Transformation of Lignin-Derived Aromatics into Nonaromatic Polymeric Substances with Fluorescent Activities (NAPSFA) by <i>Pseudomonas</i> sp. ITH-SA‑1

We examined bacteria capable of transforming lignin-derived compounds into industrially or economically valuable substances from the seawater after the Great East Japan Earthquake-caused tsunami. Pseudomonas sp. ITH-SA-1 produced water-soluble fluorescent substances from the lignin-derived aromatic, syringaldehyde (SYAL). They: are polymeric substances derived from 3-<i>O</i>-methyl gallate produced through transformation of SYAL via syringate; are not known compounds reported previously; have excitation/emission peaks at 365/498 nm, respectively; and have an average molecular weight of 7.2 kDa. Despite the fact that aromatic structure generally plays an important role in the planarity and rigidity of organic fluorescent substance, the spectroscopic analyses revealed that aromatic rings were not detected in the molecules. Their activity is particularly rare and the biotransforming capabilities will contribute to the development of new basic techniques for the effective utilization of lignin.