Studies on some Enzymes from Germinating oil and Cereal Seeds

Abstract

Degradation of three varieties of Brassica and wheat seed storage substances at different periods of germination have been studied to have a comparative data on their chemical composition. Free sugar contents of the three varieties of Brassica and wheat seeds differ slightly. Wheat seeds contain a little higher amount of free sugar than that of Brassica seeds. Reducing sugar contents also vary in Brassica and wheat seeds. During germination, the degradation of free sugar and reducing sugar in Brassica seeds is faster than in wheat seeds. Wheat seeds contain a larger amount of starch than that of Brassica seeds. Among the three varieties of wheat seeds, Akbar variety has the highest percentage of starch. The starch contents of both seeds decrease gradually dming germination. Total protein and water-􀀷oluble protein content of the three varieties of Brassica seeds is slightly higher than that of wheat seeds. During germination, protein depletion starts after initial imbibition, and is completed in between 96 to 120 hours. Brassica seeds contain a significant amounts of lipid. Among Brassica seeds, napus variety contains the highest amount of lipid, followed by campestries and jtmcia varieties. Lipid degradation starts after 24 hours of ( germination and is completed within 72 to 96 hours. The results suggest that degradation of seed reserve nutrients accelerate the development of seedling growth during germination. Lipid degrading enzyme lipase was identified in germinating Brassica napus L. The enzyme was purified to homogeneity by solvent extraction, followed by Sephadex G- 75, DEAE and CM-cellulose ion exchange chromatography. The enzyme was purified to 68 fold with the final specific activity of 39-mmol min·1 mg·1 at 37°C using olive oil as a substrate. ---------