title: Bioflocculant production by a consortium of Streptomyces and Cellulomonas species and media optimization via surface response model.
abstract: Species of actinobacteria previously isolated from Tyume River in the Eastern Cape Province of South Africa and identified by 16S rDNA sequence as Cellulomonas and Streptomyces species were evaluated as a consortium for the production of bioflocculant. Sucrose, peptone and magnesium chloride were the nutritional sources which supported optimal production of bioflocculant resulting in flocculation activities of 91%, 82% and 78% respectively. Response surface design revealed sucrose, peptone and magnesium chloride as critical media components following Plackett-Burman design, while the central composite design showed optimum concentration of the critical nutritional source as 16.0 g/L (sucrose), 1.5 g/L (peptone) and 1.6g/L (magnesium chloride) yielding optimal flocculation activity of 98.9% and bioflocculant yield of 4.45 g/L. FTIR spectrometry of the bioflocculant indicated the presence of carboxyl, hydroxyl and amino groups, typical for heteropolysaccharide, while SEM imaging revealed an interwoven clump-like structure. The molecular weight distribution of the constituents of the bioflocculants ranged 494.81-18,300.26 Da thus, an indication of heterogeneity in composition. Additionally, the chemical analyses of the purified bioflocculant revealed the presence of polysaccharides and proteins with neutral sugar, amino sugar and uronic acids in the following concentration: 5.7 mg, 9.3mg and 17.8 mg per 100mg. The high flocculation activity of the bioflocculant suggests commercial potential.
authors: Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa. Electronic address: UNwodo@ufh.ac.za.
authors: Uchechukwu U
authors: UU
authors: Nwodo
authors: Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa. Electronic address: EGreen@ufh.ac.za.
authors: Ezekiel
authors: E
authors: Green
authors: Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa. Electronic address: LMabinya@ufh.ac.za.
authors: Leonard V
authors: LV
authors: Mabinya
authors: Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa. Electronic address: okaiyetofranciskunle@yahoo.ca.
authors: Kunle
authors: K
authors: Okaiyeto
authors: School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, Gauteng ZA 2050, South Africa. Electronic address: Karl.rumbold@wits.ac.za.
authors: Karl
authors: K
authors: Rumbold
authors: Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa. Electronic address: LObi@ufh.ac.za.
authors: Lawrence C
authors: LC
authors: Obi
authors: Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa. Electronic address: AOkoh@ufh.ac.za.
authors: Anthony I
authors: AI
authors: Okoh
mesh_terms: D040143:Cellulomonas / Q000378:metabolism*; D005427:Flocculation; D015636:Magnesium Chloride / Q000737:chemistry / Q000378:metabolism; D059013:Microbial Consortia; D008954:Models, Biological; D008970:Molecular Weight; D010461:Peptones / Q000737:chemistry / Q000378:metabolism; D011134:Polysaccharides / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D012044:Regression Analysis; D013302:Streptomyces / Q000378:metabolism*; D013395:Sucrose / Q000737:chemistry / Q000378:metabolism; D013499:Surface Properties
chemical_list: D010461:Peptones; D011134:Polysaccharides; D015636:Magnesium Chloride; D013395:Sucrose
keywords: Cellulomonas; Consortium; Heteropolysaccharide; Plackett–Burman; Streptomyces