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Licensed Unlicensed Requires Authentication Published by De Gruyter May 14, 2021

Improved chemical pulping and saccharification of a natural mulberry mutant deficient in cinnamyl alcohol dehydrogenase

  • Tsutomu Ikeda , Naoki Takata ORCID logo , Shingo Sakamoto ORCID logo , Shi Hu , Nuoendagula , Shojiro Hishiyama , Nobutaka Mitsuda ORCID logo , Wout Boerjan ORCID logo , John Ralph ORCID logo and Shinya Kajita ORCID logo EMAIL logo
From the journal Holzforschung


Lignin content and its molecular structure influence various wood characteristics. In this study, the anatomical and physicochemical properties of wood derived from a naturally occurring mulberry mutant deficient in cinnamyl alcohol dehydrogenase (CAD), a key enzyme in lignin biosynthesis, were analyzed using conventional staining assays on stem sections, length and width measurements of xylem fiber cells, wood pulping and saccharification assays, and sugar compositional analysis of extractive-free wood powder. The present data indicate that the mutation in the CAD gene leads to improved wood delignification efficiency, increased pulp yield under alkaline pulping conditions, and enhanced saccharification efficiency following alkaline pretreatment. This study opens up new avenues for the multipurpose use of the mulberry CAD-deficient mutant as a raw material for biorefinery processes, in addition to its traditional use as a favored feed for silkworms.

Corresponding author: Shinya Kajita, Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo184-8588, Japan, E-mail:
Tsutomu Ikeda and Naoki Takata contributed equally to this work.

Funding source: Japan Society for the Promotion of Science

Award Identifier / Grant number: JP18K45678, 19K22326

Funding source: Japan Science and Technology Agency

Award Identifier / Grant number: JPMJAL1107


The authors gratefully acknowledge Mr. Hirokazu Tomiyama, Dr. Hisato Okuizumi, Mr. Akio Koyama, Ms. Shiho Kamikabeya, and Prof. Toshiyuki Takano for their helpful suggestions and/or technical support. We also thank the National Agriculture and Food Research Organization Genebank for the distribution of the mulberry cultivars.

  1. Author contributions: TI, NT, SS, HS, N, and SH conducted experiments. NM, WB, JR, and SK analyzed data. TI, NT, NM, WB, JR, and SK wrote the manuscript. All the authors have accepted responsibility for the manuscript and approved the submission.

  2. Research funding: This work was supported by the Japan Society for the Promotion of Science (JSPS) (JP18K45678 and 19K22326 to S.K.), Japan Science and Technology Agency (JST) (JPMJAL1107 to N.M.). JR was funded by the DOE Great Lakes Bioenergy Research Center (DOE BER Office of Science DE-SC0018409).

  3. Conflict of interest statement: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.


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Received: 2021-01-25
Accepted: 2021-04-07
Published Online: 2021-05-14
Published in Print: 2021-10-26

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