Saccharomyces cerevisiaeimmobilized onto cross-linked chitosan beads: application of a novel material for the removal of dye toxicity

Abstract

Waste from textile industries can severely harm the environment. Dyes are the main residues of these effluents. Saccharomyces cerevisiae is already known to be an efficient adsorbent for the removal of dyes. However, the lack of applicability and limitation of the use of cell biomass in an industrial treatment makes it impossible to apply them. Thus the aim of this work was to immobilize S. cerevisiae in cross-linked chitosan beads by two different techniques (contact immobilization and encapsulation in the polymer matrix), proposing two new materials for adsorption. Adsorption experiments were carried out to analyse the kinetics, isotherm and thermodynamics adsorptive of the synthesized materials. The adsorption data obtained were compared with the S. cerevisiae biomass and with the cell-free cross-linked chitosan beads to evaluate the efficiency of the two synthesized materials. The Fourier transform infrared spectrophotometer was used to characterize and analyse the main adsorption sites of the tested materials. Bioassays using the microcrustacean Daphnia similis verified if the materials could reduce the toxicity of the medium after its application in the treatment. Both materials synthesized in this work can potentially remove dyes from effluents, in addition to being able to significantly decrease dye toxicity from an aqueous medium.

Eco-Friendly Biosorbents Based on Microbial Biomass and Natural Polymers: Synthesis, Characterization and Application for the Removal of Drugs and Dyes from Aqueous Solutions

“…For SC-C-2.5% and SP-C-2.5% adsorption bands can be attributed as follows: 2920 cm −1 to CH 3 symmetric stretch; 1646 cm −1 to N-H vibration (amide II) and 1576 cm −1 to C=O stretching (amide I) from chitosan but also specific for yeast cell walls constituents; 1363 cm −1 to CH 3 vibration [32,61].…”

“…Natural polymers such as chitosan and alginate have been used successfully in the processes of immobilization/encapsulation of enzymes and pharmaceuticals [29][30][31]. So, studies have expanded to obtain adsorbents/biosorbents by immobilizing microorganisms or other materials [4,7,24,26,[32][33][34][35][36][37][38][39][40][41].…”

“…Chitosan has been demonstrated that it can be used in adsorption processes because it is an inert, biocompatible, biodegradable and nontoxic material [7,32,41].…”

Application of Saccharomyces cerevisiae/Calcium Alginate Composite Beads for Cephalexin Antibiotic Biosorption from Aqueous Solutions

“…At 1646 cm −1 a vibration of amide was recorded; at 1635 cm −1 a peak of carbonyl group C=O can be remarked. At 1362 cm −1 , at 1313 cm −1 and at 1238 cm −1 , stretching for C-OH, for amide III (proteins) and for PO 2 -asymmetric and symmetric (phosphorylated proteins, phospholipids) can be distinguished [51,52]. Figure 5 depicts the Saccharomyces cerevisiae/calcium alginate beads FT-IR spectra.…”

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“…Furthermore, several yeasts have been found capable to treat TWWs. 59 The genus Candida is widely used in dye decolorization and through biodegradation mechanism [60][61][62] or biosorption 63,64 or also by bioaugmentation. 65 Thermo-tolerant yeast, Kluyveromyces marxianus IMB3C has shown the ability to remove Remazol Black-B.…”