Department of Marine Sciences, University of Connecticut, Groton, Connecticut, USA.
Astrobiology. 2009 Nov;9(9):861-74. doi: 10.1089/ast.2008.0329.
Microbial mats in the hypersaline lake of Salt Pan, Eleuthera, Bahamas, display a gradient of lithification along a transect from the center to the shore of the lake. These mats exist under similar geochemical conditions, with light quantity and quality as the sole major environmental difference. Therefore, we hypothesized that the microbial community may be driving the differences in lithification and, by extension, mineral biosignature formation. The lithifying and non-lithifying mat communities were compared (via 16S rRNA gene sequencing, 485 and 464 sequences, respectively) over both temporal and spatial scales. Seven bacterial groups dominated in all the microbial mat libraries: bacteriodetes, alphaproteobacteria, deltaproetobacteria, chloroflexi, spirochaetes, cyanobacteria, and planctomycetes. The mat communities were all significantly different over space, time, and lithification state. Species richness is significantly higher in the non-lithifying mats, potentially due to differences in mat structure and activity. This increased richness may impact lithification and, hence, biosignature production.
巴哈马埃卢thera 盐滩的高盐湖中存在微生物席，这些微生物席在从湖中心到湖岸的一条横截线上呈现出石化梯度。这些席子存在相似的地球化学条件下，光的数量和质量是唯一的主要环境差异。因此，我们假设微生物群落可能是导致石化差异的原因，进而影响矿物生物特征的形成。我们在时间和空间尺度上比较了石化和非石化席子群落（分别通过 16S rRNA 基因测序获得 485 和 464 个序列）。在所有微生物席子文库中，有七个细菌群占主导地位：拟杆菌门、α-变形菌门、δ-变形菌门、绿弯菌门、螺旋体门、蓝细菌门和浮霉菌门。席子群落无论在空间、时间还是石化状态上都有显著差异。非石化席子中的物种丰富度明显更高，这可能是由于席子结构和活性的差异所致。这种丰富度的增加可能会影响石化作用，从而影响生物特征的产生。
