Bioemulsifier production by Acinetobacter venetianus AMO1502: Potential for bioremediation and environmentally friendly applications

At the best conditions of the bioprocess (30 °C, pH 7.0, 3.0 g/L NaCl) were obtained 0.66 g/L cell concentration, 3.3 g/L of bioemulsifier, which showed high emulsifying activity (53 % ± 2), reducing the surface tension of the water in 47.2 % (38 mN/m). The polymeric structure of the purified bioemulsifier comprised a carbohydrate backbone composed of hexose-based amino sugars with a monomeric mass of 1099 Da, structurally similar to emulsan. A. venetianus bioemulsifier is non-phytotoxic (GI% > 80 %) against Ocimum basilicum and Brassica oleracea and non-cytotoxic (LC₅₀ 5794 mg/L) against Artemia salina, being safe local organisms in comparison to other less eco-friendly synthetic emulsifiers. This bioemulsifier effectively dispersed spilled oil in vitro (C₂₂-C₃₃), reducing oil mass by 12 % (w/w) and dispersing oil in a displacement area of 75 cm² (23.8 % of the spilled area). Thus, the isolated A. venetianus AMO1502 produced a bioemulsifier potentially applicable for environmentally friendly oil spill remediation.