Production of Nanocellulose from Lignocellulosic biomass by Enzymatic hydrolysis

Author: Sindhu Sureshsingh, CNAM-Bio Center and Department of Nanoscience and Nanoengineering

Mentor: Dr. Rajesh Sani, CNAM-Bio Center and Department of Nanoscience and Nanoengineering

Mentor: Dr. David Salem, CNAM-Bio Center and Department of Nanoscience and Nanoengineering

Cellulose is a polysaccharide composed of a linear chain of β-1, 4 linked D-glucose units. It is most abundant organic polymer on the earth. Cellulose is a constituent of many natural lignocellulosic plant materials which are highly abundant. The plant cell wall is divided into 3 different layers: 1. Middle lamella. 2. Primary wall and 3. Secondary wall. The middle lamella contains a high amount of lignin. The primary wall contains 3 main components: cellulose, hemicellulose and pectin in which cellulose microfibrils are arranged cross wise. The secondary cell wall is further divided into 3 layers outer, middle and inner, with the middle layer containing the highest amount of cellulose. The components in lignocellulosic biomass are strongly intermeshed and bonded through covalent and non-covalent bonds which cause recalcitrance of the biomass and makes it difficult to extract the cellulose. Conventional methods of extracting nanocellulose generally use harsh chemical treatments and high energy thermomechanical processes. Our main aim is to produce nanocellulose fibrils and/or crystals by enzymatic hydrolysis using wild or recombinant enzymes as an enzyme cocktail. The enzymes used are in-house bacterial enzymes which have high reaction rate and higher thermal stability compared to fungal enzymes. The main focus of our research is to use only enzymes for degradation of lignocellulosic biomass and to produce nanocellulose in form of cellulose nanofibrils (CNF), which is a greener approach, and to scale up the process for the production of nanocellulose for bio-nanocomposites.