Neisseria bacterium dividing. Coloured trans- mission electron micrograph (TEM) of a section through neisseria lactamica bacterium undergoing mitotic division. This harmless bacterium is found in the lining of the nasal passages. It is a Gram-negative coccus (spherical bacterium). It takes species name from the ability to utilise the milk sugar, lactose, unlike other Neisseriaceae bacteria. Magnification: x18,000 at 6x7cm size.