Antimicrobial Activity of Purified Peptides/Proteins Isolated from Nigella sativa Seeds

Author(s) : Muhammad Afzal & Muhammad Shahid

Abstract:

Objective:
To study the antimicrobial activity of the purified peptides/proteins isolated from the seeds extract of Nigella sativa (Kalongi).
Material and Methods:
Peptides/proteins isolates of Nigella sativa was screened for their antimicrobial activity against the bacterial strains including Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Pasturella multocida and fungal strains including Aspergillus niger, Alterneria alternata, Aspergillus flavis and Rhizopus solani. Purification was carried out by dialysis, ammonium sulphate ((NH4)2SO4) precipitation, gel filtration chromatography using Sephadex G-100 gel and ion exchange by using DEAE-Sephadex A-50, fractions eluted using the gradient buffered NaCl (0.2-1 M).
Results:
Nigella sativa showed good antibacterial activity against S. aureus and E. coli while minimum zones of inhibition were noted against fungal strain A. niger and poor antifungal activity against Rhizopus solani. SDS-polyacrylamide gel electrophoresis revealed that the purified protein was a monomer with molecular mass of 14 kDa which possesses a strong and broad spectrum antimicrobial activity.
Conclusion:
Peptides/proteins contained by the N. sativa showed good antimicrobial activities.

Keyword: N. sativa, antimicribial, peptides, proteins