CRITICAL THINKING 1. What ingredient makes mannitol salt selective? 2. Fill in t
ID: 302799 • Letter: C
Question
CRITICAL THINKING 1. What ingredient makes mannitol salt selective? 2. Fill in the blanks in this diagram to make a key to these bacteria . Escherichia coli . Alcaligenes faecalis . Staphylococcus aureus Staphylococcus epidermidis Growth on EMB Growth on mannitol salt agar Color Metallic green colonies Colorless colonies Yellow medium White medium Circle or highlight the gram-positive bacteria in one color; use a different color to circle or highlight the gram- negative bacteria. CLINICAL APPLICATION Clinical samples are routinely inoculated onto differential and selective media. Determine whether the media listed below are selective or differential.Explanation / Answer
(1)High concentration of salt in mannitol salt enables it to select organisms which can tolerate salinity.
It also contain pH indicator phenol red and sugar mannitol,if an organism can ferment mannitol it produces acidic by products which can change red phenol colour to yellow.
(2)Starting from left:-
1.Eschersia coli
2.Alcaligenes facialis
3.staphylococcus aureus
4.Staphylococcus epiderdimis