SPOILAGE OF BREAD BY BACILLUS

Bacteria belonging to the genus Bacillus are capable of causing the fo od spoilage condition in bread known as rope. This involves mainly Bac illus subtilis, but also B. licheniformis, B. megaterium and B. cereus . Rope is characterized by a sweet fruity odour, often described as re sembling over-ripe pineapples, together with patchy discolouration and softening of the loaf crumb. Differentiation of microorganisms can be carried out in a variety of ways. These include classical methods, fo r example the Gram stain, commercially available kits, such as the Ana lytical Profile Index (API) strip, and modern molecular methods, such as ribotyping. The various methods used to differentiate the strains a re an important aid in highlighting the areas within the bakery proces sing line that are involved in contributing to the food spoilage condi tion known as ropey bread.