Assessment of bacterial biosurfactant production and application in Enhanced Oil Recovery (EOR)—A green approach

Abstract

The present work attempts to investigate production of biosurfactant, in a modified synthetic media, by less explored bacterial strain isolated from iron factory waste effluent from West Bengal, India and its application in enhanced oil recovery operations. The screened isolate was identified to be Pseudomonas mendocina by 16s rDNA gene homology (NCBI-Genebank accession no. MH091331). It showed a high emulsification of 68.3 ± 2.86%, lowering surface tension of water to 31 mN/ m and CMC of 125 mg l −1 and found to be alkalophillic (pH 6 to 12) and halophilic (up to 6% NaCl) in nature. Batch study in optimized media led to maximum yield of 3.09 ± 0.12 g l −1 . Production kinetic analysis by Luedeking Piret model successfully predicted mixed growth associated biosurfactant production with α and β values of 0.73 and 1.60 respectively and a yield coefficient of 0.82. Cost estimation for production of biosurfactant was calculated under lab scale conditions. Characterization of the extracted biosurfactant by anthrone test and Lowry’s protein estimation, TLC, FTIR, H 1 NMR and FESEM revealed the presence of sugar, peptides and lipid moieties. The biosurfactant obtained is extremely robust with high stability, sustaining wide range of pH (4 to 12), salinity (0.5 to 10% NaCl) and temperature (up to 100 °C). Toxicity assessment by Vigna radiata seed bioassay and MTT assay using and HEK293 cell line showed the non-toxic nature of the biosurfactant. Crude biosurfactant could play effective role in oil recovery with 44.3 ± 0.5 % enhanced oil recovery using sand packed column. • Biosurfactant (BS) from newly isolated halo-alkalophillic bacterial strain. • BS production in economically suitable optimized media. • Notably stable BS, tolerating extreme physiological conditions. • BS exhibiting presence of both glycolipids and lipopeptides: blend nature. • Potential use of crude biosurfactant for enhanced oil recovery.