Metabolism of isoeugenol via isoeugenol-diol by a newly isolated strain of Bacillussubtilis HS8

Abstract

A bacterium designated as HS8 was newly isolated from soil based on its ability to degrade isoeugenol. The strain was identified as Bacillus subtilis according to its 16S rDNA sequence analysis and biochemical characteristics. The metabolic pathway for the degradation of isoeugenol was examined. Isoeugenol-diol, for the first time, was detected as an intermediate from isoeugenol to vanillin by a bacterial strain. Isoeugenol was converted to vanillin via isoeugenol-diol, and vanillin was then metabolized via vanillic acid to guaiacol by strain HS8. These metabolites, vanillin, vanillic acid, and guaiacol, are all valuable aromatic compounds in flavor production. At the same time, the bipolymerization of isoeugenol was observed, which produced dehydrodiisoeugenol and decreased the vanillin yield. High level of vanillic acid decarboxylase activity was detected in cell-free extract. These findings provided a detailed profile of isoeugenol metabolism by a B. subtilis strain for the first time, which would improve the production of valuable aromatic compounds by biotechnology.

Isolation of a Gene Responsible for the Oxidation of trans -Anethole to para -Anisaldehyde by Pseudomonas putida JYR-1 and Its Expression in Escherichia coli

“…In related research that deals with the biotransformation of plant origin phenylpropanoid compounds, many investigators have focused on isoeugenol and eugenol, both of which can be metabolized into vanillin. For this purpose, diverse bacterial strains, including strains of Bacillus fusiformis (36), B. pumilus strain S-1 (32), B. subtilis HS8 (35), B. subtilis B2 (23), Brevibacillus agri 13 (30), Pseudomonas chlororaphis CDAE5 (6), P. nitroreducens Jin1 (29), P. putida IE27 (33), Psychrobacter sp. strain CSW4 (1), and Nocardia iowensis DSM 45197 (20), have been isolated.…”

Transcriptional Control of the Isoeugenol Monooxygenase ofPseudomonas nitroreducensJin1 inEscherichia coli

“…[5][6][7] Numerous attempts to produce vanillin from abundantly available phenylpropanoid precursor compounds such as isoeugenol (2-methoxy-4-(1-propenyl) phenol) have been made, 3,[8][9][10][11][12][13][14][15][16][17][18][19][20] but thus far only two cloned genes have been identified as isoeugenol monooxygenases responsible for the conversion of isoeugenol to vanillin (Fig. 1A).…”

Conversion of Isoeugenol to Vanillin by Psychrobacter sp. Strain CSW4

“…Many bacterial strains accumulate vanillin as an intermediate during the degradation of isoeugenol. Microbial bioconversion of isoeugenol to vanillin has been the aim of extensive investigations in the recent years [9,[13][14][15][16][17][18]. The main object of these studies was the isolation and characterization of novel strains capable of efficient conversion of isoeugenol into vanillin.…”

“…Bioconversion of isoeugenol has always been topic of intense research because it is a natural renewable resource and the conversion processes are environmentally friendly [9]. Although vanillin production via conversion of isoeugenol has been widely reported in various microorganisms, including Aspergillus niger [10]; strains of the genera Klebsiella, Enterobacter, and Serratia [11]; Rhodococcus rhodochrous [12]; Bacillus subtilis B2 [13]; Bacillus fusiformis [14]; B. subtilis HS8 [9]; Pseudomonas nitroreducens [15]; Pseudomonas putida [16]; Pseudomonas chlororaphis [17]; Bacillus pumilus [18]; and Nocardia iowensis [19]. However, to date, few works have been addressed to the production of vanillin and/or associated metabolites under saline conditions.…”