Effect of the cyanobacterium Anabaena spiroides Klebahn on the quantity of bacterioplankton in water of varied trophicity.

The authors investigated the effect of the cyanobacterium Anabaena spiroides on the quantity of bacterioplankton in water of varied trophicity. The cyanobacterium Anabaena spiroides, introduced to the polluted water of the river Biała has the strongest effect on bacterioplankton--the number of bacteria decreases to 31.78%. The spherical:cylindrical ratio changes in favour of the latter when affected by the cyanobacterium. This is the most pronounced in the river Biała, where spherical:cylindrical changes from 1:0.88 to 1:1.96. Anabaena spiroides exerts the most significant effect on the quantity of bacterioplankton in lake Sniardwy and pond Fosa after 24 hours, and in the other water bodies after 72 hours following the introduction of the cyanobacterium.