Bioluminescent algae has long fascinated humans as a beautiful natural phenomenon. This creative project uses bioluminescent algae to push the limit of biomimicry, using the algae not as a model but as a technology. Through experimentation with algae samples and industrial design, two potential applications of bioluminescent algae as a sustainable lighting technology were generated. One design focuses on indoor, private lighting, while the other focuses on outdoor, public lighting. Both outcomes attempt to solve problems generated by nighttime lighting including light pollution, wasted electricity usage, and negative impacts on human and environmental health while retaining the benefits of safety and convenience.

Phosphorus (P) is a limiting nutrient in ecosystems and is mainly used as fertilizer to grow food. The demand for P is increasing due to the need for increased food supply to support a growing population. However, P is obtained from phosphate rock, a finite resource that takes millions of years to form. These phosphate rock deposits are found in only a few countries. This uneven distribution of phosphate rock leads to a potential imbalance in socio-economic systems, generating food security pressure due to unaffordability of P fertilizer. Thus, the first P-sustainability concern is a stable supply of affordable P fertilizer for agriculture. In addition, improper management of P from field to fork leaves an open end in the global P cycle that results in widespread water pollution. This eutrophication leads to toxic algal blooms and hypoxic “dead zones”. Thus, the second P-sustainability concern involves P pollution from agriculture and cities. This thesis focuses on P flows in a city (Macau as a case study) and on potential strategies for improvements of sustainable P management in city and agriculture. Chapter 2 showed a P-substance-flow analysis for Macau from 1998-2016. Macau is a city with a unique economy build on tourism. The major P flows into Macau were from food, detergent, and sand (for land reclamation). P recovery from wastewater treatment could enhance Macau’s overall P sustainability if the recovered P could be directed towards replacing mined P used to produce food. Chapters 3 and 4 tested a combination of P sustainability management tactics including recycling P from cities and enhancing P-use efficiency (PUE) in agriculture. Algae and biosolids were used as recycled-P fertilizers, and genetically transformed lettuce was used as the a PUE-enhanced crop. This P sustainable system was compared to the conventional agricultural system using commercial fertilizer and the wild type lettuce. Chapters 3 and 4 showed that trying to combine a PUE-enhancement strategy with P recycling did not work well, although organic fertilizers like algae and biosolids may be more beneficial as part of longer-term agricultural practices. This would be a good area for future research.

Cyanidioschyzon merolae, a unicellular extremophilic red algae, is found in hot, acidic groundwater with high concentrations of heavy metals. The association makes it an ideal species to investigate mechanisms of heavy metal tolerance, which may lead to its use in phyco- remediation wherein photosynthetic algae use biological processes to bind and remove toxic substances. Two strains of C. merolae, MS1 and 10D, are genetically very similar, despite the latter lacking a cell wall. To investigate heavy metal toxicity and the role of the cell wall, the two strains of C. merolae were exposed to various concentrations of cadmium and cultures were evaluated spectrophotometrically to assess the impact on growth over a 7-day period. The IC50 values of MS1 and 10D were estimated to be 15 and 0.5 ppm CdCl2 respectively, indicating that the cell wall provides protection under the presence of heavy metals. Cadmium uptake was also measured using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) to investigate metal ion exclusion and acidocalcisome-Cd2+ chelation as potential tolerance mechanisms. ICP-OES data indicated that 10D inoculum pretreated with phosphate depletion and re-supplementation, to induce Cd chelation in acidocalcisomes, then cultured in MA2 had the highest biomass Cd content of all strains and treatments (0.321 ppm; 31.55%). The cell wall clearly promotes survival and resistance to higher concentrations of environmental heavy metals, however, neither MS1 nor 10D seemed to be strains primed for phyco-remediation of heavy metal contamination through cellular uptake and sequestration.