Bacteria Filtration Research Articles

Leveraging the Dielectric Barrier Discharge Plasma Process to Create Regenerative Biocidal ePTFE Membranes.

The utilization of dielectric barrier discharge (DBD) plasma treatment for modifying substrate surfaces constitutes an easy and simple approach with a potential for diverse applications. This technique was used to modify the surface of a commercial porous expanded poly(tetrafluoroethylene) (ePTFE) film with either dimethylaminoethyl methacrylate (DMAEMA) or (trimethylamino)ethyl methacrylate chloride (TMAEMA) monomers, aiming to obtain antibacterial ePTFE. Physicochemical analyses of the membranes revealed that DBD successfully enhanced the surface energy and surface charge of the membranes while maintaining high porosity (>75%) and large pore size (>1.0 μm). Evaluation of the bacteria killing-releasing (K-R) function revealed that both DMAEMA and TMAEMA endowed ePTFE with the ability to kill Escherichia coli bacteria. However, only TMAEMA-grafted ePTFE allowed for the release of dead bacteria from the surface upon washing with sodium hexametaphosphate (SHMP) saline solution, owing to its cationic charge derived from the quaternary amine. Washing with SHMP disturbed the electrostatic force between the polymer brushes and dead bacteria, which caused the release of the dead bacteria. Lastly, dead-end bacteria filtration showed that the TMAEMA-grafted ePTFE was able to kill 99.78% of the bacteria, while approximately 61.55% of bacteria were killed upon contact. The present findings support the feasibility of using DBD plasma treatment for designing surfaces that target bacteria and aid in the containment of disease-causing pathogens.

ZnO-PLLA/PLLA Preparation and Application in Air Filtration by Electrospinning Technology.

With the increasing environmental pollution caused by disposable masks, it is crucial to develop new degradable filtration materials for medical masks. ZnO-PLLA/PLLA (L-lactide) copolymers prepared from nano ZnO and L-lactide were used to prepare fiber films for air filtration by electrospinning technology. Structural characterization of ZnO-PLLA by H-NMR, XPS, and XRD demonstrated that ZnO was successfully grafted onto PLLA. An L9(43) standard orthogonal array was employed to evaluate the effects of the ZnO-PLLA concentration, ZnO-PLLA/PLLA content, DCM(dichloromethane) to DMF(N,N-dimethylformamide) ratio, and spinning time on the air filtration capacity of ZnO-PLLA/PLLA nanofiber films. It is noteworthy that the introduction of ZnO is important for the enhancement of the quality factor (QF). The optimal group obtained was sample No. 7, where the QF was 0.1403 Pa-1, the particle filtration efficiency (PFE) was 98.3%, the bacteria filtration efficiency (BFE) was 98.42%, and the airflow resistance (Δp) was 29.2 Pa. Therefore, the as-prepared ZnO-PLLA/PLLA film has potential for the development of degradable masks.

Polydopamine/UiO-66-NH2 induced photothermal antibacterial electrospun membrane for efficient point-of-use drinking water treatment

A miniaturized point-of-use (POU) water treatment device to achieve convenient and efficient water disinfection for remote and post-disaster areas remains a challenge. Herein, such as POU device consisted of a self-polymerized polydopamine (PDA) layer and UiO-66-NH2 nanoparticles covered electrospun polyacrylonitrile (PAN) membrane (PAN@PDA@UiO-66-NH2) with bacteria filtration and photothermal antibacterial property is successfully fabricated. The membrane achieves a good interception effect of microorganisms in water because of the synergistic pore interception and adsorption effect. A nearly 100% bacterial retention efficiency was obtained by the PAN@PDA@UiO-66-NH2 membrane. In addition, the obtained PAN@PDA@UiO-66-NH2 membrane exhibits nearly 100% photothermal sterilization efficiency against Escherichia coli (E. coli) under 6 min of 808 nm infrared irradiation (1.21 W). The great photothermal effect comes from the synergistic effect of good photothermal conversion efficiency and absorption of incident light caused by the PDA layer and rough UiO-66-NH2 particles, respectively. Through the good filtration performance and photothermal effect of the membrane, the filtration for water containing bacteria and sterilization of membrane can be realized. Meanwhile, the membrane fouling caused by bacterial growth can be inhibited. In this way, this innovative membrane has the ability to maintain great filtration and sterilization ability during long-term operation, and thus, having great potential to be used as an effective, convenient, practical, and safe POU water-treatment device.

Selenium modified graphitic carbon nitride membrane with improved antibacterial properties against Bacillus cereus and Escherichia coli

In this study a nanocomposite membrane, consisting of hyperbranched polyethyleneimine (HPEI) and graphic carbon nitride (g-C3N4) embedded with selenium nanoparticles (SeNPs), was used in the removal of Bacillus cereus (B. cereus) and Escherichia coli (E. coli) in water. The prepared Se/g-C3N4/HPEI nanocomposite was incorporated into a polyethersulfone (PES) matrix through the phase inversion method. The synthesized nanocomposite and membranes were characterized using transmission electron microscopy (TEM), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX), contact angles, water intake capacity, water flux and filtration studies. The TEM micrographs of the Se/g-C3N4/HPEI nanocomposite showed a typical rippled 2D flat layered structure with dispersed Se nanorods with an average diameter of 37.60 nm. The hybrid membranes exhibited lower pure water flux (40.28–26.53 Lm−2 h−1), improved hydrophilicity (63.21–35.54°) and higher bacteria rejection (28.03–100%) as compared to the pristine PES (127.36 Lm−2h−1, 67.75° and 19.67%). The modified nanocomposite membranes displayed improved antibacterial properties against B. cereus and E. coli achieving an inhibition of growth rate of approximately 100% at the highest concentration (0.9%). The SEM analysis of the modified membrane after bacteria filtration shows that the cell morphology of the B. cereus and E. coli was damaged and the cell membrane lost its integrity. This was due to the bactericidal effect of the modified membrane.

Dispersion of motile bacteria in a porous medium

Understanding flow and transport of bacteria in porous media is crucial to technologies such as bioremediation, biomineralization and enhanced oil recovery. While physicochemical bacteria filtration is well documented, recent studies showed that bacterial motility plays a key role in the transport process. Flow and transport experiments performed in microfluidic chips containing randomly placed obstacles confirmed that the distributions of non-motile bacteria stays compact, whereas for the motile strains, the distributions are characterized by both significant retention as well as fast downstream motion. For motile bacteria, the detailed microscopic study of individual bacteria trajectories reveals two salient features: (i) the emergence of an active retention process triggered by motility, (ii) enhancement of dispersion due to the exchange between fast flow channels and low flow regions in the vicinity of the solid grains. We propose a physical model based on a continuous time random walk approach. This approach accounts for bacteria dispersion via variable pore-scale flow velocities through a Markov model for equidistant particle speeds. Motility of bacteria is modelled by a two-rate trapping process that accounts for the motion towards and active trapping at the obstacles. This approach captures the forward tails observed for the distribution of bacteria displacements, and quantifies an enhanced hydrodynamic dispersion effect that originates in the combined effect of pore-scale flow variability and bacterial motility. The model reproduces the experimental observations, and predicts bacteria dispersion and transport at the macroscale.

Application of Nanofibers in Virus and Bacteria Filtration

Air pollution is an increasing concern all over the world due to its adverse effects on human health. It claims thousands of lives every year. Hence, the demand for the ventilator, respirator, facemask, body protection, and hospital air filtration has been surging dramatically during the COVID-19 pandemic. Nanofiber membranes with optimal characteristics, such as a high specific surface area and porous microstructure with interconnected pores, can efficiently capture the fine particles (such as bacteria, fungi, virus, etc.). Recently, various types of polymers have been fabricated as electrospun fibrous membranes to be used as an anti-bacterial or anti-viral air filtration media. This review presents a brief overview of air filtration history and its main mechanisms and then the latest research about air filtration with antibacterial and antiviral properties will be reviewed.

Graphene‐Based Bacterial Filtration via Electrostatic Adsorption

AbstractFlexible graphene oxide (GO) microsheets with attached positively charged polymers, termed GOX microsheets, are efficient at bacterial adsorption, as they bind electrostatically to bacterial membranes’ negative surface charge. The authors explore an antimicrobial water filter application for GOX's extremely high surface area and its previously described efficient bacterial adsorption.Cellulose‐fiber carrier material is functionalized with GOX microsheets to create an adsorption‐based bacteria filtration material. The morphology and charge density (7.8 × 1019 g–1) of the prepared GOX fibers are determined by scanning electron microscopy and dye adsorption assay, and widefield fluorescence microscopy is used to visualize the adsorption of stained Escherichia coli bacterial cells on the fibers. GOX fibers are tested in filtration setups to investigate their bacteria removal performance. The experimental results, with 100 mg of GOX fibers filtering 2.4 × 109 colony‐forming units (CFU) from an E. coli bacterial culture with 99.5% bacterial reduction, demonstrate the fibers’ high bacteria loading capacity. The electrostatic adsorption‐based filtration mechanism allows the filter to be operated at higher flow rates than micropore membrane filters, while maintaining 3‐log bacterial reduction. GOX filter materials removing bacteria via adsorption are a high flow rate alternative to current water filtration processes that rely on size‐exclusion.

Exploring Reusability of Disposable Face Masks: Effects of Disinfection Methods on Filtration Efficiency, Breathability, and Fluid Resistance.

To curb the spread of the COVID‐19 virus, the use of face masks such as disposable surgical masks and N95 respirators is being encouraged and even enforced in some countries. The widespread use of masks has resulted in global shortages and individuals are reusing them. This calls for proper disinfection of the masks while retaining their protective capability. In this study, the killing efficiency of ultraviolet‐C (UV‐C) irradiation, dry heat, and steam sterilization against bacteria (Staphylococcus aureus), fungi (Candida albicans), and nonpathogenic virus (Salmonella virus P22) is investigated. UV‐C irradiation for 10 min in a commercial UV sterilizer effectively disinfects surgical masks. N95 respirators require dry heat at 100 °C for hours while steam treatment works within 5 min. To address the question on safe reuse of the disinfected masks, their bacteria filtration efficiency, particle filtration efficiency, breathability, and fluid resistance are assessed. These performance factors are unaffected after 5 cycles of steam (10 min per cycle) and 10 cycles of dry heat at 100 °C (40 min per cycle) for N95 respirators, and 10 cycles of UV‐C irradiation for surgical masks (10 min per side per cycle). These findings provide insights into formulating the standard procedures for reusing masks without compromising their protective ability.

Effect of the biogenic precipitation of calcium carbonate on bacterial transport in sand columns

Prediction of bacteria transport to riparian shallow groundwater is very important to prevent the pollution of water resources by coliform bacteria. The objective of this study was to investigate the effectiveness of microbially induced calcium carbonate precipitation (MICCP) in reducing bacteria (Escherichia coli and Pseudomonas fluorescens) transport. To perform the MICCP process, air-dried sterile sand was poured into polyvinyl chloride (PVC) cylinders (4.8 × 14.92 cm) and incubated for 3 days in the presence of Sporosarcina pasteurii (~108 Cell g−1sand), urea and CaCl2 (1.5 M). A pulse (0.1 pore volume (PV)) of bacteria suspension (108 CFU mL−1) was added on top of the sand columns (MICCP treated and control) and leaching experiments were followed at steady-state, saturated flow condition. Culturable bacteria were determined in the leachate and the sand extracts (resident bacteria) by colony count method. The MICCP treatment reduced saturated hydraulic conductivity (Ks) value 3.9 times compared to the control and thereby reduced bacteria leaching. Bioprecipitated calcium carbonate in MICCP columns increased bacteria straining compared to control columns especially in surface layer (0-3 cm). MICCP process increased filtration coefficient (λf), and relative adsorption index (SR), and decreased maximum depth of bacteria transport (Zmax). The average (Cav) and cumulative cell density (Ccum) of both bacteria passed from the MICCP column decreased around 3.9-fold compared to the control. Overall, the MICCP process has potential in bacteria filtration in the porous media reducing the risk of groundwater pollution.

Development of AgCl-TiO2 xerogels entrapped antibacterial polyacrylonitrile membranes: The effect of high salinity water on silver release, antibiofouling and antibacterial efficacies

Silver-containing antibacterial membranes are commonly used to control biofouling during bacteria filtration. Unfortunately, fast and uncontrolled release of silver to water is a challenge since this causes mass accumulation of silver in water resources and insufficient long-term antimicrobial effect. To overcome these disadvantages, we propose to add AgCl-TiO2 xerogels (0–0.8 wt%) in the polyacrylonitrile membranes. The long-term silver retaining of the membranes was evaluated by measuring the silver release under filtration of deionized water in the absence and the presence of 1 M NaCl up to 5 days. The antibiofouling and the antibacterial efficacies were determined by measuring the changes in antibacterial activity and DI water flux of the membranes at the end of 5 days of E. coli filtration. The 0.2 wt% AgCl-TiO2 xerogel incorporated polyacrylonitrile membrane demonstrated a constant ~1 μg of silver release/cm2 per filtration cycle after a total filtration of 0.05 L/cm2 with 1 M NaCl solution. Additionally, it showed antibacterial efficacy and ~100% recovery of deionized water flux by simple backwashing with water after having been used in many E. coli filtration cycles. Thus, this membrane could potentially be used up to ~5.8 years for 8000 h a year for the filtration of high salinity water. Statement of noveltySilver-containing antibacterial membranes are commonly used to control biofouling during bacteria filtration. Uncontrolled release of silver from the membrane causes massive silver accumulation in water which in turn leads to contamination of water resources and threat to aquatic organisms. Although silver release is strongly influenced by the salinity of water, the release data was collected through filtration of pure DI water or tap water in literature. To overcome the shortcomings of the published studies, we propose to use AgCl-TiO2 xerogels in membranes due to low solubility of AgCl in water and measure the release by filtering high-salinity water.

Formation of multifunctional ZrO2–MgO-hBN nanocomposite for enhanced bone regeneration and E coli bacteria filtration applications

Due to adequate properties, bone implant materials have attracted much attention to repair the large-sized bone fractures which cannot be auto-healed. Recently, three-dimensional (3-D) nanocomposites were synthesized using two-dimensional (2-D) materials which reveals unexpected performances. In the present study, 3-D mesoporous biocomposites were developed for bone/dental implant applications. A ternary novel biocomposite system ZrO2–MgO-hBN was fabricated with low density, high strength, and mesoporous interconnected architecture using conventional bottom-up synthesis method. Due to remarkable stability in different fluids such as water, minimum essential medium eagle-alpha modification (α-MEM), acids and oils, the fabricated biocomposites displayed multifunctional activities along with suitable proliferation of osteoblast like MG63 cell and filtration of Escherichia coli (E-coli) bacteria from the water. Moreover, the biocomposite exhibited protective nature from harmful ultraviolet (UV) radiation. A new phase of hexagonal boron nitride (h-BN) in the form of highly porous nanotubes was observed that opens the new possibility to optimize the synthesis of porous h-BN nanotubes to explore their further applications. Therefore, based on mechanical, tribological and biological performances, the nanocomposite is a biomimetic material having potential as bone/dental implant and can be used for multifunctional applications.

Modeling of Designed Textile Fibrous Media for Liquid Filtration

This study is undertaken to provide a mathematical model designed by using colloidal filtration theory based on the orientation of fibers in the textile media for bacteria filtration. A model of colloidal filtration process is formulated based on the previous published works by considering relevant parameters affecting the filtration process like fiber orientation, fiber diameter, fiber length, and porosity of the media. The output value of the filtration efficiency of the model and the experimental data are compared. It is noted that the trends in the filtration efficiency data of the model and the experimental values are similar in nature which indicates the validity of the model.

Near-infrared-driven Au-decorated polymer-metal protein microfibers with bacterial filtration ability for use in photothermal sterilization

The use of protein nanostructures can be widely applied in medical devices and biomaterials. However, the synthesis of photothermic bovine serum albumin (BSA) microfibers remains a challenge. In this study, novel protein microfibers (MS@BDA@Au) with bacterial filtration abilities were developed for use in inactivating bacteria under near-infrared (NIR) irradiation. Three types of MS@BDA microfibers were fabricated through the assembly of proteins with M2+ (Fe2+, Cu2+, Mn2+)/Na2S and the assistance of dopamine (DA). These were further decorated with gold nanoparticles to produce MS@BDA@Au microfibers, which exhibited a filtering capacity of 1 × 108 CFU bacteria per milligram, and obvious antibacterial effects at concentrations of 0.5 mg/mL. This paper presents a method that can be used in the functional micro-crystallization of proteins and the development of new types of protein fibers that can be employed in bacteria filtration and photothermal killing.

A facile route to the preparation of antibacterial polysulfone-sulfonated polyethersulfone ultrafiltration membranes using a cationic surfactant cetyltrimethylammonium bromide

Cetyltrimethylammonium bromide (CTAB), a cationic surfactant, is known to have strong bactericidal potential. In this study, we report a facile approach for preparing CTAB-containing polysulfone-sulfonated polyethersulfone (PSF-SPES) based ultrafiltration membranes with antibacterial properties. The CTAB was added in gelation medium at three different concentrations and made an electrostatic interaction with SPES at the polymer/bath interface during phase inversion. The successful incorporation of the CTAB in the membrane structure was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The CTAB-containing membranes had higher contact angle, lower pure water permeability (PWP) and molecular weight cut-off than the pristine membrane. The membranes prepared at critical and above critical micelle concentration (CMC) of the CTAB showed excellent antibacterial activity on both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. On the other hand, the PWP of the membrane decreased from 93 ± 1.6 to 39.3 ± 3.2 L/m2 h bar upon increasing the CTAB concentration from 10−3 M (=CMC) to 10−2 M, consequently, CMC was chosen as the optimal concentration. The membrane prepared at the CMC displayed almost 100% flux recoveries after dynamic bacteria filtration followed by simple rinsing with PBS solution. Leaching experiments continued up to 30 days demonstrated that 96% of the CTAB remained in this membrane. Furthermore, at the end of 1 month of storage in 1 M NaCl solution, no change was observed in the antibacterial activity of this membrane compared to fresh membrane. These findings emphasize the potential of the facile approach proposed in this study to develop antibacterial ultrafiltration membranes in a single step.

Detection of wheat damping off and root rot disease pathogenic fungi and it bio control by pseudomonas fluorescens

This study was conducted to determine the fungal cause and bio control of damping off and root rot of wheat plants by using pseudomonas fluorescens under greenhouse and field conditions. Results showed isolation of eight species from the soil and roots to deferent region of Baghdad government. Rhizoctonia solani (Rs) and Fusarium solani (Fs) were the predominant damping off fungus with frequency 60 and 52% respectively. Led the using of bacteria formulations such as crud suspension , pure bacteria filtration and pure living cells in culture medium inhibit all type fungi with rates ranging from 84-96% , 80- 93% and 75-88% respectively. Rs and Fs were more pathogenesis under greenhouse conditions, with incidence of 80 and 68% and disease severity up to 41,20 and 30,20% respectively. The results of test bacterial formulation (dry, liquid and bacterial filtrate ) with seeds, soil and water irrigation showed high effectiveness for all treatments with superiority of the treatment of seeds in reducing the incidence which reached for the three formulation 21-34% compared with the infested control of Fs, Rs which reached 70 and 55%, respectively. Field experiments results showed superiority of seeds bacterization with dry formulation to reduce the disease incidence to 38% compared with the infested control (75%).These results reflected on the increasing of the shoot and rot dry weight and increasing the productivity (63%) compared with the infested control treatment .

Detection of wheat damping off and root rot disease pathogenic fungi and it bio control by pseudomonas fluorescens

This study was conducted to determine the fungal cause and bio control of damping off and root rot of wheat plants by using pseudomonas fluorescens under greenhouse and field conditions. Results showed isolation of eight species from the soil and roots to deferent region of Baghdad government. Rhizoctonia solani (Rs) and Fusarium solani (Fs) were the predominant damping off fungus with frequency 60 and 52% respectively. Led the using of bacteria formulations such as crud suspension , pure bacteria filtration and pure living cells in culture medium inhibit all type fungi with rates ranging from 84-96% , 80- 93% and 75-88% respectively. Rs and Fs were more pathogenesis under greenhouse conditions, with incidence of 80 and 68% and disease severity up to 41,20 and 30,20% respectively. The results of test bacterial formulation (dry, liquid and bacterial filtrate ) with seeds, soil and water irrigation showed high effectiveness for all treatments with superiority of the treatment of seeds in reducing the incidence which reached for the three formulation 21-34% compared with the infested control of Fs, Rs which reached 70 and 55%, respectively. Field experiments results showed superiority of seeds bacterization with dry formulation to reduce the disease incidence to 38% compared with the infested control (75%).These results reflected on the increasing of the shoot and rot dry weight and increasing the productivity (63%) compared with the infested control treatment .

입-입 인공호흡(Mouth-to-mouth ventilation)을 위한 감염방지 도구의 병원성 세균 여과 효과

Purpose: The purpose of this study was to investigate the effect of a pathogenic bacteria filtration instrument for infection prevention during mouth-to-mouth ventilation. Methods: Two kinds of face shields were used for the study. One rescuer blew the filter through a bag valve mask and the filter was then cultured for bacteria. The mask was tested both on the front and back side. Results: Two kinds of face shields including the KF shield and CM shield were tested. The KF shield has received national certification and it prevented transmission of bacterial infection but the CM shield showed the opposite result and did not prevent bacterial transmission. Pathogenic bacteria were found on the back of the CM shield. Conclusion: A certified face shield is very important to prevent bacterial transmission. Face shields should be demonstrated and used by paramedic students.

NOM fouling behavior during ultrafiltration: Effect of membrane hydrophilicity

Polyethylene oxide (PEO)-modified ultrafiltration (UF) membranes were prepared using polyacrylonitrile-graft-polyethylene oxide (PAN-g-PEO) copolymers through immersion precipitation phase inversion method. Compared to PAN membrane, the PEO-modified UF membranes possessed extraordinary hydrophilic surface owing to the enrichment of PEO segments, which was confirmed by X-ray photoelectronic spectroscopy (XPS). The effects of membrane hydrophilicity on the organic fouling resistance were investigated by means of the resistance-in-series model. The results showed that the hydrophilic modification of UF membrane contributed to the fouling control in bovine serum albumin (BSA) and Escherichia coli (E. coli) bacteria filtration. The antifouling ability of the membranes increased with increasing PEO content. The pure water flux could recover completely after filtering BSA and bacteria, respectively, for the membranes with 25.2% and 8.5% PEO content. In contract, the increase of membrane hydrophilicity had a negative effect on the humic acid (HA) and sodium alginate (SA) filtration. The membrane permeability of the PAN membrane unexpectedly increased after HA or SA filtration, while the flux recovery ratio of PEO-modified membranes decreased with increasing PEO content. The differences in fouling behavior of the various organic foulants on hydrophobic or hydrophilic membrane were attributed to the nature of organic foulants and their interaction with membranes.

NANOTEXTILNÍ MEMBRÁNY PRO ZACHYCENÍ BAKTERIÍ Escherichia coli

The article describes an experimental study dealing with the possibility of nanotextile materials usa­ge for microbiologically contaminated water filtration. The aim of the study is to verify filtration ability of different nanotextile materials and evaluate the possibilities of practical usage. Good detention ability of these materials in the air filtration is the presumption for nanotextile to be used for bacteria filtration from a liquid. High nanotextile porosity with the nanotextile pores dimensions smaller than a bacteria size predicates the possibility of a successful usage of these materials. For the experiment were used materials made from electrospinning nanofibres under the label PA612, PUR1, PUR2 s PUR3 on the supporting unwoven textiles (viscose and PP). As a model simulation of the microbial contamination, bacteria Escherichia coli was chosen. Contaminated water was filtered during the overpressure activity of 105Pa on the input side of the filter from the mentioned material. After three-day incubation on the nutrient medium, cultures found in the samples before and after filtration were compared. In the filtrated water, bacteria E. coli were indicated, which did not verify the theoretical presumptions about an absolut bacteria detention. However, used materials caught at least 94% of bacteria in case of material PUR1 and up to 99,996% in case of material PUR2. These results predict the possibility of producing effective nanotextile filters for microbiologically contaminated water filtration.Recommendation: For the production of materials with better filtrating qualities, experiments need to be done, enabling better understanding of the bacteria detention mechanisms on the nanotextile material, and parameters of the used materials that influence the filtrating abilities need to be verified.

Highly Efficient Enzyme-Functionalized Porous Zirconia Microtubes for Bacteria Filtration

In contrast to polymer membranes, ceramic membranes offer considerable advantages for safe drinking water provision due to their excellent chemical, thermal, and mechanical endurance. In this study, porous ceramic microtubes made of yttria stabilized zirconia (YSZ) are presented, which are conditioned for bacteria filtration by immobilizing lysozyme as an antibacterial enzyme. In accordance with determined membrane pore sizes of the nonfunctionalized microtube of ≤200 nm, log reduction values (LRV) of nearly 3 (i.e., bacterial retention of 99.9%) were obtained for bacterial retention studies using gram-positive model bacterium Micrococcus luteus. Immobilization studies of lysozyme on the membrane surface reveal an up to six times higher lysozyme loading for the covalent immobilization route as compared to unspecific immobilization. Antibacterial activity of lysozyme-functionalized microtubes was assessed by qualitative agar plate test using Micrococcus luteus as substrate showing that both the unspecific and the covalent lysozyme immobilization enhance the microtubes' antibacterial properties. Quantification of the enzyme activity at flow conditions by photometric assays reveals that the enzyme activities of lysozyme-functionalized microtubes depend strongly on applied flow rates. Intracapillary feeding of bacteria solution and higher flow rates lead to reduced enzyme activities. In consideration of different applied flow rates in the range of 0.2-0.5 mL/min, the total lysozyme activity increases by a factor of 2 for the covalent immobilization route as compared to the unspecific binding. Lysozyme leaching experiments at flow conditions for 1 h show a significant higher amount of washed-out lysozyme (factor 1.7-3.4) for the unspecific immobilization route when compared to the covalent route where the initial level of antibacterial effectiveness could be achieved by reimmobilization with lysozyme. The presented platform is highly promising for sustainable bacteria filtration.