Using a CytoSense the researchers from the Mediterranean Institute of Oceanography (MIO), Aix-Marseille University, successfully analyzed Prochlorococcus marina. With diameter of around 0.6 μm, this marine cyanobacterium is the smallest known photosynthetic organism. At the same time it is the most abundant photosynthetic organism on Earth. Quantitative analysis of Prochlorococcus marina with the CytoSense facilitates understanding of the role of this species in ocean ecosystems.
The wide particle size range measured in the CytoSense enabled researchers to analyze Microcystis single cells and colonies present in Lake Taihu. Since September 2016 a CytoSense is applied to continuously monitor dynamics of this harmful cyanobacterium. It is a part of a large-scale program set up to protect water quality in Lake Taihu, drinking water source to over 30 million people. The CytoSense project is realized by the Taihu Basin Authority in partnership with the Dutch Ministry of Infrastructure and the Environment.
The CytoSense on the river Meuse analyses phytoplankton community hourly from March till November. It is an important part of the early warning system on this drinking water providing river. The project is led by the Dutch Ministry of Infrastructure and the Environment, in close collaboration with CytoBuoy and Thomas Rutten Projects.
The researchers from the Mediterranean Institute of Oceanography (MIO), Aix-Marseille University were the first to place a flow cytometer on a moored solar-powered buoy EOL (OVLFR). Throughout the 2 months deployment the CytoSub was controlled remotely. Resulting data was transferred via WIFI connection on a distance of 1.7 km. With this innovative approach, the researchers observed influence of wind, precipitation and phytoplankton community structure on the development of a spring bloom. Data collected every 2 hours showed phytoplankton community dynamics related to the daily cell cycle.
More information: Thyssen et al. 2014
High frequency (hourly) monitoring of phytoplankton community in the largest brackish water lagoon in Mediterranean area was realized by means of a CytoSense by the researchers from MIO, Aix-Marseille University. Clusters revealed upon analysis of phytoplankton community were shown to be functional response groups, both regarding the daily variations as well as sudden environmental changes. The measurements showed dynamics of Akashiwo sanguinea throughout a strong wind episode (mistral). This species is known to form harmful algal blooms (HAB).
Synechococcus spp., picoeukaryotes (< 2 μm), haploid and diploid Phaeocystis globosa, Cryptophytes, Diatoms and Coccolitophores. During another cruise, the CytoSense detected on average 10x more Cryptophytes in comparison with microscopic quantification which required sample fixation.
At the start of august 2012, a dangerously high concentration of the dinoflagellate Alexandrium Ostenfeldii was found within a creek near Ouwerkerk, Zeeland. This species is known to produce very toxic substances (saxitoxine among others), and with concentrations of millions of cells per liter this could pose a threat to humans and wildlife. Luckily these algae could be isolated in time. But how to get rid of them?
In a cooperative effort between Rijkswaterstaat, Arcadis, the University of Amsterdam and the local authorities a newly developed method was tested. By adding low concentrations of hydrogen peroxide the bloom could be destroyed. The CytoSense instrument owned by Rijkswaterstaat was used for analyzing the effects of the treatment. By closely monitoring the concentrations and activity of the species using the Cytosense, the effects of the treatment could be tracked in real time. The results of this analysis were used to tune the exact amounts of H2O2 to be added. Within two hours after the addition of the peroxide the photosynthetic capacity was dimished by 97%, and after two days the concentrations of Alexandrium Ostenfeldii was brought back to only 1% of its original value, making the water fit for mixing with other surface waters again. Since peroxide breaks down into water and oxygen, it poses no long-term threats to the ecosystem.
The CytoSense at the Swiss Federal Institute of Aquatic Science and Technology provided interesting data on the influence of micropollutants present in common pharmaceuticals and personal care products on the phytoplankton diversity and biomass.
More information: Pomati et al. 2017
The researchers from TU Wien monitored spore germination real-time by means of a CytoSense with accuracy >95%. Analysis of stained Penicillium chrysogenum spore with a CytoSense revealed activation of their metabolic activity and simultaneous change in their size and surface character. This flow cytometric analysis was possible despite the presence of other particles common for complex media used in filamentous bioprocess.