Sulfate uptake as a measure of planktonic microbial production in freshwater ecosystems

1974 ◽  
Vol 20 (6) ◽  
pp. 825-831 ◽  
Author(s):  
Richard H. Monheimer
Keyword(s):  
Biomass Production ◽  
Aquatic Ecosystems ◽  
Freshwater Ecosystems ◽  
Microbial Production ◽  
Sulfate Uptake ◽  
Aerobic Conditions ◽  
Field Samples ◽  
Laboratory Cultures ◽  
Satisfactory Method ◽  
Micro Organisms

A method is needed by which biomass production resulting from non-photosynthetic micro-organisms in natural aquatic ecosystems can be included in microbial production measurements. Both laboratory cultures and field samples were used for examining the suitability of measuring sulfate uptake as a yardstick of microbial production. Sulfate uptake, using 35SO4, was com pared with 14CO2 uptake and it was found that sulfate uptake measures significantly more microbial production than does 14CO2 uptake. With further study, the use of sulfate uptake may become a very satisfactory method for better estimating the total planktonic microbial production under aerobic conditions.

Cladocera (Crustacea: Branchiopoda) from the state of Mato Grosso, Brazil

2020 ◽  
Vol 56 ◽  
pp. 7
Author(s):  
Maiara Tábatha da Silva Brito ◽  
Leidiane Pereira Diniz ◽  
Ully M. Pozzobom ◽  
Victor Lemes Landeiro ◽  
Francisco Diogo R. Sousa
Keyword(s):  
Aquatic Ecosystems ◽  
Littoral Zone ◽  
New Records ◽  
Freshwater Ecosystems ◽  
The State ◽  
Sampling Effort ◽  
Mato Grosso ◽  
Occurrence Data ◽  
Cladoceran Species ◽  
Hydrographic Regions

Studies on Cladocera biodiversity in Brazilian freshwater ecosystems are intensifying. However, the fauna of some hydrographic regions is still poorly known. We investigated the richness and species composition of cladocerans in lakes of the Pantanal from the state of Mato Grosso (Paraguay hydrographic region), Brazil. In addition, we cataloged the known cladoceran species in each hydrographic region of the state. Occurrence data were obtained from the literature and samples collected from 50 lakes in the northern Pantanal. We recorded 120 cladoceran species from eight families in the state of Mato Grosso. The occurrence of these species was recorded in the Amazon and Paraguay hydrographic regions. We are unaware of studies on cladocerans conducted in the Tocantins-Araguaia hydrographic region. We reported 17 new records in the Pantanal samples (Paraguay hydrographic region). Overall, richness estimates reveal that 72.6% of the state's cladoceran fauna is already known, while for the Paraguay hydrographic region this estimate is 72.2%. In general, the cladocerans from the Amazon and Paraguay regions did not differ. Our findings allow us to infer the need for further studies in the different hydrographic regions found in Mato Grosso in order to improve the knowledge of cladoceran biodiversity. We suggest a greater sampling effort, particularly in the littoral zone of aquatic ecosystems in this state, which can harbor great biodiversity.

scholarly journals Regulation of Sulfate Uptake and Assimilation in Barley (Hordeum vulgare) as Affected by Rhizospheric and Atmospheric Sulfur Nutrition

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1283
Author(s):  
Ties Ausma ◽  
Luit J. De Kok
Keyword(s):  
Hordeum Vulgare ◽  
Biomass Production ◽  
Signal Transduction Pathway ◽  
Mineral Nutrient ◽  
Sulfur Source ◽  
Sulfate Uptake ◽  
Protein Levels ◽  
Amino Acid Contents ◽  
Uptake Transporters ◽  
Expression And Activity

To study the regulation of sulfate metabolism in barley (Hordeum vulgare), seedlings were exposed to atmospheric hydrogen sulfide (H2S) in the presence and absence of a sulfate supply. Sulfate deprivation reduced shoot and root biomass production by 60% and 70%, respectively, and it affected the plant’s mineral nutrient composition. It resulted in a 5.7- and 2.9-fold increased shoot and root molybdenum content, respectively, and a decreased content of several other mineral nutrients. Particularly, it decreased shoot and root total sulfur contents by 60% and 70%, respectively. These decreases could be ascribed to decreased sulfate contents. Sulfate deficiency was additionally characterized by significantly lowered cysteine, glutathione and soluble protein levels, enhanced dry matter, nitrate and free amino acid contents, an increased APS reductase (APR) activity and an increased expression and activity of the root sulfate uptake transporters. When sulfate-deprived barley was exposed to 0.6 µL L−1 atmospheric H2S, the decrease in biomass production and the development of other sulfur deficiency symptoms were alleviated. Clearly, barley could use H2S, absorbed by the foliage, as a sulfur source for growth. H2S fumigation of both sulfate-deprived and sulfate-sufficient plants downregulated APR activity as well as the expression and activity of the sulfate uptake transporters. Evidently, barley switched from rhizospheric sulfate to atmospheric H2S as sulfur source. Though this indicates that sulfate utilization in barley is controlled by signals originating in the shoot, the signal transduction pathway involved in the shoot-to-root regulation must be further elucidated.

The contamination of inland waters by microplastic fibres under different anthropogenic pressure: Preliminary study in Central Europe (Poland)

2020 ◽  
Vol 38 (11) ◽  
pp. 1231-1238
Author(s):  
Anita Kaliszewicz ◽  
Michał Winczek ◽  
Kamil Karaban ◽  
Dominik Kurzydłowski ◽  
Maria Górska ◽  
...  
Keyword(s):  
High Probability ◽  
Control Sample ◽  
Mesh Size ◽  
Freshwater Ecosystems ◽  
Inland Waters ◽  
Anthropogenic Pressure ◽  
Large Cities ◽  
Field Samples ◽  
Northeastern Poland ◽  
Preliminary Study

The contamination of freshwater ecosystems with microfibres has not yet been studied in Poland. We analysed samples from a river and three lakes located in central and northeastern Poland. A significantly higher number of fibres were reported in the river, which runs through large cities, compared with the lake situated within the Landscape Park. Fibres smaller than 1.0 mm dominated, especially in the river where they constituted 39% of all fibres detected. We found more microplastics (⩽ 4930 fibres·m−3) by using a mesh size of 20 µm compared with other studies of inland waters. The use of Raman spectroscopy allowed us to identify conventional plastic polymers: polyethylene terephthalate, polyester and polyurethane. We estimated that up to 25 g of microplastic in the form of fibres might be in the lake water under the surface. We found microplastic fibres in Majcz Lake situated within the Masurian Landscape Park. This suggests that microfibres are carried by the wind and rain and enter freshwater isolated from sewage outlets. By using the control sample and an air-test of microfibres in the laboratory, we observed that there is a high probability of contamination with microplastic in the field samples (up to 30% of all fibres detected). The contamination risk noted from the samples cannot be ignored; this could be particularly important for analysis of microplastic in remote freshwater ecosystems.

scholarly journals Fungi and viruses as important players in microbial mats

2020 ◽  
Vol 96 (11) ◽  
Author(s):  
Cátia Carreira ◽  
Christian Lønborg ◽  
Michael Kühl ◽  
Ana I Lillebø ◽  
Ruth-Anne Sandaa ◽  
...  
Keyword(s):  
Organic Matter ◽  
Aquatic Ecosystems ◽  
Microbial Mats ◽  
Freshwater Ecosystems ◽  
Food Web Structure ◽  
Element Cycling ◽  
Functional Roles ◽  
Web Structure ◽  
Experimental Approaches ◽  
And Function

ABSTRACT Microbial mats are compacted, surface-associated microbial ecosystems reminiscent of the first living communities on early Earth. While often considered predominantly prokaryotic, recent findings show that both fungi and viruses are ubiquitous in microbial mats, albeit their functional roles remain unknown. Fungal research has mostly focused on terrestrial and freshwater ecosystems where fungi are known as important recyclers of organic matter, whereas viruses are exceptionally abundant and important in aquatic ecosystems. Here, viruses have shown to affect organic matter cycling and the diversity of microbial communities by facilitating horizontal gene transfer and cell lysis. We hypothesise fungi and viruses to have similar roles in microbial mats. Based on the analysis of previous research in terrestrial and aquatic ecosystems, we outline novel hypotheses proposing strong impacts of fungi and viruses on element cycling, food web structure and function in microbial mats, and outline experimental approaches for studies needed to understand these interactions.

Detection of microcystin-producingMicrocystisin Guanqiao Lake using a sandwich hybridization assay

2012 ◽  
Vol 58 (4) ◽  
pp. 442-447 ◽  
Author(s):  
Jing Ping Zhu ◽  
Shi Du ◽  
Xian Li
Keyword(s):  
Calibration Curve ◽  
Cell Number ◽  
Hybridization Assay ◽  
Sequence Analyses ◽  
Sandwich Hybridization ◽  
Cyanobacterial Culture ◽  
Field Samples ◽  
Laboratory Cultures ◽  
Pcr Technology ◽  
Sandwich Hybridization Assay

Based on sequence analyses of the mcyJ gene from Microcystis strains, a probe pair TJF and TJR was designed and a sandwich hybridization assay (SHA) was established to quantitatively detect microcystin-producing Microcystis. Through BLAST and cyanobacterial culture tests, TJF and TJR were demonstrated to be specific for microcystin-producing Microcystis. A calibration curve for the SHA was established, and the lowest detected concentration was 100 cells·mL–1. Laboratory cultures and field samples from Guanqiao Lake were analyzed with both the SHA and microscopy. The cell number of microcystin-producing Microcystis and that of total Microcystis were compared. The biotic and abiotic components of the samples were of little disturbance to the SHA. In this study, a SHA was established to detect Microcystis, providing an alternative to PCR–ELISA and real-time PCR technology.

scholarly journals Water, Sediment and Macrophyte Quality of Some Shrimp Culture Ponds and Freshwater Ecosystems of Koyra

2012 ◽  
Vol 41 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Abdullah Harun Chowdhury ◽  
Roxana Ahmed
Keyword(s):  
Aquatic Ecosystems ◽  
Aquatic Macrophytes ◽  
High Salinity ◽  
Freshwater Ecosystems ◽  
Shrimp Culture ◽  
Physicochemical Conditions

A total of 29 genera belonging to 24 families of aquatic macrophytes were recorded. Among these, 25 species were recorded from the freshwater aquatic ecosystems, 4 species from both the shrimp culture ponds and freshwater aquatic ecosystems and only one from the shrimp culture ponds. The physicochemical conditions of both the habitats indicate that very poor number of macrophytes can grow in the shrimp culture ponds due to high salinity of water and soil. Low population and abundance indicate that the macrophytes are in alarming condition in Koyra due to increasing salinity. DOI: http://dx.doi.org/10.3329/bjb.v41i1.11080 Bangladesh J. Bot. 41(1): 35-41, 2012 (June)

scholarly journals Strategies and Approaches Towards Environmental Biomonitoring of Freshwater Ecosystems in Philippines

2021 ◽  
Vol 20 (4) ◽  
Author(s):  
J. S. Berame ◽  
M. B. Hojilla ◽  
E. Trinidad ◽  
N. L. Lawsin ◽  
J. A. Orozco ◽  
...  
Keyword(s):  
Aquatic Ecosystems ◽  
Anthropogenic Activities ◽  
Low Cost ◽  
Action Plan ◽  
The Philippines ◽  
Freshwater Ecosystems ◽  
Current Status ◽  
Biochemical Alterations ◽  
Pollution Levels ◽  
Environmental Biomonitoring

The Philippines, like many other Asian countries, is struggling to combat the current widespread aquatic pollution levels caused by anthropogenic activities. Environmental biomonitoring is an efficient tool to detect and monitor the fluctuating toxicity levels in a dynamic ecosystem using bioindicators like algae, macrophytes, zooplankton, insect, bivalve mollusks, gastropod, fish, amphibians, and others to assess the extent and levels of pollution in aquatic ecosystems. The present review deliberates on the biomonitoring techniques such as bioaccumulation, biochemical alterations, population, and community-level approaches to evaluate the current status with respect to the extent and levels of pollution in the aquatic ecosystems in the Philippines which also is one of the biodiversity hotspots. Therefore, the potential applications for biomonitoring are proposed to mainly include evaluation of actual aquatic pollutions, bioremediation, toxicology prediction, and research on toxicological mechanisms. The purpose of such evaluations is to critically analyze and help stakeholders to come up with a strategic action plan with recommendations on a low-cost, sensitive, and effective bioindicator for rapid and efficient environmental biomonitoring.

scholarly journals Reviews and Syntheses: Effects of permafrost thaw on arctic aquatic ecosystems

2015 ◽  
Vol 12 (13) ◽  
pp. 10719-10815 ◽  
Author(s):  
J. E. Vonk ◽  
S. E. Tank ◽  
W. B. Bowden ◽  
I. Laurion ◽  
W. F. Vincent ◽  
...  
Keyword(s):  
Organic Matter ◽  
Aquatic Ecosystems ◽  
Soil Layer ◽  
Freshwater Ecosystems ◽  
The Arctic ◽  
Food Web Structure ◽  
Thermokarst Lakes ◽  
Freshwater Systems ◽  
Permafrost Thaw ◽  
Lake Morphology

Abstract. The Arctic is a water-rich region, with freshwater systems covering 16 % of the northern permafrost landscape. The thawing of this permafrost creates new freshwater ecosystems, while at the same time modifying the existing lakes, streams, and rivers that are impacted by thaw. Here, we describe the current state of knowledge regarding how permafrost thaw affects lentic and lotic systems, exploring the effects of both thermokarst (thawing and collapse of ice-rich permafrost) and deepening of the active layer (the surface soil layer that thaws and refreezes each year). Within thermokarst, we further differentiate between the effects of thermokarst in lowland areas, vs. that on hillslopes. For almost all of the processes that we explore, the effects of thaw vary regionally, and between lake and stream systems. Much of this regional variation is caused by differences in ground ice content, topography, soil type, and permafrost coverage. Together, these modifying variables determine the degree to which permafrost thaw manifests as thermokarst, whether thermokarst leads to slumping or the formation of thermokarst lakes, and the manner in which constituent delivery to freshwater systems is altered by thaw. Differences in thaw-enabled constituent delivery can be considerable, with these modifying variables determining, for example, the balance between delivery of particulate vs. dissolved constituents, and inorganic vs. organic materials. Changes in the composition of thaw-impacted waters, coupled with changes in lake morphology, can strongly affect the physical and optical properties of thermokarst lakes. The ecology of thaw-impacted systems is also likely to change, with thaw-impacted lakes and streams having unique microbiological communities, and showing differences in respiration, primary production, and food web structure that are largely driven by differences in sediment, dissolved organic matter and nutrient delivery. The degree to which thaw enables the delivery of dissolved vs. particulate organic matter, coupled with the composition of that organic matter and the morphology and stratification characteristics of recipient systems will play an important role in determining the balance between the release of organic matter as greenhouse gases (CO2 and CH4), its burial in sediments, and its loss downstream. The magnitude of thaw impacts on northern aquatic ecosystems is increasing, as is the prevalence of thaw-impacted lakes and streams. There is therefore an urgent need to address the key gaps in understanding in order to predict the full effects of permafrost thaw on aquatic ecosystems throughout the Arctic, and their consequential feedbacks to climate.

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