Limits...
Characterization of a Bioflocculant (MBF-UFH) Produced by Bacillus sp. AEMREG7.

Okaiyeto K, Nwodo UU, Mabinya LV, Okoli AS, Okoh AI - Int J Mol Sci (2015)

Bottom Line: The production of the bioflocculant was observed to be closely associated with cell growth.The bioflocculant retained high flocculating activity of 90% after heating at 100 °C for 1 h.MBF-UFH appears to have immense potential as an alternative to conventional chemical flocculants.

View Article: PubMed Central - PubMed

Affiliation: South Africa-Medical Research Council (SA-MRC), Microbial Water Quality Monitoring Centre, University of Fort Hare, 5700 Alice, South Africa. okaiyetofranciskunle@yahoo.ca.

ABSTRACT
A bioflocculant named MBF-UFH produced by a Bacillus species isolated from sediment samples of Algoa Bay of the Eastern Cape Province of South Africa was characterized. The bacterial identification was through 16S rDNA sequencing; nucleotide sequences were deposited in GenBank as Bacillus sp. AEMREG7 with Accession Number KP659187. The production of the bioflocculant was observed to be closely associated with cell growth. The bioflocculant had the highest flocculating activity of 83.2% after 72 h of cultivation, and approximately 1.6 g of purified MBF-UFH was recovered from 1 L of fermentation broth. Its chemical analyses indicated that it is a glycoprotein composed of polysaccharide (76%) and protein (14%). Fourier transform infrared spectroscopy (FTIR) revealed that it consisted of hydroxyl, amide, carboxyl and methoxyl as the functional moieties. Scanning electron microscopy (SEM) revealed the amorphous structure of MBF-UFH and flocculated kaolin clay particles. The maximum flocculating activity of 92.6% against kaolin clay suspension was achieved at 0.3 mg/mL over pH ranges of 3-11 with the peak flocculating rate at pH 8 in the presence of MgCl2. The bioflocculant retained high flocculating activity of 90% after heating at 100 °C for 1 h. MBF-UFH appears to have immense potential as an alternative to conventional chemical flocculants.

No MeSH data available.


Effect of pH on the flocculating activity of purified MBF-UFH produced by Bacillus sp. AEMREG7.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4490482&req=5

ijms-16-12986-f005: Effect of pH on the flocculating activity of purified MBF-UFH produced by Bacillus sp. AEMREG7.

Mentions: The pH of reaction mixtures is a key factor influencing the flocculation process [38]. One of the ways in which pH influences flocculating activity is by affecting the stability of suspended particles and floc formation [44]; the effect of pH on the flocculating activity of purified MBF-UFH was evaluated, and the results are depicted in Figure 5. The bioflocculant had a strong flocculating activity over a wide range of pH, 3–11. There was no significant difference in the flocculating activity of MBF-UFH between the pH ranges 3–8. However, the peak flocculating activity of 95.4% was achieved at weak alkaline condition, pH 8, and a sharp decline in flocculating activity was noticed at pH 9, which might be due to the fact that the surface charge spatial arrangement is both pH and temperature dependent. Thus, it would be safe to assume that the spatial charge arrangements for flocculation were not ambient at pH 9 and within the alkaline range. MBF-UFH was tolerant to the extreme pH and showed excellent flocculating activity in a strong acidic than basic condition. Hence, this suggested that MBF-UFH could be applied under acidic, neutral and alkaline circumstances, as it shows different electric states at different pH, which, in turn, influences the bridging efficiency of MBF-UFH for kaolin clay particles [38,45]. These observations are similar to the findings reported by Ugbenyen et al. [44] in which the flocculating activity of the bioflocculant produced by a consortium of Cobetia and Bacillus species was over 70% across a wide pH range of 3–11 with the highest flocculating activity attained at pH 8. The flocculating activity of the bioflocculant produced by Bacillus sp. F19 reached the maximum at pH 2 and maintained excellent flocculating activity within a range of pH 2–9. On the other hand, the bioflocculant produced by Ruditapesphilippinarum flocculated over a wide pH range with the optimum flocculation rate between pH 7 and 9 [45].


Characterization of a Bioflocculant (MBF-UFH) Produced by Bacillus sp. AEMREG7.

Okaiyeto K, Nwodo UU, Mabinya LV, Okoli AS, Okoh AI - Int J Mol Sci (2015)

Effect of pH on the flocculating activity of purified MBF-UFH produced by Bacillus sp. AEMREG7.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490482&req=5

ijms-16-12986-f005: Effect of pH on the flocculating activity of purified MBF-UFH produced by Bacillus sp. AEMREG7.
Mentions: The pH of reaction mixtures is a key factor influencing the flocculation process [38]. One of the ways in which pH influences flocculating activity is by affecting the stability of suspended particles and floc formation [44]; the effect of pH on the flocculating activity of purified MBF-UFH was evaluated, and the results are depicted in Figure 5. The bioflocculant had a strong flocculating activity over a wide range of pH, 3–11. There was no significant difference in the flocculating activity of MBF-UFH between the pH ranges 3–8. However, the peak flocculating activity of 95.4% was achieved at weak alkaline condition, pH 8, and a sharp decline in flocculating activity was noticed at pH 9, which might be due to the fact that the surface charge spatial arrangement is both pH and temperature dependent. Thus, it would be safe to assume that the spatial charge arrangements for flocculation were not ambient at pH 9 and within the alkaline range. MBF-UFH was tolerant to the extreme pH and showed excellent flocculating activity in a strong acidic than basic condition. Hence, this suggested that MBF-UFH could be applied under acidic, neutral and alkaline circumstances, as it shows different electric states at different pH, which, in turn, influences the bridging efficiency of MBF-UFH for kaolin clay particles [38,45]. These observations are similar to the findings reported by Ugbenyen et al. [44] in which the flocculating activity of the bioflocculant produced by a consortium of Cobetia and Bacillus species was over 70% across a wide pH range of 3–11 with the highest flocculating activity attained at pH 8. The flocculating activity of the bioflocculant produced by Bacillus sp. F19 reached the maximum at pH 2 and maintained excellent flocculating activity within a range of pH 2–9. On the other hand, the bioflocculant produced by Ruditapesphilippinarum flocculated over a wide pH range with the optimum flocculation rate between pH 7 and 9 [45].

Bottom Line: The production of the bioflocculant was observed to be closely associated with cell growth.The bioflocculant retained high flocculating activity of 90% after heating at 100 °C for 1 h.MBF-UFH appears to have immense potential as an alternative to conventional chemical flocculants.

View Article: PubMed Central - PubMed

Affiliation: South Africa-Medical Research Council (SA-MRC), Microbial Water Quality Monitoring Centre, University of Fort Hare, 5700 Alice, South Africa. okaiyetofranciskunle@yahoo.ca.

ABSTRACT
A bioflocculant named MBF-UFH produced by a Bacillus species isolated from sediment samples of Algoa Bay of the Eastern Cape Province of South Africa was characterized. The bacterial identification was through 16S rDNA sequencing; nucleotide sequences were deposited in GenBank as Bacillus sp. AEMREG7 with Accession Number KP659187. The production of the bioflocculant was observed to be closely associated with cell growth. The bioflocculant had the highest flocculating activity of 83.2% after 72 h of cultivation, and approximately 1.6 g of purified MBF-UFH was recovered from 1 L of fermentation broth. Its chemical analyses indicated that it is a glycoprotein composed of polysaccharide (76%) and protein (14%). Fourier transform infrared spectroscopy (FTIR) revealed that it consisted of hydroxyl, amide, carboxyl and methoxyl as the functional moieties. Scanning electron microscopy (SEM) revealed the amorphous structure of MBF-UFH and flocculated kaolin clay particles. The maximum flocculating activity of 92.6% against kaolin clay suspension was achieved at 0.3 mg/mL over pH ranges of 3-11 with the peak flocculating rate at pH 8 in the presence of MgCl2. The bioflocculant retained high flocculating activity of 90% after heating at 100 °C for 1 h. MBF-UFH appears to have immense potential as an alternative to conventional chemical flocculants.

No MeSH data available.