{"title":"Can photocatalysis inhibit interspecies bacterial cooperation to quench the formation of robust complex bacterial biofilms in water environments?","authors":"","doi":"10.1016/j.watres.2024.122137","DOIUrl":null,"url":null,"abstract":"<div><p>Bacterial biofilms pose significant a public health risk as an environmental reservoir for opportunistic aquatic bacterial pathogens. Understanding the interspecies roles of complex bacterial biofilms under different stimuli and regulatory mechanisms of stress responses is the key to controlling their dissemination. Herein, two-species mixture (TSM) biofilms (<em>Staphylococcus aureus</em> and <em>Pseudomonas aeruginosa</em>) were constructed in a flowthrough reactor. Compared with the single-species biofilms, the TSM biofilm had higher growth activity to reach maturity faster, forming a staggered community structure. Moreover, the TSM biofilm exhibited greatly improved resistance to different antibiotics (16−128 times higher), especially to those that act on protein synthesis and cell membrane integrity, when compared to single planktonic microorganisms. In the presence of stimuli, photocatalysis effectively inactivated the TSM biofilm within 10 h, a 4-fold shorter inactivation time compared to UVC irradiation. In addition, photocatalysis effectively depleted the extracellular polymers of the TSM biofilm and inhibited secretion of their interspecies quorum sensing signaling molecule autoinducer-2 (AI-2). However, the expression of AI-2 induced related virulence factors, and biofilm growth-related genes were initially up-regulated 3 − 10 fold for the TSM biofilm within the first 2 − 4 h of photocatalysis, followed by significant down-regulation. Furthermore, the addition of the AI-2 precursor 4,5-dihydroxy-2,3-pentanedione effectively delayed the photocatalytic inactivation efficiency of the TSM biofilm compared to the control. These results suggest that photocatalysis can effectively inactivate biofilms by inhibiting interspecies cooperation by quenching AI-2 in the TSM biofilm. This work sheds light on controlling biofilms in public health engineering systems.</p></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":null,"pages":null},"PeriodicalIF":11.4000,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Research","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0043135424010364","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Bacterial biofilms pose significant a public health risk as an environmental reservoir for opportunistic aquatic bacterial pathogens. Understanding the interspecies roles of complex bacterial biofilms under different stimuli and regulatory mechanisms of stress responses is the key to controlling their dissemination. Herein, two-species mixture (TSM) biofilms (Staphylococcus aureus and Pseudomonas aeruginosa) were constructed in a flowthrough reactor. Compared with the single-species biofilms, the TSM biofilm had higher growth activity to reach maturity faster, forming a staggered community structure. Moreover, the TSM biofilm exhibited greatly improved resistance to different antibiotics (16−128 times higher), especially to those that act on protein synthesis and cell membrane integrity, when compared to single planktonic microorganisms. In the presence of stimuli, photocatalysis effectively inactivated the TSM biofilm within 10 h, a 4-fold shorter inactivation time compared to UVC irradiation. In addition, photocatalysis effectively depleted the extracellular polymers of the TSM biofilm and inhibited secretion of their interspecies quorum sensing signaling molecule autoinducer-2 (AI-2). However, the expression of AI-2 induced related virulence factors, and biofilm growth-related genes were initially up-regulated 3 − 10 fold for the TSM biofilm within the first 2 − 4 h of photocatalysis, followed by significant down-regulation. Furthermore, the addition of the AI-2 precursor 4,5-dihydroxy-2,3-pentanedione effectively delayed the photocatalytic inactivation efficiency of the TSM biofilm compared to the control. These results suggest that photocatalysis can effectively inactivate biofilms by inhibiting interspecies cooperation by quenching AI-2 in the TSM biofilm. This work sheds light on controlling biofilms in public health engineering systems.
期刊介绍:
Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include:
•Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management;
•Urban hydrology including sewer systems, stormwater management, and green infrastructure;
•Drinking water treatment and distribution;
•Potable and non-potable water reuse;
•Sanitation, public health, and risk assessment;
•Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions;
•Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment;
•Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution;
•Environmental restoration, linked to surface water, groundwater and groundwater remediation;
•Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts;
•Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle;
•Socio-economic, policy, and regulations studies.