Freshwater cyanobacterial (photosynthetic microoganism) blooms are frequent phenomena increasing worldwide, and a matter of concern due to the associate negative effects on the ecosystem and water quality. Some bloom-forming cyanobacterial strains also produce toxins (cyanotoxins) that adversely affect humans and other animals. Among the array of toxins produced by these massive cyanobacterial proliferations, microcystins (a group of potent hepatotoxins) are the most frequent and widespread cyanotoxins in freshwater systems.
Cyanobacterial massive proliferations coexist and exert different interactions with other microorganisms present in the aquatic environment, in particular with a group of bacteria with the ability to degrade efficiently microcystins is frequently associated with toxic cyanobacterial blooms.
This doctoral thesis onsets on the assessment of the biological microcystin degradation capacity in a reservoir from central Spain, and further dives into the genetic and ecological characteristics, as well as the bacterial diversity underlying this biodegradation process. The thesis approaches the freshwater bacteria associated with cyanobacterial blooms from different angles, using various analytical methods and including a three-year field study.
The study of cyanobacterial blooms and microcystins allow to improve water management strategies and water treatment processes for cyanobacterial and toxin removal. In this line of study, Mª Ángeles Lezcano, predoctoral researcher in IMDEA Water, has defended her doctoral thesis on September 14 in Autonomous University of Madrid. The thesis entitled “Biodegradation of microcystins by freshwater bacteria: New genetic and ecological perspectives” was directed by Dr. Rehab El-Shehawy, principal researcher of Cyanobacteria and Cyanotoxins Group of IMDEA Water, and Dr. Antonio Quesada del Corra, professor of Autonomous University of Madrid.