[Effects of sediment on the growth of Microcystis and Anabaena in Yanghe reservoir].

Batch culture experiments were used to study the effect of leachate from sediment of Yanghe reservoir on the growth of Microcystis and Anabaena isolated from Yanghe reservoir. The results showed that the growth of Microcystis was significantly inhibited when the addition of anaerobic leachate from sediment in M11 culture medium was high (> or = 20% V/V). The maximum biomass of Microcystis was lower than that grown in pure M11 culture medium. But there was an obvious promotion on the growth of Anabaena when anaerobic leachate from sediment was added. The growth rate of Anabaena increased 36.6%, 47.2% and 36.0%, respectively, compared to M11 culture medium when adding 2%, 20% and 50% (V/V) anaerobic leachate. Compared to adding anaerobic leachate, aerobic leachate had no influence on the growth of Microcystis, while the growth rate of Anabaena was promoted by aerobic leachate. The growth rate of Anabaena increased 37.2% compared with M11 when adding 20% (V/V) of aerobic leachate. But after addition of Fe-citrate to the mixed culture medium (50% M11 culture medium +50% anaerobic leachate), the maximum biomass of Microcystis significantly increased. The results suggest that high organic matter concentration decreases iron availability for Microcystis.