Pneumococci growing on blood agar under anaerobic conditions. Anaerobic cultivation and colony morphology of Streptococcus pneumoniae. Colonies in S phase (smooth form of peumococci).

encapsulated S.pneumoniae colony morphology in S-phase

Convex, smooth colonies of Streptococcus pneumoniae after 48 hours, anaerobic atmosphere, 37°C. Smooth form of colonies (S form).
Columbia sheep blood agar.