Metabolism of 4-Amino-3-hydroxybenzoic Acid byBordetellasp. Strain 10d: A Different ModifiedMeta-Cleavage Pathway for 2-Aminophenols

Abstract

Bordetella sp. strain 10d metabolizes 4-amino-3-hydroxybenzoic acid via 2-hydroxymuconic 6-semialdehyde. Cell extracts from 4-amino-3-hydroxybenzoate-grown cells showed high NAD(+)-dependent 2-hydroxymuconic 6-semialdehyde dehydrogenase, 4-oxalocrotonate tautomerase, 4-oxalocrotonate decarboxylase, and 2-oxopent-4-enoate hydratase activities, but no 2-hydroxymuconic 6-semialdehyde hydrolase activity. These enzymes involved in 4-amino-3-hydroxybenzoate metabolism were purified and characterized. When 2-hydroxymuconic 6-semialdehyde was used as substrate in a reaction mixture containing NAD(+) and cell extracts from 4-amino-3-hydroxybenzoate-grown cells, 4-oxalocrotonic acid, 2-oxopent-4-enoic acid, and 4-hydroxy-2-oxovaleric acid were identified as intermediates, and pyruvic acid was identified as the final product. A complete pathway for the metabolism of 4-amino-3-hydroxybenzoic acid in strain 10d is proposed. Strain 10d metabolized 2-hydroxymuconic 6-semialdehyde derived from 4-amino-3-hydroxybenzoic acid via a dehydrogenative route, not via a hydrolytic route. This proposed metabolic pathway differs considerably from the modified meta-cleavage pathway of 2-aminophenol and those previously reported for methyl- and chloro-derivatives.

Bacterial degradation of monocyclic aromatic amines

“…JS329 ( Qu and Spain, 2010 ) and (B) 4-amino-3-hydroxybenzoate in Bordetella sp. 10d ( Orii et al, 2006 ) .…”

“…The degradation pathway of 4-amino-3-hydroxybenzoate was studied in 4-amino-3-hydroxybenzoate-assimilating Bordetella sp. 10d ( Orii et al, 2006 ). The degradation pathway is initiated with conversion of 4-amino-3-hydroxybenzoate to 2-amino-5-carboxymuconic-6-semialdehyde by a 2-amino-3-hydroxybenzoate-2,3-dioxygenase ( Orii et al, 2006 ).…”

Toward Biorecycling: Isolation of a Soil Bacterium That Grows on a Polyurethane Oligomer and Monomer

“…In the metabolization of 4-amino-3-hydroxybenzoic acid in Bordetella sp. 10d the amino group is cleaved off already from the muconic semialdehyde intermediate by a 2-amino-5-carboxymuconicsemialdehyde deaminase (Orii et al, 2006). The resulting intermediate 2,5-dihydroxy-muconate probably undergoes tautomerization (gene 05105) and could be further subjected to a decarboxylation step (gene 05120 or 05125).…”

Gene cloning and characterization of a deaminase from the 4-amino-3-hydroxybenzoate-assimilatingBordetellasp. strain 10d

“…Purified genomic DNA (0.25 mg) was used as a template for PCR. To amplify the DNA fragment containing ahdB, we synthesized the following degenerate oligonucleotide primers based on the deduced NH 2 -terminal amino acid sequence of the deaminase (MPKILVHS) and the deduced NH 2 -terminal amino acid sequence of 2-oxopent-4-enoate hydratase (MDDKKIQQYGD) (Orii et al, 2004(Orii et al, , 2006: forward primer, Deaminase_F (5 0 -ATGCCCAAGATTCT CGTTCATTCG-3 0 ); and reverse primer, Hydratase_R (5 0 -CCRTAYTGYTGDATYTTYTTRTCRTCCAT-3 0 ), where R is A or G and Y is C or T. The amplification reaction in 50 mL PCR buffer contained 0.2 mM of each deoxynucleoside triphosphate, 2.5 mM MgCl 2 , 1 mM of each primer, and 2.5 U (0.5 mL) of Takara Ex Taq polymerase (Takara Bio Inc., Otsu) with an initial denaturation at 95 1C for 2 min; 35 cycles of 95 1C for 1 min, 57 1C for 2 min, and 72 1C for 1 min; and a final incubation at 72 1C for 5 min.…”

“…ahdB was expressed in E. coli (pAHDB24). The recombinant was grown in 70 mL LB medium containing (Orii et al, 2004(Orii et al, , 2006 and (b) location of the cloned genes. (a) Open arrows show ORFs and the direction of transcription.…”