Distribution of HNA and LNA bacterial groups in the Southwest Atlantic Ocean

Andrade, Luciana Segura de; Gonzalez, Alessandra M.; Rezende, Carlos Eduardo de; Suzuki, Marina Satika; Valentin, Jean Louis; Paranhos, Rodolfo

doi:10.1590/s1517-83822007000200028

Cited by 28 publications

(27 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Furthermore, the annual average of the investigated oligotrophic open sea stations showed percentages of HNA bacteria below 50 %. This is in accordance with the predominance of the LNA group over HNA, which has also been established for other oligotrophic areas, such as the Celtic Sea, Gulf of Mexico and the Atlantic (Zubkov et al 2001;Jochem et al 2004;Andrade et al 2007). …”

Section: Discussionsupporting

confidence: 89%

Dynamics of prokaryotic picoplankton community in the central and southern Adriatic Sea (Croatia)

et al. 2012

View full text Add to dashboard Cite

This paper addresses the dynamics of the prokaryotic picoplankton community in the coastal and open sea areas of the central Adriatic and in the coastal area of the southern Adriatic. This involved the study, from January to December 2005, of bacteria (total number of non-pigmented bacteria; high nucleic acid content (HNA) bacteria; low nucleic acid content (LNA) bacteria), cyanobacteria (Synechococcus and Prochlorococcus) and heterotrophic nanoflagellates. During the warmer seasons, in the mainly oligotrophic area under investigation into the Adriatic Sea, bacterial densities and bacterial production have shown an increase in values and domination of the LNA group of the bacterial population. In contrast, in those areas influenced by karstic rivers, the domination of HNA bacteria in total abundance of non-pigmented bacteria and high values of bacterial production was estimated throughout the investigated period. Our results show the importance of both HNA and LNA bacterial groups in the total bacterial activity throughout the investigated area. The biomass of bacteria was mostly predominant in the prokaryotic community, while within the autotrophic community Synechococcus biomass mostly predominated. During the warmer seasons, an increase in autotrophic biomass was observed in relation to non-pigmented biomass. The importance of predation in controlling bacteria by heterotrophic nanoflagellates was pronounced during the warmer period and in the coastal areas.

show abstract

Section: Discussionsupporting

confidence: 89%

Dynamics of prokaryotic picoplankton community in the central and southern Adriatic Sea (Croatia)

et al. 2012

View full text Add to dashboard Cite

show abstract

“…Surface values for %HNA, ranging from 30 % at SD15 to 51 % at SD1, are similar to previously reported values, as is the observed increase in %HNA with depth (Van Wambeke et al, 2011). The reduced values for %HNA reported for GY are similar to those reported for other nutrient-limited regions, and may be the result of LNA cells being capable of more rapid growth than HNA under nutrient limitation (Andrade et al, 2007;Nishimura et al, 2005).…”

Section: Factors Controlling Bacterial Abundance and The Role Of Hnfsupporting

confidence: 88%

Microbial community structure in the western tropical South Pacific

2018

View full text Add to dashboard Cite

Abstract. Oligotrophic regions play a central role in global biogeochemical cycles, with microbial communities in these areas representing an important term in global carbon budgets. While the general structure of microbial communities has been well documented in the global ocean, some remote regions such as the western tropical South Pacific (WTSP) remain fundamentally unexplored. Moreover, the biotic and abiotic factors constraining microbial abundances and distribution remain not well resolved. In this study, we quantified the spatial (vertical and horizontal) distribution of major microbial plankton groups along a transect through the WTSP during the austral summer of 2015, capturing important autotrophic and heterotrophic assemblages including cytometrically determined abundances of non-pigmented protists (also called flagellates). Using environmental parameters (e.g., nutrients and light availability) as well as statistical analyses, we estimated the role of bottom-up and top-down controls in constraining the structure of the WTSP microbial communities in biogeochemically distinct regions. At the most general level, we found a "typical tropical structure", characterized by a shallow mixed layer, a clear deep chlorophyll maximum at all sampling sites, and a deep nitracline. Prochlorococcus was especially abundant along the transect, accounting for 68 ± 10.6 % of depth-integrated phytoplankton biomass. Despite their relatively low abundances, picophytoeukaryotes (PPE) accounted for up to 26 ± 11.6 % of depth-integrated phytoplankton biomass, while Synechococcus accounted for only 6 ± 6.9 %. Our results show that the microbial community structure of the WTSP is typical of highly stratified regions, and underline the significant contribution to total biomass by PPE populations. Strong relationships between N 2 fixation rates and plankton abundances demonstrate the central role of N 2 fixation in regulating ecosystem processes in the WTSP, while comparative analyses of abundance data suggest microbial community structure to be increasingly regulated by bottom-up processes under nutrient limitation, possibly in response to shifts in abundances of high nucleic acid bacteria (HNA).

show abstract

“…The average proportion of HNA bacteria in the central and southern coastal area ranged approximately from 20 % to 90 % and LNA bacteria from 10 % to 80 %, while in the open sea HNA and LNA ranged from 30 % to 70 %. In our research the prevalence of the LNA group over HNA was determined, as also established in oligotrophic areas of world's seas and oceans (Zubkov et al, 2001;Jochem et al, 2004;Andrade et al, 2007). In our research of the Adriatic Sea area, the prevalence of the HNA bacterial group in the water column was shown at stations which have a higher trophic level and our finding is consistent with studies that found that the dominance of the HNA over the LNA group in eutrophic areas directly influenced by river inflow (Li et al, 1995;Šolić et al, 2009).…”

Section: Resultssupporting

confidence: 55%