Launching Demonstration Project to Build a Carbon Recycling Supply Chain: 2025-11-27

— Tsuneishi Kamtecs, Phytolipid Technologies, PtBio, and Leave a Nest Collaborate to Establish a “Low-Cost Seed Algae” Production Model Utilizing Flue Gas —

PtBio Inc. (Headquarters: Higashi-Hiroshima, Hiroshima; CEO: Keisuke Okuhara, hereinafter “PtBio”) has launched a demonstration project (“the Project”) in collaboration with Tsuneishi Kamtecs Corporation (Headquarters: Fukuyama, Hiroshima; President: Fumio Kambara, “Tsuneishi Kamtecs”), Phytolipid Technologies Co., Ltd. (Headquarters: Yokohama, Kanagawa; CEO: Hiroyuki Ota, “PLT”), and Leave a Nest Co., Ltd. (Headquarters: Shinjuku, Tokyo; President & COO: Shuichiro Takahashi, “Leave a Nest”).

The Project aims to establish a cost-efficient production model for seed algae by cultivating the microalga Nannochloropsis in outdoor environments using flue gas emitted from Tsuneishi Kamtecs’ incinerator facilities.

This Project is being carried out as part of an initiative adopted by Tsuneishi Kamtecs under the “Hiroshima Prefecture Carbon Recycling Technology Research and Development Support Program,” which Leave a Nest has been commissioned to operate since FY2022.

Background and Achievements to Date

Tsuneishi Kamtecs, headquartered in Fukuyama City, Hiroshima Prefecture, operates waste treatment and recycling businesses and positions decarbonization and the realization of a circular economy as key management priorities. In response to these challenges, the company was selected for the Hiroshima Prefecture Carbon Recycling Technology Research and Development Support Program in FY2023. Together with PLT, PtBio, and Leave a Nest, the company has been conducting research on cultivating the microalga Nannochloropsis, which absorbs CO₂ and produces valuable compounds.

In studies conducted thus far (FY2023–2024), the team examined optimal culture conditions at the laboratory scale and discovered an acclimation phenomenon in Nannochloropsis when the culture medium directly absorbed flue gas from the incinerator. The consortium also comprehensively identified genes related to this acclimation, yielding key biological insights for future practical applications.

In parallel, cultivation trials were conducted on the Tsuneishi Kamtecs site using actual flue gas. These trials successfully identified and addressed real-world environmental challenges such as pH fluctuations, oxygen depletion, and both low and high temperature conditions—resulting in the acquisition of strong growth data.

Toward Further Advancement of This Project

Building on the insights gained through foundational research to date, the project is now shifting from the “laboratory scale” to the phase of “practical application and commercialization.” The primary goal is to address the largest bottleneck in the entire supply chain for microalgae-based fuel and chemical production—dramatically reducing the cost of seed algae cultivation.

To tackle this challenge, the team began outdoor demonstration trials in October 2025 on the Tsuneishi Kamtecs site, integrating the following two components into a unique low-cost seed algae production system:

1. Development of Low-Cost Hardware

   A proprietary panel-type outdoor cultivation tank, designed to be low-cost and highly scalable, will be developed and installed. This system can be placed in underutilized spaces such as factory perimeter fences and parking-lot dead zones.

2. Utilization of Low-Cost Inputs (Nutrient Sources)

   The project aims to establish cultivation technologies that directly use flue gas and unused elements contained in waste streams from Tsuneishi Kamtecs’ waste treatment operations—such as CO₂, nitrogen, and phosphorus—as nutrient sources.

Nannochloropsis can be cultured in seawater, is well-suited for high-density cultivation, and is capable of producing edible oils, high-value omega-3 fatty acids, and biofuels. In the future, the project envisions standardizing this system and deploying it across industrial sites throughout the Setouchi region. This demonstration marks the first step toward establishing the core technologies that will support that vision.

Roles of Each Partner Company

In driving this project forward, the four participating companies will take on the following roles:

• Tsuneishi Kamtecs Corporation Tsuneishi Kamtecs will oversee the overall project and conduct microalgae cultivation. The company will also provide the demonstration site as well as unused elements—such as CO₂, nitrogen, and phosphorus—derived from flue gas and waste streams. In addition, Tsuneishi Kamtecs will lead the design and fabrication of the core technology: the low-cost, panel-type outdoor cultivation tank.

• Phytolipid Technologies Co., Ltd. Leveraging its extensive experience in outdoor cultivation of Nannochloropsis, PLT will take the technical lead in defining the specifications for the panel-type outdoor cultivation tank and establishing optimal cultivation conditions for outdoor environments, including medium composition and monitoring methods.

• PtBio Inc. PtBio will continue and advance its current research to build a breeding foundation aimed at developing high-performance algal strains capable of thriving in harsh outdoor environments, such as high temperatures, strong light, and inhibitory substances in flue gas. Through gene expression analyses under stress conditions, PtBio will identify target genes for genome editing, with the aim of creating future strains with enhanced environmental tolerance.

• Leave a Nest Co., Ltd. Leave a Nest will oversee overall project management under the Hiroshima Prefecture Carbon Recycling Technology R&D Support Program. The company will lead efforts toward commercialization and develop strategies for deploying the cultivation system to other regions.

  

Message for the Future

This project represents a new form of “knowledge manufacturing” that combines the extensive demonstration fields and CO₂ resources from the incineration facilities of Tsuneishi Kamtecs—a local company supporting Hiroshima’s core industries—with the advanced technologies and expertise of innovative venture firms PLT and PtBio. Through this collaboration, we aim to establish a carbon-recycling model that transforms “waste” into “resources,” starting here in Hiroshima. We will accelerate the expansion of algae cultivation throughout the Setouchi region and contribute to the creation of new industries.