Process optimization and bioflocculative insights of glycoprotein bioflocculant produced by marine bacterium Bacillus oceanisediminis LBB1

Abstract

A type of environmentally benign and biodegradable biopolymers made by different microorganisms, bioflocculants have drawn more attention as viable substitutes for traditional chemical flocculants in the treatment of wastewater and the removal of pollutants. However, a number of obstacles prevent bioflocculants from being scaled up industrially, such as expensive substrate prices, limited manufacturing yields, and complex purifying procedures. A careful consideration must be given to the potential of microbiological contamination and the resulting health consequences linked to the use of bioflocculants. In present study, the bio-flocculative activity of Bacillus oceanisediminis LBB1 isolated from the gut of a finfish Lutjanus biguttanus, has been documented for the first time-the glycoproteinaceous bioflocculant BOB1 found to be an excellent bioflocculant with 80 % flocculating activity. The process standardization and optimization elucidated the most feasible and favourable reaction conditions ascertaining the synthesis and reaction kinetics of the bioflocculant BOB1 against kaolin clay suspension. The pattern of thermal stability of BOB1 was found to be fairly steady and stable with the maximal value reaching 94.6 % ± 1.0 % at 30 °C. The presence of various functional groups was analysed by FT-IR whereas the SEM micrographs exhibited the compact nature and fine and scattered particles of BOB-1. Hence, the creation of multipurpose flocculants based on MBF and its cooperative use with other treatment technologies are recognized as new developments for improved resource recovery and wastewater treatment.