Team:CCU Taiwan/Design

Design

  Our goal is to make a new material - Liggreen. We want to use a lignin monomer (monolignol) for polymerization. By the polymerization, we are desirable to make a material called Liggreen that is biodegradable, thermoplastic, and more transparent than the lignin.

  The structure of Picea abies contains up to 94% of Coniferyl alcohol (monolignol G). In general, the lignin structure of tree with high Coniferyl alcohol content is relatively easy to be biodegraded and structurally tough, so it is also called soft lignin. And Picea abies is also the mainstream of European tree species research. The lignin structure and related research of Picea abies are comprehensive, so we chose Picea abies as our tree species reference.

  In terms of enzyme selection, we found two enzymes (peroxidase and laccase) that help Coniferyl alcohol form bonds. In this regard, we mainly refer to a paper on DHP (lignin composed of 100% Coniferyl alcohol). It mentioned that the bond effect of Coniferyl alcohol is mainly derived from peroxidase and laccase. Peroxidase and laccase of different tree species will produce different bonds, while in Picea abies, it is mainly Lac1, Px16 and Px18.

  In the production of DHP, the enzymes extracted from plants are used for monomer polymerization, and there are two enzymes---peroxidase and laccase. Lac1 take a reaction between a monomer and a monomer. Lac1 reacts at a specific angle of Coniferyl alcohol according to enzyme specificity, and then there would generate three resonance structures ----β-β, β-O-4, β-5; Px16 and Px18 mainly act on the polymerization between dimer and dimer, Px16 and Px18 will polymerize β-O-4 and β-5. According to the action of enzyme specificity, Px16 and Px18 would react β-.O-4 and β-5.

  Based on the above theory, we want to synthesize Liggreen through Coniferyl alcohol, Lac1, Px16 and Px18. We produce these three enzymes by synthetic biology. Using p.pastoris as bacteria to produce enzymes, p.pastoris can provide the N-Link glycosylation modification required by our enzymes, and achieve high protein expression and exogenous gene regulation (α-factor), making our results can be compared to the experimental conditions of the above papers. With further environmental regulation, we can achieve the results we have predicted.