Overview

  Our goal is to make a new material - Liggreen. We mimic the lignin of Picea abies and determine to use one type of monolignol for polymerization. By going through polymerization, we desire to make a material called Liggreen that is biodegradable, thermoplastic, and more transparent than natural lignin.

Production method

  In the production of Liggreen, we start from the production of enzymes. We found three enzymes:Px16, Px18 and Lac1 (Shigeto J et al.2016, Zhao Q et al. 2013), that help Coniferyl alcohol form bonds. In this regard, we want to produce dehydrogenase polymer (DHP) lignin (Ferrer JL et al. 2008). As mentioned, bonds between coniferyl alcohol are promoted by peroxidase and laccase. Peroxidase and laccase of different tree species will produce different bonds,while in Picea abies, the enzymes present are mainly Lac1, Px16 and Px18.

Safety:

  For our production methods, we have designed an effective biological control. In the production line, we have a filter between the fermentation tank and the reaction tank. In addition, our production line will be heat-sterilized after the reaction tank. We have done experiments to prove that our yeast will not cause a biological crisis.

  In the production of Liggreen, two enzymes extracted from plants are used for monolignol polymerization: peroxidase and laccase. Laccase reacts at a specific point on Coniferyl alcohol according to enzyme specificity, generating three binding structures—β-β, β-O-4, β-5 (Vanholme R et al. 2010); Peroxidase mainly cause polymerization between dimers, polymerizing β-O-4 and β-5 bonds.

  Based on the above theory, we want to synthesize Liggreen using Coniferyl alcohol, Lac1, Px16 and Px18. We produce these enzymes by synthetic biology. Using P. pastoris to produce enzymes, P. pastoris can provide the N-Link glycosylation modification required by our enzymes (Spadiut O et al. 2013), and achieve high protein expression and exogenous gene regulation (α-factor).

Reference

Jun S.,Yuji T. (2016). Diverse functions and reactions of class III peroxidases. New Phytologist (2016) 209: 1395–1402. doi: 10.1111/nph.13738

Ferrer JL, Austin MB, Stewart C Jr, Noel JP (2008). Structure and function of enzymes involved in the biosynthesis of phenylpropanoids. Plant Physiol Biochem (2008) 46(3):356-70. doi: 10.1016/j.plaphy.2007.12.009

Shigeto J, Tsutsumi Y. (2016) Diverse functions and reactions of class III peroxidases. New Phytol.(2016) 209(4):1395-402. doi: 10.1111/nph.13738

Zhao Q, Nakashima J, Chen F, Yin Y, Fu C, Yun J, Shao H, Wang X, Wang ZY, Dixon RA. (2013) Laccase is necessary and nonredundant with peroxidase for lignin polymerization during vascular development in Arabidopsis. Plant Cell (2013) 25(10):3976-87. doi: 10.1105/tpc.113.117770

Spadiut O, Herwig C, (2013) Production and purification of the multifunctional enzyme horseradish peroxidase. Pharm Bioprocess. 1(3): 283–295. doi: 10.4155/pbp.13.23

Vanholme R, Demedts B, Morreel K, Ralph J, Boerjan W. (2010) Lignin biosynthesis and structure. Plant Physiol. (2010) 153(3):895-905. doi: 10.1104/pp.110.155119