You set up an anaerobic jar and after incubation the indicator strip is blue. What can you conclude from this? Are the organisms growing on your plate anaerobes? Explain.

The following plates were inoculated with organisms A, B, C, and D on each sector of this plate. Each plate was grown at the the temperature indicated (4C, 25C, 40C, and 60C). Choose the organism that is the psychrophile.    A B D C

When the microbes were exposed to different temperatures how was it possible to see minimal growth? What had to be functional in order for growth to occur?

Two cultures of a facultative anaerobe are grown in the same medium, but one culture is exposed to air and the other is maintained under anaerobic conditions. Which of the two cultures will contain more cells at the end of a week? Why?

You applied hydrogen peroxide to a bacterial culture growing on a Petri dish and obtained bubbles within 10 seconds of application. What test did you perform? Catalase O Oxidase Triple Sugar Iron agar O MacConkey agar

You are given a mixed culture of 3 bacteria with following characteristics- 1) Bacteria 1 - Methicillin- resistant Staphylococcus aureus (MRSA) (does not ferment any of these 4 sugars but forms endospores and is sensitive to penicillin) 2) Bacteria 2 - Escherichia coli (can ferment glucose, maltose, sucrose and lactose) and also produce carbon dioxide gas on fermenting these 3) Bacteria 3 - Enterobacter aerogenes. (can ferment only sucrose and cannot ferment glucose, maltose and lactose. Also on fermenting sucrose it produces hydrogen sulphide gas.) Also they all give similar looking white-colored colonies on an agar plate. Question: Generate separate pure cultures of these 3 bacteria from the mixed culture using the following tools that you learned in the lab. Use any (some or all) of these tools to generate pure cultures as well as confirm them. Any other technique that you use should be one you learned in lab. No need to give detailed info about how to perform the technique but it…

What is one difference between fermentation and anaerobic respiration?  Since neither requires oxygen, why would a microbe select one of these versus the other?  Name a specific microbe which uses fermentation and a specific microbe which uses anaerobic respiration.

Why do obligate aerobes (and facultative anaerobes) need oxygen? Be specific.

Why would you not expect an obligate aerobe to have a fermentative pathway?

Give an example of a bacterium that can be described as an “anaerobic chemoorganoheterotroph ”. Also explain what the different parts of the description mean