Rhodospirillum is a spiral-shaped bacterium that reproduces in bipartite division and moves with polar hairs. The bacteria belong to Gram-negative bacteria. It contains chlorophyll a and some carotenoids. These two pigments are located in the inner membrane system (cystic, tubular, lamellar pile, lamella-like). They originate from the plasma membrane and are connected to the plasma membrane. Rhodospirillum belongs to anaerobic photoautotrophic bacteria; in addition, most species can carry out oxidative metabolism in the dark and slightly aerobic to aerobic conditions.
Figure 1. Rhodospirillum sp. (form microbewiki.kenyon.edu)
When the simple organic carbon compounds is exists, they have photosynthetic capacity. These compounds have two functions: direct light assimilation and the source of reducing power needed to fix CO2. Among them, molecular hydrogen can be used as a donor of electrons. No molecular oxygen is produced during photosynthesis. Cell suspensions are often red to brown due to photosynthetic pigments.
The cell width is 0.8-1.0 microns; the cell is arc-shaped to spiral under the microscope, and a spiral circle is 1.0-2.5 microns wide and 7-10 microns long. Under unsuitable conditions, abnormal cells of various shapes and sizes will appear. The inner membrane system of photosynthesis is cystic. During the culture process, the anaerobic liquid culture initially showed a light pink, and later showed a deep purple-red without brown; under aerobic conditions, the cells appeared colorless to pale pink.
The cells are 0.3-0.5 wide, 3.0-6.0 microns long, and some are longer. The cells are curved in one or two full circles of spirals. One circle of the spiral is 0.8-1.0 microns wide and 3 microns long. In addition to the cytoplasmic membrane, there are only a few finger-like membrane inner folds as in Pseudomonas rubrum. During the cultivation process, the color of the anaerobic liquid culture is brown-red or purple-violet; the aerobic cultured cells are colorless to light red.
The cell width is 0.5-0.7 microns (arc to spiral), a whole spiral is 1.0-1.6 microns wide and 3.5 microns long, and some strains are 1.0-1.5 microns. The photosynthetic intimal system is composed of several stacks of short slices; these short slices are not parallel to the plasma membrane of the cell but have an acute angle. During the cultivation process, the anaerobic liquid culture was orange-brown first, then dark brown.
The cell width is 0.7-1.0 microns; the cell shape is arc to spiral. A full circle is 1.5-2.5 microns wide and 4-6 or 7-9 microns long. The photosynthetic inner membrane system is composed of several stacks of short slices, which are not parallel to the plasma membrane of the cell but present an acute angle. During the cultivation process, the anaerobic liquid culture is orange-brown to reddish brown.
The cells of Rhodospirillum Photometricum are relatively large. Its cells are 14-30 micrometers long and 1.2-1.5 micrometers wide, and they are spiral shaped. The width of a complete spiral loop is 4-6 microns and the length is 7-10 microns. The photosynthetic inner membrane is composed of several short slices; the short slices are not parallel to the plasma membrane of the cell, but have an acute angle. Anaerobic liquid cultures are orange-brown to reddish brown.
|Type of Nutrition
|Types of bacterial growth media
|Belongs to heterotrophic bacterium with light energy and is facultative aerobic
|It can grow in an inorganic medium with a simple organic substrate and bicarbonate, supplemented with biotin. In addition to simple organic substrates, the addition of a small amount of yeast extract is necessary for optimal growth. pH range: 6.0-8.5, the most suitable pH is 6.8-7.0. Optimum temperature: 30-35°C.
|Belongs to photoautotrophic or photoheterotroph, facultative aerobic
|The optimum pH is 6.6-7.4. It grows well at 30°C. No growth factors are required. In the presence of complex organic nutrition or yeast extract, it can increase the growth rate. Cells have a tendency to form clumps and viscous sediments.
|Belongs to light-energy heterotrophic bacterium
|The bacteria can grow in a medium containing simple organic matter and bicarbonate, supplemented with para-aminobenzoate. For optimal growth, especially for small-scale inoculation, 0.05% ascorbate or thioglycolate needs to be added as a reducing agent. pH range: 6.0-8.5; the optimum pH is 7.3; the optimum growth temperature is 30℃.
|Belongs to heterotrophic bacterium with light energy
|It can be grown in an inorganic medium with simple organic matter and bicarbonate; aldehyde mother cream or vitamin casamino acid can significantly stimulate growth. Especially for small-scale inoculation, the optimum growth requires the addition of 0.05% ascorbic acid or thioglycolate as a reducing agent. pH range: 6-8.5; optimal pH, 7.3. Growth temperature: 30°C.
|Belongs to light-energy heterotrophic bacterium
|In a medium containing citrate, ethanol, fatty acids, fructose, alkyd and asparagine, it can grow under strict anaerobic conditions.
The culture of Rhodospirillum requires specific formulations of growth media for use in cloning, plasmid DNA preparation, and protein expression. Creative Biogene offers a selection of bacterial growth media and custom services for your specific application. If you are interested in our microbial anaerobic and aerobic culture platform, please contact us for more details.