ANALYSIS OF THE MICROCYSTIN-LR PRODUCTION ABILITY OF METAGENOMIC MCY GENES IN FRESHWATER AQUACULTURE PONDS FOCUSING ON THE ABUNDANCE OF METAGENOMIC MCY GENES AND SNP

MCs pollution have become a worldwide problem for freshwater aquaculture, and MC-LR has attracted considerable attention due to its potent hepatotoxicity. To analysis the MC-LR production ability of cyanobacteria in field, the relationship between the MC-LR production ability and MC-LR content, TN content, TP content, SNP of the metagenomic mcy genes were investigated in 5 freshwater fishponds during July 2018. The results showed that MC-LR content was significantly positively correlated with the abundance of metagenomic mcy gene A-J, while the MC-LR production ability of metagenomic mcy gene A-J was in indistinctive correlation with the abundance of metagenomic mcy gene, and MC-LR content, and the content of TN and TP in sufficient nitrogen and phosphate conditions. 18 SNPs significantly positively correlated with the MC-LR production ability and 388 SNPs significantly negatively correlated with the MC-LR production ability. The genotype of mcy C and mcy B in Microcystis aeruginosa NIES-843 was the most favorable for the MC-LR production in present study. There might be some mechanism to avoid substrate specific changes caused by genetic mutation of mcy C.