Effective Gold Biosorption by Electrospun and Electrosprayed Bio-Composites with Immobilized Lysinibacillus sphaericus CBAM5

Abstract

Electro-hydrodynamic processing, comprising electrospinning and electrospraying techniques, is a novel technology used in the production of nano- and sub-micro-scale materials with specific properties suitable for environmental remediation processes. Polycaprolactone (PCL) micro-fibrous mats and alginate microcapsules were produced using electrospinning and electrospraying techniques respectively, and Lysinibacillus sphaericus CBAM5, a bacterium capable of metal removal by adsorption and accumulation inside the cell, was immobilized in these matrices. The polymeric structure was able to protect and maintain cell viability and the bio-composite materials were used to capture gold from synthetic water samples. The micro-fibrous membranes with immobilized bacteria were able to remove 93% of the gold after 120 h of inclusion in the aqueous medium. Using a filtration system, an efficiency of 64% was obtained for the removal of the precious metal after 10 cycles of filtration (2 h of exposure to the gold solution). In contrast, the microencapsulated L. sphaericus CBAM5 captured 64% of the gold after 4 h of the assay. Thus, both micro-structured matrices were suitable for the immobilization and protection of L. sphaericus CBAM5 and they showed high efficiencies of gold biosorption. Hence, these bio-composite materials could be used to concentrate gold from industrial wastewaters.

Biosorption: A Review of the Latest Advances

“…These materials with polymeric structures allow to protect and maintain the viability of living systems, which makes it possible to take advantage of the highest efficiency of these systems. An example of this was the use of biomass from Lysinibacillus sphaericus CBAM5 immobilized in polycaprolactone microfibrous mats and alginate microcapsules to capture gold from synthetic water samples [28]. Although the application of nanoparticles in the field of biosorption has been developing for a long time, more recently the application of magnetic nanoparticles as a support for the immobilization of microorganisms has also been assessed, as evidenced in the review by Giese et al (2020) [29].…”

Biosorption Potential of Microbial and Residual Biomass of Saccharomyces pastorianus Immobilized in Calcium Alginate Matrix for Pharmaceuticals Removal from Aqueous Solutions

“…The microbial biomass can be applied directly or immobilized/encapsulated in different matrices, such as chitosan, alginate, etc. [ 30 , 31 , 32 , 33 ]. Immobilization/encapsulation techniques allow for the microbial biomass to be easy separated from effluents with low cost and increase their mechanical resistance.…”

Electrosprayed Ultra-Thin Coating of Ethyl Cellulose on Drug Nanoparticles for Improved Sustained Release

“…Electrospinning, as a brother technique of electrospraying, has broadly demonstrated its great power in creating core-shell nanofibers [44,45]. In literature, coaxial electrospinning [44][45][46], modified coaxial electrospinning [46], modified triaxial electrospinning [47][48][49][50], and other complicated processes [51] are reported to generate a thin layer of coating one the core medicated nanofibers. The created core-shell nanostructures with a polymer nanocoating are verified to be very useful for manipulating the drug-loading amount and also their sustained release profiles.…”

“…In a broad meaning, the coating of polymer on a medicated core represents a shell section of a core-shell structure [ 38 , 39 , 40 , 41 , 42 , 43 ]. Electrospinning, as a brother technique of electrospraying, has broadly demonstrated its great power in creating core-shell nanofibers [ 44 , 45 ]. In literature, coaxial electrospinning [ 44 , 45 , 46 ], modified coaxial electrospinning [ 46 ], modified triaxial electrospinning [ 47 , 48 , 49 , 50 ], and other complicated processes [ 51 ] are reported to generate a thin layer of coating one the core medicated nanofibers.…”