Xylanase for paper and pulp industry

Xylans, the main component of hemicelluloses are the second abundant carbohydrate next to cellulose and hetero polysaccharides containing subsistent groups of acetyl 1,4-O-methyl-D-glucanosyl & a arabino furanosyl residues linked to the backbone of b-1,4 linked xylopyranose unit. They form an interface between lignin, cellulose, and other polymers. The degradation of xylan requires a synergistic action of exo- and endo- xylanases of microbial origin. The major enzymes of the above are endo-xylanases are (1,4- b D xylan hydrolase), which release xylooligosaccharides and xylose residues from xylan back bone.

Xylanases are generally produced from microbes by different modes of fermentation utilizing hemicelluose rich lignocellulosic substrates with required pH temperature, age & size of inoculums and aeration.

RRL-Trivandrum has developed a hyper productive bacterial endoxylanase belonging to the family of F11 and its enzyme characteristics proved that it could be useful for paper pulp processing both in pulp refining process and for eco-friendly biobleaching process of paper pulp. The enzyme is cellulase-free.

Description of bioprocess: Enzyme pretreated pulp (pH 9.0, Temp-500C, treatment time – 1 hour) prior to chlorination (2 % chlorination treatment) and peroxide treatment (5 % H2O2 treatment) followed by a wash with 1N NaOH ( 15.0 ml - 30 minutes) improved the Brightness of the pulp – more than 4% than the control. Enzyme treatment has made the fibers to swell and have effected in easy penetration of chemical to the interior than in the control. This process involves an indigenously isolated bacterial strain and its cultivation in solid-state fermentation using agro-industrial residue as substrate.

Microorganism: The above process is carried out using a bacterial strain of Bacillus pumilus –SP34, isolated and developed for the production of endoxylanase.

Feedstock: Agro-industrial wastes

Advantages of the process:

• Alternative technology
• Cheaper raw material
• Eco-friendly
• Advantage on effluent generation
• Higher productivities
• Cheaper cost of production
• Ease on extraction of enzyme
• Option to use the whole fermented matter without extracting enzyme, thus further cost saving
• Easy penetration of chemical to the interior than in the control for enzymatic swelling of fibre.
• Improvement in the Brightness of the pulp – more than 4% than the control

Scale: The process has been carried out at laboratory scale (1 kg substrate).

Results achieved during trial runs carried out with the enzyme in recycling of waste paper:

• There is marked changes in the Burst Force (BF) - increase in the BF beyond 25. The BF value increased when enzyme dosages were increased.
• Formation of the paper was better than the control
• Uniformity in the BF values
• Water drainage of the pulp was increased without much change in 0SR

Enzyme properties: The enzyme is optimally active at 50oC and is active in acidic as well as alkaline range.

The technology has been filed for Indian patent and is ready for transfer. For further queries please contact:

Prof. Ashok Pandey
Regional Research Laboratory
Industrial Estate
P.O. Poppanamcode
Thiruvananthapuram – 695019
Phone Number: + 91-3222-283104/283105(R)
Mob: 09447072265
Email: ashokpandey56@yahoo.co.in