Production and characterization of surfactin-like biosurfactant produced by novel strain Bacillus nealsonii S2MT and it's potential for oil contaminated soil remediation

Abstract

Background Biosurfactants, being highly biodegradable, ecofriendly and multifunctional compounds have wide applications in various industrial sectors including environmental bioremediation. Surfactin a member of lipopeptide family which considered as one of the most powerful biosurfactant due to its environmental applications, emulsification activities as well as therapeutic properties. Therefore, the aim of this study to investigate the surfactin like biosurfactants produced by newly strain S2MT and their potential applications for soil remediation. Results In this study, a novel biosurfactant producing strain Bacillus nealsonii S2MT was investigated from the lake sediment that reduced the surface tension 34.15± 0.6 mN/m -1 with excellent emulsifying potential 55± 0.3% in kerosene oil. Additionally, the highest biosurfactant product 1300 mg/L -1 was achieved during which the composition of the culture medium was optimized through a response surface methodology (RSM). Results showed that 2% glycerol and 0.1% NH 4 NO 3 were the best carbon/nitrogen substrates for biosurfactant production. The most significant parameters such as temperature (30 °C), pH (8), agitation (100 rpm), NH 4 NO 3 (0.1%), yeast extract (0%) and NaCl (0.5%) contributed to the surface tension reduction and therefore enhancing the biosurfactant yield. Moreover, the obtained product was found to be highly stable at environmental factors such as salinity, pH and temperature variations. In addition, the biosurfactant product was chemically characterized as cyclic lipopeptide relating to surfactin-like isoforms (C 13 -C 15 ) with a thin-layer chromatography (TLC) and liquid chromatography and mass spectroscopy (LC/MS) respectively. The corresponding biosurfactant displayed 43.6± 0.08 and 46.7± 0.01% remediation of heavy engine-oil contaminated soil at 10 and 40 mg/L concentrations respectively. Conclusion This study, therefore, confirmed that the strain S2MT was not only a potential biosurfactant producer but also an efficient and environmentally acceptable candidate for soil remediation compared to synthetic compounds.

Valorization of Oil Waste for Biodetergent Production Using Serratia Marcescens N2 and Gamma Irradiation Assisted Biorecovery

“…Our results indicate that Serratia marcescens N2 produces high yield of biosurfactant that increased with the exposure of cell cultures to gamma radiation, the highest yield was obtained at 1000 Gy. This result is higher than that reported by (Phulpoto et al, 2020) who obtained lower yields that were more than half what we obtained even after optimization of cultivation conditions. The use of gamma radiation did not incur any structural changes except in the peptide peak after exposing the cells to 2000 Gy, this change can be attributed to the effect of gamma radiation on the peptide fragment of the biosurfactant (Blanco et al, 2018)reported fragmentation as one of the effects exerted by ionizing radiation on proteins.…”

“…Although gamma radiation was previously reported by some researchers to induce hyper producing bacterial mutants (El-Housseiny, Aboshanab, Aboulwafa, & Hassouna, 2019)yet in the current study, we used gamma radiation as a tool to enhance biorecovery and decrease the number of steps required for biosurfactant biorecovery. This is considered economic in the bioprocess of biosurfactant production since the steps involves acid precipitation overnight, refrigeration and centrifugation (Phulpoto et al, 2020), the yield obtained is dependent on the amount of biosurfactant released in the cultivation media. Our results indicate that Serratia marcescens N2 produces high yield of biosurfactant that increased with the exposure of cell cultures to gamma radiation, the highest yield was obtained at 1000 Gy.…”

Biosurfactant Production by Streptomyces sp. CGS B11 Using Molasses and Spent Yeast Medium

“…Stability of the biosurfactant at different temperatures makes it useful in food, pharmaceuticals, and cosmetics industries since sterilization at high temperatures and storage at low temperatures are common processes involved in the production(Elazzazy et al 2015). Furthermore, the stability of the biosurfactant at different pH and salinity shows its applicability in soap production, acidic food products, and bioremediation(Prieto et al 2008;Phulpoto et al 2020;Araújo et al 2019).…”

Valorization of frying oil waste for biodetergent production using Serratia marcescens N2 and gamma irradiation assisted biorecovery

“…The use of gamma radiation did not incur any structural changes except in the peptide peak after exposing the cells to 2000 Gy, this change can be attributed to the effect of gamma radiation on the peptide fragment of the biosurfactant. Blanco et al [30]reported fragmentation as one of the effects exerted by ionizing radiation on proteins. This result confirms that exposure of cell culture to 1000 Gy can result in yield increase with no structural changes or functional changes.…”