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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

Phylogenetic neighbor-joining tree based on the C23O amino acid sequences.The clones isolated in this study are indicated with boldface type. The sequences with the underline are previously reported C23Os from non-halophiles (classic C23Os) which were classified by Eltis and Bolin24. The C23O amino acid sequences of Sphingobium yanoikuyae (AAB03690) and Novosphingobium aromaticivorans (AAD03998), two members of subfamily I.2.B were used as an outgroup. Bootstrap values (>60) expressed as percentages of 1000 replications are indicated at the branch points. Bar, 0.05 substitutions amino acid per site.
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f3: Phylogenetic neighbor-joining tree based on the C23O amino acid sequences.The clones isolated in this study are indicated with boldface type. The sequences with the underline are previously reported C23Os from non-halophiles (classic C23Os) which were classified by Eltis and Bolin24. The C23O amino acid sequences of Sphingobium yanoikuyae (AAB03690) and Novosphingobium aromaticivorans (AAD03998), two members of subfamily I.2.B were used as an outgroup. Bootstrap values (>60) expressed as percentages of 1000 replications are indicated at the branch points. Bar, 0.05 substitutions amino acid per site.

Mentions: BLASTp analyses revealed that the two C23Os showed highest similarity (95% and 93%) with the proteins from Marinobacter algicola DG893. The sequence similarities with other C23Os were summarized in Table S1. Two phylogenetic trees were constructed with deduced amino acid sequences of C23O enzymes selected from subfamily I.2.A (Fig. 3 and Fig. S2). Phylogenetic neighbor-joining tree analysis (Fig. 3) presented that C23O1, C23O2 and their seven relatives formed a unique branch (group II) in the tree, and they cannot be confidently assigned to the branch with the previously reported C23Os from non-halophiles (classic C23Os) classified by Eltis and Bolin24 (group I). The maximum-parsimony tree presented the same results (Fig. S2). The two phylogenetic trees showed the new formed branch with high bootstrap support: 99% with the neighbour-joining method (Fig. 3) and 93% with the maximum-parsimony method (Fig. S2), respectively. In group II, C23O1 and C23O2 showed highest homology with putative protein EDM48673 and EDM49408, two proteins only described from whole-genome sequences of the halophilic bacteria Marinobacter algicola DG89328. Another four relatives are also the proteins predicted from whole-genome sequences from Marinobacter adhaerens HP15, Haliea salexigens and Spongiibacter tropicus.


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)

Phylogenetic neighbor-joining tree based on the C23O amino acid sequences.The clones isolated in this study are indicated with boldface type. The sequences with the underline are previously reported C23Os from non-halophiles (classic C23Os) which were classified by Eltis and Bolin24. The C23O amino acid sequences of Sphingobium yanoikuyae (AAB03690) and Novosphingobium aromaticivorans (AAD03998), two members of subfamily I.2.B were used as an outgroup. Bootstrap values (>60) expressed as percentages of 1000 replications are indicated at the branch points. Bar, 0.05 substitutions amino acid per site.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f3: Phylogenetic neighbor-joining tree based on the C23O amino acid sequences.The clones isolated in this study are indicated with boldface type. The sequences with the underline are previously reported C23Os from non-halophiles (classic C23Os) which were classified by Eltis and Bolin24. The C23O amino acid sequences of Sphingobium yanoikuyae (AAB03690) and Novosphingobium aromaticivorans (AAD03998), two members of subfamily I.2.B were used as an outgroup. Bootstrap values (>60) expressed as percentages of 1000 replications are indicated at the branch points. Bar, 0.05 substitutions amino acid per site.
Mentions: BLASTp analyses revealed that the two C23Os showed highest similarity (95% and 93%) with the proteins from Marinobacter algicola DG893. The sequence similarities with other C23Os were summarized in Table S1. Two phylogenetic trees were constructed with deduced amino acid sequences of C23O enzymes selected from subfamily I.2.A (Fig. 3 and Fig. S2). Phylogenetic neighbor-joining tree analysis (Fig. 3) presented that C23O1, C23O2 and their seven relatives formed a unique branch (group II) in the tree, and they cannot be confidently assigned to the branch with the previously reported C23Os from non-halophiles (classic C23Os) classified by Eltis and Bolin24 (group I). The maximum-parsimony tree presented the same results (Fig. S2). The two phylogenetic trees showed the new formed branch with high bootstrap support: 99% with the neighbour-joining method (Fig. 3) and 93% with the maximum-parsimony method (Fig. S2), respectively. In group II, C23O1 and C23O2 showed highest homology with putative protein EDM48673 and EDM49408, two proteins only described from whole-genome sequences of the halophilic bacteria Marinobacter algicola DG89328. Another four relatives are also the proteins predicted from whole-genome sequences from Marinobacter adhaerens HP15, Haliea salexigens and Spongiibacter tropicus.

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