Screening for Bio-flocculant Producing Bacterial Strains from Asa River in Ilorin Kwara State

Synthetic flocculants in water treatment have been reported to be detrimental to both human health and the environment. Thus, there is a constant search for bio-flocculants that is safe and addresses the effects of synthetic polymers. This study was aimed at isolating bacteria with bio-flocculating potential, their molecular identification and phylogenetic relatedness, and the optimization of their flocculating abilities from an open water (Asa River) in Ilorin Kwara State. The effect of carbon source (glucose, lactose and starch), cations (FeSO4, KCl and CaCl2) and pH (2 to 12) was evaluated on the bio-flocculating activities of the isolates using kaolin clay. The seven (7) novel (new strains) isolates with their respective accession number from National Center for Biotechnology Information (NCBI) after molecular confirmation are Pseudomonas otitidis MTK01 (MK263227), Aeromonas caviea MTK02 (MK263228), Providencia alcalifaciens MTK03 (MK263229), Providencia sp. MTK05 (MK263230), Alcaligenes sp. MTK06 (MK263231), Klebsiella pneumoniae MTK07 (MK263232) and Klebsiella sp. MTK08 (MK263233) while Raoultella ornithinolytica MTK04 was also identified. Phylogenetic tree of relatedness showed close kin of the isolates to established bacteria sequence deposited at the NCBI GenBank. Although the flocculating rate of each isolates varied with different parameters that was used in the study, glucose was the most supportive followed by lactose and starch, CaCl2 was most supportive cation followed by KCl and FeSO4 while pH 12, 6, 8, 10, 2 and 4 were the order of decreasing flocculating rate of the medium. This study has reported the presence of eight (8) bio-flocculating bacteria (out of which 7 are new strains of bacteria) in an open water which has been further optimized for effective flocculating rate and thus provides an ecofriendly and harmless flocculants source that can be employed in water treatment procedures.

Isolation, Characterization, and Pharmaceutical Applications of an Exopolysaccharide from Aerococcus Uriaeequi

Many marine bacteria secrete exopolysaccharides (EPSs), which are made up of a substantial component of the macro-molecules surrounding cells. Recently, the wide demand for EPSs for food, cosmetics, pharmaceutical and other applications has led to great interest in them. In this study, an EPS produced by marine bacteria Aerococcus uriaeequi HZ strains (EPS-A) was isolated and purified to examine its structure and biological function. The molecular weight of EPS-A analyzed by high-performance liquid gel filtration chromatography (HPGFC) is found to have a number average of 2.22 × 105 and weight average of 2.84 × 105, respectively. High-performance liquid chromatography (HPLC) and Fourier-transform–infrared (FT–IR) analysis indicate that EPS-A was a polysaccharide composed of glucose and a little mannose. In addition, the flocculating rate of sewage of EPS-A was 79.90%. The hygroscopicity studies showed that hygroscopicity of EPS-A was higher than chitosan but lower than that of sodium hyaluronate. The moisture retention of EPS-A showed similar retention activity to both chitosan and sodium hyaluronate. EPS-A also can scavenge free radicals including both OH• free radical and O2•− free radical and the activity to O2•− free radical is similar to vitamin C. Safety assessment on mice indicated that the EPS-A is safe for external use and oral administration. EPS-A has great potential for applications in medicine due to its characteristics mentioned above.

Bioflocculant production by Haloplanus vescus and its application in acid brilliant scarlet yellow/red removal

A novel bioflocculant MBF057 produced by a salt-tolerant Haloplanus vescus HW0579 was investigated in this study. The effects of culture conditions such as initial pH, inoculum size, and chemical oxygen demand (COD) of K-acid wastewater on MBF0579 production were studied. The result showed that 8.09 g/L purified MBF0579 was extracted with the following optimized conditions: 780 mg/L COD of K-acid wastewater as carbon source, inoculum size 12.5%, and initial pH 7.0. The biopolymer contained 78.6% polysaccharides and 21.1% proteins. The highest flocculating rate of 81.86 and 95.07% for the COD and chroma of acid brilliant scarlet gelb rot (yellow/red, GR) dye wastewater were achieved at a dosage of 150 mg/L, pH 2.0 and contact time 100 min. Overall, these findings indicate bioflocculation offers an effective alternative method of decreasing acid brilliant scarlet GR during dye wastewater treatment.

Preparation and Flocculating Performance of P (AM-DAC-AANa) Copolymer

Amphoteric ionic polyacrylamide P (AM-DAC-AANa) was prepared in aqueous solution using acrylamide (AM), 2-(acryloyloxy) ethyltrimethylammonium chloride (DAC) and sodium acrylate (AANa) as materials by photo assisted initiation. The influences of reaction conditions on intrinsic viscosity and solubility of product were studied. Under the conditions of initiation temperature 20°C, monomer concentration 32%, pH=6 and initiator concentration 0.010%, the intrinsic viscosity and dissolving time of polymer were 13.56dL/g and 66min respectively. Moreover, the flocculating performance of the obtained copolymer was also studied. The results showed that under the conditions of P(AM-DAC-AANa) dosage 0.0250%, intrinsic viscosity 12.13dL·g-1, ionic degree 25%, m (DAC):m (AANa)=1:2, the transmittance of the supernatant, flocculating rate and dewatering rate were 93.90%, 84.47% and 92.41% respectively.

Preliminary Screening of Microorganisms Producing Flocculent

In order to reduce the production cost of Microbial Flocculation，this article uses the cheap straw-inorganic nitrogen medium，directly domesticated and screened out a stable and efficient microbial flocculant producing strain B-15，which has better flocculation on kaolin clay suspension system. Preliminary identify as bacillu, the strain produce flocculant has flocculating rate of 81.08% for suspension.

Study on the Optimal Fermentation Time and Kinetics of Bioflocculant Produced by Bacterium F2

We isolated flocculants-producing bacteria F2 from soil. It shows high and stable flocculating activity for Kaolin clay suspension. In order to increase yield of flocculants, we need determine the optimal obtained time. We measured the changes of several parameters using shaking flask experiment, including flocculating- rate, the content of polysaccharide, protein and glucose. It’s showed that the optimal obtained time of bio-flocculants is 21 h. And we built the model about the production of bio-flocculants. Through the comparison of experimental data and the corresponding calculated values from the models, we found that the data joint well and the model can provide theoretical basis for Industrialization of bio-flocculants.