NUTRITIVE EFFECTS OF ASPARAGINE AND GLUTAMINE ON THE SILKWORM, BOMBYX-MORI

Nutritive effects of asparagine and glutamine on Bombyx mori were investigated by the use of defined diets and also by analysis of free amino acids in the larval hemolymph. Dietary asparagine supported larval growth, but glutamine was less effective than asparagine, and preliminary information on their effect was confirmed. When both aspartic and glutamic acids were deleted from the complete diet, the composition of free amino acid of larval hemolymph underwent a large change. Among them glutamine, alanine and lysine decreased markedly, whereas histidine, isoleucine, leucine, methionine, ornithine and valine increased noticeably. A normal pattern of free amino acids was recovered by including either aspartic acid or glutamic acid into the deficient diet. Asparagine and glutamine were considerably effective for reactivating a normal pattern. This means that the amides are utilized fairly well by Bombyx, and supports the result of the growth experiment.