An investigation onto the economic feasibility of using micro algae cultures for CO2 biofixation and biomass production

• Grant number: 15/07315-2
• Support type: Research Grants - Visiting Researcher Grant - International
• Duration: August 13, 2015 - September 12, 2015
• Field of knowledge: Biological Sciences - Botany - Applied Botany
• Principal researcher: Ana Teresa Lombardi
• Grantee: Ana Teresa Lombardi
• Visiting researcher: Pedro Antonio Rodrigues Ramos
• Visiting researcher institution: Instituto Superior Politécnico José Antonio Echeverría (CUJAE), Cuba
• Home Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Climate change and increased levels of CO2 and other greenhouse gases in the atmosphere became important environmental issues in recent years. Specific CO2 emissions as processes of energy generation and cement production are contributors of this increase. Biological CO2 mitigation by microalgae is a potentially viable option to reduce atmospheric levels of this gas, since these microorganisms present high growth rates, exhibit high rates of carbon fixation, and in many cases, are able to withstand severe conditions imposed by industrial wastes. Microalgae have biotechnological attributes such as physiological plasticity, which result in ability to adjust their metabolism to increased concentration of CO2. The survival of microalgae for increasing CO2 concentrations can be stimulated by induction using a metabolic acclimation process. This investigation is a contribution to the study of photosynthesis in conditions of altered CO2 and its importance is related to the increased levels of atmospheric CO2 that are predicted for a short future. We expect to obtain results that will help clarify the potentials and limitations of microalgae in the process of CO2 remediation, as well as what effects this may cause in the biomass both in qualitative and quantitative terms. We complement that microalgae are organisms base of food chains in aquatic environments and any factor that affects its dynamics can unbalance these ecosystems. This project aims to quantify the CO2 fixation by two microalgae Chlorophyceae (Chlorella sp and Ankistrodemsus densus) using the techniques of photosynthetic efficiency through modulated fluorescence ( PhytoPAM ) and the 14C method, well known for its application in the determination of primary production. Through modulated fluorescence we will quantify the quantum yield of photosystem II, the rate of electron transport, and based on this information, the carbon fixation. The cultures will be monitored for chlorophyll a concentration, elemental composition (CHNS), growth rate and biochemical composition of the biomass. The study will focus on laboratory scale experiments (up to 1000 mL) with both species, and 200 L cultures with one Chlorophyceae that will be defined based on the results obtained in laboratory. We expect that the results contribute significantly to applications of microalgae in the remediation of CO2. Moreover, it is expected to provide support for the chlorophyll fluorescence base methodology (simple and noninvasive) for the quantitation of carbon fixation by microalgae. A detailed study about the economic viability of the biofixation of CO2 by microalgal biomass will also be performed. (AU)