Recent progress in microbial cell surface display systems and their application on biosensors

Microbial cell surface display technology is a recombinant technology to express target proteins on the cell membrane,which can be used to redesign the cell surface with functional proteins and peptides.Bacterial and yeast surface display systems are the most common cell surface display systems of prokaryotic and eukaryotic proteins,that are widely applied as the core elements in the field of biosensors due to their advantages,including enhanced stability,high yield,good safety,expression of larger and more complex proteins.To further promote the performance of biosensors,the biomineralized microbial surface display technology was proposed.This review summarized the different microbial surface display systems and the biomineralized surface display systems,where the mechanisms of surface display and biomineralization were introduced.Then we described the recent progress of their applications on biosensors for different types of detection targets.Finally,the outlooks and tendencies were discussed and forecasted with the expectation to provide some general functions and enlightenments to this aspect of research.

Aggregation-induced emission artificial enzyme(AIEzyme)with DNase-like activity:Imaging and matrix cleavage for combating bacterial biofilm

DNase-catalyzed hydrolysis of extracellular DNA(eDNA)has been widely employed to eradicate intractable biofilms.Although aggregation-induced emission(AIE)has become the ideal tool for killing planktonic bacteria,AIE luminogens(AIEgens)often lack DNase-mimetic activity,so as to suffer from poor anti-biofilm capacity.Here,an“AIEzyme”,a kind of AIE nanomaterial with enzyme-like activity,is designed and synthesized,where the AIEgens are used as the ligands of Zr-based coordination polymer nanoparticles.Not only does AIEzyme have enduring DNasemimetic activity with low activation energy,but also structural rigidity-stabilized fluorescence.Due to the long-acting hydrolysis for eDNA in biofilm,AIEzyme can efficiently disorganize the established biofilms with good penetrability and realize the healing of superbug-infected wounds under only one dose of AIEzyme.This work provides a strategy to endow ordinary AIEgens with DNase-like and antibiofilm activities.Moreover,AIEzymes can be observed by virtue of their own AIE character,facilitating the study on self-positioning and residual amount of AIEzymes in wounds.The concept“AIEzyme”would hopefully stimulate the tremendous expansion for the tool kits and the application of AIEgens and artificial enzymes.