Picochlorum celeri as a model system for robust outdoor algal growth in seawater

With fast growth rates, broad halotolerance and the ability to thrive at high temperatures, algae in the genus Picochlorum are emerging as promising biomass producers. Recently, we isolated a remarkably productive strain, Picochlorum celeri, that attains > 40 g m(-2) day(-1) productivities using simulated outdoor light. To test outdoor productivities, Picochlorum celeri was cultivated in 820 L raceway ponds at the Arizona Center for Algae Technology and Innovation. Picochlorum celeri demonstrated the highest outdoor biomass productivities reported to date at this testbed averaging similar to 31 g m(-2) day(-1) over four months with a monthly (August) high of similar to 36 g m(-2) day(-1). Several single day productivities were > 40 g m(-2) day(-1). Importantly for sustainability, Picochlorum celeri achieved these productivities in saline water ranging from seawater to 50 parts per thousand sea salts, without any biocides or pond crashes, for over 143 days. Lastly, we report robust genetic engineering tools for future strain improvements.

Automated summary

Algae in the genus Picochlorum, particularly the strain Picochlorum celeri, show promising potential as biomass producers due to their fast growth rates, broad halotolerance, and high outdoor productivities. Picochlorum celeri demonstrated the highest outdoor biomass productivities reported to date, achieving impressive results in a real-world testbed in Arizona. These algae have the ability to thrive in saline water without the need for biocides, making them a sustainable option for biomass production. Additionally, genetic engineering tools are available for further strain improvements in the future.