The main bacterial species carrying out putrefaction is Cl. welchii. This bacterium contributes to gas formation, breakdown of remaining blood clots, disintegration of tissue, and marked hemolysis.
Putrefaction is considered the final step following death, and is carried out mainly by anaerobic organisms from the bowel. Putrefying bacteria produce a plethora of enzymes which aid in disintegration of the body. Because of the lack of immune function within the body, these bacteria spread through blood vessels and utilize the carbohydrates and proteins in the blood as an energy source.