Furthermore, information on dosage requirement is important for future prospect in water treatment applications. Therefore, the objectives of this study are to determine the cation-dependent characteristics sellckchem of the bioflocculant produced, to assess the tolerance of the bioflocculant towards pH change, and to establish the dosage requirement of the bioflocculant. This paper will discuss these composite effects on the flocculation performance optimization of a bioflocculant produced by Bacillus spp. UPMB13, and the potential of this bioflocculant in water treatment applications.2. Materials and Methods2.1. Bioflocculant SourceA bioflocculant-producing bacterial strain obtained from the culture collection of locally isolated rhizobacteria from oil palm roots, of the Department of Land Management, Universiti of Putra Malaysia identified as Bacillus spp.

UPMB13 [15] was primarily screened based on its mucoid and ropy colony morphology characteristics as the basic properties for identification of a potential bioflocculant-producing bacterium. Biochemical identification of the strain based on 29 biochemical and enzymatic reaction tests (BBL Crystal Gram-Positive ID System) including hydrolysis of amide and glycosidic bonds with positive release of several fluorescent coumarin derivatives, positive utilization of carbohydrates such as sucrose, mannitol, glycerol, and additional positive utilization of arginine showed high similarity to the characteristics of Bacillus subtilis (99%). Batch cultures of the strain Bacillus spp.

UPMB13 were prepared by cultivation in tryptic soy broth on an orbital shaker (150rpm) at room temperature for the determination of its flocculating capabilities, based on different parameters by kaolin assays [16].2.2. Flocculation AssayFlocculation assay using kaolin clay as suspended particles was conducted according to the combination of methods described by Feng and Xu [17] and Zheng et al. [11], with modifications. Batch flocculation tests were prepared by suspending 5g of kaolin clay, with an average size of 4-5��m, dried at 105��C for 1 hour and kept dry in a dessicator, in 1L of ultra pure water. The pH of the suspension was then adjusted to 6.8 with HCl or NaOH. After pH adjustment, 50mL of the suspension was pipetted into 100mL conical flasks and autoclaved at 121��C for 20min. The sterile suspensions were subjected to treatments Drug_discovery with the addition of 0.5mL cultured broths (culture aged 24�C72hrs with optical density reading of cell growth at 660nm varied between 0.5�C1.5) and 4.5mL of 0.1% CaCl2. Treatment substitution of sterile ultra pure water and sterile broth acts as control for CaCl2 and bioflocculant, respectively.