Sulfide utilization by purple nonsulfur bacteria
Sulfide utilization by purple nonsulfur bacteria
复制标题
紫色非硫细菌对硫化物的利用
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
H. Gemerden
中科院分区：
文献类型：
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作者：
T. Hansen;H. Gemerden
紫色非硫细菌红色红螺菌SMG 107，胶囊红假单胞菌SMG 155，RPS。SphaeroidesSMG 158和RPS。对SMG124沼泽沼泽进行了硫化物利用的可能性试验。前三个菌株仅能将硫化物氧化为胞外单质硫，而RPS则不能。沼泽藻SMG 124将硫化物转化为硫酸盐，没有元素硫的中间积累。当硫化物浓度低于紫色硫磺细菌时，细菌的生长停止。由于硫化物耐性较低，因此无法通过分批培养获得硫化物作为光合作用电子供体时所能获得的比生长速率信息。RPS的硫化物限速恒化培养。胶囊酵母SMG155的最大比生长速率接近0.14h-1(倍增时间为5h)。在所测试的所有稀释速率下，硫化物被转化为胞外元素硫。RPS的最大比增长率。沼泽中的SMG-124显著低于0.03h-1。硫酸盐是硫化物转化的唯一产物。这些数据表明，自然界中至少有一些紫色非硫细菌可能在异化硫循环中发挥了作用。讨论了我们结果的分类学意义。
SummaryThe purple nonsulfur bacteria Rhodospirillum rubrum SMG 107, Rhodopseudomonas capsulata SMG 155, Rps. sphaeroides SMG 158 and Rps. palustris SMG 124 were tested for a possible utilization of sulfide. The first three strains were found to oxidize sulfide to extracellular elemental sulfur only, whereas Rps. palustris SMG 124 converted sulfide into sulfate without intermediate accumulation of elemental sulfur. Growth ceased at lower sulfide concentrations than usually found with purple sulfur bacteria. In consequence of the low sulfide tolerance information on the specific growth rates obtainable with sulfide as photosynthetic electron donor could not be provided by cultivation in batch cultures. Sulfide-limited chemostat cultures of Rps. capsulata SMG 155 showed that the maximum specific growth rate was close to 0.14 h-1 (doubling time 5 h). Sulfide was converted into extracellular elemental sulfur at all dilution rates tested. The maximum specific growth rate of Rps. palustris SMG 124 was found to be much lower (less than 0.03 h-1). Sulfate was the only product of the conversion of sulfide.These data show that at least some purple nonsulfur bacteria may play a role in the dissimilatory sulfur cycle in nature. Taxonomic implications of our results are discussed.