Antimicrobial activity of escherichia coli using n tio2 PMMA composite

THAI NGUYEN UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY LE THUY LINH ANTIMICROBIAL ACTIVITY OF ESCHERICHIA COLI USING N-TiO2PMMA COMPOSITE BACHELOR THESIS Study Mode : Full-time Major: Environmental Science and Management Faculty: International Programs Office Batch : 2013-2017 Thai Nguyen, 2017 Thai Nguyen University of Agriculture and Forestry Degree Program Bachelor of Environmental Science and Management Student Name Le Thuy Linh Student ID DTN1353110171 Thesis Title Antimicrobial activity of E coli using N-TiO2-PMMA Composite Assoc Prof Nguyen The Hung Supervisor Prof Yao Tung-Lin Abstract: Titanium dioxide (TiO2) is a semiconductor and photocatalyst in the decomposition and disinfection of bacteria In particular, TiO2 were work under ultraviolet light and visible light It also had capable of producing a pair of electron holes due to exposure to ultraviolet and visible light From that Titanium dioxide can be used in combination with nitrogen (Nitrogen doped titanium dioxide) to create a substance that inhibits the activity and growth of bacteria in which clarify ability to inactivate, especially bacterial Escherichia Coli This experiment would use the dipcoating method with antibacterial by Nitrogen doped titanium dioxide (N-TiO2) and then saw the disinfection activity of E.coli for 24 hours by N-TiO2 0.5%, 1% and 2% During experiment took polymethyl methacrylate (PMMA) pieces dip-coating with NTiO2 and put PMMA under visible light with the amount 990 to 1010 lux In all experiments process, E.coli concentration was dilution by 104 and 105 CFU/ mL The results of the experiment showed that E.coli was affected by N-TiO2 antibacterial The number of growth and decomposition bacteria has a distinct gap when using Ni TiO2with different percentages It would reduce the growth of bacteria and cough complete disinfection around 24 hours Antibacterial by N-TiO2 has showed as the optimum one to directly active on bacterial Titanium dioxide, Nitrogen doped titanium dioxide, Keywords Escherichia coli, Polymethyl Methacrylate Number of Pages 43 Date of Submission 20/09/2017 Supervisor’s signature ii ACKNOWLEDGMENTS From bottom of my heart, I would like to express my deepest appreciation to all those who provided me the opportunity to complete this research First and foremost, I would like to express my sincere gratitude and deep regards to my supervisor: Pro Yao Tung-Ling of National Chung Hsing University, Taichung, Taiwan, who guided me wholeheartedly when I implemented this research He is always willing to give suggestions on scientific problems and personal issues He is very supportive and a good listener Under his instruction with patience, knowledge and talent, I’m able to fulfill to my thesis I also want to express my thanks to Assoc Prof Nguyen The Hung, the second supervisor, for his supervision, encouragement, advice, and guidance in writing this thesis In addition, formal thanks should be offered to the Rector of National Chung Hsing University for granting my internship acceptance I want to thank all of my colleagues in the ENM ( Environmental Nano Material) Laboratory, Miss Jing-Hua Tzeng, Mr Chakkrit Poonpakdee, Miss Li-Ting Yen, Miss Ya-Zhen Huang, Mr Le Quoc Anh, Miss Kai-Fen, Mr Che-Chien, Miss Than Thi Nhu Anh They are very generous and supportive It was a great pleasure to work with them I want to express my sincerest appreciation to my parents, my friends and my team for their love and support me everytime Thai Nguyen, 20thSeptember, 2017 Student Le Thuy Linh iii TABLE OF CONTENT CHAPTER I: INTRODUCTION 1.1Introduction .1 1.2Objective of the study .3 CHAPTER II: Literiature Review 2.1 Bacteria species 2.2 Photocatalysis 2.3 Visible light responsive 2.4 N-TiO2 2.5 Polymethyl methacrylate ( PMMA) CHAPTER III: Material & methods 10 3.1 Material and equipment .11 3.2 Dip-coating of PMMA 14 3.3 Nutrient preparation .15 3.4 Antibacterial experiment 16 3.4.1 Dosage bacteria without N-TiO2 16 CHAPTER IV: Result &Discussion 19 4.1 Control experiment to E.coli 19 4.2 N-TiO2 dosage effect 21 4.3 Compare N-TiO2 dosage effect .34 4.4 Compare control and N-TiO2 dosage effect 37 4.5 Compare S.aureus and E.coli .38 CHAPTER V: Conclusion .40 Reference : .41 iv LIST OF TABLES Table 1: The bacteria used in experiment…………………………………………… 11 Table 2: Some of nutrient used in experiment……………………………………… 11 Table 3: Some of chemical used in experiment………………………………………12 Table 4: Some of equipments used in experiment ……………………………………13 v LIST OF FIGURES Figure 1: Bacterial Escherichia coli ( E.coli)………………………………………….4 Figure 2: The Polymethyl methacrylate plastic ( PMMA)……………………………8 Figure 3: Flow chart of work…………………………………………………………10 Figure 4:Show the Dip-coating process…………………………………………… 15 Figure 5:Dosage effect without N-TiO2…………………………………………… 19 Figure 6: Another control experiment……………………………………………… 20 Figure7: N-TiO2 0.5% dosage effect with visible light intensity 2.2x10-4 lux: a, survival of bacteria ; b amount of bacteria………………………………………… 22 Figure 8:N-TiO2 0.5% dosage effect with visible light intensity 3.09x10-4 lux: a, survival of bacteria ; b amount of bacteria………………………………………… 22 Figure 9: N-TiO2 0.5% dosage effect with visible light intensity 1019 lux: a, survival of bacteria; b amount of bacteria…………………………………………………….23 Figure 10:N -TiO2 1% dosage effect with visible light intensity 2.91x10-4-1006 lux: a, survival or bacterial; b, amount of bacterial………………………………………… 25 Figure 11:N-TiO2 1% dosage effect with visible light intensity 2.95x10-4, 1000 lux in Box A: a, survival or bacterial; b, amount of bacterial……………………………….26 Figure 12:N-TiO2 1% dosage effect with visible light intensity 2.95x10-4, 1000 lux in Box B: a, survival or bacterial; b, amount of bacterial……………………………….27 vi Figure 13:N-TiO2 1% dosage effect with visible light intensity 1004 lux : a, survival or bacterial; b, amount of bacterial……………………………………………………28 Figure 14:N-TiO2 1% dosage effect with visible light intensity 1007 lux: a, survival or bacterial; b, amount of bacterial………………………………………………… 29 Figure 15:N-TiO2 2% dosage effect with visible light intensity 2.96x10-4- 1007 lux in Box A: a, survival or bacterial; b, amount of bacterial……………………………….30 Figure 16: N-TiO2 2% dosage effect with visible light intensity 2.95x10-4-1000 lux in Box B: a, survival or bacterial; b, amount of bacterial……………………………….31 Figure 17: N-TiO2 2% dosage effect with visible light intensity 1005lux in Box A: a, survival or bacterial; b, amount of bacterial………………………………………….32 Figure 18: N-TiO2 2% dosage effect with visible light intensity 1005 lux in Box A: a, survival or bacterial; b, amount of bacterial……………………………………… 33 Figure 19: Compare N-TiO2 dosage effect: a, survival or bacterial; b, amount of bacterial……………………………………………………………………………….35 Figure 20: N-TiO2 dosage effect to S.aureus: a, survival or bacterial; b, amount of bacterial……………………………………………………………………………….36 vii For the amount of bacterial in Figure 14b, the result had not stabilization and change in 24 hour Specific, it was fluctuated around 104 to 107 log from to 1320 Finally, it completed disinfection achieved log in the last time point 10 Amount of bacteria (log) Survival of bacteria (%) 300 250 200 150 100 50 10 10 10 10 100 10 500 1000 1500 500 1000 Time (min) Time (min) Figure 14: N-TiO2 1% dosage effectwith light intensity 1007 lux,: a, survival or bacterial; b, amount of bacterial Experiment conditions: Date: 02.05.2017, N-TiO2 1%, Box B, E.coli concentration 105 CFU/mL, light intensity 1007 lux, temperature 27°C To compare all of experiment had done, the resultssurvival of E.coli effect by N-TiO2 1% dosage were the same because bacterial always grow up in first time point and slightly decreasing After that E.coli was strongly increased to highest percentage the number of bacterial and almost finishinactivation around 1200 to 1440 min.But the result still had some different thing, because the conditions and the ligh intensity effect to PMMA with N-TiO21% were different so the number of bacterial non-uniform grow up For amount of bacteria compare with all experiment also had fluctuated but the amount had distance not the same with each experiment 29 1500 4.2.3 Result of N-TiO2 2% dosage effect The result shown Figure 15, E.coli had dosage effect by antibacterial N-TiO2 2% with the experiment in conditions were E.coli dilution in 105 CFU/mL and the light intensity around 2.96x10-4-1007 lux, temperature not change at 27 degree E.coli was inactivation when it had strong effect by the N-TiO2 and consider under in visible In figure 15a the result of E.coli survival almost grew up under 20% and only had the higest percentage ( about 40%) in 900 Until 1440 min, the number of bacterial were died and cough not increasing more The amount of bacterial had shown in Figure 15b, from to 180 was little decreasing and behind that bacterial more grow up until 900 around 105 to 107log After 900 min, the amount of bacterial was slowly decreased and finished disinfection until 1440 10 Amount of bacteria (log) Survival of bacteria (%) 600 500 400 300 200 100 10 10 10 10 100 10 500 1000 1500 500 TIme 1000 TIme Figure 15: N-TiO2 2% dosage effect with light intensity 2.96x10-4-1007 lux in Box A: a, survival or bacterial; b, amount of bacterial Experiment conditions: Date 09.04.2017, N-TiO2-2%, Box A, E.coli concentration 105 CFU/mL, light intensity 2.96x10-4-1007 lux, , temperature 27°C 30 1500 The experiment in Figure 16, had shown the data of E.coli inactivation of antibacterial solution by N-TiO2 2% and the conditions include E.coli dilution 105 CFU/mL, visible light intensity 2.95x104-1000 lux, temperature around 27 degree Compare with figure 15, because two experiments perform in same day with different the light intensity but not much and the temperature also 27 degree The result of two experiment had different For example, Figure 15 a, the survival of bacterial got the highest percentage in 900 around 40% while in Figure 16 a, the highest percentage of bacterial survival less than and about 25% grow up in 1080 Following that, the number of E.coli survival were reduced until 1320 Consequently, E.coli almost disintegrated in the last time point (1440 min) In Figure 16b, the number of E.coli amount had unstable and around 103 to 106 The amount had higher than another experiment in the same day In the Figure 15b, the amount of E.coli had completed disinfection by N-TiO2 at log On the contrary, the number of bacterial in Figure 13b, was large and finish experiment 10 Amount of bacteria (log) Survival of bacteria (%) 600 500 400 300 200 100 0 500 1000 10 10 10 100 10 1500 TIme 500 1000 TIme Figure 16: N-TiO2 2% dosage effect with light intensity 2.95x10-4-1000 lux in Box B: a, survival or bacterial; b, amount of bacterial 31 1500 Experiment conditions: Date 09.04.2017, N-TiO2-2%, Box B, E.coli concentration 105 CFU/mL, light intensity 2.95x10-4-1000 lux, temperature 27°C Figure 17 had shown the result effect of loading on E.coli inactivation in deferent loading range of N-TiO2 2% with the initial concentration of E.coli ranged 105 CFU/mL, the visible light lamp intensity 1005lux and temperature around 27 degree The number of E.coli survival had a lot of change in each period time in Figure 17a The highest not exceed 30 percentage of bacterial survival In experiment process, the survival of bacterial strongly increased two times at 720 and 1200 The bacterial inactivation became percentage from 1320 until finish experiment Figure 17b shown that the amount of bacteria grew up in 24 hours It was fluctuated in about 105 to 106 log from to 1200 After 1200min, it start to drop and finish to disinfection at 1440 10 Amount of bacteria (log) Survival of bacteria (%) 600 500 400 300 200 100 10 10 10 10 100 10 500 1000 1500 Time (min) 500 1000 1500 Time (min) Figure 17: N-TiO2 2% dosage effect with light intensity 1005 lux in Box A:a, survival or bacterial; b, amount of bacterial Experiment conditions: date.26.04.2017, N-TiO2-2%, Box concentration 105 CFU/mL, light intensity 1005lux, temperature 27°C 32 A, E.coli 10 Amount of bacteria (log) Survival of bacteria (%) 600 500 400 300 200 100 10 10 10 10 100 10 500 1000 1500 Time (min) 500 1000 1500 Time (min) Figure 18: N-TiO2 2% dosage effect with light intensity 1005lux in Box B: a, survival or bacterial; b, amount of bacterial Experiment conditions: Date 22.05.2017, N-TiO2 2%, Box B, E.coli concentration 104 CFU/mL, light intensity 1004 lux, temperature 27°C In Figure 18, had shown the experiment effect to loading on E.coli inactivation in deferent loading range of N-TiO2 2% with visible light 1004 lux and temperature about 27 degree The E.coli concentration dilution in 104 CFU/mL That experiment in Figure 18a, have the result deferent and the number of E.coli survival got the highest in two times around 40 percentage However, After strongly grew up, number of bacterial were declined and became percentage in 1200 until 1440 For the results of bacterial amount was unstable 104 to 107 around to 1200 and achieve the highest number of bacteria at 1080 in Figure 18b Then was slowly decreased and completed to disinfection of bacterial 33 Overall, all of experiment used antibacterial by N-TiO2 2% and got the deferent result In each experiment, the number of E.coli survival development and stop to grow up in different period time The highest percentage of bacterial survival around 40% and almost finish decomposition process The amount of bacterial was changed in among 104 to 107 log and decreased to become log from 1200 to 1440min 4.3 Compare N-TiO2dosage effect Figure 19, all of experiment had used antibacterial by N-TiO2 to disinfection E.coli bacterial Figure 19 was combined and summaries all of experiment with different dose of antibacterial by N-TiO2 ( 0.5%, 1% and 2%) That figure had shown all of experiment results same as conditions with E.coli concentration 105 CFU/mL and the visible light intensity around 990 to 1010 lux with the temperature not change about 27 degree around 24 hours 10 Amount of bacteria (log) Survival of bacteria (%) 800 600 400 200 10 10 10 10 100 10 500 1000 1500 500 1000 1500 Time (min) Time (min) Figure 19: Compare N-TiO2 dosage effect: a, survival or bacterial; b, amount of bacterial Experiment conditions: E.coli concentration 105 CFU/mL, light intensity 990 t0 1010 lux, temperature around 27°C 34 Figure 19 shows the result of E.coli bacterial with N-TiO2 dosage effect 0.5%,1% and 2% and visible light lamp intensity around 990 to 1010 lux with temperature 27°C in 24 hours The initial concentration of E.coli ranged 105 CFU/mL The result of bacterial when used different amount of N-TiO2 dosage Figure19 showed that survival of bacterial had different result The first, NTiO2 0.5% had highest number of bacteria survival See in Figure 19, when used solution more higher N-TiO2 percentage, the bacterial survival had changed the result and more less than In figure 19a, compare the result of N-TiO2 0.5 %had higher and more increased than N-TiO2 2% four time Therefore, from these experiments can use antibacterial N-TiO2 % apply to our life cause the solution by N-TiO2 2% more optimal than N-TiO2 0.5% and 1% The proportion of E.coli was grew up around 20 percentage which used antibacterial by N-TiO22% For the amount of bacterial had not much different result when used a N-TiO2 solution with other percentage, three types of experiment almost shown the same result from to 1080 and then completed disinfection to effect E.coli in deferent rate at 1440 The amount of bacterial effect loading by N-TiO2 2% also had great result than N-TiO2 0.5% and 1% From all of experiment, it candemonstrate, N-TiO2 2% is the best solution and suitable for research and manufacture more to prevent E.coli spread in environment and daily life It is certain that can protect human healthy in the face of disease 35 4.3.1 Result of N-TiO2 dosage effect to S.aureus Amount of bacteria (log) Survival of bacteria (%) 10 100 80 60 40 20 10 10 10 100 10 500 1000 1500 500 1000 Time (min) Time (min) Figure 20: N-TiO2 dosage effect to S.aureus: a, survival or bacterial; b, amount of bacterial Experiment conditions: Date 11.05.2017, N-TiO2 2%, S-aureus concentration 105 CFU/mL, light intensity 1008 lux, temperature 27°C In Figure 20 had shown the result of inactivation S.aureus experiment by antibacterial N-TiO2 2% with the bacterial concentration and dilution at 105 CFU/mL Another conditions are the light lamp intensity around 1008 lux and the temperature about 27 degree Figure 20a,The result of S.aureus survival got highest about 100 percentage in the first time point However, the number of bacterial survival was strongly decreased after and fell around 20 percentage in 60 After 180 min, the of S.aureus survival drop one more time and finish inactivation effect by NTiO2 from 360 until 1440 36 1500 For the amount of S.aureus was development in the first time point but that got strong impact by antibacterial and quickly decreased after ( drop around 106 to log) until finish all of experiment process 4.4 Compare control and N-TiO2 dosage effect The difference between control experiment and antibacterial by N-TiO2 dosage effect had shown on all of the results done before Control experiment and antibacterial by N-TiO2 experiment were prepared by same conditions with the light lamp intensity around 990 to 1010 lux and the temperature about 27 degree When experiment process, control experiment showed that the survival of bacterial only grow up and increasing after each time point That experiment had approved without antibacterial solution by N-TiO2, the bacterial can not decomposition and inactivation The number of E.coli would not impacted by the light and temperature while it will be a favorable condition for the growth of bacteria However, other experiment have been performed with antibacterial by N-TiO2 That N-TiO2 experiment had shown the result better than control experiment The bacterial were reaction and inactivation with antibacterial All of experiment proceeded around 24 hours as the bacterial have to grow up Then N-TiO2 solution will effect to the development process of bacterial and decreasing the number of bacterial survival Overall, control experiments were the premise for comparisonthe development of bacterial while N-TiO2 experiment has show the ability to control and kill bacteria Such as, when using antibacterial by N-TiO2 more effective and better than control and 37 without N-TiO2 In fact, when applied antibacterial by N-TiO2in life, we can prevent and minimizes significantly the development of bacterial to affect our life and health 4.5 Compare S.aureus and E.coli Compare the result of E.coli bacterial with S.aureus bacterial, the result of S.aureus more better than E.coli bacterial and differ markedly even same conditions and solution in some experiment Figure 20 had shown the result effect of loading on E.aureus inactivation in deferent loading range of solution N-TiO2 2% with visible light 1008 lux and temperature about 27 degree Compared some of the E.coli experiment same conditions with the S.aureus experiment, the results E.coli survival had considerable change, the number of E.coli were grew up and got the highest percentage in the middle of experiment time around 360 to 1080 After that start to decrease and die from 1080 until finish experiment process in 24 hours Conversely, the number of S.aureus survival were grew up and got the highest percentage in first time point but after strong develop S.aureus start to slowly drop and complete inactivation effect to antibacterial from 60 to 1440 That mean, N-TiO2 had strong impact to S.aureus survival and development in all of process to disinfection time The rate of bacterial survival between two experiment had big different Cause of antibacterial by N-TiO2 to effect two bacterial had deferent function and structure In fact, to protect people from disease and spread of bacterial while can be apply and use N-TiO2 solution to S.aureus to be kill and disinfection All of experiment had applied the antibacterial by N-TiO2 to S.aureus show the better result than E.coli experiment 38 CHAPTER V:Conclusion This study develops modified photocatalytic nanomaterials (N-TiO2) that can work efficiently under visible light irradiation Some conclusion of this study are shown as following: • N-TiO2 photocatalyst was synthesized in laboratory conditions and it have been observed able to inactivate the E.coli bacteria signficantly in the presence of visible light • E.coli inactivation in deferent loading range of control and N-TiO2 dosage effect with visible light lamp intensity around 1000 to 1030 lux in period 24 hours • Two initial concentration of bacterial ( 104 and 105 CFU/mL) were used to determent the effect of initial concentration on deactivation rate • The mechanisms of photodisinfection was clarified in this experiment 39 Reference : Journal Ansari, S A., & Cho, M H (2016) Highly Visible Light Responsive, Narrow Band gap TiO2 Nanoparticles Modified by Elemental Red Phosphorus for Photocatalysis and Photoelectrochemical Applications Sci Rep, 6, page 25405 Ansari, S A., Khan, M M., Ansari, M O., & Cho, M H (2016) Nitrogen-doped titanium dioxide (N-doped TiO2) for visible light photocatalysis New J Chem., 40(4), page 3000-3009 Castellote, M., & Bengtsson, N (2011) Principles of TiO2 Photocatalysis page 5-10 Factorovich, M., Guz, L., & Candal, R (2011) N-: Chemical Synthesis and Photocatalysis Advances in Physical Chemistry, 2011, page 1-8 Yoshida, T., Niimi, S., Yamamoto, M., Nomoto, T., & Yagi, S (2015) Effective nitrogen doping into TiO2 (N-TiO2) for visible light response photocatalysis J Colloid Interface Sci, 447, page 278-281 Acevedo, A n., Carpio, E A., Rodríguez, J., & Manzano, M A (2012) Disinfection of Natural Water by Solar Photocatalysis Using Immobilized TiO2 Devices: Efficiency in Eliminating Indicator Bacteria and Operating Life of the System Journal of Solar Energy Engineering, 134(1), page 011008 Chen, S., Guo, Y., Zhong, H., Chen, S., Li, J., Ge, Z., & Tang, J (2014) Synergistic antibacterial mechanism and coating application of copper/titanium dioxide nanoparticles Chemical Engineering Journal, 256, page 238-246 40 Chawengkijwanich, C., & Hayata, Y (2008) Development of TiO2 powder-coated food packaging film and its ability to inactivate Escherichia coli in vitro and in actual tests Int J Food Microbiol, 123(3), page 288-292 Rumaiz, A K., Woicik, J C., Cockayne, E., Lin, H Y., Jaffari, G H., & Shah, S I (2009) Oxygen vacancies in N doped anatase TiO2: Experiment and first-principles calculations Applied Physics Letters, 95(26),page 262111 Zhou, R W., Zhou, R S., Zhang, X H., Li, J W., Wang, X Q., Chen, Q., Ostrikov, K (2016) Synergistic Effect of Atmospheric-pressure Plasma and TiO2 Photocatalysis on Inactivation of Escherichia coli Cells in Aqueous Media Scientific Reports, Donnenberg MS (2010) Infections due to Escherichia coliand other enteric Gramnegative bacilli In EG Nabel, ed., ACP Medicine, section 7, chap Hamilton, ON: BC Decker Internet resource Cristiana Figus (2015).“Synergic combination of the sol–gel method with dip coating for plasmonic devices” Retrieved fromhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC4362208/ Titaniumart (2011) “Photocatalysis Applications of Titanium Dioxide Ti02” Retrieved from http://www.titaniumart.com/photocatalysis-ti02.html 41 Christian Nordqvis ( 06/2017).“E Coli diarrheal infection: Symptoms, causes, and treatment” Retrieved fromhttp://www.medicalnewstoday.com/articles/68511.php Caratto V (2017).“Antibacterial activity of standard and N-doped titanium dioxidecoated endotracheal tubes: an in vitro study” Retrieved fromhttps://www.ncbi.nlm.nih.gov/pubmed/28444073 Ananpattarachai J (2016) “Visible light photocatalytic antibacterial activity of Nidoped and N-doped TiO2 on Staphylococcus aureus and Escherichia coli bacteria”.Retrieved fromhttps://www.ncbi.nlm.nih.gov/pubmed/26028352 Jim Lucas, Live Science Contributor (2015) “ What is Visible light” Retrieved fromhttps://www.livescience.com/50678-visible-light.html Hoa Nguyen (2016).“Vietnam in top one the list of antibiotic resistance, who's fail?” Retrieved fromhttp://baophapluat.vn/camera-benh-vien/viet-nam-dung-dau-danh-sachkhang-khang-sinh-loi-tai-ai-308164.html Thai Binh (04/2017).“Vietnam in the group of countries with the highest proportion of antibiotic resistant bacteria” Retrieved fromhttp://news.zing.vn/viet-nam-thuoc-nhomnuoc-co-ty-le-vi-khuan-khang-khang-sinh-cao-nhat-post737671.html T.Hanh (04/2017) “Vietnam appears to be resistant to all of antibiotics” Retrieved fromhttp://vietnamnet.vn/vn/suc-khoe/suc-khoe-24h/viet-nam-xuat-hien-sieu-vikhuan-khang-tat-ca-khang-sinh-366907.html Ha Vinh (2011) “Escherichia coli ( E.coli) Benefits and harms to people healthy.” Retrieved fromhttp://www.csql.gov.vn/External_TinYTe_Detail.aspx?idtin=48 42 Quynh Nhu (2011) “Bacterial E.Coli” Retrieved from http://www.rfa.org/vietnamese/in_depth/e-coli06172011092559.html?searchterm=None 43 ... diseases of intestinal tract of humans and animals E coli usually parasitic in the large intestine Most of E .coli can easily be found in the environment of facal, warmth and can survive for a long... thanks should be offered to the Rector of National Chung Hsing University for granting my internship acceptance I want to thank all of my colleagues in the ENM ( Environmental Nano Material) Laboratory,... activity of E coli using N- TiO2- PMMA Composite Assoc Prof Nguyen The Hung Supervisor Prof Yao Tung-Lin Abstract: Titanium dioxide (TiO2) is a semiconductor and photocatalyst in the decomposition and