Question

4&5 please

4. Juan is a new lab tech who needs to inoculate agar slants that students will be using to make endospore stain smears. He inoculates the tubes on Monday for a lab the following day. Did the students find endospores on their slides? Explain why or why not. 1 point 5. After inoculating with her unknown, Letitia's Phenyl Red Glucose, Lactose, and Sucrose tubes are all yellow. Her TSI tube results are K/H2S. The EMB plate result is + +. Do all results agree? Explain why, or why not. Be thorough! I point - All tests do not agree.

Answer 1

4, Normally when we are suppose to do endopsore staining , we are asked to use the culture which is 48hrs to 5 days older. the uniformity in spore production is not seen in case of cultures growing normally with their sole source of energy and carbon. When given time, spore forming bacteria produces spores. Old cultures are preferred for staining endopsores.

So most probably students will not be able to view the endospores because the chance of endospore formation is less in a 24hr culture.

5, Carbohydrate fermentation tests-

Glucose- yellow

Lactose- yellow

sucrose- yellow

Results indicate that the bacteria can ferment all the sugars

TSI

In TSI slant, the three sugars- glucose, lactose and sucrose are added in the media to check if the bacteria can ferment these sugar

sodium thiosulfate and ferrous sulfate is used to detect the Hydrogen sulphide gas production

result given - K/H2S

K- alkaline condition in the tube which means that none of the sugars are fermented.

EMB

It is a differential media supplied with lactose. Lactose fermentors can be identified by the growth

Result given- +,+

it means that lactose is fermented

So the result of TSI do not coincide with the result of other two tests. SO all the results do not agree.