Cronobacter Support
05-20-2009, 07:50 PM
1st International Conference on Cronobacter Poster Abstract 46
Antimicrobial Peptides from fermented bovine milk
With the recent restriction of antibiotic use in food producing animals the greater concerns about antibiotic resistant bacteria in both the animal and human population and the desire to reduce food borne pathogen levels, an increasing need to develop effective but human and animal compatible, antibiotic alternatives for the medical industry has arisen. Recently, natural proteins have been identified that possess these attributes. In vitro, these proteins upon degradation by digestive enzymes or microbial enzymes have been shown to release antimicrobial peptides (AMPs), which exhibit unique mechanism for killing bacteria compared with current antibiotics. These AMPs selectively binds to the outer lipid membrane of the bacterium and form blisters and pores, which eventually result in lyses of the cell and cellular death. To study antimicrobial activity of peptides five strains of Lactobacillus helveticus obtained from NCDC, NDRI, Karnal, were screened for antimicrobial activity exerted by the individual strains in the whey supernatant when grown in bovine skim milk. The cell free extract of different strains of L. helveticus showed variable activity in case of both Gram’s positive, Gram’s negative pathogens and spoilage organisms. L. helveticus NCDC-288 was found to be more effective than that of the rest strains. The agar well assay inhibition zone diameter for Gram’s positive Bacillus cereus, Streptococcus agalactiae and Staphylococcus aureus was 3.2, 3.0 and 2.4cm respectively. The supernatant also showed good activity against Gram’s negative pathogens. It showed more than 2.2 inhibition zones against Escherichia coli, Enterobacter faeciua, Pseudomonnas fragi, Serratia marcesens and Salmonella typhi. The factor responsible for the antimicrobial activity was found to be peptide in nature. To achieve maximum antimicrobial activity in terms of the peptide content, conditions were optimized. Purification of the desired peptide was carried out using gel filtration, ion exchange chromatography and HPLC. In addition to the antimicrobial activity these peptides also exhibited anti-oxidative activity. Moreover the ACE inhibitory activity in these peptides also has been demonstrated. This observation has been supported with analytical data indicating relatively higher valine content responsible for properties. The peptide thus obtained may be beneficial to explore the possibility for treatment against microbial infection and cardiovascular risk including hypertension.
Bhagat Singh and Renu Singh
Department of Microbiology, Institute of Applied Medicines and Research, Duhai, Ghaziabad Utter Pradesh, India.
Antimicrobial Peptides from fermented bovine milk
With the recent restriction of antibiotic use in food producing animals the greater concerns about antibiotic resistant bacteria in both the animal and human population and the desire to reduce food borne pathogen levels, an increasing need to develop effective but human and animal compatible, antibiotic alternatives for the medical industry has arisen. Recently, natural proteins have been identified that possess these attributes. In vitro, these proteins upon degradation by digestive enzymes or microbial enzymes have been shown to release antimicrobial peptides (AMPs), which exhibit unique mechanism for killing bacteria compared with current antibiotics. These AMPs selectively binds to the outer lipid membrane of the bacterium and form blisters and pores, which eventually result in lyses of the cell and cellular death. To study antimicrobial activity of peptides five strains of Lactobacillus helveticus obtained from NCDC, NDRI, Karnal, were screened for antimicrobial activity exerted by the individual strains in the whey supernatant when grown in bovine skim milk. The cell free extract of different strains of L. helveticus showed variable activity in case of both Gram’s positive, Gram’s negative pathogens and spoilage organisms. L. helveticus NCDC-288 was found to be more effective than that of the rest strains. The agar well assay inhibition zone diameter for Gram’s positive Bacillus cereus, Streptococcus agalactiae and Staphylococcus aureus was 3.2, 3.0 and 2.4cm respectively. The supernatant also showed good activity against Gram’s negative pathogens. It showed more than 2.2 inhibition zones against Escherichia coli, Enterobacter faeciua, Pseudomonnas fragi, Serratia marcesens and Salmonella typhi. The factor responsible for the antimicrobial activity was found to be peptide in nature. To achieve maximum antimicrobial activity in terms of the peptide content, conditions were optimized. Purification of the desired peptide was carried out using gel filtration, ion exchange chromatography and HPLC. In addition to the antimicrobial activity these peptides also exhibited anti-oxidative activity. Moreover the ACE inhibitory activity in these peptides also has been demonstrated. This observation has been supported with analytical data indicating relatively higher valine content responsible for properties. The peptide thus obtained may be beneficial to explore the possibility for treatment against microbial infection and cardiovascular risk including hypertension.
Bhagat Singh and Renu Singh
Department of Microbiology, Institute of Applied Medicines and Research, Duhai, Ghaziabad Utter Pradesh, India.