Role of a serine-type D-alanyl-D-alanine carboxypeptidase on the survival of Ochrobactrum sp. 11a under ionic and hyperosmotic stress.
FEMS Microbiol Lett
; 295(2): 261-73, 2009 Jun.
Article
em En
| MEDLINE
| ID: mdl-19646181
ABSTRACT
The plant growth-promoting rhizobacterium, Ochrobactrum sp. 11a displays a high intrinsic salinity tolerance and has been used in this work to study the molecular basis of bacterial responses to high concentrations of NaCl. A collection of Ochrobactrum sp. 11a mutants was generated by Tn5-B21 mutagenesis and screened for sensitivity to salinity. One clone, designated PBP and unable to grow on glutamate mannitol salt agar medium supplemented with 300 mM NaCl was selected and further characterized. The PBP mutant carries a single transposon insertion in a gene showing a high degree of identity to the serine-type d-alanyl-d-alanine carboxypeptidase gene of Ochrobactrum anthropi. Interestingly, the expression of this gene was shown to be upregulated by salt in the PBP mutant. Moreover, evidence is presented for the requirement of the gene product for adaptation to high-salt conditions as well as to overcome the toxicity of LiCl, KCl, sucrose, polyethylene glycol (PEG), AlCl(3), CuSO(4), and ZnSO(4). In addition to the altered tolerance to both ionic and osmotic stresses, the PBP mutant exhibited changes in colony and cell morphology, exopolysaccharide production, and an increased sensitivity to detergents.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pressão Osmótica
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Resposta ao Choque Térmico
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Ochrobactrum
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D-Ala-D-Ala Carboxipeptidase Tipo Serina
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Tolerância ao Sal
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Íons
Idioma:
En
Revista:
FEMS Microbiol Lett
Ano de publicação:
2009
Tipo de documento:
Article