Study on the use of bovine blood protein hydrolysate as a peptone in microbial culture media

Abstract

Livestock blood is a protein-rich waste byproduct produced during meat production processes in slaughterhouses. Its utilization through conversion into value-added products is an intriguing management strategy. In this study, bovine blood was used to obtain the protein hydrolysate for use as a peptone for microbial growth medium. Lyophilized bovine blood was heat treated to make it susceptible to enzymic hydrolysis, and then enzymatically treated with trypsin (bovine pancreas protease) to produce protein hydrolysate. Physico-chemical features were determined for protein hydrolysate and compared to commercial Merck peptone from meat. Amino acid compositions of bovine blood and commercial peptones were subjected to multivariate analysis based on Euclidean similarity matrix using software PAST. Strains of Staphylococcus aureus 25,923, Pseudomonas aeruginosa 27,853, Staphylococcus aureus 6538 P, Enterococcus faecalis 11,700, Escherichia coli 8739, Klebsiella pneumoniae 13,883, Salmonella typhimurium 14,028 and Listeria monocytogenes 13,932 were used as test microbial strains. Growth of bacteria in culture media based on the peptone from bovine protein hydrolysate was compared to that in corresponding reference media based on commercial peptone. The results of these growth tests were comparable. Growth data were depicted and statistically analyzed using R packages ggplot2 and growthcurver, respectively, providing data fitting a standard form of logistic equation.

Keywords:

• Bacterial growth
• blood by-products
• bovine blood protein
• microbial culture medium
• protein hydrolysate

Acknowledgements

Authors also wish to acknowledge Dr. Farzaneh Aziz Mohseni (Persian Type Culture Collection, Iranian Research Organization for Science and Technology (IROST)), for her assistance in preparing the active cultures of the bacterial strains and for her valuable advice in designing the culture medium used to evaluate the growth of Enterococcus faecalis ATCC 11700 and Listeria monocytogenes ATCC 13932.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors gratefully acknowledge the financial support granted by the Biotechnology Development Council [Contract no. 11/37719]. Also, we would like to acknowledge the generous support provided by the National Institute of Genetic Engineering and Biotechnology [Project no. 115T].