Response of microcystin biosynthesis and its biosynthesis gene cluster transcription in Microcystis aeruginosa on electrochemical oxidation

ABSTRACTMicrocystin-LR (MC-LR), which is one of the most commonly found microcystins (MCs) in fresh water, has been proved to be a potential tumour promoter and classified as 2B by the International Agency for Research on Cancer. MC-LR decomposition and inhibition of MC-LR production in Microcystis aeruginosa were investigated under electrolysis condition using an electrolysis cell consisting of Ti/Pt electrodes and Nafion membrane. The relationship between the decrease in MC-LR concentration and transcription of MC-LR synthesis gene clusters was determined by performing real-time reverse transcription polymerase chain reaction (RT-qPCR) to monitor changes in the levels of transcription encoding mcyB and mcyD (cDNA to DNA) in M. aeruginosa NIES 1086 under electrolysis condition and three different conditions (i.e. oxygenated, air aerated and unaerated) as controls. Cell density decreased from day 2 under electrolysis than under the three controls. Intracellular MC-LR concentration was approximately 33 fg ...