Clara Simon1, Alisha Nelly1, Marcus McHale1, Ronan Sulpice1
1National University of Ireland Galway, Plant Systems Biology Laboratory, Ryan Institute, Plant and AgriBiosciences Research Centre, School of Natural Sciences, H91 TK33 Galway, Ireland.
Sea lettuce (Ulva spp.) is recognised for its potential in food, pharmaceutical, nutraceutical, biorefinery and bioremediation industries and is increasingly being cultivated in aquaculture. The demands of industrial applications vary widely in terms of biomass composition and cultivation requirements. To screen a large diversity of wild-isolates, we tested the suitability of garden experiments, i.e. co-cultivation of many strains under specific growth conditions. We have characterised species composition over time among foliose strains cultivated in seawater and brackish waters, the latter being suited for bioremediation of land-based wastewaters. Our findings reflect the competitive advantage of strains displaying fastest growth in both environments. Interestingly, growth rates after a month were very similar, suggesting that selected strains cope equally well in either media. Further, we found significant variation in the composition of biomass produced in both conditions, in particular protein and carbohydrate content. We have now applied this protocol to the identification of filamentous Ulva strains with improved tolerance to long-term low salinity and are establishing similar trials for selecting locally-sourced strains adapted to aquaculture and industrial waste-water treatment. The established bulk-selection protocol provides a distinct advantage in efficiently screening large numbers of strains for their suitability to a target application.