Need help with identification and justification. Lab Report Environmental Effect
ID: 252716 • Letter: N
Question
Need help with identification and justification. Lab Report Environmental Effects on Microbial Growth (21 points) 1. Nutritional Requirements (6 points) Justification should be given for each table to support your answer s Use appropriate ter msto describe the or ganisms examples- ther mophile, acidophile, obligate aer obe etc. (1) (2 points) Complete Table 1 below Table 1. Nutritional requirements for microbial growth. Minimal glucose+ yeast extract Trypticase soy broth (TSB) Minimal glucose Organism 2 day 7 day 2 day 7 day 2 day 7 day Negative control (sterile H o) Sample#1 Sample #2 Sample#3 Sample #4 No growth,-; sight growth, +; moderate growth, ++: heavy growth,+ H I- (2) (2 points) Based on Table 1, identify the most probable bacteria for the bateria samples #14 ad justify for your condusion. Possibilities are Escherichia coli, Bacillus subtilis Lactobacillus plantar um and Saphylococcus epidermidis Sample #1 : Sample #2: Sample#3: Sample#4 Justification: (3) (2 points) We have a negative control (sterile H20). Discuss the usefulness of thisExplanation / Answer
E.coli - 3 - Escherichia coli grows very slowly.
bacillus subtills -2
lactobacillus - 1 - Require special medium containing glucose and yeast extract and frequent subculturing to
maintain viability.
staphylococcus - 4 - Staphylococcus cannot grow b/c the minimal media (glucose is the only organic compound) is lacking a growth factor that the bacteria needs but cannot synthesize (e.g. an amino acid)
3. Negative control produces no response or no desired effect of the experiment.
No growth should be there in negative control. If growth found in the negative control then that test would be considered invalid and one can repeat the test after proper investigation.