Enhancement of biodiesel yield from a halophilic green microalga isolated under extreme hypersaline conditions through stepwise salinity adaptation strategy

Abd El-Fatah Abomohra; Amal H El-Naggar; Saleh O Alaswad; Mahdy Elsayed; Mei Li; Wenyuan Li

doi:10.1016/j.biortech.2020.123462

Enhancement of biodiesel yield from a halophilic green microalga isolated under extreme hypersaline conditions through stepwise salinity adaptation strategy

Bioresour Technol. 2020 Aug:310:123462. doi: 10.1016/j.biortech.2020.123462. Epub 2020 Apr 29.

Authors

Abd El-Fatah Abomohra¹, Amal H El-Naggar², Saleh O Alaswad³, Mahdy Elsayed⁴, Mei Li⁵, Wenyuan Li⁶

Affiliations

¹ Department of Environmental Engineering, School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, China; Botany and Microbiology Department, Faculty of Science, Tanta University, Tanta 31527, Egypt.
² Botany and Microbiology Department, Faculty of Science, Tanta University, Tanta 31527, Egypt.
³ Nuclear Science Research Institute (NSRI), King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia.
⁴ Department of Agricultural Engineering, Faculty of Agriculture, Cairo University, Giza 12613, Egypt.
⁵ Department of Environmental Engineering, School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, China. Electronic address: limeigm@gmail.com.
⁶ Department of Environmental Engineering, School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, China.

PMID: 32388355
DOI: 10.1016/j.biortech.2020.123462

Abstract

In the present study, a halophilic microalgal species was isolated from a hypersaline lagoon with salinity average of 45.3‰ and identified as Dunaliella salina KSA-HS022. It was further cultivated at a salinity range of 50-250‰, applied directly to batch cultures or through stepwise increase in a semi-continuous culture. The later showed the highest biomass productivity of 0.191 g L^-1 d^-1 at 125‰, which represented 45.8% higher than the corresponding batch culture (control). Oxidative markers in the control cultures were significantly higher than those of the adapted culture, confirming reduction of oxidative stress by adaptation. In addition, stepwise adaptation showed the highest lipid productivity of 56.5 mg L^-1 d^-1 at 150‰ (39.9% higher than the corresponding control), which resulted in the highest fatty acid methyl esters productivity. Moreover, stepwise increase of salinity up to 150‰ enhanced the biodiesel characteristics, offering a new route for enhanced biodiesel production at extraordinary salinity levels.

Keywords: Biodiesel; Dunaliella salina; Halophiles; Marine microalgae; Salinity adaptation.

MeSH terms

Batch Cell Culture Techniques
Biofuels*
Biomass
Microalgae*
Salinity

Substances

Biofuels