This Weeks Media

Eosin-Methylene Blue is used to select G- lactose fermenters. The selective agent is eosin and methylene blue. The differential agent is methylene blue and lactose. If the organism ferments lactose it is most likely G- and lactose +. Medium is used to grow enteric microbes.
E coli: Microbe tolerates EMB. Microbe ferments lactose. Microbe is most likely G-
S. Aureus: Microbe does not tolerate EMB. Microbe does not ferment lactose. Microbe most likely G+
Ps. aeroginosa:Microbe tolerates EMB. Microbe does not ferment lactose. Microbe most likely G-
Unknown #30: Microbe does not tolerate Eosin & MB. Does not ferment lactose. Most likely G+

Phenyl Ethyl Alcohol is a medium used to select G+ cocci. The selective agent is phenyl ethyl alcohol and there is not a differential agent. Organisms that show good growth on this medium are most likely G+.

E. coli: Microbe does not tolerate Phenyl Ethyl Alcohol. Most likely G-

Ps. aeruginosa: Microbe does not tolerate PEA. Most like G-

S. Aureus: Microbe tolerates PEA. Most likely G+

Unknown #30: Microbe tolerates PEA. Most likely G+

MacConkey Agar is a medium used to select G- lactose fermenters. The selective agent is bile salts and the differential agent is neutral red and lactose. Lactose + microbes appear pink-red. Lactose - microbes appear cream to colorless. This medium is used to grow G- enteric microbes. E. coli: Microbe tolerates bile salts & Crystal Violet dye. Does ferment lactose. Most likely G-

Ps. Aerug: Microbe tolerates bile salts & CV. Does not ferment lactose. Most likely G-

S. Aureus: Microbe does not tolerate Bile salts or CV. Does not ferment lactose. Most likely G+
Unknown #30: Microbe does not tolerate bile salts or CV. Does not ferment lactose. Most likely G+

Mannitol Salt Agar is a medium used to select mannitol fermenting staph microbes. The selective agent is sodium chloride and the differential agent is phenol red. Positive mannitol fermenters turn yellow.
E coli: Microbe does not tolerate Sodium Chloride. Does not ferment Mannitol. Most likely G-

Ps. Aerug: Microbe does not tolerate NaCl. Does not ferment Mannitol. Microbe most likely G-

S. aureus: Microbe tolerates NaCl. Microbe ferments Mannitol. Microbe most likely G+

Unknown #30: Microbe tolerates NaCl. Microbe ferments Mannitol. Microbe most likely G+

Summary:

Unknown #30 had similare growth and fermentation patterns as S. aureus. However, unkown #30 had slightly better growth and fermentation when compared to S. aureus.

Unknown #3o tolerates MSA & PEA and does not tolerate EMB & MAC. It tolerates Phenyl Ethyl Alcohol, NaCl and ferments Mannitol. This microbe is most likely Gram + and tolerates a salty environment.