Benzoate degradation byRhodococcus opacus1CP after dormancy: Characterization of dioxygenases involved in the process

Abstract

The process of benzoate degradation by strain Rhodococcus opacus 1CP after a five-year dormancy was investigated and its peculiarities were revealed. The strain was shown to be capable of growth on benzoate at a concentration of up to 10 g L(-1). The substrate specificity of benzoate dioxygenase (BDO) during the culture growth on a medium with a low (200-250 mg L(-1)) and high (4 g L(-1)) concentration of benzoate was assessed. BDO of R. opacus 1CP was shown to be an extremely narrow specificity enzyme. Out of 31 substituted benzoates, only with one, 3-chlorobenzoate, its activity was higher than 9% of that of benzoate. Two dioxygenases, catechol 1,2-dioxygenase (Cat 1,2-DO) and protocatechuate 3,4-dioxygenase (PCA 3,4-DO), were identified in a cell-free extract, purified and characterized. The substrate specificity of Cat 1,2-DO isolated from cells of strain 1CP after the dormancy was found to differ significantly from that of Cat 1,2-DO isolated earlier from cells of this strain grown on benzoate. By its substrate specificity, the described Cat 1,2-DO was close to the Cat 1,2-DO from strain 1CP grown on 4-methylbenzoate. Neither activity nor inhibition by protocatechuate was observed during the reaction of Cat 1,2-DO with catechol, and catechol had no inhibitory effect on the reaction of PCA 3,4-DO with protocatechuate.

Genome Functional Analysis of the Psychrotrophic Lignin-Degrading Bacterium Arthrobacter sp. C2 and the Role of DyP in Catalyzing Lignin Degradation

“…Based on the transcriptomic analysis, DyP was expressed in the wild-type strain but not in the mutant strain C2Δ DyP , and the transcriptional level of some other genes correlated with lignin degradation, such as genes encoding vanillate O -demethylase oxidoreductase (1.45-fold), catechol 1,2-dioxygenase (1.48-fold), catechol 2,3-dioxygenase (2.17-fold), and protocatechuate 3,4-dioxygenase (1.76-fold), increased. These enzymes catalyze the formation of the intermediate products of lignin degradation ( Solyanikova et al, 2015 ).…”

“…Catechol 1,2-dioxygenase and catechol 2,3-dioxygenase may participate in the catechol ring-opening reaction. Protocatechuic acid 3,4-dioxygenase is involved in the protocatechuic acid ring-opening process ( Solyanikova et al, 2015 ).…”

“…In addition, vanillate/3- O -methylgallate O -demethylase and vanillate O -demethylase oxygenases were found in only the psychrotrophic strain C2 ( Table 1 ). The demethylation activity of these two enzymes can convert vanillic acid to protocatechuic acid ( Solyanikova et al, 2015 ). Vanillic acid and protocatechuic acid are intermediate products of lignin degradation ( Wang et al, 2013 ).…”

Rhodococcus as a Versatile Biocatalyst in Organic Synthesis

“…Several other Rhodococcus species have been investigated for their degradation potential toward the group of BTEXS (benzene, toluene, ethylbenzene, xylene isomers, styrene) aromatics. For example, the conversion of benzoate was catalyzed by a benzoate dioxygenase with a narrow substrate scope from R. opacus 1CP [87]. 2,3-dihydroxybiphenyl-1,2-dioxygenases from Rhodococcus have been recombinantly expressed, showing activity toward a number of catechols with 2,3-dihydroxybiphenyl being the best accepted substrate [88,89] and several catechol-1,2-dioxygenases were shown to cleave (alkyl-substituted and halogenated) catechols [90,91].…”

Simultaneous 3-/4-Hydroxybenzoates Biodegradation and Arsenite Oxidation by Hydrogenophaga sp. H7

“…3-HBA and 4-HBA can be catalyzed via the gentisate degradation pathway by 3-HBA 6-monooxygenase (NagX) and intramolecular migration (NIH shift), respectively (Wang et al, 1987; Fairley et al, 2002). In addition, BA can also enter the catechol degradation pathway via cis -benzeneglycol (Solyanikova et al, 2016). Some microorganisms that engage in aromatic degradation utilize more than one of the above degradation pathways (Donoso et al, 2011; Romero-Silva et al, 2013).…”