Isolation and characterization of peptide(s) from Pisum sativum having antimicrobial activity against various bacteria

A systematic approach was taken to isolate and characterize the antimicrobial peptide(s) from the crude aqueous extract,solubilized ammonium sulphate precipitates and purified gel filtration chromatographic fractions of seed/pod of pisum sativum l. (garden pea). their antibacterial activity was investigated against a number of bacteria: micrococcus luteus,staphylococcus aureus,staphylococcus epidermidis,escherichia coli,klebsiella pneumonia,salmonella typhi,proteus vulgaris pasterurella multocida,and pseudomonas aeruginosa using disc diffusion method. two active peptides from seed i.e.,s4,s5 and pod i.e.,p7,p8 were obtained having molecular weight ~19 kda,~22 kda,~10 kda and ~11 kda,respectively. the bioactivity of each peptide was tested against different enzymes,temperatures and ph. the results showed that the all purified peptides were susceptible to inactivation by trypsin and proteinase k,stable at temperature 4,25 °c and active at ph 5-7. further s. aureus was found to be the most sensitive strain based on minimum inhibition concentration (mic) value.