TABLE 2.

Stimulation of methane emission by isolated hindguts of P. ephippiata (third instar) incubated in Ringer's solution by the addition of external electron donors

Substrate addedCH4 formation rate (μmol g−1 h−1)aStimulation (fold)an
BasalAfter addition
H2b0.13 ± 0.030.21 ± 0.011.8 ± 0.43
Methanolc0.15 ± 0.080.50 ± 0.204.3 ± 1.25
Formated0.28 ± 0.191.04 ± 0.504.9 ± 1.24
  • a All values are based on the fresh weight of the hindgut and are means ± standard errors for n different larvae.

  • b Headspace partial pressure of 20 kPa.

  • c Final concentration of 5 mM.

  • d Final concentration of 10 mM.