title: A novel thermally stable heteropolysaccharide-based bioflocculant from hydrocarbonoclastic strain Kocuria rosea BU22S and its application in dye removal.
abstract: A new bioflocculant named pKr produced by hydrocarbonoclastic strain Kocuria rosea BU22S (KC152976) was investigated. Gas chromatography-flame ionization detector (GC-FID) analysis confirmed the high potential of the strain BU22S in the degradation of n-alkanes. Plackett-Burman experimental design and response surface methodology were carried out to optimize pKr production. Glucose, peptone and incubation time were found to be the most significant factors affecting bioflocculant production. Maximum pKr production was about 4.72 ± 0.02 g/L achieved with 15.61 g/L glucose, 6.45 g/L peptone and 3 days incubation time. Chemical analysis of pKr indicated that it contained 71.62% polysaccharides, 16.36% uronic acid and 2.83% proteins. Thin layer chromatography analysis showed that polysaccharides fraction consisted of galactose and xylose. Fourier transform infrared analysis revealed the presence of many functional groups, hydroxyl, carboxyl, methoxyl, acetyl and amide that likely contribute to flocculation. K. rosea pKr showed high flocculant potential using kaolin clay at different pH (2-11), temperature (0-100°C) and cation concentrations. The bioflocculant was particularly effective in flocculating soluble anionic dyes, Reactive Blue 4 and Acid Yellow, with a decolorization efficiency of 76.4% and 72.6%, respectively. The outstanding flocculating performances suggest that pKr could be useful for bioremediation applications.
authors.affiliation: a Univ. Manouba , ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020 , Ariana , Tunisia.
authors.forename: Habib
authors.initials: H
authors.lastname: Chouchane
authors.affiliation: a Univ. Manouba , ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020 , Ariana , Tunisia.|b Faculty of Science of Bizerte , University of Carthage , Bizerte , Tunisia.
authors.forename: Mouna
authors.initials: M
authors.lastname: Mahjoubi
authors.affiliation: c Department of Food Environmental and Nutritional Sciences (DeFENS) , University of Milan , Milan , Italy.
authors.forename: Besma
authors.initials: B
authors.lastname: Ettoumi
authors.affiliation: a Univ. Manouba , ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020 , Ariana , Tunisia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Neifar
authors.affiliation: a Univ. Manouba , ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020 , Ariana , Tunisia.
authors.forename: Ameur
authors.initials: A
authors.lastname: Cherif
mesh_terms: D004396:Coloring Agents / Q000737:chemistry*; D005427:Flocculation; D006863:Hydrogen-Ion Concentration; D007616:Kaolin; D011134:Polysaccharides / Q000737:chemistry*; D013696:Temperature; D018508:Water Purification
chemical_list: D004396:Coloring Agents; D011134:Polysaccharides; D007616:Kaolin
keywords: Kocuria rosea BU22S; bioflocculant; crude oil degradation; dye removal; flocculation activity; response surface methodology