Conversion of Chitinous Wastes to Hydrogen Gas by Clostridium paraputrificum M-21.

Abstract

The chitinolytic bacterium Clostridium paraputrificum strain M-21 produced 2.2 and 1.5 mol hydrogen gas from 1 mol N-acetyl-D-glucosamine (GlcNAc) and ball-milled chitin equivalent to 1 mol of GlcNAc, respectively, at pH 6.0. In addition, strain M-21 efficiently degraded and fermented ball-milled raw shrimp and lobster shells to produce hydrogen gas: 11.4 mmol H2 from 2.6 g of the former and 7.8 mmol H2 from 1.5 g of the latter. Hydrogen evolution from these shell wastes were enhanced two fold by employing acid and alkali pretreatment. Waste from the starch industry was also converted to hydrogen. When C. paraputrificum M-21 was cultivated on ball-milled chitin and ball-milled shrimp shells for 14 and 12 h, respectively, chitinases ChiA and/or ChiB were detected as the major chitinase species in the supernatant of the cultures, suggesting that the play a critical role in the degradation of chitinous materials.

Thermophilic anaerobic co-digestion of organic fraction of municipal solid waste (OFMSW) with food waste (FW): Enhancement of bio-hydrogen production

“…AAD with formation mainly of acetic and butyric is normally one of the most efficient ways for bio-hydrogen production especially by Clostridium sp. (Evvyernie et al, 2001). The rest of VFAs determined (propionic, valeric and heptanoic) were detected always in very low concentrations for all the SRTs tested.…”

Integrated biological hydrogen production

“…Higher rates of fermentative H 2 production have been reported with a consortium of mesophilic or hyperthermophilic bacteria in optimized bioreactors [54,55]. Depending on the bacterial species and organic nutrients employed, such fermentations result in the generation of an abundance of small organic acids, such as malate, lactate, propionate, butyrate, and/or acetate [41,[56][57][58][59][60][61][62]. The further conversion of these small organic acids to H 2 is not an energetically favorable reaction and cannot be supported by the fermentative metabolism of the anaerobic bacteria.…”

Hydrogen production by Clostridium thermolacticum during continuous fermentation of lactose

“…Most of the studies were carried out on glucose as a substrate. However it has been reported that many other organic substrates, such as inulin [20], sucrose [16,21], acetylglucosamine and chitin [22], wastestreams containing xylose [23], lignocellulosic waste [24] and even wastewater sludge [4], are potential sources for hydrogen production. According to our knowledge, lactose as the sole carbon source for hydrogen production has never been reported.…”