Substrate	Reference(s)	Comment(s)
protocatechuic acid	Yoshida, T., Inami, Y., Matsui, T., & Nagasawa, T. (2010). Regioselective carboxylation of catechol by 3,4-dihydroxybenzoate decarboxylase of Enterobacter cloacae P. Biotechnology Letters, 32(5), 701–705. https://doi.org/10.1007/s10529-010-0210-3	-