High-yield production of extracellular type-I cellulose by the cyanobacterium Synechococcus sp. PCC 7002

Chi Zhao; Zhongkui Li; Tao Li; Yingjiao Zhang; Donald A Bryant; Jindong Zhao

doi:10.1038/celldisc.2015.4

High-yield production of extracellular type-I cellulose by the cyanobacterium Synechococcus sp. PCC 7002

Cell Discov. 2015 Apr 28:1:15004. doi: 10.1038/celldisc.2015.4. eCollection 2015.

Authors

Chi Zhao¹, Zhongkui Li², Tao Li³, Yingjiao Zhang⁴, Donald A Bryant⁵, Jindong Zhao⁶

Affiliations

¹ State Key Laboratory of Protein and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing, China; Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA.
² Department of Biochemistry and Molecular Biology, The Pennsylvania State University , University Park, PA, USA.
³ CAS Key Laboratory of Phycology, Institute of Hydrobiology, Chinese Academy of Sciences , Wuhan, Hubei, China.
⁴ State Key Laboratory of Protein and Plant Genetic Engineering, College of Life Sciences, Peking University , Beijing, China.
⁵ Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA; Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA.
⁶ State Key Laboratory of Protein and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing, China; CAS Key Laboratory of Phycology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China.

Abstract

Cellulose synthase, encoded by the cesA gene, is responsible for the synthesis of cellulose in nature. We show that the cell wall of the cyanobacterium Synechococcus sp. PCC 7002 naturally contains cellulose. Cellulose occurs as a possibly laminated layer between the inner and outer membrane, as well as being an important component of the extracellular glycocalyx in this cyanobacterium. Overexpression of six genes, cmc-ccp-cesAB-cesC-cesD-bgl, from Gluconacetobacter xylinus in Synechococcus sp. PCC 7002 resulted in very high-yield production of extracellular type-I cellulose. High-level cellulose production only occurred when the native cesA gene was inactivated and when cells were grown at low salinity. This system provides a method for the production of lignin-free cellulose from sunlight and CO2 for biofuel production and other biotechnological applications.

Keywords: bioethanol; cell wall; cellulose; photosynthesis; synthetic biology.

Grants and funding

R21 AA021405/AA/NIAAA NIH HHS/United States