Compounds produced by food-borne microorganisms. To this group belong the toxins produced by Clostridium botulinum, which are a group of motile, gram-positive, rod-shaped, spore-forming, anaerobic bacteria that are capable of producing neurotoxins. According to the toxin they produce, there are seven types and three subtypes of Clostridium botulinum: type A, subtype Af (A toxin); type B (B toxin); type C, subtype Ca (Cl, C2, and D toxins), subtype Cb (C2 toxin); type D (Cl and D toxins); type E (E toxin); type F (F toxin); and type G (G toxin). Based on their ability to digest proteins and break down sugars, Clostridium botulinum can be divided into four groups: group I, strains that are strongly proteolytic and saccharolytic (all strains of type A, several strains of types B and F); group II, strains that are nonproteolytic but strongly saccharolytic (all strains of type E, several strains of types B and F); group III, strains that are nonproteolytic except that they can digest gelatin (all strains of types C and D); and group IV, strains that are proteolytic but non-saccharolytic (a single strain of type G). All types can deaminate and decarboxylate amino acids and desulfurize cystine to produce H2S. Thus, all types can produce NH3, H2S, CO2, and volatile amines from amino acids.