The Metabolism of Coumarin by a Strain of Pseudomonas

Biodegradation of 7-Hydroxycoumarin in Pseudomonas mandelii 7HK4 via ipso-Hydroxylation of 3-(2,4-Dihydroxyphenyl)-propionic Acid

“…After the completion of bioconversions, there were no visible spectra observed for the residual aromatic compound in the reaction mixtures with 7-hydroxycoumarin, except for the reactions with 6-hydroxycoumarin, 6,7-dihydroxycoumarin, and coumarin, which had non-disappearing UV absorption maxima at 260–270 nm wavelengths. These spectra are similar to that of 3-phenylpropionic acid (data not shown), suggesting that 7-hydroxycoumarin-induced 7HK4 strain can only catalyze the hydrolysis and reduction of lactone moiety of coumarin, 6-hydroxycoumarin, and 6,7-dihydroxycoumarin producing 3-(2-hydroxyphenyl)-propionic, 3-(2,5-dihydroxyphenyl)-propionic, and 3-(2,4,5-trihydroxyphenyl)-propionic acids, respectively, comparable to similar biotransformations in other microorganisms [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. In addition, uninduced Pseudomonas sp.…”

“…It has been shown previously that a number of soil microorganisms, such as Pseudomonas , Arthrobacter , Aspergillus , Penicillium , and Fusarium spp. can grow on coumarin ( 1 ) as a sole source of carbon [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. The key intermediate during coumarin catabolism in bacteria is 3-(2-hydroxyphenyl)-propionic acid ( 4 ) [ 10 , 11 , 16 ].…”

“…can grow on coumarin ( 1 ) as a sole source of carbon [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. The key intermediate during coumarin catabolism in bacteria is 3-(2-hydroxyphenyl)-propionic acid ( 4 ) [ 10 , 11 , 16 ]. The bioconversion of coumarin to 3-(2-hydroxyphenyl)-propionic acid can be achieved in two different metabolic pathways, as shown in Figure 1 A. Bacteria belonging to the Arthrobacter genus enzymatically hydrolyze the lactone moiety to give 3-(2-hydroxyphenyl)-2-propenoic acid ( 2 ), and then reduce a double bond by using a NADH-dependent enzyme to yield 3-(2-hydroxyphenyl)-propionic acid [ 11 ].…”

“…In the case of Pseudomonas sp. 30-1 and Aspergillus niger ATCC 11394 cells, coumarin is initially reduced to dihydrocoumarin ( 3 ) by a NADH-dependent oxidoreductase and only then enzymatically hydrolyzed [ 9 , 10 , 14 ]. Arthrobacter and Pseudomonas species are capable of oxidizing 3-(2-hydroxyphenyl)-propionic acid to 3-(2,3-dihydroxyphenyl)-propionic acid by using specific flavin-binding aromatic hydroxylases [ 16 ].…”

Biocatalytic Production of Dihydrocoumarin from Coumarin by Saccharomyces cerevisiae

“…S. cereVisiae (baker's yeast) was purchased at a local supermarket. Several microorganisms were isolated from soil, using COU as a sole source of carbon as described previously (16). The optical density of liquid media at 600 nm (OD600) was determined by UV mini 1240 (Shimadzu, Duisburg, Germany).…”