Environment & Energy
Carbon Recycling with Microalgae
With Tsuneishi Kamtecs, Phytolipid Technologies, and Leave a Nest, we began a demonstration project in October 2025 that grows microalgae outdoors on factory flue gas. PtBio analyzes genes to help develop strains that hold up in outdoor conditions.
Project Vision
Guided by our mission of “designing biological functions to solve social challenges,” PtBio is focused on microalgae that convert carbon dioxide into useful substances, aiming to bring carbon recycling into practical use in society.
Approach
We combine Bio-DX (Bio-Digital Transformation), our approach to analyzing genomic information, with genome editing to improve the ability of microalgae to produce useful substances, supporting a decarbonized society.
Demonstration Project: Low-Cost Seed Algae Grown on Flue Gas
The cost of producing seed algae, the starter cultures for growing microalgae at scale, is a major challenge in making fuels and chemicals from microalgae. In October 2025, a joint project led by Tsuneishi Kamtecs began outdoor trials at the company’s site in Fukuyama, Hiroshima, growing the microalga Nannochloropsis on flue gas from the company’s incinerator. According to the November 2025 announcement, the project plans to develop and install panel-type outdoor culture tanks that fit in unused spaces such as along factory fences or in parking lots, and to establish culture methods that use flue gas and nutrients such as nitrogen and phosphorus from waste directly.
Nannochloropsis grows in seawater and reaches high culture densities. It can be used to produce edible oils, omega-3 fatty acids, and biofuels.
Results So Far
In laboratory work in fiscal 2023 and 2024, the four-company team found that Nannochloropsis acclimates to culture medium that has absorbed incinerator flue gas directly, and identified genes associated with this acclimation. Culture tests with real flue gas on site addressed outdoor problems such as pH shifts in the medium, oxygen shortage, and low and high temperatures, and produced good growth data.
PtBio’s Role
PtBio carries out the basic research for breeding algae that can tolerate harsh outdoor conditions: high temperatures, strong light, and growth-inhibiting substances in flue gas. By analyzing gene expression under stress, we look for target genes for genome editing, with the aim of building strains that withstand these conditions.
Related information
- Partners: Tsuneishi Kamtecs / Phytolipid Technologies / Leave a Nest / PtBio
- Field: Environment & Energy, carbon recycling
- Support program: Hiroshima Prefecture Carbon Recycling Technology Research and Development Support Program (selected project led by Tsuneishi Kamtecs)
- News: Launching Demonstration Project to Build a Carbon Recycling Supply Chain (November 27, 2025)