MICROBIAL MATS IN THE HYPERSALINE PONDS OF MEDITERRANEAN SALTERNS (SALINS-DE-GIRAUD, FRANCE)
MICROBIAL MATS IN THE HYPERSALINE PONDS OF MEDITERRANEAN SALTERNS (SALINS-DE-GIRAUD, FRANCE)
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DOI：
10.1111/j.1574-6941.1994.tb00074.x
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发表时间：
1994-03-01
影响因子：
4.2
通讯作者：
RELEXANS, JC
中科院分区：
文献类型：
--
作者：
CAUMETTE, P;MATHERON, R;RELEXANS, JC
1989年至1991年期间，仔细研究了在高盐池塘（法国卡马格）的石膏壳中发育的微生物垫。在温暖的季节，当这些垫完全发展，分析微生物的活动和氧和硫化物的微观配置文件显示了一个伟大的活动的不同种类的细菌在垫下面的石膏地壳。在最大日光下，氧的产生量可达2 μ mol cm（-3）h（-1），而硫化物在光照下的氧化量经计算为12.7 μ mol cm（-3）h（-1），即假定8-10小时的恒定日光和厚度为3 mm的硫化物氧化区，氧化量为300 - 180 mmol m（-2）day-l。这种硫化物氧化消耗了约65-95%的每日硫化物产量，据估计，每日硫化物产量为400 - 450 mmol m（-2）day-l，来自于沉积物加垫的6 cm深度层中发生的硫酸盐还原。根据以石膏形式沉淀在沉积物表面的硫酸盐的量，硫酸盐还原从未受到限制，并且被发现是文献中报道的最高值之一（平均值为8200 nmol cm（-3）day（-1））。这个生态系统完全被石膏壳覆盖，被发现作为一个封闭的系统反应。因此，硫化物不会逸出并在地壳下积聚。几个小时的黑暗之后，它被探测到了垫子的顶部。它在白天被形成垫子的光合生物再氧化。后者垫由2至3层的光合生物：上层的蓝细菌Aphanothece的棕色层，中间绿色层的蓝细菌Phormidium和紫色硫氧化细菌的红色层，其中两个新的嗜盐物种被分离（Chromatium salexigens和Thiocapsa halophila）。已经发现，积累的硫化物不仅被硫化物氧化带中的光养细菌氧化，而且被能够在硫化物存在下进行光合作用的蓝藻产生的氧氧化。
Microbial mats that develop in the gypsum crust of the hypersaline ponds of Salins-de-Giraud (Camargue, France) were carefully investigated between 1989 and 1991. During the warm seasons, when these mats were fully developed, analyses of microbial activities and microprofiles of oxygen and sulfide have shown a great activity of the different kinds of bacteria found in the mat below the gypsum crust. Oxygen production could amount to 2 mu mol cm(-3) h(-1) during the maximum daylight whereas the oxidation of sulfide in the light was calculated to be 12.7 mu mol cm(-3) h(-1), i.e. 300 to 180 mmol m(-2) day-l assuming 8-10 hours of constant daylight and a sulfide oxidation zone of 3 mm in thickness. This sulfide oxidation consumes about 65-95% of the diel sulfide production which has been estimated to be 400 to 450 mmol m(-2) day-l originating from sulfate reduction which takes place in the 6 cm depth horizon of sediment plus mat. According to the amounts of sulfate precipitated at the sediment surface in the form of gypsum, sulfate reduction is never limited and was found to be among the highest values reported in the literature (average value of 8200 nmols cm(-3) day(-1)). Completely covered by the gypsum crust, this ecosystem has been found to react as a closed system. Consequently, the sulfide does not escape and accumulate below the crust. It was detected up to the top of the mat after a few hours of darkness. It is reoxidized during the day by the photosynthetic organisms that form the mats. These latter mats were composed of 2 to 3 laminated layers of phototrophic organisms: an upper brown layer of the cyanobacterium Aphanothece, an intermediate green layer of the cyanobacterium Phormidium and an underlying red layer of purple sulfur-oxidizing bacteria from which two new halophilic species were isolated (Chromatium salexigens and Thiocapsa halophila). It has been found that the accumulated sulfide is oxidized not only by the phototrophic bacteria in the sulfide oxidation zone but also by the oxygen produced by the cyanobacteria which are able to photosynthesize in the presence of sulfide.