UTILIZATION OF WASTE AGAR GENERATED IN PLANT TISSUE CULTURE LABORATORY FOR PRODUCTION OF GALACTOSE BY AGAROLYTIC BACTERIA AND THEIR ENZYME AGARASE

Abstract

Large amount of waste agar is generated in plant tissue culture units. In the present investigation, agarolytic bacteria isolated from enrichments of dumped waste agar and soil collected from a plant tissue culture laboratory were used to hydrolyze waste agar   to obtain value added product like galactose. Out of 35 microbial cultures, seven cultures could hydrolyze waste agar yielding galactose in the range of 39 to 63 mg/kg waste agar. Biochemical characterization revealed their identification as species of Enterobacter, Micrococcus and Serratia, being reported  for the first time. The two selected strains of Enterobacter sp. were studied for the production of enzyme agarase and maximum enzyme activity was 0.97 U/ml/min using nutrient broth with 0.2% waste agar, shaking culture condition, cell density 10⁹ cells/ml, incubation temperature 35°C and incubation period of 48 h. The studies pointed out the potential of bacterial isolates for conversion of waste of plant tissue culture industry into galactose, a product with commercial value as well as production of enzyme; agarase.