Bacterioplankton features and its relations with doc characteristics and other limnological variables in Paraná river floodplain environments (PR/MS-Brazil)

Abstract

Since the introduction of the Microbial Loop concept, many studies aimed to explain the role of bacterioplankton and dissolved organic carbon (DOC) in aquatic ecosystems. Paraná River floodplain system is a very complex environment where these subjects were little explored. The aim of this work was to characterize bacterial community in terms of density, biomass and biovolume in some water bodies of this floodplain and to verify its temporal variation and its relation with some limnological variables, including some indicators of DOC quality, obtained through Ultraviolet-visible (UV-VIS) and fluorescence spectroscopic analysis. Bacterial density, biomass and biovolume are similar to those from other freshwater environments and both density and biomass were higher in the period with less rain. The limnological and spectroscopic features that showed any relation with bacterioplankton were the concentrations of N-NH4 and P-PO4, water transparency, and some indicators of DOC quality and origin. The analysis of these relations showed a possible competition between bacterioplankton and phytoplankton for inorganic nutrients and that the DOC used by bacterioplankton is labile and probably from aquatic macrophytes.

Eichhornia azurea decomposition and the bacterial dynamic: an experimental research

“…47 In this study, the bacterial density was 10 7 in the control group, reaching 10 8 in the treatment group. Teixeira et al, 48 working in similar environments, found bacterioplankton densities varying between 1.3 ± 0.7 × 10 9 cells L −1 and 22.0 ± 4.7 × 10 9 cells L −1 . The increase of density with the E. azurea biomass can simulate the effect of the typical nutritional contribution of the flood pulse process when large amounts of biomass decompose, causing an increase in nutrient cycling.…”

Coupling Between Heterotrophic Nanoflagellates and Bacteria in Fresh Waters: Does Latitude Make a Difference?

“…In a comparative analysis using different types of Brazilian freshwater ecosystems, Roland et al (2010) found a much weaker HB:chlorophyll- a correlation in tropical when compared to the non-tropical environments. In this way, the bacteria–phytoplankton uncoupling seems to be a recurrent situation in south-American lowland lakes (e.g., Carvalho et al, 2003 ; Gocke et al, 2004 ; Rejas et al, 2005 ; Petrucio et al, 2006 ; Teixeira et al, 2011 ; Almeida et al, 2015 ), which are generally smaller and shallower, comparing to the East-African Great Lakes. White et al (1991) reported a rather weak correlation between SGR and chlorophyll- a in freshwaters, and suggested that variations in the importance of grazing pressure may have contributed to this finding.…”

Spatial variability of chromophoric dissolved organic matter in a large floodplain river: control factors and relations with phytoplankton during a low water period

“…Fourth, isolation improves phytoplankton growth, which is shown at La3 by high Chl‐ a and low Pheo‐ a :Chl‐ a ratio; the alkaline conditions of the water because of the photosynthetic activity of phytoplankton increase the susceptibility of CDOM to photobleaching (Reche et al ., ). Fifth, isolation increases the production of autochthonous CDOM with low MW because of development of phytoplankton and bacteria (Sundh and Bell, ; Peduzzi et al ., ; Teixeira et al ., , ). Finally, groundwater hydrological connection reduces the input of high‐MW‐CDOM because this fraction is preferentially sorbed and retained by soil particles (Kaiser et al ., ).…”

“…The analysis of the spatial patterns of CDOM could contribute to the understanding of the functioning of these systems. CDOM affects multiple limnological characteristics, such as light climate (Williamson et al, 1996;Costa et al, 2013) and bioavailability of inorganic nutrients (Shaw, 1994), toxic compounds (Sakkas et al, 2002), and carbon sources for microorganisms (Granéli et al, 1999;Teixeira et al, 2011a). Hence, spatial variations of CDOM influence ecological and biogeochemical processes.…”