Pyrosequencing Reveals Bacteria Carried in Different Wind-Eroded Sediments

作者:Gardner Terrence*; Acosta Martinez Veronica; Calderon Francisco J; Zobeck Ted M; Baddock Matthew; Van Pelt R Scott; Senwo Zachary; Dowd Scot; Cox Stephen
来源:Journal of Environmental Quality, 2012, 41(3): 744-753.
DOI:10.2134/jeq2011.0347

摘要

Little is known about the microbial communities carried in wind-eroded sediments from various soil types and land management systems. The novel technique of pyrosequencing promises to expand our understanding of the microbial diversity of soils and eroded sediments because it can sequence 10 to 100 times more DNA fragments than previous techniques, providing enhanced exploration into what microbes are being lost from soil due to wind erosion. Our study evaluated the bacterial diversity of two types of wind-eroded sediments collected from three different organic-rich soils in Michigan using a portable field wind tunnel. The wind-eroded sediments evaluated were a coarse sized fraction with 66% of particles >106 mu m (coarse eroded sediment) and a finer eroded sediment with 72% of particles <106 mu m. Our findings suggested that (i) bacteria carried in the coarser sediment and fine dust were effective fingerprints of the source soil, although their distribution may vary dependingon the soil characteristics because certain bacteria may be more protected in soil surfaces than others; (ii) coarser wind-eroded sediment showed higher bacterial diversity than fine dust in two of the three soils evaluated; and (iii) certain bacteria were more predominant in fine dust (Bacteroidetes, Chloroflexi, and Firmicutes) than coarse sediment (Proteobacteria and Acidobacteria), revealing different locations and niches of bacteria in soil, which, depending on wind erosion processes, can have important implications on the soil sustainability and functioning. Infrared spectroscopy showed that wind erosion preferentially removes particular kinds of C from the soil that are lost via fine dust. Our study shows that eroded sediments remove the active labile organic soil particulates containing key microorganisms involved in soil biogeochemical processes, which can have a negative impact on the quality and functioning of the source soil.

  • 出版日期2012-6