Developing Next Generation Algae Bioplastic Technology
- Publication Type:
- Thesis
- Issue Date:
- 2022
Open Access
Copyright Clearance Process
- Recently Added
- In Progress
- Open Access
This item is open access.
Cyanobacteria are microscopic photosynthetic organisms capable of converting atmospheric COโ into a bioplastic, PHB (poly-hydroxy-butyrate). Unfortunately, the industrial production of cyanobacterial PHB is still not economically viable due to lower PHB productivity rates and high cultivation equipment costs compared to fermentation. Thus, four areas were explored as separate data chapters in this thesis:
๐๐ต๐ฎ๐ฝ๐๐ฒ๐ฟ ๐ฎ: ๐ฅ๐ฎ๐ป๐ฑ๐ผ๐บ ๐บ๐๐๐ฎ๐ด๐ฒ๐ป๐ฒ๐๐ถ๐ ๐ณ๐ผ๐ฟ ๐๐๐ฝ๐ฒ๐ฟ๐ถ๐ผ๐ฟ ๐ฐ๐๐ฎ๐ป๐ผ๐ฏ๐ฎ๐ฐ๐๐ฒ๐ฟ๐ถ๐ฎ๐น ๐ฃ๐๐ ๐ฝ๐ฟ๐ผ๐ฑ๐๐ฐ๐๐ถ๐๐ถ๐๐
Ethyl methane sulfonate (EMS) was used to create a mutant library which was screened using fluorescent activated cell sorting (FACS) to sort single cells with BODIPY 493/503 (a neutral lipid dye) into well plates. Mutants were screened for growth rate and PHB productivity with two mutant strains found to have enhanced PHB yields (29% and 26% higher than wild type), biomass densities (36% and 33% higher than wild type) and PHB volumetric densities (75% and 67% higher than wild type).
๐๐ต๐ฎ๐ฝ๐๐ฒ๐ฟ ๐ฏ: ๐๐ต๐ฒ๐บ๐ถ๐ฐ๐ฎ๐น ๐ฒ๐ป๐ต๐ฎ๐ป๐ฐ๐ฒ๐ฟ๐ ๐ฎ๐ป๐ฑ ๐ถ๐ป๐ต๐ถ๐ฏ๐ถ๐๐ผ๐ฟ๐ ๐ผ๐ณ ๐ฐ๐๐ฎ๐ป๐ผ๐ฏ๐ฎ๐ฐ๐๐ฒ๐ฟ๐ถ๐ฎ๐น ๐ฃ๐๐
10 different compounds (including oxidants, antioxidants, phytohormones) were screened at 3 concentrations (0.1 ยตM, 1 ยตM and 10 ยตM) to identify compounds which boosted and reduced PHB production. Two treatments, 0.1 ยตM IAA and 1 ยตM methyl jasmonate were found to increase PHB yield (55% and 19% compared to control). Two treatments, 10 ยตM allopurinol and 10 ยตM ethynylestradiol, were found to decrease biomass density, PHB yield and PHB density.
๐๐ต๐ฎ๐ฝ๐๐ฒ๐ฟ ๐ฐ: ๐ ๐๐ป๐ถ๐ฐ๐ถ๐ฝ๐ฎ๐น ๐๐ฎ๐๐๐ฒ๐๐ฎ๐๐ฒ๐ฟ ๐ฎ๐ ๐ฎ ๐บ๐ฒ๐ฑ๐ถ๐ฎ ๐ณ๐ผ๐ฟ ๐ฐ๐๐ฎ๐ป๐ผ๐ฏ๐ฎ๐ฐ๐๐ฒ๐ฟ๐ถ๐ฎ๐น ๐ฃ๐๐ ๐ฝ๐ฟ๐ผ๐ฑ๐๐ฐ๐๐ถ๐ผ๐ป
This study demonstrated the potential for primary domestic wastewater as a nutrient source of cyanobacterial biomass cultivation with no significant difference between biomass densities compared to the control culture. However, PHB yield was significantly inhibited (85% lower than control) which may have been linked to non-cyanobacterial biomass.
๐๐ต๐ฎ๐ฝ๐๐ฒ๐ฟ ๐ฑ: ๐ง๐ฒ๐ฐ๐ต๐ป๐ผ-๐ฒ๐ฐ๐ผ๐ป๐ผ๐บ๐ถ๐ฐ ๐บ๐ผ๐ฑ๐ฒ๐น๐น๐ถ๐ป๐ด ๐ผ๐ณ ๐ฐ๐๐ฎ๐ป๐ผ๐ฏ๐ฎ๐ฐ๐๐ฒ๐ฟ๐ถ๐ฎ๐น ๐ฃ๐๐ ๐ฝ๐ฟ๐ผ๐ณ๐ถ๐๐ฎ๐ฏ๐ถ๐น๐ถ๐๐
This techno-economic modelling study breaks down the key capital and operating costs and identifies the major financial barriers to profitability. For a base case scenario, a 10,000 tonnes of PHB bioplastic resin per year facility in Australia was used with breakeven and sensitivity analysis to assess economic viability. The results revealed that the cost of production was $18.1k USD/tonne which is over four times the current market price of PHB. However, through the combination of several optimistic scenarios, the breakeven price could potentially reach $7.7k USD/tonne.
Please use this identifier to cite or link to this item: