Effect of Inoculation of Pectinolytic Mixed Bacterial Culture on Improvement of Ribbon Retting of Jute and Kenaf

Abstract

Jute and kenaf are among the annually renewable fibre crops mainly grown over tropical and subtropical Asian countries. They are possibly the world's largest source of lignocellulosic bast fibre which is extracted from plants by a natural microbial process known as retting. But acute shortage of water for retting and the environmental pollution created from conventional system of retting has demanded for new method of retting. The new method of retting launched has been recognized as ribbon retting. In ribbon retting barks are removed from jute and kenaf plants mechanically or manually in the form of ribbon. The ribbons are coiled and then allowed for retting in water with or without using a microbial inoculum. Ribbon retting has the following advantages over conventional retting: (1) It requires lesser volume of water, (2) it is faster, (3) it produces lesser environmental pollution, and (4) it produces improved quality fibre. Addition of efficient pectinolytic microbial inoculum may further boost up or improve the ribbon retting process. From the present study it is understood that inoculation of a specific mixed bacterial culture in combination with 0.5% urea as N-supplement caused faster ribbon retting of jute and kenaf. Ribbon retting conducted in cement retting tank was faster than that in polythene tank. The mixed bacterial culture in combination with urea produced stronger, finer and brighter coloured jute and kenaf fibre in comparison to uninoculated control. One hundred twenty-day-old plant was found most suitable for ribbon retting. Ribbon retted fibre with pectinolytic mixed bacterial culture in combination with urea obtained higher grade in comparison to uninoculated control. Such ribbon retted fibres produced standard and regular quality yarn.