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Isolation and characterization of two novel halotolerant Catechol 2, 3-dioxygenases from a halophilic bacterial consortium.

Guo G, Fang T, Wang C, Huang Y, Tian F, Cui Q, Wang H - Sci Rep (2015)

Bottom Line: The enzymes activity both increased in the presence of Fe(3+), Fe(2+), Cu(2+) and Al(3+) and showed no significant inhibition by other tested metal ions.The optimal temperatures for the C23Os were 40 °C and 60 °C and their best substrates were catechol and 4-methylcatechol respectively.As the firstly isolated and characterized catechol dioxygenases from halophiles, the two halotolerant C23Os presented novel characteristics suggesting their potential application in aromatic hydrocarbons biodegradation.

View Article: PubMed Central - PubMed

Affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China.

ABSTRACT
Study of enzymes in halophiles will help to understand the mechanism of aromatic hydrocarbons degradation in saline environment. In this study, two novel catechol 2,3-dioxygenases (C23O1 and C23O2) were cloned and overexpressed from a halophilic bacterial consortium enriched from an oil-contaminated saline soil. Phylogenetic analysis indicated that the novel C23Os and their relatives formed a new branch in subfamily I.2.A of extradiol dioxygenases and the sequence differences were further analyzed by amino acid sequence alignment. Two enzymes with the halotolerant feature were active over a range of 0-30% salinity and they performed more stable at high salinity than in the absence of salt. Surface electrostatic potential and amino acids composition calculation suggested high acidic residues content, accounting for their tolerance to high salinity. Moreover, two enzymes were further characterized. The enzymes activity both increased in the presence of Fe(3+), Fe(2+), Cu(2+) and Al(3+) and showed no significant inhibition by other tested metal ions. The optimal temperatures for the C23Os were 40 °C and 60 °C and their best substrates were catechol and 4-methylcatechol respectively. As the firstly isolated and characterized catechol dioxygenases from halophiles, the two halotolerant C23Os presented novel characteristics suggesting their potential application in aromatic hydrocarbons biodegradation.

No MeSH data available.


Related in: MedlinePlus

Relative expression levels of the C23O genes during phenanthrene degradation.The transcript/gene ratios were calculated for the microcosm incubation. Three independent experiments were performed. Vertical bars represent the mean of three measure replicates and three microcosm replicates (i.e. mean of nine measures).
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f1: Relative expression levels of the C23O genes during phenanthrene degradation.The transcript/gene ratios were calculated for the microcosm incubation. Three independent experiments were performed. Vertical bars represent the mean of three measure replicates and three microcosm replicates (i.e. mean of nine measures).

Mentions: To examine whether the two C23O genes are specifically involved in phenanthrene degradation process, expression profile of the C23O genes was measured by RT-PCR. The results revealed the expression of both genes during phenanthrene degradation process (Fig. 1). C23O1 was expressed rapidly after phenanthrene addition. The relative expression of C23O1 reached a peak value at 8 h, while that of C23O2 reached the peak value at 36 h. Although the expression of C23O2 subsequently decreased after 36 h, the relative expression level still remained higher than that in the beginning. The two C23O genes showed different expression profile in this phenanthrene degradation process.


Isolation and characterization of two novel halotolerant Catechol 2, 3-dioxygenases from a halophilic bacterial consortium.

Guo G, Fang T, Wang C, Huang Y, Tian F, Cui Q, Wang H - Sci Rep (2015)

Relative expression levels of the C23O genes during phenanthrene degradation.The transcript/gene ratios were calculated for the microcosm incubation. Three independent experiments were performed. Vertical bars represent the mean of three measure replicates and three microcosm replicates (i.e. mean of nine measures).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664950&req=5

f1: Relative expression levels of the C23O genes during phenanthrene degradation.The transcript/gene ratios were calculated for the microcosm incubation. Three independent experiments were performed. Vertical bars represent the mean of three measure replicates and three microcosm replicates (i.e. mean of nine measures).
Mentions: To examine whether the two C23O genes are specifically involved in phenanthrene degradation process, expression profile of the C23O genes was measured by RT-PCR. The results revealed the expression of both genes during phenanthrene degradation process (Fig. 1). C23O1 was expressed rapidly after phenanthrene addition. The relative expression of C23O1 reached a peak value at 8 h, while that of C23O2 reached the peak value at 36 h. Although the expression of C23O2 subsequently decreased after 36 h, the relative expression level still remained higher than that in the beginning. The two C23O genes showed different expression profile in this phenanthrene degradation process.

Bottom Line: The enzymes activity both increased in the presence of Fe(3+), Fe(2+), Cu(2+) and Al(3+) and showed no significant inhibition by other tested metal ions.The optimal temperatures for the C23Os were 40 °C and 60 °C and their best substrates were catechol and 4-methylcatechol respectively.As the firstly isolated and characterized catechol dioxygenases from halophiles, the two halotolerant C23Os presented novel characteristics suggesting their potential application in aromatic hydrocarbons biodegradation.

View Article: PubMed Central - PubMed

Affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China.

ABSTRACT
Study of enzymes in halophiles will help to understand the mechanism of aromatic hydrocarbons degradation in saline environment. In this study, two novel catechol 2,3-dioxygenases (C23O1 and C23O2) were cloned and overexpressed from a halophilic bacterial consortium enriched from an oil-contaminated saline soil. Phylogenetic analysis indicated that the novel C23Os and their relatives formed a new branch in subfamily I.2.A of extradiol dioxygenases and the sequence differences were further analyzed by amino acid sequence alignment. Two enzymes with the halotolerant feature were active over a range of 0-30% salinity and they performed more stable at high salinity than in the absence of salt. Surface electrostatic potential and amino acids composition calculation suggested high acidic residues content, accounting for their tolerance to high salinity. Moreover, two enzymes were further characterized. The enzymes activity both increased in the presence of Fe(3+), Fe(2+), Cu(2+) and Al(3+) and showed no significant inhibition by other tested metal ions. The optimal temperatures for the C23Os were 40 °C and 60 °C and their best substrates were catechol and 4-methylcatechol respectively. As the firstly isolated and characterized catechol dioxygenases from halophiles, the two halotolerant C23Os presented novel characteristics suggesting their potential application in aromatic hydrocarbons biodegradation.

No MeSH data available.


Related in: MedlinePlus