Comparing the Effect of Different Peptone Media Formulations on Growth of Various Strains of Escherichia coli

 

 

Enzymatically Hydrolyzed proteins are commonly used in media formulations to provide a rich source of complex nitrogen, carbon, peptides, carbohydrates, and amino acids necessary to provide reliable growth of microorganisms.

As media formulations have evolved, so have requirements for nitrogen sources to be animal free, kosher, non genetically modified, and allergen free solutions. Based on several protein sources, a variety of commercial peptones have been developed.

Along with the variation in composition of these peptones comes the question of performance: What effect does using these different peptones have on bacterial growth?

Methodology: Cultures were grown in liquid media using the various peptones obtained from Nu-tek Bioscience in their formulations, with amounts based on the total percent nitrogen. During this time, the absorbance at 600 nanometers of the cultures was monitored at certain time intervals using a spectrophotometer.  This allowed for the data to be plotted and compiled into comparative growth curves.

Escherichia coli

  • Some strains are harmless, some pathogenic , and can cause illness or even death, along with strains developed for lab use.
  • Easily culturable, genes are easy to manipulate, and has a well documented genome

Media Formulations:

For 100 mL Media:

50 mL 0.2% total N Peptone solution

20 mL 5x M9 Salts

5 mL 10% Glucose

25 mL Sterile Nanopure Water

Each component is sterilized separately using an autoclave on liquid cycle for 35 minutes.

 

Peptone Amino Nitrogen and Total Nitrogen:
Peptone % TN AN/TN Ratio
Soy Nu-tek HSP-A 7.6 0.41
Soy Competitor 1 9.2 0.21
Soy Competitor 2 9.2 0.25
Soy Competitor 3 10.2 0.24
Pea Nu-tek HPP-A 12.4 0.40
Nut-tek Soy-YE A 9.1 0.48
Nut-tek Soy-YE B 8.1 0.42
Nut-tek Soy-YE C 8.9 0.46

 

Amino Acid Comparison
Nu-Tek Soy 1 Peptone Nu-Tek Pea Peptone
Amino Acid Free (mg/g) Total (mg/g) Amino Acid Free (mg/g)
Aspartic Acid 6 45 Aspartic Acid 14
Cysteine NA 5 Cysteine NA
Serine 9 30 Serine 8
Tyrosine 5 15 Tyrosine 2
Glutamic Acid 15 85 Glutamic Acid 2
Valine 8 20 Valine 18
Glycine 2 20 Glycine 3
Methionine 4 5 Methionine 1
Histidine 6 15 Histidine 6
Lysine 16 30 Lysine 19
Arginine 14 40 Arginine 2
Isoleucine 9 20 Isoleucine 17
Threonine 5 20 Threonine 11
Leucine 19 30 Leucine 35
Alanine 5 20 Alanine 10
Phenylalanine 11 20 Phenylalanine 20
Total 137 445 Total 168

 

References:

BD Bionutrients Technical Manual. 3rd ed. N.p .: Beckton, Dickenson, 2006.

Michiels, J. F., Sart, S., Schneider, Y. J., & Agathos, S. N. (2011). Effects of a soy peptone on γ-IFN production steps in CHO-320 cells. Process Biochemistry, 46(9), 1759-1766.

Pasupuleti, V. K., & Braun, S. (2010). State of the art manufacturing of protein hydrolysates. In Protein Hydrolysates in Biotechnology (pp. 11-32). Springer Netherlands.

Rasko, D. A., Rosovitz, M. J., Myers, G. S., Mongodin, E. F., Fricke, W. F., Gajer, P., … & Ravel, J. (2008). The pangenome structure of Escherichia coli: comparative genomic analysis of E. coli commensal and pathogenic isolates. Journal of bacteriology, 190(20), 6881-6893

Jennifer FitzGerald, Maddy Riemenschneider, Hailley Cound, Thomas C. Marsh, Ph. D Chemistry Department, University of Saint Thomas, St. Paul, MN