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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

The role of alginate and Psl in stress resistance of mixed species biofilms. Three species biofilms were formed for 4 days and exposed to 0.1% SDS for 2 h. The biofilm biovolumes of P. aeruginosa mucA(left), psl(right), Pf-5, and KP-1 were determined by quantitative image analysis before and after SDS treatment. Statistical analysis was performed vs. the corresponding WT samples grown in parallel, which were very similar in all cases ****P < 0.0001.
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Figure 4: The role of alginate and Psl in stress resistance of mixed species biofilms. Three species biofilms were formed for 4 days and exposed to 0.1% SDS for 2 h. The biofilm biovolumes of P. aeruginosa mucA(left), psl(right), Pf-5, and KP-1 were determined by quantitative image analysis before and after SDS treatment. Statistical analysis was performed vs. the corresponding WT samples grown in parallel, which were very similar in all cases ****P < 0.0001.

Mentions: It was previously shown that this mixed species biofilm community displays enhanced resistance to SDS and antibiotic stress relative to biofilms formed by the individual species alone (Lee et al., 2014). Further, the stress resistance was a communal property, where all three species were equally protected, despite monospecies biofilms of P. protegens being highly sensitive to SDS exposure. To determine the role of the polysaccharide component of the EPS in stress resistance of mixed species biofilms, mutants that either overproduce alginate, mucA, or that were defective for the production of Psl were tested for their contribution to the SDS resistance of the three species biofilms. These two strains were used since the mucA strain showed an increased proportion in the mixed species biofilm, while the psl mutant was less competitive during mixed species growth. Mixed species biofilms formed with the mucA mutant showed similar protection as the WT P. aeruginosa and protection was shared across all three species (Figure 4). In contrast, mixed species biofilms that included the psl mutant showed a significant reduction in biofilm biomass after SDS stress. The biomass of P. protegens was reduced by fivefold, indicating that it was no longer protected during mixed species biofilm growth. The biomass of K. pneumoniae showed similar amounts of biofilm before and after surfactant exposure and hence was unaffected by the change in biofilm composition.


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)

The role of alginate and Psl in stress resistance of mixed species biofilms. Three species biofilms were formed for 4 days and exposed to 0.1% SDS for 2 h. The biofilm biovolumes of P. aeruginosa mucA(left), psl(right), Pf-5, and KP-1 were determined by quantitative image analysis before and after SDS treatment. Statistical analysis was performed vs. the corresponding WT samples grown in parallel, which were very similar in all cases ****P < 0.0001.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 4: The role of alginate and Psl in stress resistance of mixed species biofilms. Three species biofilms were formed for 4 days and exposed to 0.1% SDS for 2 h. The biofilm biovolumes of P. aeruginosa mucA(left), psl(right), Pf-5, and KP-1 were determined by quantitative image analysis before and after SDS treatment. Statistical analysis was performed vs. the corresponding WT samples grown in parallel, which were very similar in all cases ****P < 0.0001.
Mentions: It was previously shown that this mixed species biofilm community displays enhanced resistance to SDS and antibiotic stress relative to biofilms formed by the individual species alone (Lee et al., 2014). Further, the stress resistance was a communal property, where all three species were equally protected, despite monospecies biofilms of P. protegens being highly sensitive to SDS exposure. To determine the role of the polysaccharide component of the EPS in stress resistance of mixed species biofilms, mutants that either overproduce alginate, mucA, or that were defective for the production of Psl were tested for their contribution to the SDS resistance of the three species biofilms. These two strains were used since the mucA strain showed an increased proportion in the mixed species biofilm, while the psl mutant was less competitive during mixed species growth. Mixed species biofilms formed with the mucA mutant showed similar protection as the WT P. aeruginosa and protection was shared across all three species (Figure 4). In contrast, mixed species biofilms that included the psl mutant showed a significant reduction in biofilm biomass after SDS stress. The biomass of P. protegens was reduced by fivefold, indicating that it was no longer protected during mixed species biofilm growth. The biomass of K. pneumoniae showed similar amounts of biofilm before and after surfactant exposure and hence was unaffected by the change in biofilm composition.

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