Colonization and degradation of polyurethane coatings by Pseudomonas protegens biofilms is promoted by PueA and PueB hydrolases

Two polyurethanases PueA and PueB are major extracellular lipases partly secreted by the mediation of their cognate ABC exporter AprDEF in Pseudomonas protegens Pf‐5

“…In accordance with this, the difference in lipase activities against p-nitrophenyl palmitate of cell-free culture supernatants between the wild-type strain Pf-5 and the mutant Pf-5DpueB is found to be not significant, whereas the mutants Pf-5DpueA and Pf-5DpueAB almost completely lose their extracellular lipase activities against p-nitrophenyl palmitate in the cell-free culture supernatants. In addition, PueA and PueB also exhibit similar roles in the degradation of polyurethane (Hung et al 2016;Nadeau et al 2021). Consequently, the results in this study also further testified that the lipase activity is one of the mechanisms of polyurethane degradation by polyurethanase (Loredo-Treviño et al 2012;Mahajan and Gupta 2015).…”

“…Mutational analysis results in Pf-5 have demonstrated that PueA may play a more major role in lipase activity than PueB based on the hydrolysis assays of synthetic p-nitrophenyl palmitate (Hung et al 2016;Nadeau et al 2021), but it is unclear whether PueA and PueB have similar roles in lipase activity against natural acylglycerols and are secreted into the extracellular environment mediated by their cognate AprDEF. To answer the aforementioned questions, four markerless deletion mutants in Pf5139 (Dupp derivative of Pf-5), two heterologous coexpression strains and their three control strains in lipasefree Escherichia coli BL21(DE3) were constructed, and the lipase activities of these strains were measured by the tributyrin plate assay and the liquid culture assay.…”

Current advances in polyurethane biodegradation

“…In addition, C. tenuissimum A2.PP.5 showed the best degrading level of PE‐PU, whose weight loss could reach up to 65% 15 . They then studied the degradability of a water PU dispersion, of which a polyether–PU–acrylate copolymer was degraded in 25 days with the cleavage of esters, CC bonds, aromatic urethanes and ether groups 51 …”

“…In 2021, Crookes‐Goodson and co‐workers identified two lipases, PueA and PueB, with degradative activity towards PS‐PU Impranil in Pseudomonas protegens Pf‐5 54 . The two hydrolases were revealed as crucial enzymes from P. protegens biofilms in the colonization, and PueA had a more obvious impact on the hydrolysis of the ester components of Impranil 51 …”

“…15 They then studied the degradability of a water PU dispersion, of which a polyether-PU-acrylate copolymer was degraded in 25 days with the cleavage of esters, C C bonds, aromatic urethanes and ether groups. 51…”