Dissertation defence (Molecular Plant Biology): MSc João Rocha Salazar
Time
5.12.2024 at 12.00 - 16.00
MSc João Rocha Salazar defends the dissertation in Molecular Plant Biology titled “Advancing Agricultural Sustainability Through Microalgae Biotechnology Innovations” at the University of Turku on 05 December 2024 at 12.00 (University of Turku, Natura, Lecture hall X, Turku).
Opponent: Associate Professor, PhD, Dorinde Kleinegris (University of Bergen, Norway)
Custos: Professor, PhD, Yagut Allahverdiyeva-Rinne (University of Turku)
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Summary of the Doctoral Dissertation:
Wastewater pollution is a major environmental problem affecting the water quality of the Baltic Sea. Agriculture plays a very significant role, contributing 30% of the total phosphorus load in the region. In my research, I explored how photosynthetic microorganisms could address this issue by purifying wastewater from a commercial hydroponic greenhouse.
In laboratory experiments, microalgae species that thrive in hydroponic wastewater were identified. Two promising candidates, Scenedesmus obliquus and Tetradesmus obliquus, were scaled up to a greenhouse setting using specialized equipment called photobioreactors. These systems allowed for the cultivation of microalgae on a large-scale, using hydroponic wastewater as growth medium for the cells. In the continuous cultivation experiment, the system circulated over 1000L of hydroponic wastewater for over 35 days of operation. In the batch mode experiments, the system was able to remove 100% of the nitrogen and phosphorus present in the wastewater while achieving microalgae densities of over 6 grams per liter.
Beyond purification, I explored how microalgae biomass could be used as a novel biopesticide and plant biostimulant. Extracts from Chlorella sorokiniana inhibited the growth of harmful fungi by 50%, while extracts of T. obliquus improved the fresh weight of lettuce by more than 15%. This research highlights the potential of microalgae integration in agriculture to foster circular and sustainable practices, mitigating pollution and providing environmentally friendly alternatives to conventional products.
Opponent: Associate Professor, PhD, Dorinde Kleinegris (University of Bergen, Norway)
Custos: Professor, PhD, Yagut Allahverdiyeva-Rinne (University of Turku)
***
Summary of the Doctoral Dissertation:
Wastewater pollution is a major environmental problem affecting the water quality of the Baltic Sea. Agriculture plays a very significant role, contributing 30% of the total phosphorus load in the region. In my research, I explored how photosynthetic microorganisms could address this issue by purifying wastewater from a commercial hydroponic greenhouse.
In laboratory experiments, microalgae species that thrive in hydroponic wastewater were identified. Two promising candidates, Scenedesmus obliquus and Tetradesmus obliquus, were scaled up to a greenhouse setting using specialized equipment called photobioreactors. These systems allowed for the cultivation of microalgae on a large-scale, using hydroponic wastewater as growth medium for the cells. In the continuous cultivation experiment, the system circulated over 1000L of hydroponic wastewater for over 35 days of operation. In the batch mode experiments, the system was able to remove 100% of the nitrogen and phosphorus present in the wastewater while achieving microalgae densities of over 6 grams per liter.
Beyond purification, I explored how microalgae biomass could be used as a novel biopesticide and plant biostimulant. Extracts from Chlorella sorokiniana inhibited the growth of harmful fungi by 50%, while extracts of T. obliquus improved the fresh weight of lettuce by more than 15%. This research highlights the potential of microalgae integration in agriculture to foster circular and sustainable practices, mitigating pollution and providing environmentally friendly alternatives to conventional products.
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