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Pseudomonas aeruginosa PAO1 exopolysaccharides are important for mixed species biofilm community development and stress tolerance.

Periasamy S, Nair HA, Lee KW, Ong J, Goh JQ, Kjelleberg S, Rice SA - Front Microbiol (2015)

Bottom Line: In contrast, overproduction of alginate resulted in biofilms that were comprised of 35-40% of P. aeruginosa, which was significantly higher than the WT (5-20%).Loss of the Psl polysaccharide significantly reduced the percentage composition of P. aeruginosa in dual species biofilms with P. protegens (<1%).Thus, the polysaccharide composition of an individual species significantly impacts mixed species biofilm development and the emergent properties of such communities.

View Article: PubMed Central - PubMed

Affiliation: Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore Singapore.

ABSTRACT
Pseudomonas aeruginosa PAO1 produces three polysaccharides, alginate, Psl, and Pel that play distinct roles in attachment and biofilm formation for monospecies biofilms. Considerably less is known about their role in the development of mixed species biofilm communities. This study has investigated the roles of alginate, Psl, and Pel during biofilm formation of P. aeruginosa in a defined and experimentally informative mixed species biofilm community, consisting of P. aeruginosa, Pseudomonas protegens, and Klebsiella pneumoniae. Loss of the Psl polysaccharide had the biggest impact on the integration of P. aeruginosa in the mixed species biofilms, where the percent composition of the psl mutant was significantly lower (0.06%) than its wild-type (WT) parent (2.44%). In contrast, loss of the Pel polysaccharide had no impact on mixed species biofilm development. Loss of alginate or its overproduction resulted in P. aeruginosa representing 8.4 and 18.11%, respectively, of the mixed species biofilm. Dual species biofilms of P. aeruginosa and K. pneumoniae were not affected by loss of alginate, Pel, or Psl, while the mucoid P. aeruginosa strain achieved a greater biomass than its parent strain. When P. aeruginosa was grown with P. protegens, loss of the Pel or alginate polysaccharides resulted in biofilms that were not significantly different from biofilms formed by the WT PAO1. In contrast, overproduction of alginate resulted in biofilms that were comprised of 35-40% of P. aeruginosa, which was significantly higher than the WT (5-20%). Loss of the Psl polysaccharide significantly reduced the percentage composition of P. aeruginosa in dual species biofilms with P. protegens (<1%). Loss of the Psl polysaccharide significantly disrupted the communal stress resistance of the three species biofilms. Thus, the polysaccharide composition of an individual species significantly impacts mixed species biofilm development and the emergent properties of such communities.

No MeSH data available.


Related in: MedlinePlus

Spatial and temporal development of Pseudomonas aeruginosa polysaccharide mutants grown with P. protegens and Klebsiella pneumoniae as three species biofilms. The proportion of the three species within the mixed species over the 7 days period was determined by quantitative image analysis. (A)P. aeruginosa wild-type (WT), (B) Δalg, (C) ΔmucA, (D) Δpel, (E) Δpsl, and (F) biovolumes of P. aeruginosa WT and polysaccharide mutants. Statistical analysis was performed vs. the corresponding WT samples grown in parallel **P < 0.01, ****P < 0.0001.
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Figure 1: Spatial and temporal development of Pseudomonas aeruginosa polysaccharide mutants grown with P. protegens and Klebsiella pneumoniae as three species biofilms. The proportion of the three species within the mixed species over the 7 days period was determined by quantitative image analysis. (A)P. aeruginosa wild-type (WT), (B) Δalg, (C) ΔmucA, (D) Δpel, (E) Δpsl, and (F) biovolumes of P. aeruginosa WT and polysaccharide mutants. Statistical analysis was performed vs. the corresponding WT samples grown in parallel **P < 0.01, ****P < 0.0001.

Mentions: To determine the roles of alginate, Psl, and Pel produced by P. aeruginosa in mixed species biofilm community development, polysaccharide mutants of P. aeruginosa, alg, mucA, pel, and psl were cultivated with P. protegens and K. pneumoniae as triple species biofilms. Initial attachment of the alginate overproducing strain, mucA, was similar to the wild-type (WT) P. aeruginosa (Figure 1; Supplementary Figure S1). However, in contrast to the WT P. aeruginosa, the biovolume of the mucA mutant remained constant at 20% throughout the duration of the experiment, which was significantly higher than the WT (2%). Mutants in the alg and pel polysaccharide genes showed an increase in the amount of P. aeruginosa present in the three species biofilm community during the initiation of biofilm formation (Figures 1B,D,F). When the alg mutant was included in the biofilm, the architecture of P. protegens changed from one dominated by microcolonies to a more filamentous biofilm and the alg mutant completely covered the top of the biofilm at day 7 (Supplementary Figure S1). In contrast, the psl mutant was below the detection level in the triple species biofilms (Figures 1E,F) with P. protegens and K. pneumoniae accounting for 52.24 and 47.69% of the biofilm biomass, respectively (Figure 1E).


Pseudomonas aeruginosa PAO1 exopolysaccharides are important for mixed species biofilm community development and stress tolerance.

Periasamy S, Nair HA, Lee KW, Ong J, Goh JQ, Kjelleberg S, Rice SA - Front Microbiol (2015)

Spatial and temporal development of Pseudomonas aeruginosa polysaccharide mutants grown with P. protegens and Klebsiella pneumoniae as three species biofilms. The proportion of the three species within the mixed species over the 7 days period was determined by quantitative image analysis. (A)P. aeruginosa wild-type (WT), (B) Δalg, (C) ΔmucA, (D) Δpel, (E) Δpsl, and (F) biovolumes of P. aeruginosa WT and polysaccharide mutants. Statistical analysis was performed vs. the corresponding WT samples grown in parallel **P < 0.01, ****P < 0.0001.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4542536&req=5

Figure 1: Spatial and temporal development of Pseudomonas aeruginosa polysaccharide mutants grown with P. protegens and Klebsiella pneumoniae as three species biofilms. The proportion of the three species within the mixed species over the 7 days period was determined by quantitative image analysis. (A)P. aeruginosa wild-type (WT), (B) Δalg, (C) ΔmucA, (D) Δpel, (E) Δpsl, and (F) biovolumes of P. aeruginosa WT and polysaccharide mutants. Statistical analysis was performed vs. the corresponding WT samples grown in parallel **P < 0.01, ****P < 0.0001.
Mentions: To determine the roles of alginate, Psl, and Pel produced by P. aeruginosa in mixed species biofilm community development, polysaccharide mutants of P. aeruginosa, alg, mucA, pel, and psl were cultivated with P. protegens and K. pneumoniae as triple species biofilms. Initial attachment of the alginate overproducing strain, mucA, was similar to the wild-type (WT) P. aeruginosa (Figure 1; Supplementary Figure S1). However, in contrast to the WT P. aeruginosa, the biovolume of the mucA mutant remained constant at 20% throughout the duration of the experiment, which was significantly higher than the WT (2%). Mutants in the alg and pel polysaccharide genes showed an increase in the amount of P. aeruginosa present in the three species biofilm community during the initiation of biofilm formation (Figures 1B,D,F). When the alg mutant was included in the biofilm, the architecture of P. protegens changed from one dominated by microcolonies to a more filamentous biofilm and the alg mutant completely covered the top of the biofilm at day 7 (Supplementary Figure S1). In contrast, the psl mutant was below the detection level in the triple species biofilms (Figures 1E,F) with P. protegens and K. pneumoniae accounting for 52.24 and 47.69% of the biofilm biomass, respectively (Figure 1E).

Bottom Line: In contrast, overproduction of alginate resulted in biofilms that were comprised of 35-40% of P. aeruginosa, which was significantly higher than the WT (5-20%).Loss of the Psl polysaccharide significantly reduced the percentage composition of P. aeruginosa in dual species biofilms with P. protegens (<1%).Thus, the polysaccharide composition of an individual species significantly impacts mixed species biofilm development and the emergent properties of such communities.

View Article: PubMed Central - PubMed

Affiliation: Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore Singapore.

ABSTRACT
Pseudomonas aeruginosa PAO1 produces three polysaccharides, alginate, Psl, and Pel that play distinct roles in attachment and biofilm formation for monospecies biofilms. Considerably less is known about their role in the development of mixed species biofilm communities. This study has investigated the roles of alginate, Psl, and Pel during biofilm formation of P. aeruginosa in a defined and experimentally informative mixed species biofilm community, consisting of P. aeruginosa, Pseudomonas protegens, and Klebsiella pneumoniae. Loss of the Psl polysaccharide had the biggest impact on the integration of P. aeruginosa in the mixed species biofilms, where the percent composition of the psl mutant was significantly lower (0.06%) than its wild-type (WT) parent (2.44%). In contrast, loss of the Pel polysaccharide had no impact on mixed species biofilm development. Loss of alginate or its overproduction resulted in P. aeruginosa representing 8.4 and 18.11%, respectively, of the mixed species biofilm. Dual species biofilms of P. aeruginosa and K. pneumoniae were not affected by loss of alginate, Pel, or Psl, while the mucoid P. aeruginosa strain achieved a greater biomass than its parent strain. When P. aeruginosa was grown with P. protegens, loss of the Pel or alginate polysaccharides resulted in biofilms that were not significantly different from biofilms formed by the WT PAO1. In contrast, overproduction of alginate resulted in biofilms that were comprised of 35-40% of P. aeruginosa, which was significantly higher than the WT (5-20%). Loss of the Psl polysaccharide significantly reduced the percentage composition of P. aeruginosa in dual species biofilms with P. protegens (<1%). Loss of the Psl polysaccharide significantly disrupted the communal stress resistance of the three species biofilms. Thus, the polysaccharide composition of an individual species significantly impacts mixed species biofilm development and the emergent properties of such communities.

No MeSH data available.


Related in: MedlinePlus