Periodic Reporting for period 1 - MMM-REBIO (Mixotrophy in marine microalgae for renewable biomass production)
Berichtszeitraum: 2019-11-04 bis 2021-11-03
Although mixotrophy is a common method to increase productivity in algal industrial cultivation (or in R&D studies), only a handful research projects have focused on understanding the underlying molecular processes in microalgae. The overall goal of the MMMREBIO project was to use the mixotrophic growth as a strategy to maximize the outdoor productivity of selected microalgal species on the Swedish west coast during the whole year combining both applied and basic research.
Other experiments are ongoing at CNRS to complete the biophysical analysis of Sm for studying the communication between mitochondria and chloroplasts in mixotrophy during the winter (i.e. ECS analysis).
The mixotrophic growth was also tested in the most productive strain Nannochloropsis granulata (Ng) isolated from the Swedish west coast and available in the GUMACC collection. This strain showed the best growth and lipid production in photobioreactors simulating the light and temperature on the west coast of Sweden during summer. In this condition the glycerol increased the biomass and the biotechnological potential of Ng, (i.e. increasing the production of high-value molecules such as carotenoids and EPA) and antitumoral activity in human cell lines. Other experiments are ongoing at SZN to complete the bioassay and metabolomic analysis in order to identify the classes of molecules responsible for the antitumoral activity of Ng. The experiments ongoing at CNRS and at SZN will complete the dataset for the publication of two scientific original articles.
During my fellowship, I also got an opportunity to be co-supervisor of two Master students, for a total of 9 months. These experiences have provided me with the skills to be a good mentor and supervisor. I also had the opportunity to give lectures and practicals during CSW’s academic courses, i.e. microalgae and plant physiology lectures for the course BIO350 'Plant Physiology in a dynamic environment’. This helped me to acquire teaching and communication skills. I presented my work in both national and international conferences, mostly in remote due to the COVID-19 pandemic. I have presented my results in several meetings within our research group at the University of Gothenburg (every two weeks), and at least twice a year with other collaborators of the project from RISE, SZN and CNRS. Moreover, two peer-reviewed, open access articles were published in two journals with an impact factor > 4. All these experiences allowed me to implement both oral and written communication skills. Two other manuscripts are currently in preparation to be submitted for publication in scientific peer-reviewed journals on: 1) the characterization of the mixotrophic growth of Sm142 and understanding the interplay between the chloroplast and mitochondrion in this strain, and 2) the optimal conditions for the mixotrophic cultivation of Ng and on bio-assay analysis. Project results and publications were promoted on the website of the University (https://www.gu.se/en/research/mixotrophy-in-marine-microalgae-for-renewable-biomass-production-mmm-rebio) and in the social media (LinkedIn, Twitter).
We also showed that the mixotrophic cultivation can be used as a strategy to increase the biotechnological potential of local strains in an outdoor system on the Swedish west coast.
Particularly interesting were the results of Ng that, when grown in mixotrophy, increased both biomass and the production of high-value molecules for employment in several fields such as pharmaceutical, food, feed, or biofuel. These findings are very important for R&D microalgal research and rise keen interest in microalgae cultivation companies in Sweden.