title: Biotransformation of eugenol via protocatechuic acid by thermophilic Geobacillus sp. AY 946034 strain.
abstract: The metabolic pathway of eugenol degradation by thermophilic Geobacillus sp. AY 946034 strain was analyzed based on the lack of data about eugenol degradation by thermophiles. TLC, GC-MS, and biotransformation with resting cells showed that eugenol was oxidized through coniferyl alcohol, and ferulic and vanillic acids to protocatechuic acid before the aromatic ring was cleaved. The cell-free extract of Geobacillus sp. AY 946034 strain grown on eugenol showed a high activity of eugenol hydroxylase, feruloyl-CoA synthetase, vanillate-O-demethylase, and protocatechuate 3,4-dioxygenase. The key enzyme, protocatechuate 3,4- dioxygenase, which plays a crucial role in the degradation of various aromatic compounds, was purified 135-fold to homogeneity with a 34% overall recovery from Geobacillus sp. AY 946034. The relative molecular mass of the native enzyme was about 450 ± 10 kDa and was composed of the non-identical subunits. The pH and temperature optima for enzyme activity were 8 and 60°C, respectively. The half-life of protocatechuate 3,4-dioxygenase at the optimum temperature was 50 min.
authors.affiliation: Department of Microbiology and Biotechnology, Faculty of Natural Sciences, Vilnius University, Vilnius LT- 03101, Lithuania.
authors.forename: Gražina
authors.initials: G
authors.lastname: Giedraityte
authors.forename: Lilija
authors.initials: L
authors.lastname: Kalėdienė
mesh_terms: D001711:Biotransformation; D002855:Chromatography, Thin Layer; D004795:Enzyme Stability; D005054:Eugenol / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D056506:Geobacillus / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D062385:Hydroxybenzoates / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D008970:Molecular Weight; D021122:Protein Subunits / Q000737:chemistry; D011520:Protocatechuate-3,4-Dioxygenase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D013696:Temperature
chemical_list: D062385:Hydroxybenzoates; D021122:Protein Subunits; C009091:protocatechuic acid; D005054:Eugenol; D011520:Protocatechuate-3,4-Dioxygenase