自养与异养小球藻脂溶性化合物对比研究

COMPARATIVE STUDY ON LIPOSOLUBLE COMPOUNDS IN AUTOTROPHIC AND HETEROTROPHIC CHLORELLA PROTOTHECOIDES

应用细胞培养技术获绿色自养小球藻与乳黄色异养小球藻细胞。异养藻细胞脂溶性化合物占细胞干重的７２％，是自养藻的４倍多。两类细胞烃类化合物的分布特征发生了显著变化，自养藻以正十七烷占绝对优势；异养藻富含长链正烷烃，以正二十五烷烃占优势。两类细胞脂溶性色素化合物和苯洗脱组分化合物以及Ｃ、Ｈ、Ｏ、Ｎ１４种有机元素相对含量也差异显著。对比实验结果对于异养小球藻的代谢研究和油脂化合物的开发利用具有重要意义。

Both autotrophically and heterotrophically grown Chlorella protothecoides cells have been obtained in cell cultures. The content of liposoluble compounds in the cells of het- erotrophic algae occupied 72% of the total cells in dry weight, which was more than 4 times as high as that in the autotrophic algal cells. There existed remarkbly different distribution patterns of the hydrocarbons in these two kinds of cells. The hydrocarbons in autotrophic cells were characterised by the predominance of C_(17) normal alkanes, wheraes the heterotrophic cells were rich in normal alkanes of higher molecular weight or longer carbon chain with C_(25) as the dominant carbon. The structure of the compounds in benzene fraction is not quite clear, but the compounds in autotrophis sample may be related to the degeneration of the pigments. The compounds in heterotrophic sample probably come from lipid acids. The visible—ultraviolet absorption spectrum of the pigment compounds demonstrated the absorption peaks of the acetone extract from the autotrophic cells at 432.5, 451.5, 472. 5 and 661. 5 nm, reflecting the existence of chlorophyll and carotenoid, both with a rather high concentration. However, the acetone extract from the hetertrophic algal cells only showed absorption peaks at 427. 4, 450. 8 and 477.5 nm. The absorption peaks of the o-riginal green cells completely disappeared at 432. 5 and 661.5 nm, reflecting the disappearance of chlorophyll in cells on the whole; the remaining absorption peaks only reflected the existence of carotenoid, but its concentration had already been greatly reduced. The resuls from comparative experiments were of essential significance on the study of physiological metabolism in heterotrophically grown C. protothecoides and on the exploration and application of the lipid compounds in this kind of algae.