Dark and acidic conditions for fermentative hydrogen production

Venkataramana Gadhamshetty, David C. Johnson, Nagamany Nirmalakhandan, Geoff B. Smith, Shuguang Deng

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


Bacterial consortium capable of producing hydrogen in low pH (LpH) range of 3.3-4.3 is reported in this study. This operational pH is two full units below that of previously reported hydrogen producing organisms. Low pH inocula were derived from a batch biohydrogen reactor inoculated with heat treated compost (∼120 °C, 2 h), which was allowed to accumulate biogas to reach three atmospheres of equivalent headspace pressure and system pH of 3.0. Acclimation effect had positive influence on H2 production and LpH inocula were passed sequentially into more than 15 generations to achieve consistent conversion efficiency and hydrogen composition, further tested in 23 other culture cycles. With hydrogen composition in the headspace ranging from 50% to 60%, conversion efficiency of ∼43% achieved in LpH systems is comparable to that of other buffered systems. Feasibility of hydrogen production in LpH systems is demonstrated in unbuffered reactors under intermittent pressure release conditions and in absence of initial pH adjustment and stirring. Conversion efficiencies, however, decreased by ∼1-fold for each 3 °C drop below the optimum temperature of 22 °C.

Original languageEnglish (US)
Pages (from-to)821-826
Number of pages6
JournalInternational Journal of Hydrogen Energy
Issue number2
StatePublished - Jan 2009
Externally publishedYes


  • Biofuel
  • Biohydrogen
  • Compost
  • Fermentation
  • Hydrogen
  • Low pH
  • Unbuffered

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology


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