Biofloculant Producing _Bacillus megaterium_ from Poultry Slaughterhouse Wastewater: Elucidation of Flocculation Efficacy and Mechanism  
[PERSON]  
1 Bioresource Engineering Research Group (_BioERC_), Department of Chemical Engineering, Faculty of Engineering and the Built Environment, Cape Peninsula University of Technology, P.O. Box 1906, Bellville 7535, South Africa; mukandimdput.ac.za (M.R.M. ); chidlekput.ac.za (B.S.C.) [PERSON]  
2  
[PERSON]  
3 Department of Chemical Engineering Technology, Doornfontein Campus, University of Johannesburg, P.O. Box 524, Auckland Park, Johannesburg 2006, South Africa; [EMAIL_ADDRESS]  
[PERSON]  
1 Bioresource Engineering Research Group (_BioERC_), Department of Chemical Engineering, Faculty of Engineering and the Built Environment, Cape Peninsula University of Technology, P.O. Box 1906, Bellville 7535, South Africa; mukandimdput.ac.za (M.R.M. ); chidlekput.ac.za (B.S.C.) Footnote 1: email: {mushin.mushin.mushin.mushin.mushin.mushin.mushin.mushin. On the other hand, organic synthetics are suitable in low dosages but have degradability problems [1]. Thus, organic and inorganic flocculants are harmful. In contrast, plant-based flocculants in the natural flocculant group are inconvenient to produce due to climate and ecological changes, leaving biofloculants as a promising alternative [5]. Bioflocculants have excellent properties, which include low to non-toxicity, low concentration usage, and adaptability to a wide range of pH levels [1]. Bioflocculants are extracellular polymeric substances (EPS) naturally synthesized by microorganisms [7]. These metabolites are secreted during the growth of microorganisms and cell lysis. Many microorganisms such as fungi, algae and bacteria have shown the ability to produce bioflocculants [3] that are produced through microbial fermentation. This process is affected by various factors, including nutrient availability and composition, physicochemical parameters, and culture conditions [8]. The polymeric characterization of bioflocculants varies in terms of their composition of proteins, polysaccharides, polyamino acids, and sugars, with the polysaccharides and proteins receiving the most attention, as they constitute the most significant proportion of the flocculants and consequently influence their flocculation activity [4; 9]. Various bioflocculation mechanisms are currently accepted, including sweeping, adsorption bridging, chemical reactions, and change neutralization [10]. The flocculation mechanisms of chemical flocculants are well known, but the mechanism related to bioflocculants needs to be fully explored [11]. According to the green chemistry analogy, chemical flocculants are unfavorable because they are environmentally hazardous; therefore, the need for safer eco-friendly alternatives does not need to be emphasized but is a necessity; consequently, bioflocculants are gaining popularity. Despite this, bioflocculants are deemed not ideal for use on an industrial scale because of their high production costs, low yields, and poor flocculation efficiency [12]. Therefore, it is of the utmost importance to screen for novel bioflocculant-producing microorganisms that produce bioflocculants with high flocculating capabilities and higher yields and understand how they function, including their optimal conditions, so that they can be applied on an industrial scale. The main aim of this study was to isolate a biofloculant-producing strain from poultry slaughterhouse wastewater (PSW), focusing on selecting the strain with the highest flocculation activity level. PSW is characterized by a complex composition of pollutants such as blood, feces, fats, oil and grease from the slaughtering of birds and also detergents from the sanitation of equipment and surfaces, resulting in high COD, suspended solids and other parameters being high in the effluent [13; 14] including the presence of microorganisms.