Corsellis Yannick Y, Krasovec Marc M, Sylvi Léa L, Cuny Philippe P, Militon Cécile C
Aix Marseille Université, CNRS/INSU, Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, Campus de Luminy, Case 901, 163 Avenue de Luminy, 13288, Marseille Cedex 09, France.
Oceanological Observatory of Banyuls, UMR 7232, Banyuls-sur-mer, 66650, France.
Extremophiles. 2016 May;20(3):235-50. doi: 10.1007/s00792-016-0818-x. Epub 2016 Mar 8.
Abiotic and biotic processes associated with the degradation of a light petroleum in brines close to the salt-saturation (~31 %) and the effect of labile organic matter (LOM) supply (casaminoacids/citrate; 0.2 and 0.1 % w/v, respectively) were followed during an incubation of 30 days. After 4-week incubation at 40 °C under light/dark cycles, a 24 % of abiotic degradation was observed in untreated brines. The stimulation of native brines community with LOM addition allowed an additional 12.8 % oil attenuation due to biodegradation processes. Successional changes in the active microbial community structure due to the oil contamination (16S rRNA DGGE approach) showed the selection of one phylotype affiliated to Salinibacter and the disappearance of Haloquadratum walsbyi in untreated brines. In LOM-amended microcosms, phylotypes related to Salinibacter, Haloarcula, Haloterrigena and Halorhabdus were selected. An effect of hydrocarbon contamination was only observed in the bacterial community with the inhibition of two dominant proteobacterial phylotypes. This study further confirms that short-term and moderate oil biodegradation is possible in LOM-stimulated brines. Biodegradation should be much more reduced under in situ conditions. Self-cleaning capacities of close to saturation hypersaline lakes appears, therefore very limited compared to non-extreme haline environments.
在30天的培养期内，研究了与接近盐饱和度（约31%）的盐水中轻质石油降解相关的非生物和生物过程，以及不稳定有机物（LOM）供应（分别为酪蛋白氨基酸/柠檬酸盐；0.2%和0.1% w/v）的影响。在40°C下经过4周的光照/黑暗循环培养后，未处理的盐水中观察到24%的非生物降解。添加LOM刺激天然盐水群落，由于生物降解过程，额外实现了12.8%的石油衰减。由于油污（16S rRNA DGGE方法）导致的活性微生物群落结构的演替变化表明，在未处理的盐水中，一种与盐杆菌属相关的系统型被选择，而沃氏嗜盐四角菌消失。在添加LOM的微观世界中，选择了与盐杆菌属、嗜盐弧菌属、嗜盐地芽孢杆菌属和嗜盐栖热菌属相关的系统型。仅在细菌群落中观察到烃污染的影响，两种优势变形菌系统型受到抑制。这项研究进一步证实，在添加LOM的盐水中，短期和适度的石油生物降解是可能的。在原位条件下，生物降解应该会大大减少。因此，与非极端盐环境相比，接近饱和的超盐湖的自净能力似乎非常有限。
