Z. Dong et al., Technical report - Rapid measurement of hydrogen concentration and its usein the determination of nitrogenase activity of legume plants, SYMBIOSIS, 29(1), 2000, pp. 71-81
A method and apparatus for rapidly measuring H-2 concentration in a gas str
eam and the use of this instrument to measure nitrogenase activity of a nit
rogen fixing plant growing in a non-porous container is described. The meth
od does not require that the plants be sealed in their growth pots for gas
exchange measurements, but allows these measurements to be made by sampling
H2 (a by-product of N-2 fixation) directly from the medium in which the pl
ants are grown. Gas containing hydrogen is sampled at the surface of the me
dium at a rate approximately equal to the rate of hydrogen diffusion from t
he medium, and the sample is passed to a hydrogen sensor where it is measur
ed and nitrogenase activity determined therefrom. This allows for very rapi
d measurements of nitrogenase activity involving Little or no manipulation
of the plant material being studied. As a result, large populations of plan
ts may be screened quickly for variations in nitrogenase activity. This met
hod would be especially useful for assessing variations in nitrogenase acti
vity caused by application of different environmental treatments to a speci
fic legume-Rhizobium symbiosis.