Alien invasion: a looming threat to microalgal culture
Loss due to invading organisms presents a crucial bottleneck to microalgal culture. Invasive organism includes other microalgal species, which cause loss through competition for resources, and protozoan grazers such as amoebae, ciliates, and flagellates, which cause loss through consumption.
Resource competition and consumption through predation has been extensively studied in the context of marine microbial ecology, but a significant disparity exists between this knowledge and the algal biotechnology sector. This disparity means that many established quantitative methodologies are not utilized in the context of invasive organisms. Additionally, current methodologies used to quantify competitive interactions are limited to monoxenic systems which is problematic as invasion by invasive organisms often includes a multitude of species. Finally, although the scope of invasive organisms is believed to be highly diverse, insufficient focus has been placed on identifying the organisms involved and establishing model species.
This project aims to resolve these issues through the establishment of a model invasive ciliate, which managed to invade an open Nannochloropsis system causing its collapse. Initially the focus of the project is to identify the ciliate and quantify factors such as ingestion rates, growth rates, and functional and numerical response utilizing conventional ecological methods thereby bridging the gap between marine microbial ecology and blue biotechnology. Additionally, the project will establish a novel way of quantifying protozoan grazing through the use of time-lapse and image recognition utilizing cell enumeration and tracking pipelines. Although the project will focus on a monoxenic system consisting of the ciliate and Nannochloropsis, in the first instance, the follow up stage will employ a dixenic system that includes an unidentified flagellate also isolated from the Nannochloropsis pond. Since the flagellate and Nannochloropsis are a similar size, fluorescent dyes applied to live cells will be utilized to distinguish between the two species.
Professor John Day, SAMS
University of the Highlands and Islands, based at SAMS
Since 2017: MSc by research in marine science (algal biotechnology). University of the Highlands and Islands
2017 BSc (Hons) Marine Science, 1st class. Dissertation topic: Assessing and modelling the impact of grazers on microalgal cultures. University of the Highlands and Islands