Staphylococcus aureus microbial biofilms degradation using cellobiose dehydrogenase from Thermothelomyces thermophilus M77

This work reports biochemical characterization of Thermothelomyces thermophilus cellobiose dehydrogenase (TthCDHIIa) and its application as an antimicrobial and antibiofilm agent. We demonstrate that TthCDHIIa is thermostable in different ionic solutions and is capable of oxidizing multiple mono and oligosaccharide substrates and to continuously produce H2O2. Kinetics measurements depict the enzyme catalytic characteristics consistent with an Ascomycota class II CDH. Our structural analyses show that TthCDHIIa substrate binding pocket is spacious enough to accommodate larger cello and xylooligosaccharides. We also reveal that TthCDHIIa supplemented with cellobiose reduces the viability of S. aureus ATCC 25923 up to 32 % in a planktonic growth model and also inhibits its biofilm growth on 62.5 %. Furthermore, TthCDHIIa eradicates preformed S. aureus biofilms via H2O2 oxidative degradation of the biofilm matrix, making these bacteria considerably more susceptible to gentamicin and tetracycline.

Automated summary

This work presents the biochemical characteristics and application of TthCDHIIa from Thermothelomyces thermophilus as an antimicrobial and antibiofilm agent. TthCDHIIa is thermostable and can oxidize various mono and oligosaccharide substrates, producing H2O2. It exhibits catalytic characteristics consistent with an Ascomycota class II CDH. TthCDHIIa can inhibit the viability and biofilm growth of S. aureus, and can also enhance the susceptibility of biofilms to gentamicin and tetracycline through oxidative degradation of the biofilm matrix using H2O2.