Recovery of bacterioruberin and proteins using aqueous solutions of surface-active compounds

Abstract

Bacterioruberin and proteins were recovered from a marine bacterium by using aqueous solutions of surface-active compounds.

Unveiling the Use of Hydrophobic Eutectic Solutions as Task-Specific Solvents To Recover Bacterioruberin from Haloferax mediterranei

“…By analyzing the trend of AcA, ButA, and DecA, it is possible to infer that the elongation of the carbon chain lowered the extraction success. This is somewhat unexpected given the reported extraction of bacterioruberin from H. mediterranei using aqueous solutions of anionic or neutral surfactants, albeit at a lower concentration of 250 mM …”

“…A bacterioruberin yield of extraction of 4.74 ± 0.01 mg bacterioruberin g wet biomass –1 was obtained experimentally, encompassing a mean relative deviation of 2.61%. Finally, an optimal point was chosen at the following operational conditions (110.4 min, 0.5 × Ment, and SLR 0.1), achieving a maximum yield of 5.16 ± 0.01 mg bacterioruberin g wet biomass –1 (see Table S2) This represents a significant increase relative to the obtained extraction yields using pure ethanol (0.76 mg bacterioruberin g wet biomass –1 ) and aqueous solutions of nonionic surfactants (0.37 mg bacterioruberin g wet biomass –1 ) . Moreover, the Ment:LevA eutectic was extensively characterized by Wils et al and was shown to be biocompatible with human epidermal keratinocytes below concentrations of 200 μg mL –1 .…”

“…This is somewhat unexpected given the reported extraction of bacterioruberin from H. mediterranei using aqueous solutions of anionic or neutral surfactants, albeit at a lower concentration of 250 mM. 31 For most systems, the addition of water was necessary to induce the extraction process, which can be ascribed to the difference in osmotic pressure between the hypersaline cellular environment of H. mediterranei and the extraction media. Interestingly, a similar extraction yield compared to that obtained using the ethanol control was obtained in the Ment:AcA and Ment:LA systems after addition of a small (10% v/v) volume of water.…”

“…The absorption spectra of the analyzed extracts were measured between 350 and 700 nm, and the bacterioruberin content was determined by eq using calibration curves at the maximum peak of absorbance observed, 494 nm, for both ethanol- and eutectic-based solutions. The bacterioruberin standard, used to determine the calibration curves, was obtained by preparative thin-layer chromatography (TLC), as previously reported by us yield of extraction false( mg bacterioruberin ⁢ normalg wet biomass − 1 false) = false[ bacterioruberin false] × volume weight Here “[Bacterioruberin]” corresponds to the concentration of bacterioruberin in the extract (mg mL –1 ), “volume” is the volume of solvent (mL), and “weight” is the weight of the wet cells tested (g).…”

“…Cell cultivation was accomplished following a protocol previously developed by us. 31 Briefly, Haloferax mediterranei ATCC 33500 was cultivated under controlled conditions aiming at maximum bacterioruberin yield, in YPC-Hv (yeast, peptone, and casamino acids media) culture medium: peptone of meat, 0.1% (w/v); casamino acids, 0.1% (w/v); yeast extract, 0.5% (w/v); NaCl, 14.4% (w/v); MgSO 4 •7H 2 O, 2.1; MgCl 2 •6H 2 O, 1.8% (w/v); KCl, 0.42% (w/v); Tris-HCl, 12 mM (pH 7.5); KOH, 1 M; and 0.5 M CaCl 2 . 32 The medium was sterilized at 121 °C prior to archaea culturing.…”