Carbon dioxide metabolism in the cells of green bacteria
M. Gorishniy, S. Hnatush, S. Gudz
Ivan Franko National University of Lviv
4, Hrushevskyi St., Lviv 79005, Ukraine
The photosynthetic green sulfur bacteria (of Chlorobiaceae family) and green non sulfur bacteria (of Chloroflexaceae family) are significantly different by morphological and physiological properties. Their common feature is the presence of chlorosomes which are surrounded by a membrane with light accept pigment complexes which are containing bacteriochlorophylls and carotenoids. The green sulfur bacteria and green non sulfur bacteria assimilate carbon dioxide in different pathways. The species of Chlorobiaceae family reduce CO2 in reactions involving reductive tricarboxylic acid cycle and the bacteria of Chloroflexaceae family use reactions of 3-hydroxypropionate way. Microorganisms of both families accumulate spare ingredients in the cells: of the Chlorobiaceae family accumulate glycogen, which properties are similar to bovine liver glycogen, and species of the Chloroflexaceae family accumulate poly-β-hydroxybutyrate. The spare substances are used by bacteria in the dark both in the processes of energy and constructive metabolism.
Keywords: Chlorobiaceae family, Chloroflexaceae family, reductive tricarboxylic acid cycle, 3-hydroxypropionate way, glycogen, β-hydroxybutyrate