Hydrogen Production by Anaerobic Microbial Communities Exposed to Repeated Heat Treatments

Abstract

Biological hydrogen production by anaerobic mixed communities was studied in laboratory-scale bioreactors using sucrose as the substrate. A bioreactor in which a fraction of the return sludge was exposed to repeated heat treatments performed better than a control bioreactor without repeated heat treatment of return sludge and produced a yield of 2.15 moles of hydrogen per mole of sucrose, with 50% hydrogen in the biogas. Terminal restriction fragment length polymorphism analysis showed that two different Clostridium groups (comprised of one or more species) were dominant during hydrogen production. The relative abundance of two other non-Clostridium groups increased during periods of decreased hydrogen production. The first group consisted of Bifidobacterium thermophilum, and the second group included one or more of Bacillus, Melissococcus, Spirochaeta, and Spiroplasma spp. Water Environ. Res., 79, 975 (2007).

The effect of low pressure and mixing on biological hydrogen production via anaerobic fermentation

“…Some studies found that hydrogen production ceased below pH 5 [29,30], while other studies indicate that the threshold is slightly lower (z 4.5) [32,33,35]. It is also possible to control pH with high substrate loading.…”

Assessing the impact of palmitic, myristic and lauric acids on hydrogen production from glucose fermentation by mixed anaerobic granular cultures

“…Regarding its effectiveness to inhibit H 2 -consuming microorganisms, heat treatment is not sufficient to develop a suitable H 2 -producing microbial consortium [54] because it does not exclusively select these microorganisms [55]. According to Duangmanee et al [56], repeated heat treatment cycles are necessary to increase H 2 production. No work to date has fully evaluated the long term impact of using heat or LCFA treated cultures.…”

Biohydrogen from food waste in a discontinuous process: Effect of HRT and microbial community analysis

“…5) and had a relative abundance of less than 0.56% of the sequences obtained from the microbial analysis. These OTUs were related to genus Olsenella, Bifidobacterium and Pelosinus, which have been reported in communities of fermentative reactors [32,39,40].…”