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BACTERIAL GROWTH and CONTROLLING BACTERIAL GROWTH lab report using virtual unkno

ID: 52560 • Letter: B

Question

BACTERIAL GROWTH and CONTROLLING BACTERIAL GROWTH lab report using virtual unknown software

Bacterial Growth

Include purpose of lab experiment>

<brief summary of topic investigating and case studies >

<state major finding>

Procedure

< Include information that the reader would need to repeat your experimental procedure. Do not include any observations or results in this section>

Observations and Results

Part I: Bacterial Growth

Result + or -

Appearance after Incubation

Gram Stain

N/A

OF Glucose Broth

OF Glucose Broth with Oil

Indole Production Test

Malonate

Bacterium identified as:

Assigned bacterium was:

Discussion & Conclusion

Based upon your results, is your bacteria sample a strict aerobe, strict anaerobe, facultative anaerobe, or microaerophile? Why? Look at your results from OF Glucose and OF Glucose with oil test.

How important is it to add the Kovac's Reagent in the Indole Utilization test? What is responsible for the color change observed in a positive test? You can read more about this test in the Test Media Reference in VUMIE2012. Click the M? button.

Did the bacteria grow in the tryptone or malonate media? Why or why not? Remember, you can tell if they grew if culture was turbid (cloudy).

For the media used in this portion of the experiment, are the media complex or synthetic? Are the media selective, differential, both, or neither? Identify the carbon and nitrogen source for each medium. Read more about what these terms mean starting on page 178 in your book right below Figure 6.11. Look up each media with the M? button. Remember, nutrient broth is a complex media, mineral salts is a defined media.

How many possible bacteria were remaining after conducting these biochemical tests?

Using the information in the Identification matrix, what additional tests might help you to identify the bacteria in your case study? Look at the View Identification Matrix under the View menu. What tests would you perform? Look for ones that have a mix of + and - because they would help distinguish between organisms.

Result + or -

Appearance after Incubation

Gram Stain

N/A

OF Glucose Broth

OF Glucose Broth with Oil

Indole Production Test

Malonate

Explanation / Answer

Bacterial Growth and Control - The bacteria can grow in the presence of nutrients for its growth, the growth medium consist of carbon source, nitrogen source, and minerals for its growth. These bacteria can multiple unless there is growth limitation in the medium.

Control of bacteria - It can be done in two different ways either by completely killing or by inhibiting the growth.

Procedure:

A colony of bacterial isolate should be inoculated in the sterile nutrient or mineral salt broth. The organism after inoculation is left for overnight growth in a microbial incubated shaker. The 16 h culture is then used for different test to identify the bacterium.

Discussion:

The OF test dertermines whether the organism if oxidative or fermentative; If the color of both the tube changes to yellow in presence and absence of oil it is called both oxidative and fermentative hence the organism is facultative anerobe or microaerophilic.

If the color changes in only tube with out oil it is strict aerobe, if the color changes only in tube with oil it is strict anaerobe.

Importance of Kovacs reagent in Indole test: The kovac's reagent consist of isoamyl alcohol,  para-Dimethylaminobenzaldehyde and Conc. HCl. The p-dimethyl amino benzaldehyde reacts with the indole produced by the fermentation of tryptophan by the organism. The iso amyl alcohol binds with the dye and precipitate it. Hence we have red color ring formation.

Growth in tryptone or Malonate medium - The capability of organism to utilize trypone is tested using this test. When there is growth in tryptone broth it shows that it can utilize tryptone as sole carbon and nitrogen source. Malonate medium is used to determine whether the organism can utilize malonate as sole carbon source.

The answers for the last two questions can be provided only if the results are provided.