(b) : Retting is the process of separating fibres that are held together in close association using a variety of bacteria. Fibres of jute are held together in close association and they are separated by the action of butyric acid bacteria e.g. Clostridium butyricum. These plants are immersed in water so that they absorb water and swell. Due to the activity of bacteria, the pectic substances of middle lamella are hydrolysed and the fibres are separated. These separated fibres are used in making of ropes and sacks.