You are trying to enrich a new unusual endospore-forming microbe that has been r

Question

You are trying to enrich a new unusual endospore-forming microbe that has been reported to exist. It is a caultatively anaerobic, anoxygenic photosynthetic microbe. Its photosynthetic apparatus appears to be very similar to that found in the purple non-sulfur photosynthetic bacteria. In this question, you will choose an enrichment broth for the microbe.

a. which medium would you choose?

b. explain why you chose the broth that you did and why the other two are unacceptable

c. would you do a pretreatment before incubation? What would it be?

Medium A Medium B Medium C compound grams/L compound grams/l compound grams/L K2HPO4 • 3H2O 4.44 glucose 5.00 tryptone 10 (NH4)2So4 0.50 Na2HPO4 6.00 yeast extract 5.00 succinic acid 4.00 KH2PO4 3.00 NaCl 10 NaCl 0.50 NH4Cl 1.00 Nitriloacetic acid 0.20 NaCl 0.50 MgSO4• 7H2O 0.30 MgSO4• 7H2O 0.12 CaCl2 • 2H2O 0.033 CaCl2 • 2H2O 0.01 FeSO4 • 7 H2O 0.002 Trace elements 0.10 ml Vitamin Solution 0.10 ml 1% Ammonium molybdate 0.02 ml

Explanation / Answer

a. which medium would you choose?

Ans: Medium A

b. Ans:

For maintenance of pure cultures or when streaking plates from enrichments, add another 1.0 g of sodium succinate and 1.0 g of yeast extract per liter of Basal Medium. These items encourage robust growth of the desired organisms and also make detection of contaminants (mainly non-pigmented colonies) easier.

C. ANS: This non-specific background can be significantly reduced by pre-treatment of cells/tissues.

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.