User:Kara Tsukashima/Notebook/Yogurt Lactobacillus RFLP identification/2013/04/15

Project name

Main project page Previous entry      Next entry

Notes Colonies were counted and observed on the plates. On plates of both yogurts, two similar visual types of colonies were observed in roughly equal quantities. All colonies were small and had rough edges. Colonies may have been umbonate, though the small colonies and me forgetting that there was a dissecting microscope even if I couldn't find a lens leaves this uncertain. Besides this, roughly half of the colonies were of a more translucent type and slightly larger while the other half appeared more opaque-white and slightly smaller. Cow: Dilution CFU 1*10^7 23 1*10^6* 9 1*10^5 5 1*10^4 100 1*10^3 480 Contaminant colony (large, spreading) on edge of plate. Chobani: Dilution CFU 1*10^7 0 1*10^6* 7 1*10^5 5 1*10^4 23 1*10^3 160 Viable Count Calculations Cow: Chobani: Observations The Brown Cow yogurt was easier to deal with and I got more cells from it. Bluntly, the thickness of the Greek yogurt (Chobani), which I should have foreseen, was likely more the cause of this than any actual viable cell/mL difference. It remains to be seen how many or which species grew. Plan If feasible, I will return on Saturday to pour plates--some for Monday and some which would then be used to streak for isolation for the Brown Cow yogurt.