Cell-Mineral Research Centre, Kroto Research Institute, University of Sheffield, Sheffield, UK.
FEMS Microbiol Ecol. 2010 Feb;71(2):208-17. doi: 10.1111/j.1574-6941.2009.00799.x. Epub 2009 Oct 15.
Forefields of receding glaciers are unique and sensitive environments representing natural soil chronosequences, where sulfate availability is assumed to be a limiting factor. Bacterial mineralization of organosulfur is an important sulfate-providing process in soils. We analyzed the diversity of sulfonate-desulfurizing (desulfonating) bacteria in the Damma glacier forefield on the basis of the key gene asfA by terminal restriction fragment length polymorphism and clone libraries. The community structure and sequence diversity of desulfonating bacteria differed significantly between forefield soils deglaciated in the 1990s and the 1950s. Soil age had a strong effect on the desulfonating rhizosphere communities of Agrostis rupestris, but only a slight impact on the ones from Leucanthemopsis alpina. AsfA affiliated to Polaromonas sp. was predominantly found in the more recent ice-free soils and the corresponding rhizospheres of A. rupestris, while a group of unidentified sequences was found to be dominating the matured soils and the corresponding rhizospheres of A. rupestris. The desulfonating bacterial diversity was not affected by varying levels of sulfate concentrations. The level of asfA diversity in recently deglaciated soils suggests that desulfonating bacteria are a critical factor in sulfur cycling, with defined groups dominating at different stages of soil formation.
后退冰川的前冰川场是独特而敏感的环境，代表了自然土壤的时间序列，其中硫酸盐的可用性被认为是一个限制因素。有机硫的细菌矿化是土壤中提供硫酸盐的重要过程。我们基于关键基因 asfA 通过末端限制性片段长度多态性和克隆文库分析了达玛冰川前冰川场中磺酸盐脱硫（脱硫）细菌的多样性。在 20 世纪 90 年代和 50 年代冰川消退的前冰川场土壤中，脱硫细菌的群落结构和序列多样性有显著差异。土壤年龄对高山羊茅根际脱硫群落有强烈影响，但对滨菊根际脱硫群落影响较小。与极地单胞菌属相关的 asfA 主要在前冰川场土壤和高山羊茅的相应根际中发现，而一组未鉴定的序列在前冰川场土壤和高山羊茅的相应根际中占主导地位。脱硫细菌多样性不受硫酸盐浓度变化的影响。最近冰川消退土壤中 asfA 多样性水平表明，脱硫细菌是硫循环的关键因素，在土壤形成的不同阶段有明确的优势群体。
