Antibacterial Activities of Nonionic and Anionic Surfactants From Citrullus lanatus Seed Oil

Background: Analysis and applications of lesser known underutilized seed oils are important, since there is little or no information on their composition and uses, most of them are discarded as waste every year. Objectives: The present work reports the antibacterial activities of diethanolamides (nonionic surfactant) and sulphated diethanolamide (anionic surfactant) synthesized from the seed oil of Citrullus lanatus. Materials and Methods: Diethanolamide biosurfactant was produced from the oil via transamidation reaction using sodium methoxide as catalyst while the diethanolamide was sulphated using chlorosulphonic acid. The conversion of the oil to the biosurfactants was monitored using FTIR spectrophotometer. Results: The iodine and saponification values of Citrullus lanatus oil were 118.50 ± 0.80 g iodine/100g and 199.10 ± 2.40 mgKOH/g respectively. Linoleic acid (56.9 %) was reported to be the most abundant fatty acid in Citrullus lanatus oil. Conclusions: The biosurfactants inhibited the growth of organisms such as Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumonia and Escherichia coli with diethanolamide biosurfactant exhibiting better antibacterial activity than sulphated diethanolamide.