Abstract
The unicellular green microalga Desmodesmus sp. S1 can produce more than 50% total lipid of cell dry weight under high light and nitrogen-limitation conditions. After irradiation by heavy 12C6+ ion beam of 10, 30, 60, 90 or 120 Gy, followed by screening of resulting mutants on 24-well microplates, more than 500 mutants were obtained. One of those, named D90G-19, exhibited lipid productivity of 0.298 g L−1⋅d−1, 20.6% higher than wild type, likely owing to an improved maximum quantum efficiency (Fv/Fm) of photosynthesis under stress. This work demonstrated that heavy-ion irradiation combined with high-throughput screening is an effective means for trait improvement. The resulting mutant D90G-19 may be used for enhanced lipid production.
Highlights
Under suitable environmental conditions, microalgae synthesize fatty acids mainly for the production of membrane glycerolipids, such as glycolipids and phospholipids
S1 and the irradiation dose of 12C6+ beam was fitted to a logistic curve equation (y = 222.20+21.096ln(x26.91), R2 = 0.98), which indicated the death rate of cells increased with increasing the radiation dosage from 10 to 120 Gy, with the highest lethality occurring between 90 to 120 Gy
A preliminary screening of the putative mutants by light microscopy showed that the morphological characteristics of the putative mutants were indistinguishable from the wild type cells
Summary
Microalgae synthesize fatty acids mainly for the production of membrane glycerolipids, such as glycolipids and phospholipids. Oleaginous microalgae have been regarded as potential next-generation feedstocks for biofuels (e.g., biodiesel and jet fuel) because they exhibit higher photosynthetic efficiency and a greater lipid production rate than terrestrial oil crops [2,3,4]. Naturally occurring microalgae that have been used so far produce much lower amounts of neutral lipid than the theoretical maximum [1]. Many methods such as physical or chemical mutagenesis and genetic engineering tools may be applied to the production strains for improving lipid production [5,6,7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
