BIOMED Engineering Experimental proposal for Growth E.Coli


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BIOMED Engineering Experimental proposal for Growth E.Coli

  1. 1. Team 3 March 31, 2014
  2. 2.  The purpose of this study is to create and validate a mathematical model of a growth curve of bacterial behavior after thermal shock at various temperatures
  3. 3.  Escherichia coli (E. coli) is a type of bacteria commonly found in the intestinal tracts of large mammals  The growth and decay rate are also affected by:  Temperature  Initial concentration of bacteria  Presence of antibacterial substances  pH levels  Oxidation reduction potential
  4. 4.  In our experiment, we demonstrate how the growth curve is affected by thermal shock  E. Coli grows well between 21oC to 50oC with an optimum at about 37oC .  E. coli can divide every 20 minutes  At temperatures of 0°C (32°F) E. coli are unable to divide, keeping the population stable  E. coli is killed above 70°C (160°F)
  5. 5.  Lag phase: the population remains temporarily unchanged  Log phase: the cells divide at a constant rate depending on temperature conditions  Stationary phase: the population growth is limited by temperature  Death phase: the number of cells decreases The E.coli Growth Curve
  6. 6.  The growth curves of colonies shocked at temperatures (45-650C) demonstrate longer lag times but accelerated exponential growth when compared to a control grown at 37°C
  7. 7. WE WILL APPLY THIS EQUATION TO CREATE THE GROWTH CURVE MODEL[17] Where:  (Nmin) = minimum population of E.coli  (Nmax) = maximum population of E.coli  r = Temperature-dependent constant  C= Adjustment factor  N= number colonies at time t
  8. 8. Materials and Equipment  Spectrophotometer and cuvettes  Inoculation Loop  1000μL and 100μL micropipettes  Beakers and hot plates  Incubator (37oC)  Reagents:  Distilled water and deionized water  Culture of E.Coli  Nutrient broth as a food source
  9. 9. Thermal Shock:  Initially raise bacterial environment temperature to 450C, 550C, 600C, and 700C  Growth continued at 370C after thermal shock  Control group grown at 370C Measure growth  Create a concentration ladder  Measure cloudiness in a test tube as the number of cells increase (turbidity) using a spectrophotometer
  10. 10.  Mintab and MATLAB software  Plot mathematical growth curve and experimental growth curves  Regression analysis
  11. 11. [1] J. E. Bailey, "Mathematical Modeling and Analysis in Biochemical Engineering: Past Accomplishments and Future Opportunities," Institute of Biotechnology, 1998, pp. 8-20. [2] J. Baranyi, "A non-autonomous differential equation to model bacterial growth," T. A. Roberts, ed., Food Microbiology, 1993, pp. 43-59. [3] J. Baranyi, "A Review Paper: A Dynamic Approach to Predicting Bacterial Growth in Food," T. A. Roberts, ed., International Journal of Food Microbiology, 1994, pp. 227-294. [4] J. Baranyi, "Mathematics of predictive food microbiology," T. A. Roberts, ed., Food Microbiology, 1995, pp. 199-218. [5] M. Berney, H. U. Weilenmann, J. Ihssen et al., “Specific growth rate determines the sensitivity of Escherichia coli to thermal, UVA, and solar disinfection,” Applied and Environmental Microbiology, vol. 72, no. 4, pp. 2586-2593, Apr, 2006. [6] M. P. Doyle, “ESCHERICHIA-COLI O157 - H7 AND ITS SIGNIFICANCE IN FOODS,” International Journal of Food Microbiology, vol. 12, no. 4, pp. 289-302, Apr, 1991. [7] J. S. Edwards, "In silico predictions of Escherichia coli metabolic capabilities are consistent with experimental data," R. U. Ibarra, ed., Nature, 2001. [8] H. Fujikawa, "A new logistic model for Escherichia coli growth at constant and dynamic temperatures,“ Morozumi, Satoshi A. Kai, ed., Food Microbiology, 2004, pp. 501-509. [9] R. Ibarra, "Escherichia coli K-12 undergoes adaptive evolution to achieve in silico predicted optimal growth," J. S. Edwards, ed., Nature, 2002. [10] A. G. Marr, "Growth Rate of Escherichia Coli," 2, American Society for Microbiology, 1991. [11] J. M. Monk, P. Charusanti, R. K. Aziz et al., “Genome-scale metabolic reconstructions of multiple Escherichia coli strains highlight strain-specific adaptations to nutritional environments,” Proceedings of the National Academy of Sciences of the United States of America, vol. 110, no. 50, pp. 20338-20343, Dec, 2013. [12] D.-H. Oh, "A New Secondary Model Developed for the Growth Rate of Escherichia coli O157:H7 in Broth," T. Ding, ed., Indian Journal of Microbiology, 2012, pp. 99-101. [13] M. O. Olanya, "Effects of temperatures and storage time on resting populations of Escherichia coli O157:H7 and Pseudomonas fluorescens in vitro," D. O. Ukuku, ed., Food Control, 2014, pp. 128-134 [14] O. Rodriguez-Gonzalez, "Escherichia coli<font class=""> O157:H7 subjected to pulsed electric fields in milk," M. Walkling-Ribeiro, ed., International Dairy Journal, 2011, pp. 953-962. [15] J. Samelis, and J. N. Sofos, “Role of glucose in enhancing the temperature-dependent growth inhibition of Escherichia coli O157 : H7 ATCC 43895 by a Pseudomonas sp,” Applied and Environmental Microbiology, vol. 68, no. 5, pp. 2600-2604, May, 2002. [16] L. J. Tranvik, and M. G. Hofle, “BACTERIAL-GROWTH IN MIXED CULTURES ON DISSOLVED ORGANIC-CARBON FROM HUMIC AND CLEAR WATERS,”Applied and Environmental Microbiology, vol. 53, no. 3, pp. 482-488, Mar, 1987. [17] G. D. Wang, "Survival and growth of Escherichia coli O157:H7 in unpasteurized and pasteurized milk.," T. Zhao, ed., Journal of Food Protection, 1997, pp. 610-613. .