Table 4, Elfects of pH on microbial growth. pH 2 day 7 day 2 day7 day 2 day 7 da
ID: 252761 • Letter: T
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Table 4, Elfects of pH on microbial growth. pH 2 day 7 day 2 day7 day 2 day 7 day 2day 7 day 3 pH 5 pH 7 pt 9 Organism Negative control (sterile H O) Sample #12 Sample #13 Sample #14 Sample #15 No growth, ; sight growth, +; moderate growh, , hesry growith, (2) (2 points) Complete Table 5 below. Table 5. Osmotic effects of salt concentr ation on microbial growth. NaCl 0% NaCl 296 NaCl 4% NaCl 6% Organism2 2 day 7 day 2 day 7 day 2 day 7 day 2 day 7 day Negative control (sterile H O) Sample #13 At lttTtItt t lttittt Sample #14 -t|tttttttttt|tt | tt Sample #15 No growth,-; slight growth,+; moderate growth,+ heavy growth,++ (3) (3 points) Based on Tables 4 &5, identify the most probable bacteria for the bacterial samples #12-14 and justify for your coduson. Posibilities are Escherichia coli, Latobacolusplantarum, Saphylococcus epidermidis and Saccharomyces cerevisiae (yeast) Sample#12: Sample#13: Sample #14: sample#15: Justification:Explanation / Answer
Results base on Tables 4 & 5 :
Sample 12 is Escherichia coli, This bacteria heavy growth in pH 5 on day 7th, moderate growth observed on day 2nd and 7th day in ph 3 and slight gwroth in another pH.
Osmotic effcts of E.coli is slight, same growth in differant types of NaCl %.
Sample 13 is Lactobaccilus plantarum, This bacteria is heavy grow in pH 5 and moderate growth in pH 7 and 9 but no growth observed in pH 3.
Osmotic effcts of L.plantarum is moderate but heavy growth observed in 2% NaCl and 4% NaCl at 7th day.
Sample 14 is Staphylococcus epidermidis, This bacteria is heavy grow in pH 5, 7 and 9, but no growth observed in
pH 3.
Osmotic effects of S.epidermidis is heavy in NaCl 2% and 0% NaCl at day 7th.
Moderate grwoths observed in 4% NaCl and 0% NaCl at day 2 , and no growth observe in 6% NaCl.
Sample 15 is Saccharomyces cerevisiar, Moderate growth observed in pH 5 and pH 7 on day 1 but heavy growth is observed on day 7th in Ph 7, no growth observed in pH 3 and 9.
Osmotic effect slight on day 2 and moderate on day 7 in 0% NaCl and no growth observed in presence of NaCl.
Justification for Conclution :
As per above results we can conclude that Escherichia coli is most probable bacteria becouase Escherichia coli can grwoth all conditions, lactobaccilus plantarum, staphylococcus epidermidis cannot grow in pH 3 and staphylococcus epidermidis cannot grow in 6% NaCl.
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