The Riddle of Rhamnolipid Molecular Biosynthesis

Research output: Contribution to conferencePoster

Abstract

Rhamnolipids (RL) were first shown to be produced by the opportunistic pathogen Pseudomonas aeruginosa. RL production is achieved via a biosynthesis pathway comprising three separate enzymes; RhlA, responsible for the synthesis of the fatty acid dimer precursor moieties (HAA); RhlB, a rhamnosyltransferase enzyme which conjugates HAA to dTDP-L-rhamnose to form mono-RL and RhlC, a second rhamnosyltransferase enzyme that adds a second rhamnose to form di-RL. Within P. aeruginosa the genes encoding the first two enzymes, rhlA and rhlB, are present in a single operon alongside genes encoding an AHL-mediated quorum sensing system rhlR and rhlI. The gene encoding the last enzyme, rhlC, is located approx. 1 Mb downstream of this operon. Since the discovery of RL synthesis by P. aeruginosa other bacterial species have also been shown to synthesise RLs, notably Burkholderia thailandensis and Burkholderia pseudomallei. Interestingly the RL biosynthesis genes within Burkholderia only show 40% similarity to those of P. aeruginosa, are located together in a single operon and are duplicated within the genome to give two functional copies of each gene. Recently we have shown RL synthesis in two marine bacteria; Pseudomonas sp. MCTG214(3b1) and Marinobacter sp. MCTG107b. In the Pseudomonas sp. we identified rhlA and rhlB homologues with 99% similarity to those of P. aeruginosa, however we have yet to identify any rhlC homologue. This presents a paradox as we have demonstrated di-RL synthesis by this strain. RL synthesis within the Marinobacter sp. presents an even greater paradox as we have yet to identify any RL synthase homologs. Here we explain the molecular differences in RL synthase homologues, the effects that these differences may create and try to explain the apparent lack of synthesis genes in the two marine strains. We also discus the methods used to investigate the molecular mechanisms of RL synthesis.

Conference

ConferenceBiosurfactants 2019
CountryGermany
CityStuttgart
Period25/09/1927/09/19
Internet address

Fingerprint

biosynthesis
Pseudomonas aeruginosa
synthesis
operon
Marinobacter
enzymes
genes
rhamnose
Pseudomonas
Burkholderia thailandensis
rhamnolipids
Burkholderia pseudomallei
Burkholderia
quorum sensing
fatty acids
genome
pathogens
bacteria

Cite this

Twigg, M., Marchant, R., & Banat, I. (2019). The Riddle of Rhamnolipid Molecular Biosynthesis. Poster session presented at Biosurfactants 2019, Stuttgart, Germany.
Twigg, Matthew ; Marchant, Roger ; Banat, Ibrahim. / The Riddle of Rhamnolipid Molecular Biosynthesis. Poster session presented at Biosurfactants 2019, Stuttgart, Germany.
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abstract = "Rhamnolipids (RL) were first shown to be produced by the opportunistic pathogen Pseudomonas aeruginosa. RL production is achieved via a biosynthesis pathway comprising three separate enzymes; RhlA, responsible for the synthesis of the fatty acid dimer precursor moieties (HAA); RhlB, a rhamnosyltransferase enzyme which conjugates HAA to dTDP-L-rhamnose to form mono-RL and RhlC, a second rhamnosyltransferase enzyme that adds a second rhamnose to form di-RL. Within P. aeruginosa the genes encoding the first two enzymes, rhlA and rhlB, are present in a single operon alongside genes encoding an AHL-mediated quorum sensing system rhlR and rhlI. The gene encoding the last enzyme, rhlC, is located approx. 1 Mb downstream of this operon. Since the discovery of RL synthesis by P. aeruginosa other bacterial species have also been shown to synthesise RLs, notably Burkholderia thailandensis and Burkholderia pseudomallei. Interestingly the RL biosynthesis genes within Burkholderia only show 40{\%} similarity to those of P. aeruginosa, are located together in a single operon and are duplicated within the genome to give two functional copies of each gene. Recently we have shown RL synthesis in two marine bacteria; Pseudomonas sp. MCTG214(3b1) and Marinobacter sp. MCTG107b. In the Pseudomonas sp. we identified rhlA and rhlB homologues with 99{\%} similarity to those of P. aeruginosa, however we have yet to identify any rhlC homologue. This presents a paradox as we have demonstrated di-RL synthesis by this strain. RL synthesis within the Marinobacter sp. presents an even greater paradox as we have yet to identify any RL synthase homologs. Here we explain the molecular differences in RL synthase homologues, the effects that these differences may create and try to explain the apparent lack of synthesis genes in the two marine strains. We also discus the methods used to investigate the molecular mechanisms of RL synthesis.",
author = "Matthew Twigg and Roger Marchant and Ibrahim Banat",
year = "2019",
month = "9",
day = "25",
language = "English",
note = "Biosurfactants 2019 ; Conference date: 25-09-2019 Through 27-09-2019",
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Twigg, M, Marchant, R & Banat, I 2019, 'The Riddle of Rhamnolipid Molecular Biosynthesis' Biosurfactants 2019, Stuttgart, Germany, 25/09/19 - 27/09/19, .

The Riddle of Rhamnolipid Molecular Biosynthesis. / Twigg, Matthew; Marchant, Roger; Banat, Ibrahim.

2019. Poster session presented at Biosurfactants 2019, Stuttgart, Germany.

Research output: Contribution to conferencePoster

TY - CONF

T1 - The Riddle of Rhamnolipid Molecular Biosynthesis

AU - Twigg, Matthew

AU - Marchant, Roger

AU - Banat, Ibrahim

PY - 2019/9/25

Y1 - 2019/9/25

N2 - Rhamnolipids (RL) were first shown to be produced by the opportunistic pathogen Pseudomonas aeruginosa. RL production is achieved via a biosynthesis pathway comprising three separate enzymes; RhlA, responsible for the synthesis of the fatty acid dimer precursor moieties (HAA); RhlB, a rhamnosyltransferase enzyme which conjugates HAA to dTDP-L-rhamnose to form mono-RL and RhlC, a second rhamnosyltransferase enzyme that adds a second rhamnose to form di-RL. Within P. aeruginosa the genes encoding the first two enzymes, rhlA and rhlB, are present in a single operon alongside genes encoding an AHL-mediated quorum sensing system rhlR and rhlI. The gene encoding the last enzyme, rhlC, is located approx. 1 Mb downstream of this operon. Since the discovery of RL synthesis by P. aeruginosa other bacterial species have also been shown to synthesise RLs, notably Burkholderia thailandensis and Burkholderia pseudomallei. Interestingly the RL biosynthesis genes within Burkholderia only show 40% similarity to those of P. aeruginosa, are located together in a single operon and are duplicated within the genome to give two functional copies of each gene. Recently we have shown RL synthesis in two marine bacteria; Pseudomonas sp. MCTG214(3b1) and Marinobacter sp. MCTG107b. In the Pseudomonas sp. we identified rhlA and rhlB homologues with 99% similarity to those of P. aeruginosa, however we have yet to identify any rhlC homologue. This presents a paradox as we have demonstrated di-RL synthesis by this strain. RL synthesis within the Marinobacter sp. presents an even greater paradox as we have yet to identify any RL synthase homologs. Here we explain the molecular differences in RL synthase homologues, the effects that these differences may create and try to explain the apparent lack of synthesis genes in the two marine strains. We also discus the methods used to investigate the molecular mechanisms of RL synthesis.

AB - Rhamnolipids (RL) were first shown to be produced by the opportunistic pathogen Pseudomonas aeruginosa. RL production is achieved via a biosynthesis pathway comprising three separate enzymes; RhlA, responsible for the synthesis of the fatty acid dimer precursor moieties (HAA); RhlB, a rhamnosyltransferase enzyme which conjugates HAA to dTDP-L-rhamnose to form mono-RL and RhlC, a second rhamnosyltransferase enzyme that adds a second rhamnose to form di-RL. Within P. aeruginosa the genes encoding the first two enzymes, rhlA and rhlB, are present in a single operon alongside genes encoding an AHL-mediated quorum sensing system rhlR and rhlI. The gene encoding the last enzyme, rhlC, is located approx. 1 Mb downstream of this operon. Since the discovery of RL synthesis by P. aeruginosa other bacterial species have also been shown to synthesise RLs, notably Burkholderia thailandensis and Burkholderia pseudomallei. Interestingly the RL biosynthesis genes within Burkholderia only show 40% similarity to those of P. aeruginosa, are located together in a single operon and are duplicated within the genome to give two functional copies of each gene. Recently we have shown RL synthesis in two marine bacteria; Pseudomonas sp. MCTG214(3b1) and Marinobacter sp. MCTG107b. In the Pseudomonas sp. we identified rhlA and rhlB homologues with 99% similarity to those of P. aeruginosa, however we have yet to identify any rhlC homologue. This presents a paradox as we have demonstrated di-RL synthesis by this strain. RL synthesis within the Marinobacter sp. presents an even greater paradox as we have yet to identify any RL synthase homologs. Here we explain the molecular differences in RL synthase homologues, the effects that these differences may create and try to explain the apparent lack of synthesis genes in the two marine strains. We also discus the methods used to investigate the molecular mechanisms of RL synthesis.

M3 - Poster

ER -

Twigg M, Marchant R, Banat I. The Riddle of Rhamnolipid Molecular Biosynthesis. 2019. Poster session presented at Biosurfactants 2019, Stuttgart, Germany.