Synthetic Biology of Biomass

Living Things Superlative: Biomass Formation

Biomass, such as wood cell walls, is (1) It is a polymeric solid (2) Synthesized by living organisms The following are some of the characteristics of this type of product. The essence of enzymatic reactions to synthesize water-insoluble macromolecules is the ability to synthesize them in an aqueous solvent without heat or pressure, a very sophisticated process. To elucidate this mechanism, we conduct synthetic biology research using biochemistry of proteins and lipids and macromolecular science.

Do you want to know more? Please enjoy the paper below.

Tomoya Imai,”Cellulose Synthase: A Molecule Machinery for Structural Control of Polymers in Aqueous Solvents at Ambient Temperature and Pressure”
Glycoforum 24(2) A4, 2021

Biochemistry of Cell Wall Formation

We conduct biochemical research on proteins and lipids to elucidate biological mechanisms. At the same time, we use macromolecular science and macromolecular structure analysis to analyze synthetic products.


TAJIMA Hirotaka, Paavo A. Penttilä, IMAI Tomoya, YAMAMOTO Kyoko, YUGUCHI Yoshiaki
Observation of in vitro cellulose synthesis by bacterial cellulose synthase with time-resolved small angle X-ray scattering.
International Journal of Biological Macromolecules 130 , 765-777 (2019)

Shi-jing Sun, HORIKAWA Yoshiki, WADA Masahisa, SUGIYAMA Junji, IMAI Tomoya
Site-directed mutagenesis of bacterial cellulose synthase highlights sulfur–arene interaction as key to catalysis.
Carbohydrate Research 434 , p. 99-106 (2016)

Paavo A. Penttilä, Junji Sugiyama, Tomoya Imai, “Effects of reaction conditions on cellulose structures synthesized in vitro by bacterial cellulose synthases”, Carbohydrate Polymers, 136, 656-666 (2016)

Synthetic Biology of Biomass

We are also working to understand the superior properties of biomass structures by mimicking and analyzing cell wall structures using synthetic biology approaches. Here, too, we make full use of biochemistry and macromolecular science.


Imai, T. Sun, S.-J., Horikawa, Y., Wada, M., Sugiyama, J., “Functional Reconstitution of Cellulose Synthase in Escherichia coli“, Biomacromolecules, 15, no.11, 4206–4213 (2014)

Hashimoto, A., Shimono, K., Horikawa, Y., Ichikawa, T., Wada, M., Imai, T., Sugiyama, J. “Extraction of cellulose-synthesizing activity of Gluconacetobacter xylinus by alkylmaltoside“, Carbohydrate Research, 346, no.17, 2760-2768 (2011)

Structural Biology of Cellulose Synthases

Cellulose synthase genes (cesA) have been identified in many cellulose-producing organisms, but their specific functions have not been analyzed at all. This is because (1) cellulose synthase is a membrane protein and (2) it is a complex composed of multiple subunits. Therefore, we are conducting experiments using the bacteria “Bacillus acetate” as a model, which is a simpler organism among cellulose-synthesizing organisms because the subunits constituting the complex can be deduced. Specifically, we are analyzing the structure and function of cellulose synthase based on the expression system. Electron microscopy is the first choice for structural analysis.

Electron microscopic view of the cellulose synthase complex/terminal complex of Bacillus acetate (rows of particles indicated by arrows), with BcsB (one of the auxiliary subunits of cellulose synthase) labeled with gold colloids.
Electron microscopic image of purified cellulose synthase. Structural analysis of the synthase is underway using techniques such as single-particle analysis.


Shi-jing Sun, IMAI Tomoya, SUGIYAMA Junji, KIMURA Satoshi
“ CesA protein is included in the terminal complex of Acetobacter. ”
Cellulose 24 (5) , 2017-2027 (2017)

Structure-Property Relationship of Wood

Wood is a natural composite material, and the mechanism for synthesizing a composite that does not undergo component separation at room temperature and pressure is also a very interesting point. For this reason, it is important to accurately understand the nanostructure of wood cell walls. Therefore, we are conducting research to explain the mechanism of physical properties based on the structure.

Synchrotron radiation experiment(BL40B2@SPring-8)

Synchrotron radiation experiment(BL8S3@AichiSR)

Small-angle X-ray scattering image


Paavo A. Penttilä, IMAI Tomoya, SUGIYAMA Junji
Fibrillar assembly of bacterial cellulose in the presence of wood-based hemicelluloses.
International Journal of Biological Macromolecules 102 , 111-118 (2017)

Research Institute for Sustainable Humanosphere
Laboratory of Material Biology

〒611-0011 Gokasho Uji KYOTO
TEL : 0774-38-3634
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