Detection, Characterization, and Controlling the Biofilm Forming Bacteria in the Cooling Water System

Abstract

Biofilms formed by various microbial communities are the main reason for the microbiologically induced corrosion of structural materials in the cooling tower systems of many industries. Plant extracts have been successfully used as natural corrosion inhibitors. Therefore, this study aims to develop green and natural inhibitors using plant extracts for controlling the biofilm formation in cooling water systems. A total of 45 bacterial strains have been isolated from Koel River water which is used as a source for cooling water in the Rourkela steel plant. The isolated bacteria were investigated for their abilities to form biofilm. The strongest biofilm-forming isolates were selected and characterized. The characterization tests included virulence tests, antibiotic susceptibility tests, biochemical tests, and molecular identification by amplifying the 16S rRNA. The plant extracts of Lantana camara linn, Agave sisalana, Azadirachta indica (Neem), Zingirber officinale, and Dracaena trifasciata, were prepared and tested for their antibacterial activity and biofilm inhibition efficiency against the selected bacterial isolates. The results showed that the methanol extract of Agave sisalana exhibited the highest antibacterial activity and biofilm inhibition efficiency of 35%, and the Neem extract showed the least efficiencies. Further research will be done to gain better results using the plant extracts.