{"id":40842,"date":"2023-08-03T14:54:56","date_gmt":"2023-08-03T09:09:56","guid":{"rendered":"https:\/\/microbenotes.com\/bacterial-growth-curve-protocol\/"},"modified":"2023-08-03T14:54:56","modified_gmt":"2023-08-03T09:09:56","slug":"bacterial-growth-curve-protocol","status":"publish","type":"post","link":"https:\/\/microbenotes.com\/bacterial-growth-curve-protocol\/","title":{"rendered":"Bacterial Growth Curve Protocol"},"content":{"rendered":"<ul>\n<li><span style=\"color: #000000;\">When fresh liquid medium is inoculated with a given number of bacteria and incubated for sufficient period of time, it gives a characteristic growth pattern of bacteria.<\/span><\/li>\n<li><span style=\"color: #000000;\">If the bacterial population is measured periodically and log of number of viable bacteria is plotted in a graph against time, it gives a characteristic growth curve which is known as\u00a0growth curve.<\/span><\/li>\n<li><span style=\"color: #000000;\">Measuring the growth rate of bacteria is a fundamental microbiological technique, and has widespread use in basic research as well as in agricultural and industrial applications.<\/span><\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1521\" src=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2019\/02\/Bacterial-growth-curve.jpg\" alt=\"Bacterial Growth Curve\" width=\"800\" height=\"420\" \/><\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_65 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title \" >Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #0a0a0a;color:#0a0a0a\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #0a0a0a;color:#0a0a0a\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/microbenotes.com\/bacterial-growth-curve-protocol\/#principle-of-bacterial-growth-curve\" title=\"Principle of\u00a0Bacterial Growth Curve\">Principle of\u00a0Bacterial Growth Curve<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/microbenotes.com\/bacterial-growth-curve-protocol\/#materials-required-for-bacterial-growth-curve\" title=\"Materials Required\u00a0for Bacterial Growth Curve\">Materials Required\u00a0for Bacterial Growth Curve<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/microbenotes.com\/bacterial-growth-curve-protocol\/#procedure-of-bacterial-growth-curve\" title=\"Procedure of\u00a0Bacterial Growth Curve\">Procedure of\u00a0Bacterial Growth Curve<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/microbenotes.com\/bacterial-growth-curve-protocol\/#expected-result-of-bacterial-growth-curve\" title=\"Expected Result of\u00a0Bacterial Growth Curve \">Expected Result of\u00a0Bacterial Growth Curve <\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/microbenotes.com\/bacterial-growth-curve-protocol\/#references\" title=\"References \">References <\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"principle-of-bacterial-growth-curve\"><\/span><span style=\"color: #000000;\"><strong>Principle of\u00a0Bacterial Growth Curve<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\">When bacteria are inoculated into a liquid medium and the cell population is counted at intervals, it is possible to plot a typical bacterial growth curve that shows the growth of cells over time. It shows four distinct phases of growth.<\/span><\/p>\n<ul>\n<li><span style=\"color: #000000;\"><strong>Lag phase:<\/strong> Slow growth or lack of growth due to physiological adaptation of cells to culture conditions or dilution of exoenzymes due to initial low cell densities.<\/span><\/li>\n<li><span style=\"color: #000000;\"><strong>Log or exponential phase:<\/strong> Optimal growth rates, during which cell numbers double at discrete time intervals known as the mean generation time.<\/span><\/li>\n<li><span style=\"color: #000000;\"><strong>Stationary phase:<\/strong> Growth (cell division) and death of cells counterbalance each other resulting in no net increase in cell numbers. The reduced growth rate is usually due to a lack of nutrients and\/or a buildup of toxic waste constituents.<\/span><\/li>\n<li><span style=\"color: #000000;\"><strong>Decline or death phase:<\/strong> Death rate exceeds growth rate resulting in a net loss of viable cells.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\">Turbidimetric determination is useful for plotting growth curves of bacteria in broth or liquid media. It is one of the simplest methods used to analyze trends in growth because it uses a spectrophotometer to track changes in the optical density (OD) over time. In other words, as the number of cells in a sample increase, the transmission of light through the sample will decrease.\u00a0<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"materials-required-for-bacterial-growth-curve\"><\/span><span style=\"color: #000000;\"><strong>Materials Required\u00a0for Bacterial Growth Curve<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\">Bacterial culture (E. coli), Broth (Luria Bertani (LB) Broth, Nutrient Broth)<\/span><\/p>\n<p><span style=\"color: #000000;\">Glass wares: Conical flasks, Measuring cylinder, Sterile test tubes, Sterile Petriplates<\/span><\/p>\n<p><span style=\"color: #000000;\">Reagents: Distilled water<\/span><\/p>\n<p><span style=\"color: #000000;\">Other requirements: <a href=\"https:\/\/microbenotes.com\/incubator-principle-parts-types-procedure-uses-examples\/\">Incubator<\/a>, Shaker, Spectrophotometer, Micropipettes, Tips, Sterile Loops<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"procedure-of-bacterial-growth-curve\"><\/span><span style=\"color: #000000;\"><strong>Procedure of\u00a0Bacterial Growth Curve<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\"><strong>Day 1:<\/strong><\/span><\/p>\n<ol>\n<li><span style=\"color: #000000;\">Using sterile loop, streak a loopful of bacterial culture onto the agar plate.<\/span><\/li>\n<li><span style=\"color: #000000;\">Incubate at 37<sup>o<\/sup>C for 18-24 hours.<\/span><\/li>\n<\/ol>\n<p><span style=\"color: #000000;\"><strong>Day 2:<\/strong><\/span><\/p>\n<ol>\n<li><span style=\"color: #000000;\">Pick up a single colony of each strain from the agar plate and inoculate it into a test tube containing 10 ml of autoclaved broth.<\/span><\/li>\n<li><span style=\"color: #000000;\">Incubate the test tube overnight at 37<sup>o<\/sup>C.<\/span><\/li>\n<\/ol>\n<p><span style=\"color: #000000;\"><strong>Day 3:<\/strong><\/span><\/p>\n<ol>\n<li><span style=\"color: #000000;\">Take 250 ml of autoclaved broth in a sterile 500 ml conical flask.<\/span><\/li>\n<li><span style=\"color: #000000;\">Inoculate 5 ml of the overnight grown culture in above flask.<\/span><\/li>\n<li><span style=\"color: #000000;\">Take OD at zero hour. Incubate the flask at 37<sup>o<\/sup>C.<\/span><\/li>\n<li><span style=\"color: #000000;\">Aliquot 1 ml of the culture suspension at an interval of every 30 minutes and take the optical density (OD) at a wavelength of 600 nm using spectrophotometer, till the reading becomes static.<\/span><\/li>\n<\/ol>\n<p><span style=\"color: #000000;\">Alternatively, 50-100 \u00b5l of formaldehyde can be added to all the 1 ml aliquots of culture suspension taken after every 30 minutes. Optical density of all the aliquots can be taken at the end of the experiment.<\/span><\/p>\n<ol start=\"5\">\n<li><span style=\"color: #000000;\">At the end of experiment, plot a graph of time in minutes on X axis versus optical density at 600nm on Y axis to obtain a growth curve of bacteria.<\/span><\/li>\n<\/ol>\n<h2><span class=\"ez-toc-section\" id=\"expected-result-of-bacterial-growth-curve\"><\/span><span style=\"color: #000000;\"><strong>Expected Result of\u00a0Bacterial Growth Curve <\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\">A logarithmic growth curve is obtained showing the changes in size of a bacterial population over time in the culture.\u00a0The growth curve is hyperbolic due to exponential bacterial growth pattern.<\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"references\"><\/span><span style=\"color: #000000;\"><strong>References <\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ol>\n<li><span style=\"color: #000000;\"><a style=\"color: #000000;\" href=\"http:\/\/himedialabs.com\/TD\/HTM001.pdf\" target=\"_blank\" rel=\"noopener\">http:\/\/himedialabs.com\/TD\/HTM001.pdf<\/a><\/span><\/li>\n<li><span style=\"color: #000000;\">Maier, R.M., Pepper, I.L., and Gerba, C.P. (2000) Environmental Microbiology. Academic Press, San Diego.<\/span><\/li>\n<li><span style=\"color: #000000;\">https:\/\/info.gbiosciences.com\/blog\/bacterial-growth-curves-turbidimetric-determination<\/span><\/li>\n<li><span style=\"color: #000000;\">file:\/\/\/C:\/Users\/I%20CAPITAL\/Downloads\/02Experiment_1.pdf<\/span><\/li>\n<li><span style=\"color: #000000;\">http:\/\/www.onlinebiologynotes.com\/bacterial-growth-curve\/<\/span><\/li>\n<li><span style=\"color: #000000;\"><a style=\"color: #000000;\" href=\"https:\/\/www.jove.com\/science-education\/10100\/bacterial-growth-curve-analysis-and-its-environmental-applications\" target=\"_blank\" rel=\"noopener\">https:\/\/www.jove.com\/science-education\/10100\/bacterial-growth-curve-analysis-and-its-environmental-applications<\/a><\/span><\/li>\n<li><span style=\"color: #000000;\"><a style=\"color: #000000;\" href=\"https:\/\/www.encyclopedia.com\/science\/dictionaries-thesauruses-pictures-and-press-releases\/bacterial-growth-curve\" target=\"_blank\" rel=\"noopener\">https:\/\/www.encyclopedia.com\/science\/dictionaries-thesauruses-pictures-and-press-releases\/bacterial-growth-curve<\/a><\/span><\/li>\n<li><span style=\"color: #000000;\">http:\/\/science.jrank.org\/pages\/714\/Bacteria.html<\/span><\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>When fresh liquid medium is inoculated with a given number of bacteria and incubated for sufficient period of time, it gives a characteristic growth pattern of bacteria. If the bacterial &#8230; <a title=\"Bacterial Growth Curve Protocol\" class=\"read-more\" href=\"https:\/\/microbenotes.com\/bacterial-growth-curve-protocol\/\" aria-label=\"Read more about Bacterial Growth Curve Protocol\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":1840,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6207],"tags":[3052,3050,3055,3057,3054,3056,3051,3058,3053],"custom":{"td_video":"","featured_image":"https:\/\/microbenotes.com\/wp-content\/uploads\/2019\/02\/Bacterial-growth-curve.jpg","author":{"name":"Sagar Aryal","avatar":"https:\/\/secure.gravatar.com\/avatar\/862472ea06500d4318f1ad82addb608e?s=96&d=mm&r=g"},"categories":[{"term_id":6207,"name":"Protocols","slug":"protocols","term_group":0,"term_taxonomy_id":6207,"taxonomy":"category","description":"Microbiology Protocols. Molecular Biology and Genetics Protocols. 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