Lab Report 3 PDF

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Lab Report 3 February 20, 2020 Cultural Characteristics of Microorganisms Introduction: Cultural characteristics are used as a basis for separating microorganisms into taxonomic groups. The purpose of this experiment is to understand and determine the characteristics of microorganisms and to learn how to classify microorganisms into groups based of their characteristics. This will be determined by culturing the organisms on agar slants, plates, nutrients broths and gelatin. 5 different bacteria will be used with each of the agar and broths to determine the different characteristics. Materials:  24-hour nutrient broth culture of  Pseudomonas aeruginosa  Bacillus cereus  Microccus luteus  Escherichia coli  72-96 hour Tryticase soy broth culture of  Mycobacterium smegmatis Media       

5 Nutrient agar plates 5 Nutrient agar slants 5 Nutrient broth tubes 5 Nutrient gelatin tubes Bunsen burner Inoculating loop and needle Glass ware marking pencil/ label tape

Procedures: Lab One Using aseptic technique, inoculate each of the appropriately labeled media listed below in the following manner: 1. a. Nutrient agar slants: With a sterile needle, make a single-line streak of each of the cultures provided, starting at the butt and drawing the needle up the center of the slanted agar surface. b. Nutrient agar plates: With a sterile loop, prepare a streak plate inoculation of each of the cultures for the isolation of discrete colonies. c. Nutrient broth cultures: Using a sterile loo, inoculate each organism into a tube of nutrients brother. Shake the loop for a few times to dislodge the inoculum. d. Nutrient gelatin: Using a sterile needle, prepare a stab inculcation of each of the cultures provided. 2. Incubate all cultures at 37’C for 24 to 48 hours.

Lab Two 1. Before begin observation of all cultures, place the gelatin cultures in the refrigerator for 30 minutes or in breaker of crushed ice for a few minutes. The gelatin culture will be the last to be observed. 2. Refer to page 26 of this experiment 3 while making observations a. Nutrient agar slants: Observe each of the nutrients agar slants cultures for the amount of pigmentation, form, and consistency of growth. b. Nutrient agar plates: Observe a single, well isolated colony on each of the nutrient agar plate cultures and identify its size, elevation, margin, form, pigmentation. M. luteus P. aeruginosa M. smegmatis E. coli B. cereus

Sediment

Floccent

Floccent

Sediment

Sediment

c. Nutrient broth cultures: Observe each of the nutrient broth cultures for the appearance of growth (flocculation, turbidity, sediments, or pellicle). Record observations. d. Nutrients gelatin: Remove gelatin cultures from refrigerator or beaker of crush ice, and observe whether liquefaction of the medium has developed and whether the organism has produced gelatinase-----not don’t as time constraints and all gelatin but one was solid Nutrient Broth Cultures

M. luteus

Liquefaction Type of Liquefaction

solid

Nurtient Gelatins Cultures P. aeruginosa M. smegmatis E. coli

B. cereus

solid

solid

Solid

+ stratififor m

-

For our result of this experiment all organisms except for E. coli were in a solid state Liquefaction did not occur. We were not able to move forward with this part of the experiment but our observation was recorded as seen above.

form

Abundance of growth pigment Optical characteristics consistency

M. luteus

Nutrient Slant Agar P. aeruginosa M. smegmatis

E. coli

B. cereus

Filiform

Filiform

Aborescent

Beaded

Echinulate

Moderate

Moderate

Moderate

Moderate

Moderate

yellow

Clear

Clear

Clear

Opaque

Transparent

Off white/clear Translucent

Transparent

Translucent

mucoid

mucoid

muciod

buttery

muciod

Nutrient Agar Plate results M. luteus agar plate colonies could be described as yellow in color, flat, pinpoint, circular, and have entire margins. P. aeruginosa was whit to clear in color, with moderate size colony, that were circular in form, and had entire shaped margins. M. smegmatis is flat almost clear I transparent with no clear defined color. It colonies are individual small in size but in very large quantities with entire margins. E. coli colonies are flat, pinpoint in size with circular entire margins, but also has colonies that are moderate sized, circular shaped and undulate margins. Finally B. cereus presented with large, clear and flat colonies. It ha undulate edges, flat, and circular in shape. Conclusion The lab experiment was in generally a success as the growth was witnessed in every single culture. This does include the broth, slant, gelatin, and plate mediums in which the bacteria were cultured in during the lab. The bacteria present itself in a variety of differentiation form. As example in the form of the E. coli being a yellow white color and B. cereus presenting it’s in a muster yellow color on the plates. Just about every exercise showed how bacteria present itself in categories such as size of colonies, the shape they take, and the colors that may have when cultured over a certain amount of time. Even more time dedicated to growth would lead to even better clearly defined results...