Fernández-Valiente Eduardo, Camacho Antonio, Rochera Carlos, Rico Eugenio, Vincent Warwick F, Quesada Antonio
Dept Biología, Universidad Autónoma de Madrid, Madrid, Spain.
FEMS Microbiol Ecol. 2007 Feb;59(2):377-85. doi: 10.1111/j.1574-6941.2006.00221.x. Epub 2006 Oct 27.
The community structure and physiological characteristics of three microbial mat communities in Byers Peninsula (Livingston Island, South Shetland Islands, Antarctica) were compared. One of the mats was located at the edge of a stream and was dominated by diatoms (with a thin basal layer of oscillatorian cyanobacteria), whereas the other two mats, located over moist soil and the bottom of a pond, respectively, were dominated by cyanobacteria throughout their vertical profiles. The predominant xanthophyll was fucoxanthin in the stream mat and myxoxanthophyll in the cyanobacteria-dominated mats. The sheath pigment scytonemin was absent in the stream mat but present in the soil and pond mats. The stream mat showed significantly lower delta13C and higher delta15N values than the other two mats. Consistent with the delta15N values, N2 fixation was negligible in the stream mat. The soil mat was the physiologically most active community. It showed rates of photosynthesis three times higher than in the other mats, and had the highest rates of ammonium uptake, nitrate uptake and N2 fixation. These observations underscore the taxonomic and physiological diversity of microbial mat communities in the maritime Antarctic region.
对位于南极南设得兰群岛利文斯顿岛拜尔斯半岛的三个微生物席群落的群落结构和生理特征进行了比较。其中一个微生物席位于溪流边缘，以硅藻为主（底部有一层薄薄的颤藻蓝细菌），而另外两个微生物席分别位于潮湿土壤和池塘底部，在其垂直剖面中均以蓝细菌为主。溪流微生物席中主要的叶黄素是岩藻黄质，而蓝细菌主导的微生物席中主要的叶黄素是粘藻叶黄素。鞘色素scytonemin在溪流微生物席中不存在，但在土壤和池塘微生物席中存在。溪流微生物席的δ13C值明显低于另外两个微生物席，而δ15N值则较高。与δ15N值一致，溪流微生物席中的固氮作用可以忽略不计。土壤微生物席是生理活性最高的群落。它的光合作用速率比其他微生物席高两倍，铵吸收、硝酸盐吸收和固氮速率也最高。这些观察结果强调了南极海洋地区微生物席群落的分类学和生理多样性。
