THE PROTEIN NUTRITIONAL EVALUATION OF ROTIFER BRACHIONUS CALYCIFLORUS AND ITS FOODS

In the study the nutritive value of seven kinds of foods, including five kinds of algae(Chlorella pyrenoidosa, Scenedesmus obliquus, Chlamydomonas microsphaera, Cryptomonas ovata, Euglena intermedia) and two kinds of yeast (Saccharomyces cerevisiae and Saccharomyces carlsbergensis) to rotifer(Brachionus plicatilis) was appraised using two indexes of protein and fatty acid. The appraisal results of the protein showed that the content of the total nitrogen (TN) and the crude protein (CP) are 10.08% and 63.0% in the rotifer's body respectively. The total amino acid (TAA) and the total essential amino acid (TEAA) account for 48% and 22.02% of crude protein respectively. The ratio of total essential amino acid with total amino acid (TEAA/TAA) is 45.8. The contents of TN are between 6.57%—10.96% of seven kinds of foods and among them the contents show highest and lowest value in Cryptomonas ovata and Saccharomyces cerevisiae respectively. The contents of CP lie between 41.06%—68.54% and keep the same with TN from high to the low permutation order of various kinds of food. The contents of TAA are between 54.694%—73.235% and show highest and lowest value in Scenedesmus obliquus and Cryptomonas ovata respectively. The contents of TEAA are between 23.836%—34.136% and show highest and lowest value in the Saccharomyces cerevisiae and Cryptomonas ovata.The ratio of TEAA/TAA are between 43.3—49.1 and show highest value in two kinds of yeasts. In the study the seventeen kinds of amino acid were mensurated. The content of the HIS is lowest (0.540%) in the protein of the rotifer, secondly it is the MET (0.556%) and the CYS (0.762%). And the contents of the ASP is the highest (5.206%), secondly it is the GLY (4.571%). In the proteins of foods the content of the MTE is lowest(0.421%—1.495%), secondly it is the HIS (0.675%—1.967%) and the GYS (0.439%—3.332%). And the content of the GLU is highest (6.073%—11.447%), secondly it is the ASP (5.519%—8.281%) and the LEU (4.143%—7.473%). When use protein of the whole ovum as the standard the first limitative amino acids are HIS for Chlorella pyrenoidosa and MET for other six kind of food respectively. When using rotifer's protein as standard the first limitative amino acid are MET for Chlorella pyrenoidosa, LYS for Saccharomyces carlsbergensis and LEU for other five kinds of food respectively. The evaluative comparative result with protein showed that the foods of Chlorella pyrenoidosa, Scenedesmus obliquus and two kinds of yeast have bester nutritional value. The appraisal results of the fatty acid showed the contents of crude fat are a wide range from 1.64 to 15.41% and there are found a highest level in Euglena intermedia and a lowest level in Saccharomyces carlsbergensis. The twenty nine kinds of fatty acid were measured in seven and a greatest number was found in Euglena intermedia in twenty four kinds and in Saccharomyces carlsbergensis in twenty two kinds, but was snowed absehce of kind's amount of fatty acid in two yeasts that they contain only nine and thirteen of kind. content of unsaturated fatty acid higher than saturated fatty acid of live kinds of foods among them, whereas was educed opposite outcome in other two kinds of foods, such as Scenedesmus obliquus and Saccharomyces carlsbergensis,namely the content of saturated fatty acid higher than unsaturated fatty acid. Main unsaturated fatty acid was α-linolenic acid (18:3ω3) (Which ranged from 11.76% to 26.58%) for live algae. Also in certain algal treatment, such as in Cryptomonas ovata the steridonic acid (18:4ω3) was higher level, the content is 22.59%, and in Chlamydomonas microsphaera the hexadecatetraenoic acid (16:4ω3) was higher level too, its contents is 15.48%. The long chain (longer than twenty carbon atomy) unsaturated fatty acids was found in a higher proportion in both algae, such as Cryptomonas ovata and Euglena intermedia, the contents are 18.7% and 16.2% respectively. In fatty acids of rotifer fed sex foods (except Saccharomyces carlsbergensis) was contained high unsaturated fatty acid.