The protein, peptide and free amino-acid contents of some species of Gracilaria from south-east coast of India

Four species of Gracilaria are investigated for their free amino-acid contents, as well as amino-acid constituents in the proteins and the peptides, using quantitative paper chromatographic technique. Amino-acid constituents of different species of Gracilaria differ only in amount, while free amino-acids and the amino-acids in the peptides vary both in quality and quantity. A number of amino-acids recorded as protein constituents have even escaped detection in the peptides, while in the free state they occur either in all the species or in some only except homocystine. Moreover, some amino-acids occur exclusively in the free state.

Effect of aureomycin on the behaviour of certain free amino acids in oil sardine (Sardinella longiceps) held in ice storage

The course of development of a few free amino acids under the influence of aureomycin in oil sardine (Sardinella lingiceps) held in ice storage was investigated. The levels of leucines and valine regularly increased in the control and aureomycin treated fush throughout the storage period. Alanines and threonine showed similar trend in both control and fish treated with 20ppm aureomycin. These amino acids however showed a gradual fall in fish treated at 5 ppm level. The changes in tyrosine+tryptophane were found to be irregular. Most of the amino acids studied indicated a remarkable change in trend by about the 16th day of ice storage in the case of fish treated with 50ppm aureimycin.

The free and combined amino acid contents in species of Caulerpa from southeast coast of India

Caulerpa racemosa var. macrophysa, C. racemosa var cornyphora and C. scalpelliformis are analyzed by quantitative paper chromatographic technique for their amino acid contents in proteins, peptides and free state. It is found that no appreciable variation occurs in the quality of amino acid make up in these algae; but quantitative differences are apparent in them. Moreover, both qualitative and quantitative variations occur in the amino acid make up of the peptides, and in the free state. The results are compared with those of the other investigations.