Optimisation of land-based cultivation conditions and enhancement of antioxidant activity in Umbraulva sp. (Chlorophyta, Ulvaceae)

Laura Sophie Belter

This thesis is part of the ’Mak-Pak Scale-Up’ project, funded by the German Ministry of Food
and Agriculture (BMEL, Förderkennzeichen 28-1-DL-02-B2-0). Aim of the project is to produce
a sustainable, compostable and edible food packaging alternative to plastic on an industrial
scale. The product is going to be made from green algae belonging to the Ulvaceae family that
will be cultivated in land-based re-circulating aquaculture systems. Suitable species and cultivation
conditions need to be identified in order to provide a high-quality product. This thesis
intends to answer questions regarding the long-term cultivation conditions and the enhancement
of antioxidant activity in Umbraulva sp. Both filtered natural seawater and re-used artificial
seawater from a show-casing aquarium were identified as suitable cultivation media. The enhancement
of antioxidant activity through the application of blue light was unsuccessful. No
increased antioxidant activity was measured in the light quantity experiment either, although
high light intensity treatment and high daily photo-dose treatments lead to an induction of light
stress in Umbraulva sp. Follow-up research is necessary in order to identify exact nutrient
compositions, stocking densities and light settings in order to cultivate Umbraulva sp. with the
desired results in biomass production and antioxidant activity.