Utilization of agro-industrial waste for biosurfactant production under submerged fermentation and its synergistic application in biosorption of Pb2+

Abstract

The biosurfactant production process was optimized using raw orange peel extract (ST reduction = 33.04 dyne cm−1; biosurfactant yield = ~3.7 g L−1) and the extracted metabolite was characterized in terms of its nature, and class/family. To the best of our knowledge, a first report utilizing biowaste as a sole carbon substrate for simultaneous biosurfactant production and Pb2+ removal under submerged fermentation by Bacillus haynesii strain E1. The results depicted the extracted biosurfactant to be of lipopeptide nature belonging to surfactin family having 50 mg L−1 of CMC. The crude biosurfactant was found to be tensioactive at temperature 70 °C, 6% salt concentration, and varying pH range. The biosurfactant-producing bacterium effectively remediated Pb2+ (high MIC = 2200 mg L−1) with a maximum adsorption capacity of 196.08 mg g−1. The biosorption mechanism followed Langmuir (R2 = 0.9724) and Pseudo second-order adsorption kinetics (R2 = 0.9996; 200 mg L−1).