Blue biotechnology: oil bioremediation using hydrocarbon-degrading bacteria immobilized on biodegradable membranes

Abstract

A novel bioremediation system to clean up oil contaminated water was developed combining hydrocarbon (HC) degrading bacteria immobilized and polylactic acid (PLA) or polycaprolactone (PCL) membranes prepared by electrospinning. The bioremediation efficiency was tested on crude oil using highly performant HC degrading bacterial strains isolated from marine and soil environments. The membrane morphology, the microbial adhesion and proliferation were evaluated using scanning electron microscopy (SEM). The SEM analysis highlighted that the fibers of the electrospun mats were in nanoscale with a similar diameter size distribution. The electrospun membranes exhibited high oil absorption capacity (q): approximately q = 40 g/g for PLA and q = 20 g/g for PCL. The bacterial strains were able to attach to the PLA and PCL membranes after 48h, reaching high proliferation and biofilm formation within the whole structure in 5 days. The biodegradation efficiency of the bacteria-membrane systems was tested by GC-FID analysis and compared with planktonic cells after 5 and 10 days incubation. The bacterial immobilization is a promoting factor for biodegradation and a new tool to be developed for bioremediation of aquatic systems.