Effects of Different Medium on the Growth and Photosynthetic Activity of Nostoc flagelliforme

The growth rate, photosynthesis and chlorophyll fluorescence of Nostoc flagelliforme Born.et Flah. cultured under different medium were tested. The results showed that after (11 d) cultivation, the content of chlorophyll a in different medium were (1.08 mg/L) (Detmer), (1.87 mg/L) (Kratz-Myers), 1.21 mg/L (hydrophilous 104), and 2.18 mg/L (BG11), respectively. N.flagelliforme in BG11 had the fastest growth rate. Compared with other concentrations of BG11, the N.flagelliforme cultured in BG11 had the highest gross photosynthesis Pm ((218.1 μmol) O₂·mg^-1(chl a)·h^-1) and the highest ratio of chlorophyll fluorescence (Fv/Fm=0.349). The results indicated that BG11 is optimal to cultivate N.flagelliforme and improves its activities of photosynthesis and chlorophyll fluorescence markedly.