Photosynthetic bacteria have a
potential doubling rate that ranges from minutes to a few hours, depending on
their biology and on chemical and physical factors in the environment in which
the cells are growing. Under natural
conditions CO2 consumption rates by phytoplankton of 0.312 g CO2
g-1 cell mass h-1 have been recorded. Based on this theoretical understanding, an
experimental bioreactor was designed and constructed to measure the CO2
consumption activity of photosynthetic bacteria. The reactor was equipped with
sensors to measure media pH and electrical conductivity and controlled CO2
gas intake. It was also equipped with a
gas sampling chamber containing sensors that measured humidity, pressure and CO2
gas exhausted from the reactors. These data were used to calculate CO2
fixation by the bacteria. In total, six
experiments were carried out, with incubation periods ranging from two days to
seven days. This study measured photosynthetic rates for one purple non sulfur
bacteria and one green non sulfur bacteria. This research measured CO2
consumption rates similar to those reported for growth under natural
conditions. For Rodospeudomonas palustris, the CO2 uptake rates were from
0.543 g CO2 g-1 cell mass h-1 to 1.038 g CO2 g-1
cell mass h-1, and for Rodobacter capsulatus the CO2
uptake was 0.359 g CO2 g-1 cell mass h-1.
R. Paul Voroney, (519) 824-4120, pvoroney.@uoguelph.ca