able to convert 100% CO in SO 4 -free media to H 2 or to methane via H 2 as intermediate (Sipma et al 2003). Recently, it was demonstrated that in anaerobic bioreactor sludges, both CO and H 2 were used by SO 4 -reducing bacteria that tolerated and used high CO (P co >1.6 bar) concentrations (Sipma et al 2004).…”