DYNAMIC CHANGES OF INORGANIC NITROGEN AND ASTAXANTHIN ACCUMULATION IN HAEMATOCOCCUS PLUVIALIS

摘要

This study on dynamic changes of culture color, astaxanthin and chlorophylls, inorganic N including N-NO-3, N-NO-2 and N-NH+4 in batch culture of Haematococcus pluvialis exposed to different additive nitrate concentrati on showed (1) ast/chl ratio was over 0.8 for brown and red algae, but was usually less than 0. 5 for green and yellow algae; (2) N-NO-3, in general, was unstable and decreased , except for a small unexpected increase in nitrate enriched treatment groups; (3) mea surable amounts of N-NO-2 and N-NH+4 were observed respectively with three cha nge modes although no external nitrite and ammonia were added into the culture; (4) a non-linear correlation between ast/chl ratio (or color) changes and th e levels of N-NO-3 , N-NO-2 , N-NH+4 in H. pluvialis culture; (5) up and down variation of the ast/chl ratio occurred simultaneously with a perceptible color change from yellow to brown (or red) when N-NO-3, N-NO-2 and N-NH+ 4 fluctuated around 30, 5, 5 μmol/L respectively; (6) existence of three d ynamic modes of N-NO-3, N-NO-2 and N-NH+4 changes, obviously associated with initial external nitrate; (7) the key level of total inorganic N concentration regulatin g the above physiological changes during indoor cultivation was about 50 μmol/L ; and (8) 0.5-10 mmol/L of nitrate was theoretically conducive to cell growth in batch culture.