Bioremediation of olein industry waste by Cytobacillus sp. OWB-43 strain

Abstract

The disposal of industrial vegetable olein waste poses a significant environmental challenge. In the present study, we investigated the bioremediation potential of Cytobacillus sp. OWB-43 to treat a waste generated from vegetable olein production, a by-product of sunflower, soybean, corn, and peanut oil industries with a chemical oxygen demand (COD) of 160,000 mg L−1. Cytobacillus sp. OWB-43 decreased the COD in 18.75% (~30,000 mg L−1) and soluble solids in ether in 24.8% (7.2 g L−1). Moreover, maximum growth in population under stirring and static conditions was 3.7 ×108CFU mL−1 and 1.5 ×109CFU mL−1, respectively. Besides, bacterial treatment (both agitation and static), reduced phytotoxicity of the residues, as observed in both lettuce seedlings and onion bulbs, used as biosensors of toxicity. Furthermore, we demonstrated that treated residues can be safely disposed on soil without harmful effects. This statement was observed in soil irrigated with Cytobacillus sp. OWB-43-treated residue, which supported lettuce growth, with fresh and dry weight values comparable to those grown in water-irrigated soil. While genera such as Bacillus and Pseudomonas are known for oily wastewater treatment, this study identifies Cytobacillus sp. as a promising and previously unreported bioremediation agent on olein waste treatment.