Lignin: untapped biopolymers in biomass conversion technologies

Lignin is the secondmost abundant natural aromatic polymer after cellulose in terrestrial ecosystems. Lignins differ in structure, depending on the method of isolation and plant source. However, such differences are not considered to be limiting factors for potential industrial applications. Owing to the lack of toxicity and versatility, several potentially attractive industrial routes exist for the more effective and diverse utilization of lignin. Lignins have been proven to elicit a number of health benefits, viz., anti-inflammatory, anti-carcinogenic, antimicrobial, prebiotic and antioxidant. In addition, lignins have been widely utilised in polymeric materials, carbon fibres, fuels, construction and agriculture. Lignin by-products may be attractive also for developing a range of commercially viable products.