Biofilm Inhibition Efficacy of Agave Sisalana Leaves Extracts Against a Bacterial Consortium in Cooling Water System

Abstract

Microbiologically induced corrosion causes serious issues in many industrial sectors. Natural compounds appeared as eco-friendly, cost-effective solutions to control biofilm formation and the corrosion induced by it. This research aims to evaluate the biofilm inhibition efficacy of many Agave sisalana extracts. The efficacy of methanol, ethyl acetate, ethanol extracts, and the extracted saponins of Agave sisalana was tested against a consortium of seven biofilm-forming strains. The bacterial strains were isolated from Koel River water used as cooling water in the Rourkela steel plant. The saponins-rich extract showed moderate biofilm-controlling efficacy, so three different solvents (glycerol, acetone, and ethanol) were used to enhance the efficacy of the saponins-rich extract. Among the various plant extract combinations, glycerol-saponins solution showed the highest biofilm inhibition efficacy. The results were confirmed by CFU, crystal violet test, and confocal laser scanning microscope. The saponins-rich extract was characterized by XRD, FTIR, Raman spectroscopy, UV-Vis spectrum, and NMR analyses. The characterization analyses confirmed the presence of saponins which is well known as a biosurfactant according to its ability to reduce the surface tension and consequently control the biofilm formation on different surfaces. Further research should be performed to increase the biofilm inhibition efficacy