Abstract
Four strains of non-sulfur purple photosynthetic bacteria isolated in the Bangkok area, Thailand, grew at 40 and 45°C under photosynthetic and strict anaerobic conditions. At higher temperature of 45°C, the bacteria did not grow under sealing with liquid paraffin. On the other hand, the organisms grew at 45°C, when they were allowed to grow as mixed culture with a strict aerobic bacterium, designated as 22 TW-S, under sealing with liquid paraffin. The respiratory activities of TR-22R-B, one of the isolated photosynthetic bacteria, and 22 TW-S were examined at 40 and 45°C. The oxygen uptake activities of 22 TW-S at 40 and 45°C were about 18 and 4 times higher than those of TR-22R-B, respectively, when DL-malate was used as a substrate. The redox-potential of the culture medium which permitted the initiation of growth of TR-22R-B was found to be much lower at 45°C than at 40°C. It was assumed that 22 TW-S acted as an oxygen scavenger under sealing with liquid paraffin, and thus established favorable conditions for growth of TR-22R-B.
