20 You are measuring growth in a bacterial culture The number of viable cells remains constant and when you check the medium you find that the carbon source has been used up In which phase of growth is the culture 2 pts A Stationary phase B Lag phase C Log phase D Death phase Use the following for next 2 questions A death phase B lag phase C log phase D stationary phase The recipe for MacConkey agar is given below MacConkey agar is often used to differentiate E coli from other on peptone and appear white Be sure to read the function of all ingredients in the media Gram negative rods because E coli can ferment lactose and produces acid Other Gram negative rods grow Ingredient Peptone Lactose ase would penicillin an antibiotic that inhibits cell wall synthesis be most effective Bile salts NaCl Neutral red Crystal violet Agar pagin efalumb Function Nutrient source C and fermentation source inhibits growth of Gram positive cells Major metal pH indicator red at low pH clear at neutral pH inhibits growth of gram positive cells Solidifying agent Amount 17 g 10 g 1 5 g 21 What types of media is MacConkey agar from this list pick all that apply complex defined selective differential Why 5 pts 5 g 0 03 g 0 001 g 13 5 g via 8 0 22 Now suppose you streaked E coli on the left half of a MacConkey Agar plate and Pseudomonas aeruginosa on the other What describes what that plate would look like after an appropriate incubation period and why would it look that way Hint Pseudomonas is a Gram negative rod that cannot ferment