Back to Search
Start Over
A novel Fe(III) dependent bioflocculant from Klebsiella oxytoca GS-4-08: culture conditions optimization and flocculation mechanism
- Source :
- Scientific Reports
- Publication Year :
- 2016
- Publisher :
- Nature Publishing Group, 2016.
-
Abstract
- In this work, the effect of cultivation factors on the flocculation efficiency (FE) of bioflocculant P-GS408 from Klebsiella oxytoca was optimized by the response surface methodology. The most significant factor, i.e. culture time, was determined by gray relational analysis. A total of 240 mg of purified P-GS408 was prepared from 1 liter of culture solution under the optimal conditions. GC-MS analysis results indicated that the polysaccharide of P-GS408 mainly contains Rhamnose and Galactose, and the existence of abundant hydroxyl, carboxyl and amino groups was evidenced by FTIR and XPS analyses. With the aid of Fe3+, the FE of kaolin solution by P-GS408 could achieve 99.48% in ten minutes. Functional groups of polysaccharide were involved in the first adsorption step and the zeta potential of kaolin solution changed from −39.0 mV to 43.4 mV in the presence of Fe3+ and P-GS408. Three-dimensional excitation-emission (EEM) fluorescence spectra demonstrates that the trivalent Fe3+ and Al3+ can bind efficiently with P-GS408, while those univalent and divalent cations cannot. With the help of SEM images, FTIR, zeta potential and EEM spectra, we proposed the P-GS408 flocculation mechanism, which consists of coordination bond combination, charge neutrality, adsorption and bridging, and net catching.
- Subjects :
- Flocculation
Rhamnose
0208 environmental biotechnology
02 engineering and technology
010501 environmental sciences
01 natural sciences
Ferric Compounds
Article
Divalent
chemistry.chemical_compound
Adsorption
Spectroscopy, Fourier Transform Infrared
Zeta potential
Response surface methodology
Fourier transform infrared spectroscopy
Kaolin
0105 earth and related environmental sciences
chemistry.chemical_classification
Bacteriological Techniques
Multidisciplinary
biology
Polysaccharides, Bacterial
Klebsiella oxytoca
Temperature
Spectrometry, X-Ray Emission
Hydrogen-Ion Concentration
biology.organism_classification
020801 environmental engineering
Culture Media
chemistry
Nuclear chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 20452322
- Volume :
- 6
- Database :
- OpenAIRE
- Journal :
- Scientific Reports
- Accession number :
- edsair.doi.dedup.....5f149616d5a2bda424277b969fd4a90a