Effects of Stirring and Hydrogen on Fermentation Products of Clostridium thermocellum.

摘要: Clostridium thermocellum produces ethanol, acetate, H2, and CO2 as major fermentation products from cellulose cellobiose. The performance of three strains this microorganism was studied to assess the potential use in producing ethanol directly cellulosic fiber. Depending on bacterial strain, an ethanol/acetate product ratio 1 high 3 observed unstirred cultures. Vigorous stirring during growth resulted a threefold decrease ratio. H2 content culture broth times greater than that stirred one. Addition exogenous gas phase increased much more fermentations. addition sufficient almost relieved effect stirring, approached condition. tritium formation tritiated water (3H2O), which indicates C. possesses hydrogenase(s) catalyzes reverse reaction. rate 3H2O about higher culture. These results demonstrate concentration plays important role formation. supersaturation present cultures is responsible for stirring. A hydrogen feedback control mechanism regulating relative concentrations reduced oxidized electron carriers proposed account metabolite distribution.