ANOXYGENIC MICROBIAL MATS OF HOT-SPRINGS - THERMOPHILIC CHLOROBIUM SP
ANOXYGENIC MICROBIAL MATS OF HOT-SPRINGS - THERMOPHILIC CHLOROBIUM SP
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DOI：
10.1016/0378-1097(90)90685-j
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发表时间：
1990-12-15
影响因子：
4.2
通讯作者：
JORGENSON, BB
中科院分区：
文献类型：
--
作者：
CASTENHOLZ, RW;BAULD, J;JORGENSON, BB
非叠层，绿色到黄绿色的微生物垫，带有氯杆菌。作为唯一的趋光性生物，出现在新西兰罗托鲁瓦及其附近的温泉中，温度从55摄氏度到大约40摄氏度。PH为4.3~6.2，硫化物为0.2~1.8 mm。这个Chlorobium sp.在55摄氏度的高温下形成种群的能力是独一无二的。利用光纤微探头在完整的氯离子质量中进行的光谱辐射测量显示，在垫子内0.7 mm深度处的入射辐射(在光合作用可用波长上)不到0.1%，非常不透明，尽管集中的氯杆菌种群有时延伸到3 mm深度。硫化物特有的微电极通过[C-14]碳酸氢盐在垫子悬浮液中的同化和在完整垫子中的[C-14]碳酸盐同化，证明了硫化物依赖的无氧光合作用。没有放氧，垫子内也没有氧气。在细胞悬浮液中也发生了对[C-14]乙酸酯的光增强吸收。硫化物不能提高这一速率。
Non-laminated, green to yellow-green microbial mats, with Chlorobium sp. as the only phototroph, occurred from 55 to about 40-degrees-C in hot springs in and near Rotorua, New Zealand. The pH ranged from 4.3 to 6.2 and sulfide from 0.2 to 1.8 mM. This Chlorobium sp. is unique in its ability to form populations at temperatures as high as 55-degrees-C. Spectroradiometric measurements with a fiber-optic microprobe in the intact chlorobium mass showed great opacity with less than 0.1% of the incident radiation (at photosynthetically usable wavelengths) available at 0.7 mm depth within the mat, although the concentrated Chlorobium population sometimes extended to 3 mm depth. Sulfide-dependent, anoxygenic photosynthesis was demonstrated by [C-14]bicarbonate assimilation in mat suspensions and in intact mats by a sulfide-specific microelectrode. No oxygen evolution occurred and no O2 was present within the mat. A light-enhanced uptake of [C-14]acetate also occurred in cell suspensions. This rate was not enhanced by sulfide.