Channel: Sci- Inspi

Category: Science & Technology

Tags: fat globulesyogurtbacteriamilkpastuerizationfat dropletspetri dishyeastmicroscopecheeseguitarhomogenizationexpiredmusicmicrobessciencecalming

Description: Microscopic footage of milk before it expires, after it expires on its "best-by-date" and after being incubated to speed up microbial growth. I also tested for bacteria at each stage with a petri dish to quantify bacterial colonies. I believe the most common bacteria after the milk was incubated to be lactobacillus because of the following criteria: gram positive rods, growth on complex medium (milk, Tryptic soy agar), non-pathogenic since the milk was pasteurized, Indole negative, Citrate negative. This is the best guess I can make with the medium and tests available to me in my lab. Visit the links below for more information on: Homogenization: en.wikipedia.org/wiki/Homogenization_(chemistry) Pasteurization: en.wikipedia.org/wiki/Pasteurization Expiration dates and how to store milk: eatbydate.com/dairy/milk/milk-shelf-life-expiration-date Curd: en.wikipedia.org/wiki/Curd Whey: en.wikipedia.org/wiki/Whey FAQ: Q: The milk was pasteurized. Where did the microbes come from? A: Pasteurization kills most but not all microbes. The ones that survived grow in the milk.  I used a Nikon D3300 DSLR camera and a Leica ATC 2000 Microscope for this video. The Microscope magnification of each shot is shown in the bottom right hand corner. Music is written and produced by Sci-inspi.