Stimulating phlorotannin production in seaweed

Bulk sampling smoothed out extremes and masked fine scale contrasts, yielding a more consistent estimate of biochemical composition for an area, whereas individual thalli captured differences in age, reproductive status, and unequal exposure to environmental stressors.<br>Following baseline characterisation, nursery experiments were conducted to optimise cultivation parameters through tailored lighting regimes. A bespoke photobioreactor was constructed with a known spectrum and intensity of photosynthetically active radiation (PAR) to determine the factors of light influencing phenolic content.

A red shifted spectrum at higher intensities (800 µmol m⁻² s⁻¹) was found to be optimal, increasing phenolic content by 40-60 %. A temporal relationship between light and phenolic content was observed, with phenolic content increasing under the red shifted high intensity treatment, reaching 76 % above baseline at 15 days. At 21 days, it declined by 74 %, indicating possible resource depletion, exudation, downregulation of biosynthesis, or the onset of alternative acclimation strategies.<br>This thesis demonstrates the potential that identifying farm locations of high natural bioproduct yields, together with optimised nursery growth conditions, can have for industry by securing predictable, stable yields.

Therefore, improving the overall commercial viability of F. serratus as a novel aquaculture target.<br><br><br><i>Thesis embargoed until 31st July 2027</i>