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Biofilm
This document provides information about biofilms. It begins with general information about what biofilms are and how they form and develop. It then discusses some positive applications of biofilms, including in bioremediation, water treatment, microbial leaching, and microbial fuel cells. Finally, it addresses some problems with biofilms. The document contains detailed information about biofilm structure, composition, formation processes, environmental factors that influence biofilms, and advantages they provide to microorganisms.
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Biofilm
- 1. Biofilm Meherunnesha (Nishat) Sungjun Bae Amnorzahira EnvironmentalBiotechnology 08/11/25
- 2. Contents General information1 Application (Positiveparts)2 3 Problems (Negative parts)
- 3. A structured community ofbacterial cells Enclosed in a self-produced extracellular polymeric substance(EPS) Structure EPS Surface Adherent to an inert or living surface Biofilms
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- 5. Environmental Biotechnology Biofilm Development Phasesof Biofilm Growth ● Attachment: adhesion ● Growth: proliferation and differentiation -Quorum-sensing involved ● Detachment
- 6. Attachment and GrowthEnvironmental Biotechnology (EPS)
- 7. Detachment Environmental Biotechnology ●Abrasion -Direct physical contact with biofilm structure ● Erosion -shear forces exerted on the biofilm ● Sloughing -Result of chemical changes -Regulated by the biofilm community ● Enzymatic EPS degradation
- 8. Biofilm Formation (Detailed)Environmental Biotechnology Free cells
- 9. Affecting Factors EnvironmentalBiotechnology ● Adhesion (Attachment) ! -Nature of surface and environment -Charge and shape of surface -Hydrophobicity -Flow characteristics ● Biofilm Growth ! -Available nutrient -Nature of biofilm (aerobic and anaerobic areas) -Heterogeneous versus homogeneous populations
- 10. Factors affecting theshape of biofilm Environmental Biotechnology Slow flow-Rough surface Flow Characteristic Fast flow-Smooth Surface Lack of nutirent-Finger surface Sufficient nutirent-Compact surface Available nutrients
- 11. Multispecies Biofilm inRumen Environmental Biotechnology
- 12. Biofilms – Thesocial life of microorganism More than 99 % of all microorganisms on earth prefer to live in biofilms WHY ? ! 7 secrets of the Good Life in Biofilms
- 13. Secret #1: EPS-TheHouse of Biofilms Cells ● What is EPS? -A high-molecular-weight polymer that is composed of polysaccharides, proteins, nucleic acids, lipids and other biological macromolecules -Secreted by a micro-organism into the surrounding environment ! ! ● What does EPS do? -Envelops cells and helps the aggregates adhere to surfaces
- 14. What does EPSkeep together? Environmental Biotechnology Weak Interactions
- 15. ● 50% ormore of void in biofilm volume ! ●Flux of oxygen into the biofilm is not simply planar -Flux from void spaces -Flux from channels ! ●Oxygen can penetrate to substratum ! ●No oxygen found inside dense cell aggregates ! ●Heterogeneity of oxygen distribution causes heterogeneous growth Secret #2 Oxygen Gradients Environmental Biotechnology Water channels Substratum
- 16. Secret #3 Microconsortia ! ● Methane-oxidizing cell aggregates from marine sediments. The aggregates contain methanogenic bacteria (red) surrounded by sulfate-reducing bacteria (green). ! ● Possible mechanism for syntrophic anoxic methane oxidation in the cell aggregates. Environmental Biotechnology
- 17. Secret #4 Resistantto Antimicrobial Compounds 1. Slow growers are spared the effects of antibiotic drugs which is effective against fast-growing cells. 2. Intracellular signals can alter the physiology of the biofilm. 3. Negatively charged biofilm binds to positively charged antimicrobials. 4. Persister cells do not grow or die in the presence of an antibiotic. 5. Population diversity – improve the chance to survive anyhow
- 18. Secret #5 NutrientSequestration Environmental Biotechnology Cell Cell Particles EPS
- 19. Secret #6 Densitydependent communicationEnvironmental Biotechnology ● First observed in Vibrio fischeri ●Bioluminescence : -Only happens when - population density reaches a certain level. -Brighter during the nighttime -Protection against – :Ultraviolet radiation damage to genes of V.fischeri :The pathogenicity of bioluminescent V. fischeri Euprymna scolopes– Host of V.fischeri V.fischeri Formation of biofilm is needed to develop the symbiotic relationship
- 20. Secret #7 Sex(as horizontal gene transfer) ● High cell density in biofilms ! ● Gene exchange facilitated Environmental Biotechnology male female Sex pilus
- 21. Advantages of “theBiofilm Mode of Life” Environmental Biotechnology ●Provide defense -Physical forces -Phagocytosis -Penetration of antimicrobials ! ●Provide favorable microniche -Can attach to nutrient rich surfaces -Can attach to surface in flowing systems -Fixes the bacterial cells where the nutrients are either abundant or often replenished ! ●Allow microbes to live in close proximity -Facilitates communication and cooperation -Can result in genetic exchange ! ●Nature’s default -Best mode of growth in the “real world” Cellular process of engulfing solid particles by the cell membrane for the acquisition of nutrients
- 22. How is aBiofilm like a CITY? Careful selection of locationLimited settlement of too many microorganism Storage of energy (EPS) Intracellular communication (Quorum Sensing) Transfer of information (genetic transfer) Emigration when population gets Too large for resources Biofilm City
- 23. Contents General information1 Application (Positiveparts)2 3 Problems (Negative parts)
- 24.
- 25. Beneficial Biofilms ● Manyplay an important role in the ecology of the earth and the sustainability of life in general. - The report, "Global Environmental Change”:. Microbes have major roles in the recycling of elements vital to life." ! - We are learning, those microbes often live in biofilm colonies on surfaces. Bioremediation Water treatment Microbial Fuel Cell Microbial Leaching
- 26.
- 27. Bioremediation ● Soil Biofilms -Continuous surface films (5-15 um in thickness) - Variety of aggregate films (5-30 um in diameter) - EPS, extracellular polymeric substances, which protrude from the surface film and form bridges to adjacent sand grains Confocal micrograph of biofilm on sand particles
- 28. ● Biofilm enhancesbioavailability -Polynuclear Aromatic Hydrocarbons (PAHs): two or more fused benzene rings Hydrophobic and low bioavailable - Strategies to promote bioavailability EPS Biofilm production Bioremediation
- 29. ● Bioavailability Enhancement -Some EPS (e.g., sphingan): effective at taking up PAHs ! : PAHs taken up by these polysaccharides are bioavailable ! : EPS acts to temporarily store pollutants for use during periods of nutrient deficiency ! : During periods of high nutrient delivery, bacteria may utilize available nutrients and collect hydrophobic contaminants for later use Bioremediation
- 30. Bioremediation ● Biowall forPAH removal
- 31. Water Treatment - Oldestdesign - 1-4” rocks, variety of plastic packing materials Water flows as thin film over rocks, most of area is void space open to air. Detached biofilm settles out, is dewatered and disposed of. ● Trickling filter ● Biological tower - Plastic media, not rocks (lighter) - Higher Surface Area - Smaller land area
- 32. Water Treatment • Attachedgrowth system • Design based on specific surface area • Aeration by rotating disks • Lower organic loading, Longer detention time Little short-circuiting ! better performance
- 33. Water Treatment ● FluidizedBed - Attached growth system ! - Media (sand, activated carbon) fluidized in reactor ! - Requires relatively small space and simple to operate ! - Used for denitrification
- 34. ● Nitrification/Denitrification - Nitrification :Oxidation of ammonia (NH4 +) to nitrate (NO3 -) via nitrite (NO2 -) : Nitrosomonas; 2NH4 + + 3O2 ! 2NO2 - + 4H+ + 2H2O : Nitrobacter; 2NO2 - + O2 ! 2NO3 - ! - Denitrification : Bacillus, Pseudomonas; nitrate (NO3 -) to nitrogen gas (N2) Water Treatment
- 35. Traditionally… Membranes can servepurpose of clarifier! Can get rid of these… …by installing these Membrane BioReactor (MBR) consists of an activated sludge reactor and a micro/ultrafiltration membrane.
- 36. Biofilms and Membranes 1BNR(Biological Nutrient Removal): advanced treatment of nitrogen and phosphorus 1Membrane unit: physical barrier for separation between water and microorganisms 3Membrane Bio-Reactor (MBR) = The SYNERGY effect ! * Increase; MLSS concentration and contact time * Decrease; sludge production * E.coli free effluent ! offering the possibility of water reuse * Compact process (50% of CASP : classic activated sludge process) + = From prof. Shin’s Lab
- 37. Activated sludge reactorMembranemodules are added to cassettes Cassettes are placed in reactor Cassettes are attached to a pump system © Zenon Environmental Inc. Material typically polypropylene, cellulose acetate, aromatic polyamide, thin-film composite (TFC) Biofilms and Membranes
- 38. ● The extractionprocess, when done with chemicals, is called "leaching." Microbial Leaching - Leaching : is commercially used for the extraction of Cu, Pb, Zn, and Ur from sulfide-containing ores - Thiobacillus thiooxidans and Thiobacillus ferrooxidans are acidophilic and generally found in acid environments e.g. hot springs and sulfide ore deposits - they obtain carbon from CO2 and energy for growth from the oxidation of either iron or sulfur
- 39. - low gradeCu ores contain <0.5% Cu in the form of covellite (CuS) 8 Fe2+ + 2 O2 +8 H+ 8 Fe3+ + 4 H2O CuS + 8 Fe3+ + 4 H2O Cu2++ 8 Fe2++ SO4 2-+ 8 H+ T. ferrooxidans ● Microbial leaching in Copper mining Microbial Leaching Thiobacillus ferrooxidans
- 40. Microbial Leaching ● Approximately20 percent of copper mined in the United States is extracted from biofilms.
- 41. ● Dump leaching MicrobialLeaching (Technical Application) - Most commonly applied method - Very slow process (3-10% of the copper content leached out per year_20 years in complete) - Simple, cheap, little labor - 2.0-3.5 of pH is circulating by liquor - Thiobacillus ferrooxidans need only inorganic nutrient taken from ore - 20-25% of total copper production in USA, 5% in the whole world by bio leaching
- 42. ● In situleaching Microbial Leaching (Technical Application) - Difficult if the ore body is impermeable - These leaching were done abiotic without using bacteria In Canadian uranium mines
- 43. Elect ron trans port chai n of cell CO2 Mox Mred An od e Sol id ele ctr oly te Ca tho de V O2 H2O H+ Organics Electron • Metalreducing bacteria (Shewanella putrefaciens or Geobacter sulfurreducens) Microbial Fuel Cell (MFC) cyanobacterium Synechocystis PCC 6803 colonizing the surface of the anode (graphite fibre)
- 44. Contents General information1 Application (Positiveparts)2 3 Problems (Negative parts)
- 45.
- 46. Biofilm is surroundingus .. Environmental Biotechnology
- 47. Disadvantages Natural environments Industrial environments Human health • Oxygendepletion ! • Mobilizing toxic elements ! • Equipment damage ! • Energy losses •Medical infections
- 48. In natural environments ●Biofilms grow virtually everywhere ● Moisture ● Nutrients ● Surface ! ! ● Producing toxic alga blooms ● Creating oxygen depletion zones in lakes, rivers and coastal environments ● Mobilize toxic elements Green algae form at surface of river.
- 49. Mobilizing toxic elements ➢Nature(2004) ■ A pink biofilm was found growing hundreds of feet underground ■ The pink biofilm ■ bacteria and fungi that grow on surfaces. ■ contain acidic solution-laden with dissolved iron, copper, zinc and arsenic-emanating Environmental Biotechnology ➢How?? ▪Formation of biofilm ▪Hazardous metals trap in it ▪Energy source !
- 50. In industrial environments Wastewater treatmentMarine Biofilms Water distribution Filtration Application Water cooling distribution Biofilms
- 51. Membrane fouling (Biofouling) Definition: Biofouling refers to undesirable accumulation of biotic deposit on surface (membrane) Membrane filtration process Adapted from Ivnitsky et al. 2005. Desalination 185: 255-268.
- 52. Membrane fouling mechanisms ●Externalfouling Hydraulic permeability and solute transmission characteristics are altered due to: ❑Increase in the effective membrane thickness ❑Blockage of pore entrance ❑Constriction of pore entrance
- 53. Environmental Biotechnology Membrane foulingmechanisms ●Internal fouling Hydraulic permeability and solute transmission characteristics are altered due to: ❑Internal blockage of pore ❑Internal constriction of pore ❑Alteration of pore tortuosity !
- 54. Membrane fouling (Biofouling) Solution ✓Backwashing ✓ Chemical washing ✓ Replacement of membrane
- 55. Biofilm effect inwater system Water Distribution Water Filtration Formation Biofilm Corrosion in Pipe line
- 56. Environmental Biotechnology Formation ofcorrosion in pipeline by biofilm
- 57. Formation of corrosionin pipeline by biofilm
- 58. ● Affect turbidity,taste, and odor ● Red (iron) and black (manganese) in H2O ● Increased frictional resistance ● Pipe corrosion ● Failure to meet water quality criteria Effect of biofilm in pipeline water distribution
- 59. Water cooling distribution Biofilms incooling water systems are known to reduce heat transfer ! Legionella is still a problem in cooling towers. ! Biofilms can cause clogging in filters and pipes. ! ! ! Piling Offshore platforms, ship hull Others ! In shipping industry • Biofilm coating the hull • Effect efficiency of the vessel ! ! Marine StructuresWater Filtration
- 60. Electron donors/acceptor System control Material Prevention Controllingbiofilm formation System hydraulic Temperature Cleaning programs Nutrients and concentration Pipe material and age Difficult way The easiest way
- 61. Human Health ●Control ofbiofilms is a major concern ➢ Health ➢ Economic ●Biofilms cause for contaminations of medical devices ➢ Nosocomial infections
- 62. Human Health -lung infectionEnvironmental Biotechnology Single microbes attach in alveoli Biofilm start to forms Biofilm become thicker (matured)
- 63. Environmental Biotechnology Human Health– Implant Heart valve •Microbial form biofilm in heart valve.. ! •Biofilm can live in our body…any prevention????
- 64. Environmental Biotechnology Human Health– Plaque on teeth Don’t forget to brush your teeth !!!!!
- 65. Solution ● Several methodsto control biofilms ➢Mechanical approach : ultrasonic energy ➢Combination approach : ultrasonic with antibiotics ! ●More effective methods are greatly needed !! Environmental Biotechnology
- 66. Environmental Biotechnology ! There isa good side and bad sites of biofilms…so our job to utilize and control them ! Thank you for listening Save our environments and earth.. PEACE!!!!
- 67. Thank You ! Anyquestions and comments???