Caption

Coloured scanning electron micrograph (SEM) of Streptomyces hygroscopicus, Gram-positive, aerobic, filamentous, biofilm-forming, rod prokaryote (bacterium). Streptomyces sp. belong to the Actinomycetes group and are bacteria that share many characteristics with the fungi. They grow usually as filaments (chains of cells) and often branch to form a network of filaments (mycelium) in the soil. These soil bacteria are responsible for the musty odour of soil. This strain of Streptomyces hygroscopicus produces the antibiotic, milbemycin, which is used as an insecticide and also to control certain parasitic infections in animals. It is also a biofilm forming bacterium. Biofilms are primarily accumulations of bacteria in aqueous environments. They form when bacteria secrete slimy, mucilaginous materials that provide the microorganisms with a means of attachment to moist surfaces. Magnification: x1,600 when shortest axis printed at 25.