Aix-Marseille Université, Université du Sud Toulon-Var, CNRS/INSU, IRD, MIO, UM 110, 13288, Marseille Cedex 09, France.
Extremophiles. 2013 Jul;17(4):669-75. doi: 10.1007/s00792-013-0550-8. Epub 2013 Jun 9.
The potential for surfactant production by the extreme halophilic archaeon Haloferax sp. MSNC14 in the presence of individual hydrocarbon substrates was studied. This strain was selected for its ability to grow on different types of hydrocarbons at high NaCl concentrations. Linear (n-heptadecane or C17) and isoprenoid (pristane) alkanes, a polyaromatic hydrocarbon (phenanthrene) and ammonium acetate (highly water-soluble control compound) were used as growth substrates. The adherence potential was demonstrated by the ability of the cells to adhere to liquid or solid hydrocarbons. The biosurfactant production was indicated by the reduction of the surface tension (ST) and by the emulsification activity (EA) of cell-free supernatants. Growth on acetate was accompanied by a low EA (lower than 0.1) and a high ST (70 mN/m), whereas an important EA (up to 0.68 ± 0.08) and a reduction of ST (down to 32 ± 2.3 mN/m) were observed during growth on the different hydrocarbons. Both ST and EA varied with the growth phase. The adhesion to hydrocarbons was higher when cells were grown on C17 (by 60-70 %) and pristane (by 30-50 %) than on phenanthrene (25 %). The results demonstrated that strain MNSC14 was able to increase the bioavailability of insoluble hydrocarbons, thus facilitating their uptake and their biodegradation even at high salt concentration.
研究了极端嗜盐古菌 Haloferax sp. MSNC14 在存在单一碳氢化合物底物的情况下产生表面活性剂的潜力。该菌株因其能够在高 NaCl 浓度下生长在不同类型的碳氢化合物上而被选中。线性（正十七烷或 C17）和异戊二烯（姥鲛烷）烷烃、多环芳烃（菲）和乙酸铵（高度水溶性的对照化合物）被用作生长底物。细胞能够附着在液体或固体碳氢化合物上，证明了其附着潜力。通过降低表面张力（ST）和细胞游离上清液的乳化活性（EA）来指示生物表面活性剂的产生。在乙酸盐上生长伴随着低 EA（低于 0.1）和高 ST（~70 mN/m），而在不同碳氢化合物上生长时观察到高 EA（高达 0.68 ± 0.08）和 ST 降低（降至 32 ± 2.3 mN/m）。ST 和 EA 随生长阶段而变化。当细胞在 C17（增加 60-70%）和姥鲛烷（增加 30-50%）上生长时，对碳氢化合物的粘附性比在菲（增加 25%）上更高。结果表明，菌株 MNSC14 能够增加不溶性碳氢化合物的生物利用度，从而促进它们的吸收和生物降解，即使在高盐浓度下也是如此。
