The trans-anethole degradation pathway in an Arthrobacter sp.
A bacterial strain (TA13) capable of utilizing t-anethole as the sole carbon source was isolated from soil. The strain was identified as Arthrobacter aurescens based on its 16 S rRNA gene sequence. Key steps of the degradation pathway of t-anethole were identified by the use of t-anethole-blocked mutants and specific inducible enzymatic activities. In addition to t-anethole, strain TA13 is capable of utilizing anisic acid, anisaldehyde, and anisic alcohol as the sole carbon source. t-Anethole-blocked mutants were obtained following mutagenesis and penicillin enrichment. Some of these blocked mutants, accumulated in the presence of t-anethole quantitative amounts of t-anethole-diol, anisic acid, and 4,6-dicarboxy-2-pyrone and traces of anisic alcohol and anisaldehyde. Enzymatic activities induced by t-anethole included: 4-methoxybenzoate O-demethylase, p-hydroxybenzoate 3-hydroxylase, and protocatechuate-4,5-dioxygenase. These findings indicate that t-anethole is metabolized to protocatechuic acid through t-anethole-diol, anisaldehyde, anisic acid, and p-hydroxybenzoic acid. The protocatechuic acid is then cleaved by protocatechuate-4,5-dioxygenase to yield 2-hydroxy-4-carboxy muconate-semialdehyde. Results from inducible uptake ability and enzymatic assays indicate that at least three regulatory units are involved in the t-anethole degradation pathway. These findings provide new routes for environmental friendly production processes of valuable aromatic chemicals via bioconversion of phenylpropenoids.
Shimoni
Eyal
E
Department of Food Engineering and Biotechnology, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Baasov
Timor
T
Ravid
Uzi
U
Shoham
Yuval
Y
D000081248:Allylbenzene Derivatives; D000840:Anisoles / Q000378:metabolism*; D001173:Arthrobacter / Q000378:metabolism*; D001547:Benzaldehydes / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D002474:Cell-Free System; D002855:Chromatography, Thin Layer; D062425:Hydroxybenzoate Ethers; D062385:Hydroxybenzoates / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D009154:Mutation; D011485:Protein Binding; D012336:RNA, Ribosomal, 16S / Q000378:metabolism; D013997:Time Factors; D014641:Vanillic Acid / Q000031:analogs & derivatives* / Q000378:metabolism
D000081248:Allylbenzene Derivatives; D000840:Anisoles; D001547:Benzaldehydes; D062425:Hydroxybenzoate Ethers; D062385:Hydroxybenzoates; D012336:RNA, Ribosomal, 16S; C004520:4-anisic acid; D002244:Carbon; C024896:4-anisaldehyde; C056267:3-methoxybenzoic acid; D014641:Vanillic Acid; C006578:anethole