Characterization of a potentially microcystin-producing Fischerella sp. isolated from Ajigol wetland of Iran

Ajigol wetland is a complex ecosystem in Northern Iran, which is ecologically important because contains up to 50% of threatened native plant species and aquatic organisms. Increasing of fish death and animal poisonings has led to an increased research interest and public awareness of harmful cyanobacterial blooms in this area. In the present work, we characterized a filamentous heterocyst-forming cyanobacterium morphologically and molecularly. Coupled with the 16S rRNA gene sequence, the rbcL gene and the 16S–23S internal transcribed spacer (ITS) secondary structures were analysed. Further, sequences of the mcyD and mcyG genes of microcystin synthetase (mcy) cluster were PCR amplified and sequenced. The secondary structures of the D1-D1’, BOX-B and V3 regions provided a better resolution of the studied strain. The sequenced mcy genes involved in the microcystin synthesis contribute to extend the understanding of the evolution of mcy genes in the genus Fischerella.