As shown in Fig. 2, a slightly decrease of chlorophyll content in B. braunii 765 cultivated in BG11 medium was observed from day 2 to day 4, which might be resulted from a lag phase of this alga. Afterwards, the chlorophyll content increased till day 24. By com- parison, the chlorophyll content in the swine wastewater kept increasing with higher rate till day 24. As the changing trends of alga growth and chlorophyll content in medium were basically consentaneous (Figs. 1 and 2), it could be concluded that the wastewater did not affect much on the algal chlorophyll content per unit biomass.
Overall, though with minor fluctuations, the algal b-carotenoid content of BG11 medium increased from the initial value of 1.54 lg L