NEW DISCOVERIES IN STUDY ON HYDROCARBONS FROM THERMAL-DEGRADATION OF HETEROTROPHICALLY YELLOWING ALGAE

Green autotrophic alga Chlorella protothecoides contains a very small quantity of hydrocarbons. Heterotrophic culture of this alga results i n the cells yellowing, chlorophyll disappearing, protein decreasing an d lipid increasing remarkably. The quantities of hydrocarbons from the m directly and from the thermal degradation of the cells at or below 2 00-degrees-C are very low. These hydrocarbons are characterized by pre dominance of high molecular weight normal alkanes with maximum at C23- C25. When these heterotrophically yellowing cells are thermally degrad ed at 300-degrees-C, the aliphatic hydrocarbons increase greatly, 32 t imes that of the green autotrophic ones at the same temperature. Meanw hile, the low molecular weight normal alkanes with C-17 as the peak be come predominant instead of the original ones of high molecular weight . The actual potential of microplanktonic algae in producing hydrocarb ons should be much greater than what people have recognized before.