Abstract
Seventeen free amino adds from the various parts of watermelon plant, including essential and non-essential amino adds were found by using Automatic Amino Add Analyzer. In addition, the antimicrobial activity study of the susceptibility of watermelon (Citrus vulgarisL) against tested microorganisms was investigated. The identified amino acids included: phenylalanine, histidine, tryptophan, lysine, omithine, arginine, aspartic acid, threonine, serine, glutamine, citrulline, alanine, valine, isoleucine and leucine. The essential amino acids (hislidine, leucine, lysine, methionine, phenylalanine, tryosine, and valine ranged between 1.8%-3.6%, 5.5-9.1%, 3.7-6.7%, 0.4-1.1%, 4.1, 6.4%, 0.8-7.2% and 5.5-7.6% in the various parts of watermelon plant, respectively. There were notable variations between the various parts of watermelon plants in their contents of amino adds. However, the highest contents of most of the essential amino acids were concentrated in the leaves, while the highest contents of most of the non-essential amino adds were concentrated in the roots. The investigated amino acids had antibacterial and and fungal activities against the tested organisms.