Evaluation of contact time and fiber morphology on bacterial immobilization for development of novel surfactant degrading nanofibrous webs

Abstract

Novel electrospun fibrous biocomposites were developed by immobilizing two different sodium dodecyl sulfate (SDS) biodegrading bacterial strains, Serratia proteamaculans STB3 and Achromobacter xylosoxidans STB4 on electrospun non-porous cellulose acetate (nCA) and porous cellulose acetate (pCA) webs. The required contact time for bacterial immobilization was determined by SEM imaging and viable cell counting of the immobilized bacteria, and bacterial attachment was ended at day 25 based on these results. SDS biodegradation capabilities of bacteria immobilized webs were evaluated at different concentrations of SDS, and found to be highly efficient at concentrations up to 100 mg L⁻¹. It was observed that SDS remediation capabilities of bacteria immobilized webs were primarily based on the bacterial existence and very similar to the free-bacterial cells. A reusability test was applied on the two most efficient webs (STB3/pCA and STB4/pCA) at 100 mg L⁻¹ SDS, and the results suggest that the webs are potentially reusable and improvable for SDS remediation in water. SEM images of bacteria immobilized webs after the reusability test demonstrate strong bacterial adhesion onto the fibrous surfaces, which was also supported by the viable cell counting results. Our results are highly promising and suggest that bacteria immobilized electrospun fibrous webs have the potential to be used effectively and continually for remediation of SDS from aqueous environments.