14-13: Extraction and isolation of acidic galactoxyloglucanases (hemicellulases) from the germinating seeds of Tamarindus indica

Monday, April 29, 2013
Exhibit Hall
Siddalinga Murthy Kora Rudraiah and Kantharaju S, Biochemistry, Bangalore University, Bangalore, India
The technology of bioprocessing agricultural wastes using hemicellulases is gaining momentum. The production of hemicellulases for depolymerization is proving to be cost effective and environmentally viable. India produces about 3,00,000 tons of tamarind per year and tamarind seed is the major byproduct, which contains about 70% of the endosperm. The endosperm contains about 55–60% polysaccharide, galactoxyloglucan. There is a growing demand for specific, efficient and cheap hemicellulase for use in the production of tamarind oligosaccharides and monosaccharides for its use as nutraceuticals and saccharification in the production of ethanol. A large number of hydrolytic enzymes, such as galactoxyloglucanases, glucosidases and galactosidases are present in the seeds.

Healthy tamarind seeds were germinated and endosperms were collected every 48hrs from 3rd to 31st day. A 20% extract of the fresh endosperm were prepared in different buffer systems. Maximum galactoxyloglucanase activity was extracted with 0.05M acetate buffer pH 5.5 containing 0.5M NaCl. The activity was determined using tamarind xyloglucan (amyloid, Megazyme, Ireland). The specific activity increased 15–fold during germination reaching maximum by 23rd day. Km of the enzyme was 66.7 mg%. The enzyme had optimum pH and temperature of 5.5 and 45°C and stable between pH 4.0 to 6.5 and 10°C to 50°C, respectively. Electrophoretic analysis of the galactoxyloglucanase activity during germination using grams iodine revealed five isozymes. Major band 2 was present on all the days while band numbers 3 & 4 appeared from 17th day onwards and band number 5 from 23rd day onwards.