Diversity of bacterioplankton in coastal seawaters of Fildes Peninsula, King George Island, Antarctica

Abstract

The bacterioplankton not only serves critical functions in marine nutrient cycles, but can also serve as indicators of the marine environment. The compositions of bacterial communities in the surface seawater of Ardley Cove and Great Wall Cove were analyzed using a 16S rRNA multiplex 454 pyrosequencing approach. Similar patterns of bacterial composition were found between the two coves, in which Bacteroidetes, Alphaproteobacteria, and Gammaproteobacteria were the dominant members of the bacterioplankton communities. In addition, a large fraction of the bacterial sequence reads (on average 5.3 % per station) could not be assigned below the domain level. Compared with Ardley Cove, Great Wall Cove showed higher chlorophyll and particulate organic carbon concentrations and exhibited relatively lower bacterial richness and diversity. Inferred metabolisms of summer bacterioplankton in the two coves were characterized by chemoheterotrophy and photoheterotrophy. Results suggest that some cosmopolitan species (e.g., Polaribacter and Sulfitobacter) belonging to a few bacterial groups that usually dominate in marine bacterioplankton communities may have similar ecological functions in similar marine environments but at different geographic locations.

Distribution and diversity of bacterioplankton communities in subtropical seawater around Xiamen Island, China

“…Meanwhile, similar conclusion was also reached in surveys about bacterioplankton of the Delaware Bay (38-40 • N) and the South China Sea (18-23 • N) (Campbell and Kirchman 2013;Zhang et al 2014), which were consistent with our results about subtropical seawater of Xiamen Island. However, researches about bacterioplankton in higher latitude regions showed different results, for instance, research about bacterioplankton of King George Island (∼62 • S) found that Bacteroidetes were more dominant than Proteobacteria (Zeng et al 2014), and study about bacterioplankton in Arctic (88-89 • N) indicated that only Pelagibacter of SAR11 clade was the most predominant bacteria (Bowman et al 2012). Therefore, even though human activities had different levels of impacts on these various latitudes of seawater, the distribution pattern of SAR11 and Rhodobacteraceae might be very predominant, stable and ubiquitous in surface seawater of relative low latitudes (such as tropical, subtropical and some temperate zones), nevertheless, distribution pattern of dominant bacterioplankton in higher latitudes showed very different.…”

“…Marine microorganisms are the majority of biomass in seawater, and bacterioplankton as their majority are typically 10 8 -10 9 cells L −1 seawater (Zeng et al 2014). Bacterioplankton communities play central roles in global marine ecosystems because they greatly affect global nutrients cycling, energy flowing and the ocean food web from the temperate to polar oceans (Steele et al 2011).…”

Spatially uniform but temporally variable bacterioplankton in a semi-enclosed coastal area

“…The recent introduction of next-generation sequencing (NGS) techniques has significantly advanced our knowledge in this field of research as it has allowed more-detailed studies of microbial communities in marine environments [40]. To date, most studies using NGS techniques have focused on the changes in bacterial diversity related to depth [9,19,34], time [5,15,28,49], or space [19,32,35,53] in oceanic and offshore waters. Similar studies of coastal environments close to and directly impacted by land masses are limited [14], while those investigating the temporal shifts of bacterioplankton in these dynamic ecosystems are even less common [52].…”

Distribution and Control of Bacterial Community Composition in Marian Cove Surface Waters, King George Island, Antarctica during the Summer of 2018

“…Previous studies pointed out that increasing freshwater inflow can alter environmental characteristics and change the community composition of living organisms (e.g., algae and benthic species) in Marian Cove [ 13 , 14 , 15 , 16 , 17 , 18 ]. In addition, it was reported that the bacterial community was significantly different within Maxwell Bay [ 19 , 20 ], possibly reflecting that bacterial community composition is substantially influenced by surrounding physical and biogeochemical properties [ 13 , 16 , 17 ].…”