You perform a spread plate to determine the bacterial population in a batch liquid media. you plate 0.1ml of a 10-5 dilution. you incubate the plate and count 10 colonies (cfu). what is the bacterial population in cfu/ml of the stock (undiluted) culture? 10 million colonies 1 million colonies 100 million colonies

10 million colonies

The volume of media used is 0.1ml and the concentration diluted to 10^-5, so the actual volume used would be: 0.1ml * 10^-5= 1ml * 10^-6

The media shows 10 colonies. The number of colonies per volume would be: 10 cfu/ (1ml * 10^-6)= 10* 10^6 cfu/ml= 10 million cfu/ml

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.