Bacteriophages infected different serotypes of Klebsiella were isolated from sewage. Among them, a heatstable polysaccharide depolymerase enzyme which could degrade bacterial exopolysaccharide effectively was prepared...Bacteriophages infected different serotypes of Klebsiella were isolated from sewage. Among them, a heatstable polysaccharide depolymerase enzyme which could degrade bacterial exopolysaccharide effectively was prepared from the phage infecting Klebsiella K13. Treatment at 60℃ for 30 min could inactivate most of the K13 phage, with the titration decreasing from 6.4×10^8 PFU/mL to 1.6×10^6 PFU/mL. However, no obvious loss of phage enzyme activity was found after this treatment. The optimum hydrolytic temperature of phage enzyme was 60℃, with an activity 57 % higher than that at 30℃. The addition of phage enzyme could result in a rapid decrease of viscosity of exopolysaccharide （EPS） solution within minutes, indicating that K13 phage polysaccharide depolymerase acts as a kind of endo-glycanohydrolase. HPLC and reducing sugar analysis showed that the hydrolysis of EPS approached approximately the maxi-mum at 4h when the final concentration of phage was 6.0 x los PFU/mL. The results showed that K/eb-siella K13 phage depolymerase enzyme could be used as a good tool for the preparation of EPS oligosac- charide.展开更多
Predatory bacteriophages have evolved a vast array of depolymerases for bacteria capture and deprotection.These depolymerases are enzymes responsible for degrading diverse bacterial surface carbohydrates.They are expl...Predatory bacteriophages have evolved a vast array of depolymerases for bacteria capture and deprotection.These depolymerases are enzymes responsible for degrading diverse bacterial surface carbohydrates.They are exploited as antibiofilm agents and antimicrobial adjuvants while rarely inducing bacterial resistance,making them an invaluable asset in the era of antibiotic resistance.Numerous depolymerases have been investigated preclinically,with evidence indicating that depolymerases with appropriate dose regimens can safely and effectively combat different multidrug-resistant pathogens in animal infection models.Additionally,some formulation approaches have been developed for improved stability and activity of depolymerases.However,depolymerase formulation is limited to liquid dosage form and remains in its infancy,posing a significant hurdle to their clinical translation,compounded by challenges in their applicability and manufacturing.Future development must address these obstacles for clinical utility.Here,after unravelling the history,diversity,and therapeutic use of depolymerases,we summarized the preclinical efficacy and existing formulation findings of recombinant depolymerases.Finally,the challenges and perspectives of depolymerases as therapeutics for humans were assessed to provide insights for their further development.展开更多
基金the National Natural Science Foundation of China(No40506027 and No30771646)the Doctoral Foundation of Shandong Province(No2005BS02015)
文摘Bacteriophages infected different serotypes of Klebsiella were isolated from sewage. Among them, a heatstable polysaccharide depolymerase enzyme which could degrade bacterial exopolysaccharide effectively was prepared from the phage infecting Klebsiella K13. Treatment at 60℃ for 30 min could inactivate most of the K13 phage, with the titration decreasing from 6.4×10^8 PFU/mL to 1.6×10^6 PFU/mL. However, no obvious loss of phage enzyme activity was found after this treatment. The optimum hydrolytic temperature of phage enzyme was 60℃, with an activity 57 % higher than that at 30℃. The addition of phage enzyme could result in a rapid decrease of viscosity of exopolysaccharide （EPS） solution within minutes, indicating that K13 phage polysaccharide depolymerase acts as a kind of endo-glycanohydrolase. HPLC and reducing sugar analysis showed that the hydrolysis of EPS approached approximately the maxi-mum at 4h when the final concentration of phage was 6.0 x los PFU/mL. The results showed that K/eb-siella K13 phage depolymerase enzyme could be used as a good tool for the preparation of EPS oligosac- charide.
基金This work was supported by the University Grants Committee,Hong Kong SAR Government(No.14112921,China).The support of HKPFS from the University Grants Committee to HonglanWang was greatly acknowledged.
文摘Predatory bacteriophages have evolved a vast array of depolymerases for bacteria capture and deprotection.These depolymerases are enzymes responsible for degrading diverse bacterial surface carbohydrates.They are exploited as antibiofilm agents and antimicrobial adjuvants while rarely inducing bacterial resistance,making them an invaluable asset in the era of antibiotic resistance.Numerous depolymerases have been investigated preclinically,with evidence indicating that depolymerases with appropriate dose regimens can safely and effectively combat different multidrug-resistant pathogens in animal infection models.Additionally,some formulation approaches have been developed for improved stability and activity of depolymerases.However,depolymerase formulation is limited to liquid dosage form and remains in its infancy,posing a significant hurdle to their clinical translation,compounded by challenges in their applicability and manufacturing.Future development must address these obstacles for clinical utility.Here,after unravelling the history,diversity,and therapeutic use of depolymerases,we summarized the preclinical efficacy and existing formulation findings of recombinant depolymerases.Finally,the challenges and perspectives of depolymerases as therapeutics for humans were assessed to provide insights for their further development.
