Detection and control of rotifer contamination in microalgal cultures

Microalgae are a promising new source of biomass for production of food, feed, fuel or bulk chemicals. Today, microalgae production is moving from lab-scale to full-scale production. One of the major challenges in large-scale systems are grazing predators (e.g. protozoa, rotifers, microcrustaceans), which can infest cultures and decimate microalgal biomass within days. So far, there has barely been research into the identity of these predators, their impact on productivity and how to effectively control them. There is a need for innovative approaches for crop control of microalgae, preferably using ecological methods that avoid the unsustainable use of chemical pesticides. The aim of this PhD study is to control microalgal predators based on ecological principles. The focus will be on ciliate predators, which are poorly known and are difficult to control. In the first phase of the PhD project, potential contamination routes will be investigated. Next, microalgal predators will be isolated and their impact on multiple freshwater and marine microalgal cultures will be assessed. Methods (i.e. flow cytometry) and predictive models will be developed to monitor and forecast predators' impact in these cultures. The project will attempt to control ciliates by a trophic cascade, i.e. by introducing predators that feed on ciliates. Besides this top-down control also a bottom-up control that relies on the principle of ecological stoichiometry will be considered. Ultimately, we will also attempt to control ciliates by means of feeding deterrents that are naturally produced by specific microalgae.

Jaar van publicatie:2020

Toegankelijkheid:Closed