Biosorption of reactive and basic dyes using fermentation waste Corynebacterium glutamicum: the effects of pH and salt concentration and characterization of the binding sites

• Published in: World journal of microbiology & biotechnology Vol. 25; no. 7; pp. 1259 - 1266
• Main Authors: Mao, Juan, Won, Sung Wook, Yun, Yeoung-Sang
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.07.2009; Springer Netherlands; Springer
• Subjects: Applied Microbiology; Binding sites; Biochemistry; Biological and medical sciences; Biomass; Biomedical and Life Sciences; Biotechnology; Charging; Corynebacterium glutamicum; Environmental Engineering/Biotechnology; Fundamental and applied biological sciences. Psychology; Life Sciences; Mathematical models; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; Microbiology; Original Paper; Sorption; Uptakes; Methylene Blue; Biosorption; Reactive Red 4; Binding sites; Dyes; Binding site; Concentration; Fermentation; Characterization; Adsorption; Corynebacterium glutamicum; pH; Bacteria; Actinomycetes; Corynebacteriaceae; Wastes
• ISSN: 0959-3993; 1573-0972
• DOI: 10.1007/s11274-009-0012-8

A low cost biosorbent, Corynebacterium glutamicum, was studied for the sorption of Reactive Red 4 (RR 4) and Methylene Blue (MB). The equilibrium isotherm data were well described by the Langmuir model. pH edge experiments showed that pH of the solution was an important controlling parameter in the sorption process. In the case of RR 4, with increases in the pH from 2 to 10, the uptake decreased from 52 to 1 mg/g; conversely, the uptake of MB increased and the maximum MB uptake was obtained at pH >= 9. An increase in the salt concentration strongly influenced the uptake of MB, but had no effect on that of RR 4. In order to identify the binding sites for the dye molecules, the biosorbent was potentiometrically titrated, the results of which showed the presents of four major functional group types on the biomass surface, which were confirmed by FTIR analysis. It was found that positively charged amine groups (Biomass-NH₃ ⁺) were the likely binding sites for anionic RR 4, and negatively charged carboxyl (Biomass-COO⁻) and phosphate groups (Biomass-HPO₄ ⁻) played a role in the electrostatic attraction of cationic MB.