PRESS RELEASE
1-6-2 Marunouchi, Chiyoda-ku, Tokyo 100-8246 Japan

December 26, 2023

Zeon, Nagoya University, and Friend Microbe Jointly Develop the World’s First Method for Using
Microorganisms to Degrade Carbon Nanotubes
Zeon Corporation
Tokai National Higher Education and Research System, Nagoya University
Friend Microbe Inc.
Zeon Corporation (Zeon; head office: Chiyoda-ku, Tokyo; President and CEO: Tetsuya Toyoshima), in collaboration with theresearch group of Professor Katsutoshi Hori of the Graduate School of Engineering at Nagoya University, Tokai National Higher
Education and Research System (Chikusa-ku, Nagoya City, Aichi Prefecture; President: Naoshi Sugiyama), and Friend Microbe Inc.
(Friend Microbe; Chikusa-ku, Nagoya City, Aichi Prefecture; President: Junichi Kanie), a startup launched by Nagoya University,
have developed the world’s first method for efficiently degrading carbon nanotubes (CNTs) using microorganisms. Before thisbreakthrough, conventional thinking had been that CNTs, an inorganic material composed of carbon, did not biodegrade in theenvironment. The latest result from the joint research not only overturns this belief but also raises the possibility of reducing theenvironmental risk of CNTs, and therefore it is expected that industrial use of this material will further accelerate.
Zeon developed single-walled carbon nanotubes (SWCNT; product name: ZEONANO®) with excellent properties in (1) aspect ratio, (2)specific surface area, and (3) purity and began commercial production at its Tokuyama Plant (Shunan City, Yamaguchi Prefecture) in2016.
Since 2019, Zeon has been collaborating with Nagoya University and Friend Microbe on research focused on the biodegradability ofCNTs, particularly SWCNTs. There had been reports of CNT degradation using the Fenton reaction*1, and we leveraged this knowledge
to develop an efficient biodegradation method for SWCNTs using bacteria of the genus Shewanella*2. The bacteria produce Fe (II) byreducing Fe (III) under anaerobic conditions and H2O2 by reducing O2 under aerobic conditions, thus efficiently inducing the Fenton
reaction. In our latest research, we applied this property to CNT degradation and subsequently confirmed that 56.3% of the CNT wasdegraded in 90 days. The result suggests that the Fenton reaction driven by Shewanella spp. can be applied to CNT degradation undera wide range of conditions and offer a promising new method for treating CNTs.
The research findings were published online*3 in the international academic journal Frontiers in Microbiology on November 30, 2023.
Roles of the Three Organizations in this Joint Research
Zeon Corporation
Provision of materials for single-walled carbon nanotubes and knowledge about the materials,
expertise in chemical degradation, and evaluation methods for degradation
Nagoya University
Development and social implementation of new industrial technologies using microorganisms
Friend Microbe
Demonstration of a carbon nanotube management system
Since CNT degradation is crucial to managing the entire life cycle from manufacturing to disposal, Zeon has been proposing to relevantorganizations a CNT management system based on the scientific evidence of degradation, and the fact that CNTs can be managed has
attracted considerable interest. Zeon will contribute to a sustainable Earth and safe and comfortable life for people by promoting its
SWCNT business.
*1 A chemical reaction in which H2O2 reacts with Fe ions to produce hydroxyl radicals, which are powerful oxidants. The Fenton reaction
is used for the oxidative degradation of organic materials and detoxification of toxic substances, and it plays an important role inenvironmental engineering and wastewater treatment.
*2 A genus of bacteria found primarily in aquatic environments that is capable of using metal ions as electron acceptors in oxygendeficient environments with the potential of being applied in the bioremediation of polluted environments and in bioenergygeneration.
*3 Takahashi, S. and Hori, K. (2023). “Long-term continuous degradation of carbon nanotubes by a bacteria-driven Fenton reaction.”
Frontiers in Microbiology. https://doi.org/10.3389/fmicb.2023.1298323

For more information, contact:
Department of Corporate Communication, Corporate Sustainability Division, Zeon Corporation Phone: +81-3-3216-2747
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