Abstract
An increase in anthropogenic Carbon Dioxide (CO2) concentrations in the atmosphere
drives the warming and change in climate systems. Many countries
have agreed to reduce these CO2 emissions across various sectors. Biological Carbon
fixing might be the most promising and cost-effective way of reducing the
Carbon footprints of some industries. This research focused on reducing waste
CO2 produced during the fermentation stage of beer production, an industry that
produces 1.3 billion tons of CO2 annually. The thesis aimed to develop a land-based
aquaculture system using Ulva spp. that utilises blow-off CO2 produced during
fermentation that could be used in the brewing industry to reduce carbon emissions.
Differences in growth rates, δ13C and δ15N tissue concentrations were analysed,
and results showed that while Ulva spp. could reduce CO2 blow-off, its growth was
negatively impacted by high CO2 concentrations. Isotope analysis suggested that
Ulva spp. likely assimilated the additional CO2 through photosynthesis. Experiments
indicated that the lack of growth could be due to pH reduction caused by
the high concentrations of CO2 and suggested that a larger scale photobioreactor
should be used. Future research should focus on optimising CO2 assimilation
by Ulva spp. to reduce brewery carbon footprints, including characterising CO2
emissions, determining growth limits, and conducting pilot tests with modified
CO2 concentrations. Overall, while Ulva spp. shows promise in CO2 mitigation,
further investigation is needed to enhance its effectiveness in brewery sustainability
efforts.