Enzymatic-assisted polymerization of the lignin obtained from a macroalgae consortium, using an extracellular laccase-like enzyme (Tg-laccase) from Tetraselmis gracilis

J Environ Sci Health A Tox Hazard Subst Environ Eng. 2020;55(6):739-747. doi: 10.1080/10934529.2020.1738171. Epub 2020 Mar 17.

Abstract

In the past decade, Mexican coasts have received an enormous influx of macroalgae species, producing serious environmental and public health concerns. Here, we developed a green methodology to generate a new polymer from the lignin contained in the macroalgae. The methodology consists in lignin extraction-by-boiling and its subsequent polymerization with a laccase-like enzyme from the green algae Tetraselmis gracilis (Tg-laccase). Mass spectrometry revealed the presence of guaiacyl (G), p-hydroxyphenyl (H), and sinapyl alcohol as the main monolignols in the lignin from Sargassum sp. On the other hand, MALDI-TOF spectra shows an increase in the size of the lignin chain after enzymatic polymerization process with Tg-laccase. Besides, the characterization of the novel polymer -using 1H NMR, FTIR, SEC-FPLC, and UV/Vis- allowed establishing that during the polymerization process there is a decrease in the number of phenolic groups as well as loss of aromatic protons, which allowed proposing a polimerizacion mechanism. This methodology could be promising in the development of a new lignin-based polymer and would open a new direction for the environmental management of the macroalgae on the Mexican beaches.

Keywords: Macroalgae; Microalgae; Sargasso sea; green method; laccase; laccase production; lignin; polymerization assay.

MeSH terms

  • Chlorophyta / enzymology*
  • Green Chemistry Technology / methods*
  • Laccase / chemistry*
  • Lignin / chemical synthesis*
  • Lignin / chemistry
  • Molecular Weight
  • Phenols / chemistry
  • Polymerization*
  • Seaweed / chemistry*

Substances

  • Phenols
  • Lignin
  • Laccase