Genetic engineering approaches to increase microalgae light use efficiency

• Main Author: Bellan, Alessandra
• Other Authors: Morosinotto, Tomas, Szabò, Ildikò
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Università degli studi di Padova 2018
• Subjects: Photosynthesis; microalgae; genetic engineering; Settore BIO/10 - Biochimica; Ocean acidification
• Online Access: http://hdl.handle.net/11577/3427159

In the next fifty years world population will reach 9-10 billion of people. This increment will drastically increase energy and food demand. The current global food and energy supply chain is not sustainable and it causes increasing CO2 emissions, exacerbating the greenhouse effect and the climate change, whose effects we are already experiencing. The Climate Change conference hold in Paris in 2015 showed a global consensus on the need to drastically reduce carbon emissions to avoid the environmental disaster, which is leading to many negative effects like desertification, animal and plants species extinction and ocean acidification. In order to face this challenge different strategies are under study and development. Microalgae are emerging as an interesting possibility for the production of energy and food. Being photosynthetic organisms, algae biomass is produced from CO2 fixation, and contains proteins, and lipids exploitable as food or fuel. Despite their potential, microalgae production on a large scale is still not competitive on the food and energy market. One of the main limitation is that photosynthetic efficiency at the industrial scale is reduced, negatively affecting growth and biomass accumulation. All first attempts of algae large scale cultivation have been pursued cultivating wild type strains (WT) that evolved in an environment extremely different and thus they are not adapted to have a maximal productivity in the industrial system. As done with crops domestication, there is the need to modify genetically strains in order to adapt them to grow in industrial systems and increase productivity. There are different algal species that are emerging as promising candidates for food and fuel production and among them the largest part of this work is focused on Nannochloropsis gaditana, a marine microalga able to accumulate lipids and molecules like β-carotene interesting for nutraceutical purposes. After a general introduction, chapter 2 described the generation of a collection of random mutants of ...