ANTIMICROBIAL ACTIVITY OF LECTIN ISOLATED FROM EGYPTIAN WHEAT CULTIVAR GIZA 171

Document Type : Original Article

Authors

Agric. Biochm. Dept., Fac. Agric., Zagazig Univ., Egypt

Abstract

In the current study crude lectin was isolated from Egyptian wheat seeds cultivar
Giza 171 and it was characterized by several methods such as sodium dodecyl sulfate-polyacrylamide
gel electrophoresis (SDS-PAGE), Native-PAGE, Iso-electric point evaluation, Fourier transform
infrared (FTIR) spectroscopy and amino acids composition. Furthermore, antibacterial and antifungal
activities were estimated against some gram positive, gram negative bacteria and pathogenic fungus.
Based on Native-PAGE (unreduced) of wheat seeds lectin indicates one major band with a molecular
weight of approximately 50 kDa. SDS-PAGE of wheat seeds lectin separated this high molecular
weight band into 2 bands corresponding to smaller molecular weights (14,20 kDa). The iso-electric
points were deduced from the protein pH-solubility curve. It is clear that the least soluble points were
obtained at pH 5.5. The content of the hydrophobic amino acids residues (proline, valine, isoleucine,
leucine and phenyl alanine) valued 27.8% and this represent 31.1% of the total amino acids. The
minimum inhibitory concentrations (MIC) of lectin against L. monocytogenes and P. aeruginosa was
800 μg/ml, 1600 μg/ml for B. subtillis and 3200 μg/ml against E. coli. Lectin inhibited mycelial
growth of F. oxysporun and F. solani at a wide concentration range (250, 500 and 1000 μg/ml). This
study has elucidated that the lectin isolated from wheat seeds cultivar Giza 171 have the potent
antibacterial and antifungal activities against selected pathogenic bacteria and fungai.

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