Bacterial diversity in ornithogenic soils compared to mineral soils on King George Island, Antarctica

Abstract

In the Narębski Point area of King George Island of Antarctica, ornithogenic soils form on land under Chinstrap and Gentoo Penguin rookeries. The purpose of this study was to compare the bacterial community compositions in the gradient of contamination by penguin feces; mineral soil with no contamination, and soils with medium or high contamination. The discrimination between mineral soils and ornithogenic soils by characterization of physicochemical properties and bacterial communities was notable. Physicochemical analyses of soil properties showed enrichment of carbon and nitrogen in ornithogenic soils. Firmicutes were present abundantly in active ornithogenic soils, Bacteroidetes and Proteobacteria in a formerly active one, and several diverse phyla such as Proteobacteria, Actinobacteria, and Acidobacteria in mineral soils. Some predominant species belonging to the Firmicutes and Gammaproteobacteria may play an important role for the mineralization of nutrients in ornithogenic soils. Results of this study indicate that dominant species may play an important role in mineralization of nutrients in these ecosystems.

Diversity and structure of soil bacterial communities in the Fildes Region (maritime Antarctica) as revealed by 454 pyrosequencing

“…The relative abundances of the dominant phyla Proteobacteria, Actinobacteria, and Acidobacteria, as well as the identification of Verrucomicrobia as one of the dominant phyla in the soils of the Fildes Region in this study, was somewhat different from those previously described for soils in the King George Island using pyrosequencing (Teixeira et al, 2010 ; Kim et al, 2012 ; Roesch et al, 2012 ). Based on the 16S rDNA pyrosequencing data, Firmicutes, Proteobacteria, Bacteroidetes, Acidobacteria and Actinobacteria were the dominant soil bacterial phyla in Antarctica, including rhizosphere soil from vascular plants (Teixeira et al, 2010 ), ornithogenic and mineral soils (Kim et al, 2012 ), soils in exposed control site and in seal-covered site (Tiao et al, 2012 ), and soils from other different sites (Lee et al, 2012 ; Roesch et al, 2012 ; Yergeau et al, 2012 ). These differences may be due to the biotic and abiotic factors in the Antarctic soils.…”

“…Hitherto, diverse soil bacterial communities have been observed in Antarctic terrestrial ecosystems using traditional isolation methods (Powell et al, 2006 ; Rinnan et al, 2009 ; Fan et al, 2013 ; Zdanowski et al, 2013 ) and traditional molecular methods (e.g., PCR-DGGE, cloning sequencing, real-time PCR, microarray) (Smith et al, 2006 , 2010 ; Shravage et al, 2007 ; Yergeau et al, 2007 , 2009 ; Niederberger et al, 2008 ; Yergeau and Kowalchuk, 2008 ; Aislabie et al, 2009 ; Chong et al, 2009 , 2010 ; Soo et al, 2009 ; Newsham et al, 2010 ; Ganzert et al, 2011 ; Ma et al, 2012 ; Stomeo et al, 2012 ; Pan et al, 2013 ; Teixeira et al, 2013 ). Recently, greater phylogenetic diversity of soil bacterial communities has been found in the Antarctic soils using Roche 454 sequencing (Teixeira et al, 2010 ; Kim et al, 2012 ; Lee et al, 2012 ; Roesch et al, 2012 ; Tiao et al, 2012 ; Yergeau et al, 2012 ), which is able to identify a great number of bacterial sequences and provide an in-depth analysis of soil bacterial diversity. Nevertheless, the vast majority of bacterial community within maritime Antarctic soils has not been characterized adequately.…”

Seabird and pinniped shape soil bacterial communities of their settlements in Cape Shirreff, Antarctica

“…To the best of our knowledge, there are no previous studies describing bacterial communities in Antarctic soils underlying vertebrate concentrations from Cape Shirreff on Livingston Island (South Shetland Islands), a site where human activity has been strictly restricted to scientific research. Conversely, in Fildes Peninsula at King George Island, also located in the South Shetland Islands, several studies have described the influence of concentrations of penguins and other birds [31,32,48] as well as pinnipeds [66] on these Antarctic soils; however in most of these analyses, human impact cannot be discarded.…”

“…This genus includes slow-growing bacteria with an anaerobic facultative metabolism; in the absence of oxygen, they grow using nitrate, nitrite and nitrous oxide as electron acceptors and exhibit complete denitrification [72,73]. This bacterial genus, and others from the Rhodanobacteraceae family, were previously identified in other Antarctic soils colonized by penguins [28,30,31], suggesting that they could be adapted to environments with a high concentration of nutrients. Additionally, Rhodanobacter was also identified in non-Antarctic soils with high nitrate contents and slightly low pH [74].…”

“…Several studies have assessed bacterial diversity in Antarctic soils influenced by marine animals using culture independent approaches, such as fingerprinting techniques [28,29], clone libraries [30] and massive sequencing [6,31–33]. Most of these studies have been conducted in areas around the scientific stations on King George Island in the South Shetland Islands, Western Antarctic Peninsula (WAP), probably because they are more readily-accessed by the scientific community.…”