LsdD has a critical role in the dehydrodiconiferyl alcohol catabolism among eight lignostilbene α,β-dioxygenase isozymes in Sphingobium sp. strain SYK-6

Lignin is the most abundant aromatic bioresource in nature, and elucidation of its biodegradation system essential for understanding carbon cycling on earth effective usage. The β−5 bond one intermolecular linkages lignin. Sphingobium sp. strain SYK-6 can assimilate various lignin-derived compounds, including a bond-containing dimer (phenylcoumaran-type), dehydrodiconiferyl alcohol (DCA). In catabolic pathway DCA, stilbene-type compound, 3-(4-hydroxy-3-(4-hydroxy-3-methoxystyryl)-5-methoxyphenyl)acrylate (DCA-S), produced. DCA-S subjected to cleavage interphenyl double by lignostilbene α,β-dioxygenase (LSD) generate 5-formylferulate vanillin. Among eight LSD genes (lsdA−lsdH) found genome, gene products lsdA, lsdC, lsdD, lsdG exhibited conversion activity. activity was induced (6.8-fold) vanillate produced as an intermediate metabolite DCA-S. Of mentioned above, only transcriptions were (2.6–10-fold) presence vanillate. Analyses mutants showed that lsdD mutant lost under vanillate-induced conditions. These results demonstrate plays critical role converting during DCA catabolism SYK-6.