Characterization of mucoid <i>Pseudomonas aeruginosa</i> strains isolated from technical water systems

Grobe, Susanne; Wingender, Jost; Trüiper, H.G.

doi:10.1111/j.1365-2672.1995.tb03129.x

Cited by 65 publications

(40 citation statements)

References 41 publications

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“…Biochemical analysis of EPS from agar-grown biofilms confirmed that the mucoid environmental strain P. aeruginosa SG81 produced high amounts of uronic acids, which have previously been identified as alginate (Grobe et al, 1995, Wingender et al, 2001. In addition, the EPS contained significant amounts of proteins.…”

Section: Discussionmentioning

confidence: 67%

“…The mucoid environmental strain P. aeruginosa SG81, originally isolated from the biofilm of a technical water system (Grobe et al, 1995), was used to investigate the influence of extracellular enzymes on biofilm composition, structure and properties. The enzymes considered in the present study were the lipolytic enzymes LipA (PA2862), LipC (PA4813) and EstA (PA5112), and the proteolytic enzyme LasB (PA3724).…”

Section: Enzyme Overexpression In Mucoid P Aeruginosamentioning

confidence: 99%

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Extracellular enzymes affect biofilm formation of mucoid Pseudomonas aeruginosa

et al. 2010

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Pseudomonas aeruginosa secretes a variety of hydrolases, many of which contribute to virulence or are thought to play a role in the nutrition of the bacterium. As most studies concerning extracellular enzymes have been performed on planktonic cultures of non-mucoid P. aeruginosa strains, knowledge of the potential role of these enzymes in biofilm formation in mucoid (alginateproducing) P. aeruginosa remains limited. Here we show that mucoid P. aeruginosa produces extracellular hydrolases during biofilm growth. Overexpression of the extracellular lipases LipA and LipC, the esterase EstA and the proteolytic elastase LasB from plasmids revealed that some of these hydrolases affected the composition and physicochemical properties of the extracellular polymeric substances (EPS). While no influence of LipA was observed, the overexpression of estA and lasB led to increased concentrations of extracellular rhamnolipids with enhanced levels of mono-rhamnolipids, elevated amounts of total carbohydrates and decreased alginate concentrations, resulting in increased EPS hydrophobicity and viscosity. Moreover, we observed an influence of the enzymes on cellular motility. Overexpression of estA resulted in a loss of twitching motility, although it enhanced the ability to swim and swarm. The lasB-overexpression strain showed an overall enhanced motility compared with the parent strain. Moreover, the EstAand LasB-overproduction strains completely lost the ability to form 3D biofilms, whereas the overproduction of LipC increased cell aggregation and the heterogeneity of the biofilms formed. Overall, these findings indicate that directly or indirectly, the secreted enzymes EstA, LasB and LipC can influence the formation and architecture of mucoid P. aeruginosa biofilms as a result of changes in EPS composition and properties, as well as the motility of the cells. INTRODUCTIONPseudomonas aeruginosa is a common environmental bacterium and represents an increasingly prevalent opportunistic human pathogen whose ecological success is based on a remarkable degree of genomic flexibility and phenotypic adaptation (Wehmhöner et al., 2003). P. aeruginosa successfully colonizes a wide range of habitats, including natural soil and aquatic environments as well as artificial water systems (Botzenhart & Döring, 1993). It is involved in acute and chronic diseases, for example in infections of surgery and burn patients, in urogenital tract and wound infections, chronic lung infections of cystic fibrosis patients, and nosocomial pneumonia in intubated and mechanically ventilated patients (Drenkard, 2003;Singh et al., 2000).The biofilm mode of life significantly contributes to the growth and persistence of P. aeruginosa under varying environmental conditions in nature, as well as in technical systems and the clinical setting. P. aeruginosa is now regarded as one of the medically most relevant biofilmforming bacterial species. Therefore, it has become one of the best-studied model organisms for biofilm formation (McDougald et al., 2008). Biofilm forma...

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Section: Discussionmentioning

confidence: 67%

Section: Enzyme Overexpression In Mucoid P Aeruginosamentioning

confidence: 99%

Extracellular enzymes affect biofilm formation of mucoid Pseudomonas aeruginosa

et al. 2010

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“…Recently, production of a minor amount of EPS by P. aeruginosa SG81R1, growing in a biofilm, has been described by Strathmann et al (2002). Alternatively, Vandevivere & Kirchman (1993) as well as Allison & Sutherland (1987) suggested that attachment stimulates bacterial EPS synthesis, and putatively non-EPSproducing P. aeruginosa strains related to cystic fibrosis could through mutation or selection turn into EPSproducing ones during adaptation to different ecological sites, such as stress and growth conditions (Boucher et al, 2000 ;Grobe et al, 1995).…”

Section: Discussionmentioning

confidence: 99%

“…Grobe et al (1995) have analysed the chemical composition of EPS excreted by P. aeruginosa SG81 grown on Pseudomonas Isolation Agar and found that the crude extracellular material of this strain contained polysaccharides (16n4 %), uronic acids (79n3 %) and small amounts of proteins (4n3 %). The chemical composition obtained by XPS of the footprints left behind by P. aeruginosa after air-bubble-induced detachment showed a greater content of uronic acid in the footprints of the EPS-producing strain than of the putatively non-EPS-producing strain.…”

Section: Discussionmentioning

confidence: 99%

“…The C "s carbon peak was decomposed in four components and attributed to : carbon bound only to carbon and hydrogen, C-(C,H), at a binding energy of 284n8 eV ; carbon singly bound to oxygen or nitrogen, C-(O,N), including ether, alcohol, amine and amide bonds, at a binding energy of 286n2 eV; carbon with either two single bonds to oxygen or one double bond, ClO, including amide, carbonyl, carboxylate, ester, acetal and hemiacetal bonds, at a binding energy of 287n8 eV ; and finally, carbon involved in carboxyl groups, OlC-OH, at 289n1 eV. The EPS of agar-grown P. aeruginosa SG81 has been described (Grobe et al, 1995) to contain uronic acids (UA), proteins (PR) and polysaccharides (PS). Based on these compositional data, the XPS results in Table 3 enable determination of the composition of the EPS left on the gold after detachment, as described by Rouxhet et al (1994).…”

Section: Substratum Surfacementioning

confidence: 99%

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Influence of extracellular polymeric substances on deposition and redeposition of Pseudomonas aeruginosa to surfaces

et al. 2002

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In this study, the role of extracellular polymeric substances (EPS) in the initial adhesion of EPS-producing Pseudomonas aeruginosa SG81 and SG81R1, a non-EPS-producing strain, to substrata with different hydrophobicity was investigated. The release of EPS by SG81 was concurrent with a decrease in surface tension of a bacterial suspension from 70 to 45 mJ m N2 that was absent for SG81R1. Both strains adhered faster and in higher numbers to a hydrophilic than to a hydrophobic substratum, but the initial deposition rates and numbers of adhering bacteria in a stationary-end point were highest for the non-EPS-producing strain SG81R1, regardless of substratum hydrophobicity. Both strains adhered less to substrata pre-coated with isolated EPS of strain SG81. Furthermore, it was investigated whether bacteria, detached by passing air-bubbles, had left behind ' footprints ' with an influence on adhesion of newly redepositing bacteria. Redeposition on glass was highest for non-EPSproducing SG81R1 and decreased linearly with the number of times these cycles of detachment and deposition were repeated to become similar to the redeposition of SG81 after six cycles. This indicates that P. aeruginosa SG81 leaves the substratum surface nearly completely covered with EPS after detachment, while SG81R1 releases only minor amounts of surface active EPS, completely covering the substratum after repeated cycles of detachment and adhesion. Atomic force microscopy showed a thick and irregular EPS layer (up to 32 nm) after the first detachment cycle of EPS-producing strain SG81, whereas the putatively non-EPS-producing strain SG81R1 left a 9 nm thin layer after one cycle. X-ray photoelectron spectroscopy indicated that the bacterial footprints consisted of uronic acids, the prevalence of which increased with the number of detachment and deposition cycles.

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