Assessing the effect of artificially reduced lignin content in jute with regard to its use as textile fiber, biofuel and raw material for paper-pulp industry

Abstract

Jute (Corchorus sp.), a lignocellulosic plant grown abundantly in Bangladesh, is known for its fiber quality. Agriculture-based, renewable and biodegradable nature together with low-cost availability puts jute at an advantage. Potential high yield of cellulosic biomass per acre is another reason for increased global interest on jute. Textile and paper industries are interested in its potential as an important ingredient for producing paper and fine textiles. As with other lingocellulosic plants, the drawback of jute when used as a source for such purpose, is the abundance of lignin polymer that renders the plant material almost inaccessible for downstream processes. Previously, a project on down regulation of lignin biosynthesis related genes in jute using RNAi technology had resulted in significant decrease in the lignin content. In this backdrop, the current study has been performed with a view to evaluating the practical application of the effect of reduced lignin content in industrially important applications of jute. After down-regulation of the lignin biosynthetic genes, the decrease in lignin content was estimated by Klason method (Tanmoy et al. 2015) in transgenic lines and the lignin content was compared with the wild type. The result exhibited ~16–25% reduction in acid insoluble lignin for the whole stem and ~13–14% reduction in fiber lignin content compared to the control lines. The increase in cellulose content 3-6% (Updegraff et al. 1969), as well as increase in glucose release after enzymatic saccharification are considered as subsequent consequences of lignin down regulation. The morphological features of jute fiber was observed under a scanning electron microscope (SEM). This showed an exposure of underlying fibrils in transgenic lines whereas fibrils were found to be hidden underneath the lignin layer in control jute fiber. Furthermore, an analysis of the mechanical properties show enriched fiber quality in all transgenic lines when compared to the wild type controls. No compensation in growth which could be linked to lignin reduction was found in transgenic jute. It can be concluded that, the application of these environment friendly high quality jute fiber in textile and paper industries, eco-friendly production of biofuel from its increased cellulosic biomass and effective increase in quality of fiber will lead to sustainability of these jute lines.