Description of Deinococcaceae
provided by BioPedia
This family houses the gram positive and extremely radiation tolerant Deinococcus. Cells spherical and dividing alternatively in two planes showing pairs and tetrads, or rods dividing in one plane to show paired cells. Not motile and without differentiated resting forms. Septa may be formed from two sides of the cell and close as curtains rather than like an iris diaphragm. Gram negative in fine structure but may stain Gram positive. Cell wall profiles show a thick peptidoglycan component, an outer membrane spaced away from the peptidoglycan, and sometimes an external paracrystalline protein S-layer. Most are pigmented pink or orange red to brick red. Aerobic, catalase positive, mesophilic, chemoorganotrophs with a respiratory metabolism. Although most strains show optimum growth rate at 25 degrees C, the temperature limits for growth of some strains may be as high as 42 degrees C and for others as low as 4 degrees C. May require vitamins and accessory growth factors. Generally inactive toward sugars and those that are metabolized cause little if any acid production. Most strains are resistant to ã-radiation, UV radiation, and desiccation.