Analysis Of Nutritional Components And Evaluation Of Immunostimulative Functions Of C.pyrenoidosa Grown Heterotrophically

Chlorella is commercially cultivated autotrophically in open pond systems, and its maximum concentration is usually 200 mg/L~600 mg/L dry weight. The low yield and high cost limit the exploitation of the Chlorella source. In order to improve this situation, a novel heterotrophical cultivation method with a maximum concentration of 48 g/L dry weight was developed in our laboratory. Chlorella grown autotrophically has been found to contain highly nutritious components and to exert various biological effects such as increasing immunity, antitumorigenesis, radioresistance and detoxification. However, there is little such information with C. pyrenoidosa grown heterotrophically. The objective of the present study was to analyze the nutritional components of C. pyrenoidosa grown heterotrophically and to evaluate its immunostimulatory activities in vivo.1. The contents of proteins, lipids and carbohydrates in C. pyrenoidosa grown heterotrophically were 27.6 %, 8.7 % and 38.2 % respectively. It also contained 19.96 % amino acids, which included 17 kinds of amino acids, and at least 7 kinds of necessary amino acids of them. 77.24 % of total lipids in C. pyrenoidosa was unsaturated fatty acids, mainly were linoleic acid and linolenic acid, two major essential fatty acids in human diet. Lutein content was 0.2 %.2. C.pyrenoidosa grown heterotrophically was shown potent immunostimulatory functions in vivo:2.1 It improved the carbon expurgation ability of mice significantly(P<0.05). A 22 % increase in the phagocytosing index was observed when a dose of 500 mg/kg.bw. was used.2.2 It increased the phagocytosing index and phagocytosing ratio of the mouse macrophage significantly (P<0.05) . The group treated with the highest dose led to a 44 % increase in phagocytosing index and a 48 % increase in phagocytosing ratio of the mouse macrophage.2.3 A potent promoter of the mouse natural killer (NK) cells. The treated group can increase the function of NK cells. Feeding with the highest dose of C. pyrenoidosa, the NK cells activities increased 77 %.2.4 It can increase the proliferation of the mouse T lymphocyte. The high treated group increased the function of the mouse T lymphocyte significantly (71 % increase).2.5 It can promote the function of the mouse T lymphocyte in the DTH. The DTH of the mice was increased significantly after treating with C.pyrenoidosa. A 14 % increase appeared in treatment group with the high dose compared to control.2.6 It increased the humoral immunity of the mice. The numbers of the vacant speckles have a significantly increase in all treatment group compared to control. A 21 % increase appeared in treatment group with the middle dose (250 mg/kg.bw) compared to control.2.7 It increased the mouse HCso significantly. A 72 % increase appeared in treatment group with the middle dose (250 mg/kg.bw) compared to control.3. C. pyrenoidosa grown heterotrophically had no Influence on the mouse weight regulation during a 30 day feeding period.4. Acute toxicological assessment proved that the C. pyrenoidosa grown heterotrophically was safe for food use.