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Distribution of ether lipids and composition of the archaeal community in terrestrial geothermal springs: impact of environmental variables

2014; Wiley; Volume: 17; Issue: 5 Linguagem: Inglês

10.1111/1462-2920.12595

1462-2920

Wei Xie, Lixin Zhang, Jinxiang Wang, Yufei Chen, Yuanqing Zhu, José R. de la Torre, Hailiang Dong, Hilairy E. Hartnett, Brian P. Hedlund, Martin G. Klotz,

Genomics and Phylogenetic Studies

Summary Archaea can respond to changes in the environment by altering the composition of their membrane lipids, for example, by modification of the abundance and composition of glycerol dialkyl glycerol tetraethers ( GDGTs ). Here, we investigated the abundance and proportions of polar GDGTs ( P ‐ GDGTs ) and core GDGTs ( C ‐ GDGTs ) sampled in different seasons from T engchong hot springs ( Y unnan, C hina), which encompassed a pH range of 2.5–10.1 and a temperature range of 43.7–93.6° C . The phylogenetic composition of the archaeal community (reanalysed from published work) divided the A rchaea in spring sediment samples into three major groups that corresponded with spring pH : acidic, circumneutral and alkaline. Cluster analysis showed correlation between spring pH and the composition of P ‐ and C ‐ GDGTs and archaeal 16 S rRNA genes, indicating an intimate link between resident A rchaea and the distribution of P ‐ and C ‐ GDGTs in T engchong hot springs. The distribution of GDGTs in T engchong springs was also significantly affected by temperature; however, the relationship was weaker than with pH . Analysis of published datasets including samples from T ibet, Y ellowstone and the US G reat B asin hot springs revealed a similar relationship between pH and GDGT content. Specifically, low pH springs had higher concentrations of GDGTs with high numbers of cyclopentyl rings than neutral and alkaline springs, which is consistent with the predominance of high cyclopentyl ring‐characterized S ulfolobales and T hermoplasmatales present in some of the low pH springs. Our study suggests that the resident A rchaea in these hot springs are acclimated if not adapted to low pH by their genetic capacity to effect the packing density of their membranes by increasing cyclopentyl rings in GDGTs at the rank of community.