Question

which is the bacteria that is present in the human excreta that makes it yellow in colour?

Answer 1

Human excreta or feces are generally brown in colour and not yellow coloured. Brown colour of the feces is not due to bacteria but due to the presence of a bile pigment, stercobilin. Heme moiety of haemoglobin gets break down through a specific pathway which ultimately produces stercobilin. Stercobilin finally gets excreted with the feces and is responsible for the brown colour of the feces.