The vegetative cells of Myxococcus are slender rod-shaped, with tapered or rounded ends, and the size is 0.4-0.7×2.0-10.0 μm. Nutrient cells can perform sliding movements. The fruiting bodies contain refracting spherical or elliptical microsporangia with a maximum diameter of 2.3 μm. Myxospores are not enclosed in sporangia. Bacterial cells provide the energy they need through respiration and metabolism. The species studied all require several amino acids and can hydrolyze proteins, starches, nucleic acids and many fatty acid esters.
Figure 1. Myxococcus fruiting bodies. (Kathrin I. Mohr. 2018)
Myxococcus is a strictly aerobic bacteria. No growth at and above 40°C. Colonies adsorb Congo red. Resistant to penicillin containing 10 units. Sensitive to 10 micrograms of neomycin and tetracycline and 5 micrograms of erythromycin.
The vegetative cells of Myxococcus fulvus are elongated in shape with rounded ends. Cells are 0.4--0.8 x 5-9 microns in size.
The fruiting bodies are spherical, oval or pear-shaped, with a constricted lower end and a distinct stalk, which won't always exist. At first the shank is attached to the fruiting body, but deliquescence occurs when wet. Fruiting body color is fleshy red, reddish-orange, pink bag or maroon. It shows dark red to brown when dried. Fruiting body size is 150-400um.
Microsporangia are round to slightly oval, refracting, and 1.1-1.7 microns in diameter.
The vegetative cells of Myxococcus virescens are slender and rod-shaped with pointed ends, and the size is 0.4-0.8×5-9 microns.
The fruiting bodies are spherical to oval in shape and yellow to greenish-yellow in color. Turns white on artificial medium. Fruit bodies can be deliquescent on continuous moist medium and are 150-500μm in size.
The microsporangia of the fungus are refracting, spherical, and 1.7-2.3 microns in diameter.
The vegetative cells of Myxococcus xanthus are elongated, flexible bacilli, 0.5-1.0 × 4.0-10 microns in size.
The fruiting bodies are spherical to subglobose, contracting at the base. The union of adjacent clumps of fruiting bodies is occasionally irregular, with diameters as large as 300 to 400 microns. Fruiting bodies are stable in color, pale yellow-orange to bright orange, never greenish-yellow.
Microsporangia are refracting, spherical, 1.1-2.3 microns in diameter. The colonies were similar to those of Myxococcus viridans, but did not form diffuse green pigments. Can be grown on synthetic media. Fruiting bodies can be formed on synthetic media.
Vegetative cells: rod-shaped slender, occasionally slightly pointed, flexible, 0.5-0.7×2.0-7.0 microns.
Fruiting body: The sporophyte is nearly spherical, milky white or yellowish white, to light pink, up to 200 microns in diameter, longer than the sporophyte. Fruiting bodies are variable on artificial media, stalk development may be poor, and adjacent fruiting bodies may adhere to irregular circles.
Microspores are oval, optically dense or weakly refracting, 1.1-1.4 × 1.3--1.8 microns in size.
Vegetative cells: rods with slightly pointed ends, 0.5-0.8 × 4-8 microns in size.
Fruiting body: hard texture, not deliquescence. Fruiting bodies vary widely in shape, size, and color, ranging from simple, attached to the substrate, barely discernible papillary (25 microns) or straight, or branched rod-like, or branched cinnamon like structure (20--30 × 50-250 microns); or a flat pad, the lower part shrinks to form a short handle (25--40 microns). In other instances, they consist of irregular coral-like clumps, up to 300 microns in size, with constricted lobes and finger-like protrusions. They may appear flesh-colored, pink, red-orange, orange or buff in different strains. When the fruiting bodies are formed on agar media, the fruiting bodies often extend straight roots into the underlying agar.
Microsporangia: spherical, optically dense, or refractive, 1.0-1.5 microns in diameter.
|Rhodospirillum||Cultivation characteristics||Bacterial Culture Condition|
|Myxococcus fulvus||Myxococcus fulvus has thin colonies on Casitone magnesium agar, with a thin filamentous edge that begins as translucent off-white to pinkish, and gradually becomes more opaque pale flesh to reddish-orange and pink. On E. coli medium, growths were similar to the above, but less colored. The bacterium is moderately bacteriolytic and forms a central circular band of fruiting bodies in the central part of the colony.||The optimum pH is 6.5-7.0. The temperature range is 18°-37°C, and the optimum temperature is 26°-30°C. Myxococcus fulvus is resistant to 5 micrograms of streptomycin. Sensitive to 10 micrograms of chloramphenicol and kanamycin.|
|Myxococcus virescens||On Casitone magnesium ion agar, the colonies were thin, with many fine interlaced radial lines, the edges were indeterminate, yellowish-white to yellow, the center of the colonies was clear, and the fruiting bodies were formed. During continuous incubation, a diffusible pigment was formed. On E. coli medium (ECM), the colonies were thinner and less colored. There are many fruiting bodies in the central circle; the bacteriolysis of the bacteria is moderate.||The optimum pH is 6.5-7.0. The temperature range is 18°-37°C, and the optimum temperature is 28°C. Myxococcus virescens is resistant to 5 micrograms of streptomycin. Sensitive to 10 micrograms of chloramphenicol and kanamycin.|
|Myxococcus xanthus||The bacteria can be grown on synthetic media. Fruiting bodies can be formed on synthetic media.||The optimum pH is 7.2-8.2, and the optimum temperature is 30°C. Myxococcus xanthus is resistant to 5 micrograms of streptomycin. Sensitive to 10 micrograms of chloramphenicol and kanamycin.|
|Myxococcus stipitatus||On Casitone magnesium ion medium, vegetative colonies are gray or yellow-white, flat and mycelial. Few fruiting bodies were formed on ECM or Casitone-Mg2+- agar. Growth is abundant in liquid medium and forms a special soft mold-like sphere. Can be grown in common bacteriological media such as nutrient broth or casein hydrolyzate broth.||Temperature range 18°-37°C. Myxococcus stipitatus is resistant to 5 micrograms of streptomycin and sensitive to 10 micrograms of chloramphenicol and kanamycin.|
|Myxococcus coralloides||On Casitone-Mg2+ agar, the colonies were flat, thin, and had dense radial lines, the color of which was comparable to that of the fruiting bodies. They are closely arranged in concentric circles in the center of the colony, and other forms. On E. coli medium, the growths were similar, but less colored; the lysis was moderate and corroded the underlying agar. Some strains form brown diffusive pigments in old cultures.||Optimum pH 7.0--7.5; temperature range 18°-37°C, optimum temperature 25°-30'°C. Sensitive to 5 micrograms of streptomycin, 10 micrograms of chloramphenicol and kanamycin.|