Identification of biofilm matrix-associated proteins from an acid mine drainage microbial community.
Appl Environ Microbiol
; 77(15): 5230-7, 2011 Aug.
Article
em En
| MEDLINE
| ID: mdl-21685158
ABSTRACT
In microbial communities, extracellular polymeric substances (EPS), also called the extracellular matrix, provide the spatial organization and structural stability during biofilm development. One of the major components of EPS is protein, but it is not clear what specific functions these proteins contribute to the extracellular matrix or to microbial physiology. To investigate this in biofilms from an extremely acidic environment, we used shotgun proteomics analyses to identify proteins associated with EPS in biofilms at two developmental stages, designated DS1 and DS2. The proteome composition of the EPS was significantly different from that of the cell fraction, with more than 80% of the cellular proteins underrepresented or undetectable in EPS. In contrast, predicted periplasmic, outer membrane, and extracellular proteins were overrepresented by 3- to 7-fold in EPS. Also, EPS proteins were more basic by â¼2 pH units on average and about half the length. When categorized by predicted function, proteins involved in motility, defense, cell envelope, and unknown functions were enriched in EPS. Chaperones, such as histone-like DNA binding protein and cold shock protein, were overrepresented in EPS. Enzymes, such as protein peptidases, disulfide-isomerases, and those associated with cell wall and polysaccharide metabolism, were also detected. Two of these enzymes, identified as ß-N-acetylhexosaminidase and cellulase, were confirmed in the EPS fraction by enzymatic activity assays. Compared to the differences between EPS and cellular fractions, the relative differences in the EPS proteomes between DS1 and DS2 were smaller and consistent with expected physiological changes during biofilm development.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Proteínas da Matriz Extracelular
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Biofilmes
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Proteômica
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Consórcios Microbianos
Tipo de estudo:
Diagnostic_studies
/
Risk_factors_studies
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article