Serratia marcesens is . . . . . . . . bacterium which is red pigmented.

Serratia marcesens is Non-spore forming bacterium that is red-pigmented.
Serratia marcescens is a species of rod-shaped, Gram-negative bacteria in the family Yersiniaceae. It is a facultative anaerobe and an opportunistic pathogen in humans.
Because of its red pigmentation, caused by the expression of the dye prodigiosin and its ability to grow on bread, S. marcescens has been evoked as a naturalistic explanation of medieval accounts of the "miraculous" appearance of blood on the Corporal of Bolsena.
S. marcescens was discovered in 1819 by Venetian pharmacist Bartolomeo Bizio, as the cause of an episode of blood-red discoloration of polenta in the city of Padua.