2.2. Ability to release ALA and reduce CH4 emissions by selected PNSB
in a rice straw broth
To confirm that the two selected PNSB strains had the potential
to produce ALA and reduce CH4 emission in a rice straw broth, the
experiments were scaled up to 1 L of rice straw broth. The amount
of ALA was now detected by high performance liquid chromatography
(HPLC). Both selected strains that earlier produced the most
ALA, and also produced the largest reduction in the CH4,
production were tested in conditions similar to a paddy field by
using rice straw as the carbon source. Each treatment set was
inoculated with a pure culture, while a set without inoculation
served as a control. The PNSB inocula were prepared as previously
described, and 100 mL of inoculum was added to a 1000 mL serum
bottle containing 3 g straw, 100 g of dry soil from a rice field area
near Talay Noi Lake Basin, and 900 mL of saline solution (NaCl
0.25%). Each serum bottle was closed with an aluminum cap with a
butyl rubber septum. All culture serum bottles were incubated
with a tungsten light intensity of 3500 200 lux for 10 days, and
gas samples were collected.