Effects of cultivation conditions on the CO2 fixation rate and production of zeaxanthin and β-carotene by Thermosynechococcus sp CL-1

Abstract

Since industrial revolution CO2 concentration in atmosphere has risen sharply Excess green house gas (GHG) has influences on extreme weather and global warming Carbon capture and sequestration (CCS) technologies are therefore under researched in recent decades to solve the problems Biological carbon mitigation (BCM) was considered as a sustainable and potential process which uses autotrophic organisms such as microalgae and cyanobacteria to absorb CO2 from atmosphere through photosynthesis In this study the combination of the advantage of the chemical-alkaline-absorption and BCM is applied as the technology of carbon fixation from one of the main CO2 emission sources power plant CO2 has much more solubility in the alkaline solution and becomes HCO3- or CO32- as the carbon source for cyanobacteria For meeting this practical requirement thermophilic and basophilic cyanobacteria Thermosynechococcus sp CL-1 (TCL-1) was chosen in this study In order to increase the biomass productivity and carbon fixation rate the higher surface-area-ratio flat panel was used as the photobioreactor (PBR) with high initial biomass concentration Light intensity DIN concentration and salinity have been needed as the operating parameters to affect the accumulation of the zeaxanthin and β-carotene in several researches The results show TCL-1 can achieve the highest biomass productivity 90 3 mg/L/h carbon fixation rate 129 1 ± 5 5 mg/L/h biomass increment 38 0 ± 2 5% the maximum zeaxanthin content 0 325 ± 0 009 mg/g at 8h the maximum β-carotene content 1 92 ± 0 02 mg/g at 12h the maximum zeaxanthin productivity 0 074 ± 0 004 mg/L/h at 8h and the maximum β-carotene productivity 0 39 ± 0 03 mg/L/h at 12h if cultivated in the 5 8 mM initial DIN under 1 000 μE/m2/s with 0 14 M salinity

Date of Award	2015 Jul 13
Original language	English
Supervisor	Hsin Chu (Supervisor)