NABEL NEGM*, SALAH TAWFIK
*Corresponding author
Egyptian petroleum research institute Department of Petrochemicals, Nasr City, Cairo, Egypt

Abstract

Two series of cationic surfactants namely:2-((benzylideneamino)amino) and 2-((4-methoxybenzylidene) amino)-(2-oxo-2-alkoxy)-1,3-isoxazol-2-ium surfactants were prepared. Their structures were confirmed using elemental analysis, FTIR, and NMR spectra. The surface activities of the different surfactants showed good tendency towards adsorption at the interfaces. That was estimated from the depression of surface tension at the CMC. The different surfactants were evaluated as biocides against different strains of bacteria, fungi, yeast and sulfate reducing bacteria (SRB) using inhibition zone diameter method. The surfactants showed good antimicrobial activities against the tested microorganisms including Gram positive, Gram negative and fungi. The promising inhibition efficiency of these compounds against the sulfate reducing bacteria (SRB) facilitates them to be applicable in the petroleum field as new categories of SRB biocides.

INTRODUCTION

Amphiphiles compounds are useful as disinfectants and sanitizers in the fields of industrial and human health. Their identical long-chain moieties impart unique surface active properties and aggregation patterns (1-5), and play an important role in their antimicrobial performances (6, 7). The design and synthesis of this type of compounds have recently attracted considerable attention due to the increasing microbial resistance to common quaternary ammonium compounds and the novel biological applications emerging from their singular interactions with lipid membranes (8-14). Several contributions have reported synthetic antimicrobial agents having new active moieties such as hetero atoms (15, 16), aromatic and non-aromatic cyclic substituents (17, 18), and perfluorinated chains (19-21). Many of these compounds have good surface-active properties and good antimicrobial activities.
In oilfield applications, sulfate reducing bacteria (SRB) are often problematic in water used for the recovery of petroleum or for oil drilling. SRB can form biofilms on equipment and in pipelines; the significant problem caused by these bacteria is that they ...