Rhodopseudomonas palustris belongs to the Rhodospirillaceae family and the genus Rhodopseudomonas in the classification of photosynthetic bacteria. Cells are rod-shaped to oval, 0.6-2.5μm×0.6-5.0μm, move or not move through polar flagella, grow with polarity, reproduce by asymmetric budding and division, Gram stain is negative, photosynthetic pigments For chlorophyll a, h and carotenoids, the best way to grow is to use various organic compounds as carbon sources and electron donors to grow under light anaerobic conditions, using hydrogen, sodium thiosulfate, It can also grow using hydrogen sulfide as an electron donor, with a G C mol of 64.8-66.4, and it can also grow heterotrophically under dark aerobic conditions. Under liquid culture conditions, the color of Rhodopseudomonas palustris bacteria liquid will gradually deepen (from light red to dark red). When the culture time is too long, the bacteria in the liquid liquid will form a flower-shaped or cluster-shaped arrangement. Under solid culture conditions (agar plate culture), Rhodopseudomonas palustris colonies are red disc-shaped, with a smooth surface, few bulges, and neat edges. (Tang Zhengshuai. Research on the culture technology and application effect of Rhodopseudomonas palustris R2 [D]. Shandong Agricultural University, 2018.)
Summary:
Light anaerobic conditions : Use organic compounds for heterotrophic growth; or use hydrogen, sulfide and other inorganic substances as electron donors for heterotrophic growth
Dark aerobic conditions: aerobic respiration and heterotrophic growth
The textbook states that some Rhodospirillum species can also grow heterotrophically under dark conditions with anaerobic respiration, but the specific situation of this species is not known.