How to Test for Unknown in Escherichia Coli. If you could explain it in flow cha

Question

How to Test for Unknown in Escherichia Coli.

If you could explain it in flow chart format, greatly appriciated

Need at least 2 tests from each category

(1) Morphology and Motility
Determ.ination

(2) Oxidation/Fermentation Tests,

(3) Hydrolysis/Biochemical Tests, and

(4) Selective/Differential media.

(5) specific and denote that result would be + for acid production
and + gas production as a result since a lactose durham tube tells not only if the organism
ferments lactose (color change) but also if it produces gas in the process (bubble).

Explanation / Answer

For morphological screening of E.coli, Gram staining is performed. In this test a smear of broth culture is taken onto the slide and stained by crystal violet stain followed by washing by alcohol and then, counter staining by safranin. In microscopic observation E. coli will aprrear rod shaped structure.

Two tubes are inoculated with OF test medium and test bacteria, and one tube is covered by paraffin. Then tubes are incubates at 350 C for 48 hours.

If pH indicator colour changes in both tubes, then presence of E,coli is confirmed.

In this test, starch agar media is used and test organism is inoculated and incubated for 24 hours at 370 C. Iodine is then applied on the agar suface. If the test orghanism does not hydrolyse starch , then colur of iodine changes. For E.coli, if present in the medium, this test is negative (-) as iodine will turn blue black, which means that starch is not hydrolysed and present in the medium.

Gas production : +

Acid production : +

Starch hydrolysis: -

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

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