In natural water,microplastics(MPs)inevitably undergo microbial colonization to form biofilm,while the effect of biofilm formation on the photoaging of MPs remains unknown.This study systematically investigated the ph...In natural water,microplastics(MPs)inevitably undergo microbial colonization to form biofilm,while the effect of biofilm formation on the photoaging of MPs remains unknown.This study systematically investigated the photoaging behavior of disposable box-derived polypropylene(PPMPs)and polystyrene(PSMPs)mediated by formed biofilm in water.After incubating in Weihe water samples for 105 d,the biofilm was validated to form in PPMPs and PSMPs,with higher formation in PSMPs.In particular,biofilm formation inhibited the photoaging of PPMPs and PSMPs,with an 11.1%and 50.6%decrease in photooxidation compared to their virgin counterparts after 20 d of ultraviolet(UV)irradiation.Moreover,the photoaging route of MPs such as the reaction priority of functional groups(e.g.,C–H,C=O,and benzene ring)was altered,indicating the important role of biofilm formation in the photoaging process of MPs.The protective effect of the biofilm was mainly caused by the role of optical light filters that absorbed UV energy by sacrificing themselves.Also,as the main attacker on MPs,the production of reactive oxygen species(ROS,mainly^(1)O_(2)and·OH)was inhibited by biofilm,which was mainly responsible for the decreased photoaging of MPs.This study revealed the important role of biofilm in the photoaging process of MPs and suggested a higher resistance of(micro)plastics in natural water than that in the laboratory using pure MPs,which contributed to a deeper understanding of the environmental fate and pollution of MPs.展开更多
Periodontitis is an inflammatory disease caused by bacterial biofilms,which leads to the destruction of periodontal tissue.Current treatments,such as mechanical cleaning and antibiotics,struggle to effectively address...Periodontitis is an inflammatory disease caused by bacterial biofilms,which leads to the destruction of periodontal tissue.Current treatments,such as mechanical cleaning and antibiotics,struggle to effectively address the persistent biofilms,inflammation,and tissue damage.A new approach involves developing a Janus nanomotor(J-CeM@Au)by coating cerium dioxide-doped mesoporous silica(CeM)with gold nanoparticles(AuNPs).This nanomotor exhibits thermophoretic motion when exposed to near-infrared(NIR)laser light due to the temperature gradient produced by the photothermal effects of asymmetrically distributed AuNPs.The NIR laser provides the energy for propulsion and activates the nanomotor's antibacterial properties,allowing it to penetrate biofilms and kill bacteria.Additionally,the nanomotor's ability to scavenge reactive oxygen species(ROS)can modulate the immune response and create a regenerative environment,promoting the healing of periodontal tissue.Overall,this multifunctional nanomotor offers a promising new approach for treating periodontitis by simultaneously addressing biofilm management and immune modulation with autonomous movement.展开更多
[Objective] Pseudomonas as one of the dominant spoilage bacteria highly form biofilms in chilled meat products and processing environment when contaminating single or mixed with other species.This study aims to invest...[Objective] Pseudomonas as one of the dominant spoilage bacteria highly form biofilms in chilled meat products and processing environment when contaminating single or mixed with other species.This study aims to investigate the antibiofilm properties of the cell-free supernatants(CFSs) of three Bacillus species isolated from fermented food and rice seeds on Pseudomonas lundensis(PL) or and Acinetobacter johnsonii(AJ) as mono-or dual-species.[Methods] Biofilm biomass,extracellular polymeric substances(EPSs),and biofilm structure were measured by crystal violet staining,spectrophotometry,confocal laser scanning microscopy(CLSM),respectively,as well as transcription of biofilm-related genes determined by qPCR.[Results] The CFSs of Bacillus amyloliquefaciens ZG08,B.velezensis B5,and B.subtilis YB11 inhibited the biofilm formation of PL and AJ without affecting their growth.The treatment with 50% CFSs of ZG08 and B5 decreased the cell viability of two biofilms by 12.73%–21.04%,which was higher than that of YB11(0.15%–4.38%).The inhibition rates of 50% CFSs of the three strains were 59.75%–79.59% against the PL biofilm and 63.62%–78.57% against the biofilm of PL+AJ,in which the CFS of YB11 had weaker activity.The content of exopolysaccharides and exoprotein in the two biofilms treated with these CFSs were reduced by 53.77%–73.30% and 54.84%–62.38%,respectively.The treatment with the three CFSs also reduced the adhesive cells,loosened biofilm structures,and thinned their thickness by 57.63%–74.49% and 60.43%–64.64%,respectively.Moreover,the CFSs of ZG08 and B5 effectively eradicated by 41.77%–69.79% against the mature biofilms of PL and PL+AJ,compared to weak activity of YB11.In addition,the antibiofilm activities of the three CFSs were stable under four enzyme digestion and heating conditions.Compared with the control,the CFSs of ZG08 and B5 significantly down-regulated the expression of six biofilm-related genes,lapA,alg44,pelG,luxR,wspR,and rpoS.[Conclusion] The CFSs of ZG08 and B5 have strong antibiofilm activities against PL and AJ as mono-or dual-species.展开更多
Considering the WHO warning about the emergence of a’post-antibiotic’era during the 21st century in which common infections and minor injuries will have a dramatic impact on human death toll,search for new potential...Considering the WHO warning about the emergence of a’post-antibiotic’era during the 21st century in which common infections and minor injuries will have a dramatic impact on human death toll,search for new potential antibacterial drug targets became a necessary need.Targets that are extensively explored concern the modulation展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42107434 and 42077351)the Postdoctoral Science Foundation of China(Grant Nos.2020M680160 and 2022T150536).
文摘In natural water,microplastics(MPs)inevitably undergo microbial colonization to form biofilm,while the effect of biofilm formation on the photoaging of MPs remains unknown.This study systematically investigated the photoaging behavior of disposable box-derived polypropylene(PPMPs)and polystyrene(PSMPs)mediated by formed biofilm in water.After incubating in Weihe water samples for 105 d,the biofilm was validated to form in PPMPs and PSMPs,with higher formation in PSMPs.In particular,biofilm formation inhibited the photoaging of PPMPs and PSMPs,with an 11.1%and 50.6%decrease in photooxidation compared to their virgin counterparts after 20 d of ultraviolet(UV)irradiation.Moreover,the photoaging route of MPs such as the reaction priority of functional groups(e.g.,C–H,C=O,and benzene ring)was altered,indicating the important role of biofilm formation in the photoaging process of MPs.The protective effect of the biofilm was mainly caused by the role of optical light filters that absorbed UV energy by sacrificing themselves.Also,as the main attacker on MPs,the production of reactive oxygen species(ROS,mainly^(1)O_(2)and·OH)was inhibited by biofilm,which was mainly responsible for the decreased photoaging of MPs.This study revealed the important role of biofilm in the photoaging process of MPs and suggested a higher resistance of(micro)plastics in natural water than that in the laboratory using pure MPs,which contributed to a deeper understanding of the environmental fate and pollution of MPs.
基金Fundamental Research Funds for the Central Universities(2042022kf1206)National Natural Science Foundation of China(82271010).
文摘Periodontitis is an inflammatory disease caused by bacterial biofilms,which leads to the destruction of periodontal tissue.Current treatments,such as mechanical cleaning and antibiotics,struggle to effectively address the persistent biofilms,inflammation,and tissue damage.A new approach involves developing a Janus nanomotor(J-CeM@Au)by coating cerium dioxide-doped mesoporous silica(CeM)with gold nanoparticles(AuNPs).This nanomotor exhibits thermophoretic motion when exposed to near-infrared(NIR)laser light due to the temperature gradient produced by the photothermal effects of asymmetrically distributed AuNPs.The NIR laser provides the energy for propulsion and activates the nanomotor's antibacterial properties,allowing it to penetrate biofilms and kill bacteria.Additionally,the nanomotor's ability to scavenge reactive oxygen species(ROS)can modulate the immune response and create a regenerative environment,promoting the healing of periodontal tissue.Overall,this multifunctional nanomotor offers a promising new approach for treating periodontitis by simultaneously addressing biofilm management and immune modulation with autonomous movement.
文摘[Objective] Pseudomonas as one of the dominant spoilage bacteria highly form biofilms in chilled meat products and processing environment when contaminating single or mixed with other species.This study aims to investigate the antibiofilm properties of the cell-free supernatants(CFSs) of three Bacillus species isolated from fermented food and rice seeds on Pseudomonas lundensis(PL) or and Acinetobacter johnsonii(AJ) as mono-or dual-species.[Methods] Biofilm biomass,extracellular polymeric substances(EPSs),and biofilm structure were measured by crystal violet staining,spectrophotometry,confocal laser scanning microscopy(CLSM),respectively,as well as transcription of biofilm-related genes determined by qPCR.[Results] The CFSs of Bacillus amyloliquefaciens ZG08,B.velezensis B5,and B.subtilis YB11 inhibited the biofilm formation of PL and AJ without affecting their growth.The treatment with 50% CFSs of ZG08 and B5 decreased the cell viability of two biofilms by 12.73%–21.04%,which was higher than that of YB11(0.15%–4.38%).The inhibition rates of 50% CFSs of the three strains were 59.75%–79.59% against the PL biofilm and 63.62%–78.57% against the biofilm of PL+AJ,in which the CFS of YB11 had weaker activity.The content of exopolysaccharides and exoprotein in the two biofilms treated with these CFSs were reduced by 53.77%–73.30% and 54.84%–62.38%,respectively.The treatment with the three CFSs also reduced the adhesive cells,loosened biofilm structures,and thinned their thickness by 57.63%–74.49% and 60.43%–64.64%,respectively.Moreover,the CFSs of ZG08 and B5 effectively eradicated by 41.77%–69.79% against the mature biofilms of PL and PL+AJ,compared to weak activity of YB11.In addition,the antibiofilm activities of the three CFSs were stable under four enzyme digestion and heating conditions.Compared with the control,the CFSs of ZG08 and B5 significantly down-regulated the expression of six biofilm-related genes,lapA,alg44,pelG,luxR,wspR,and rpoS.[Conclusion] The CFSs of ZG08 and B5 have strong antibiofilm activities against PL and AJ as mono-or dual-species.
文摘Considering the WHO warning about the emergence of a’post-antibiotic’era during the 21st century in which common infections and minor injuries will have a dramatic impact on human death toll,search for new potential antibacterial drug targets became a necessary need.Targets that are extensively explored concern the modulation
