scholarly journals Resilience to multiple stressors in an aquatic plant and its microbiome

2019 ◽  
Author(s):  
Anna M. O’Brien ◽  
Zhu Hao Yu ◽  
Dian-ya Luo ◽  
Jason Laurich ◽  
Elodie Passeport ◽  
...  

AbstractPremiseEnvironments are changing rapidly, and outcomes of species interactions, especially mutualisms, are notoriously dependent on the environment. A growing number of studies have investigated responses of mutualisms to anthropogenic changes, yet most studies have focused on nutrient pollution or climate change, and tested single stressors. Relatively little is known about impacts of simultaneous chemical contaminants, which may differ fundamentally from nutrient or climate stressors, and are especially widespread in aquatic habitats.MethodsWe investigated the impacts of two common contaminants on interactions between the common duckweed Lemna minor and its microbiome. Sodium chloride (salt) and benzotriazole (a corrosion inhibitor) negatively affect aquatic organisms individually, yet commonly co-occur in runoff to duckweed-inhabited sites. We tested three L. minor genotypes with and without the culturable portion of their microbiome across field realistic gradients of salt (3 levels) and benzotriazole (4 levels) in a fully factorial experiment (72 treatments), and measured plant and microbial growth.Key ResultsWe found that stressors had conditional effects. Salt decreased both plant and microbial growth, but decreased plant survival more as benzotriazole concentrations increased. In contrast, benzotriazole did not affect microbial abundance, and benefited plants when salt and microbes were absent, perhaps due to the biotrans-formation we observed without salt. Microbes did not ameliorate duckweed stressors, as microbial inoculation increased plant growth, but not at high salt concentrations.ConclusionsOur results suggest that multistressor effects matter when predicting responses of mutualisms to global change, but that mutualisms may not buffer organisms from stressors.

2020 ◽  
Author(s):  
Anna M. O’Brien ◽  
Tiago F. Lins ◽  
Yamin Yang ◽  
Megan E. Frederickson ◽  
David Sinton ◽  
...  

AbstractAnthropogenic stressors, such as climate change or chemical pollution, affect individual species and alter species interactions. Moreover, species interactions can modify effects of anthropogenic stressors on interacting species - a process which may vary amongst stressors or stressor combinations. Most ecotoxicological work focuses on single stressors on single species. Here, we test hypotheses about multiple stressors (climate change and tire wear particles) and interacting species, and whether species interactions modify responses. We use duckweed and its microbiome to model responses of plant-microbe interactions. Climate change is occurring globally, and with increasing urbanization, tire wear particles increasingly contaminate road runoff. Their leachate is associated with zinc, PAHs, plastic additives, and other toxic compounds. We crossed perpendicular gradients of temperature and CO2 in a well plate with factorial manipulation of leachate from tire wear particles and presence of duckweed microbiomes. We measured duckweed and microbial growth, duckweed greenness, and plant-microbe growth correlations. We found that tire leachate and warmer temperatures enhanced duckweed and microbial growth, but microbes diminished positive responses in duck-weed, meaning microbiomes became costly for duckweed. These costs of microbiomes were less-than-additive with warming and leachate, and might be caused by leachate-disrupted endocrine signaling in duckweed. We observed reduced greenness at higher CO2 without tire leachate, suggesting a relative increase in plant nutrient demand, and possibly underlying positive plant-microbe growth correlations in these conditions, as microbes presumably increase nutrient availability. However, with tire leachate, growth correlations were never positive, and shifted negative at lower CO2, further suggesting leachate favors mutualism disruption. In summary, while individual stressors of global change can affect individual species, in ecology we know species interact; and in ecotoxicology, we know stressors interact. Our results demonstrate this complexity: multiple stressors can affect species interactions, and species interactions can alter effects of multiple stressors.


2013 ◽  
Vol 5 (3) ◽  
pp. 110-116
Author(s):  
Joan L. Slonczewski ◽  
James A. Coker ◽  
Shiladitya DasSarma

Author(s):  
Lorena Lanthemann ◽  
Sofia van Moorsel

Duckweeds (Lemnaceae) are increasingly studied for their potential for phytoremediation of heavy-metal polluted water bodies. A prerequisite for metal removal, however, is the tolerance of the organism to the pollutant, e.g., the metal zinc (Zn). Duckweeds have been shown to differ in their tolerances to Zn, however, despite them most commonly co-occurring with other species, there is a lack of research concerning the effect of species interactions on Zn tolerance. Here we tested whether the presence of a second species influenced the growth rate of the three duckweed species Lemna minor, Lemna gibba, and Lemna turionifera. We used four different Zn concentrations in a replicated microcosm experiment under sterile conditions, either growing the species in isolation or in a 2-species mixture. The response to Zn differed between species, but all three species showed a high tolerance to Zn, with low levels of Zn even increasing the growth rates. The growth rates of the individual species were influenced by the identity of the competing species, but this was independent of the Zn concentration. Our results suggest that species interactions should be considered in future research with duckweeds and that several duckweed species have high tolerance to metal pollution, making them candidates for phytoremediation efforts.


Author(s):  
Bianca Boros ◽  
Nathalie Grau ◽  
Adriana Isvoran ◽  
Adina Datcu ◽  
Nicoleta Ianovici ◽  
...  

Sodium alginate (ALG) and sodium carboxymethyl cellulose (CMC) are two polysaccharides that have a wide range of applications which could lead to accidental pollution of the environment, making the assessment of their potential ecotoxicity imperative. The present study assesses the ALG and CMC effects on the growth response of the common duckweed (Lemna minor L.). The results emphasize that both polysaccharides can be classified as practically nontoxic based on their EC50 values, with ALG having a relatively higher toxicity compared to CMC. It was also observed that high doses of 1, 5 and 10 mg mL-1 of the two polysaccharides produced growth inhibitory effects against common duckweed. The toxicity of biopolymers against common duckweed, measured as EC50 values, seems to be correlated to the hydrophobicity of the monomers building the polymer. The EC50 values increase linearly with the increase of water solubility (log S) values and decrease linearly with the lipophilicity (log P) values.


2020 ◽  
Vol 103 (2) ◽  
pp. 439-448
Author(s):  
Aleksandra Kaleniecka ◽  
Paweł K Zarzycki

Abstract Background: This research reports a multivariate experiment enabling observation of the potential application of macrocyclic compound [β-cyclodextrin (β-CD)] and/or duckweed organisms as the active factors for elimination of selected bisphenols A, B, and S from water samples. Objective: Target bisphenols selection was based on observation that such components can be present in food or environmental samples (e.g., vegetable/fruit juices, milk, drinking water, or treated wastewater). Methods: Biological research was carried out using aquatic organisms containing chlorophyll, particularly duckweed (Lemna minor L), that may work as an active biomass for the elimination or extraction of bisphenols micropollutants from water. Using such a system, we studied the potential encapsulation effect and removal efficiency of nontoxic macrocyclic oligosaccharide (β-cyclodextrin) acting as an encapsulation reagent to promote the removal of selected bisphenols from liquid phase both with and without the presence of duckweed biomass. Results: Experimental data have revealed that β-CD or combined β-CD/duckweed system has an effect on bisphenols elimination from water. The initial data set obtained from this preliminary experiment (and combined with supramolecular complex formation data calculated from chromatographic experiments, published previously) enables designing of further experiments focusing on the development of green chemistry technology. Conclusions: It is hoped that this may be used for the efficient removal of low-molecular-mass micropollutants using classical technological wastewater treatment processes modified by biomass and macrocyclic additives. This process needs to be optimized, but the results presented have revealed that such green chemistry technology, if successful, may be an interesting alternative for the selective removal of the micropollutants investigated from wastewater using classical adsorbents (e.g., carbons and carbon-related nanomaterials), particularly in terms of the worldwide problem with microplastic pollutants in the environment and food products.


1985 ◽  
Vol 68 (6) ◽  
pp. 1063-1068 ◽  
Author(s):  
Charles F Jelinek

Abstract In the late 1930s and early 1940s, almost the only analyses carried out for chemical contaminants in foods were for lead arsenate and other arsenical pesticides in fruits. Since then, a tremendous expansion has occurred in the types of chemical contaminants found in foods and in the activities of the U.S. Food and Drug Administration and other organizations responsible for monitoring and controlling the presence of these contaminants in the food supply. This paper describes the findings and control of additional chemical contaminants in foods, including synthetic pesticides, PCBs (polychlorinated biphenyls), other industrial chemicals, fungal metabolites such as aflatoxins, toxic metals, and radionuclides. The common characteristics of problems connected with these defferent types of contaminants include uncontrolled entry into the food supply, incidents causing extreme public worry, and near impossibility in removing these contaminants from the food supply. Problems may also arise from new technologies and environmental developments. New approaches beyond ordinary regulatory activities are being used to meet these problems. Broader analytical methods requiring less time and faster and more sophisticated toxicological methods are needed to assess the hazard of these environmental food contaminants


Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 599
Author(s):  
Olga Radulović ◽  
Slaviša Stanković ◽  
Branka Uzelac ◽  
Vojin Tadić ◽  
Milana Trifunović-Momčilov ◽  
...  

The main topic of this study is the bioremediation potential of the common duckweed, Lemna minor L., and selected rhizospheric bacterial strains in removing phenol from aqueous environments at extremely high initial phenol concentrations. To that end, fluorescence microscopy, MIC tests, biofilm formation, the phenol removal test (4-AAP method), the Salkowski essay, and studies of multiplication rates of sterile and inoculated duckweed in MS medium with phenol (200, 500, 750, and 1000 mg L−1) were conducted. Out of seven bacterial strains, six were identified as epiphytes or endophytes that efficiently removed phenol. The phenol removal experiment showed that the bacteria/duckweed system was more efficient during the first 24 h compared to the sterile duckweed control group. At the end of this experiment, almost 90% of the initial phenol concentration was removed by both groups, respectively. The bacteria stimulated the duckweed multiplication even at a high bacterial population density (>105 CFU mL−1) over a prolonged period of time (14 days). All bacterial strains were sensitive to all the applied antibiotics and formed biofilms in vitro. The dual bacteria/duckweed system, especially the one containing strain 43-Hafnia paralvei C32-106/3, Accession No. MF526939, had a number of characteristics that are advantageous in bioremediation, such as high phenol removal efficiency, biofilm formation, safety (antibiotic sensitivity), and stimulation of duckweed multiplication.


1979 ◽  
Vol 53 (1) ◽  
pp. 7-14 ◽  
Author(s):  
N. Ø. Christensen

ABSTRACTSchistosoma mansonicercariae labelled with75Se-methionine were used to study host-finding capacity by determining the radioactivity of exposed mouse “target” tails. Possible interfering effects of some aquatic vertebrates and invertebrates, plants and algae and secretions and excretions of aquatic organisms were examined.A marked interferent effect due to predatory behaviour was produced byCyclops strenuus(Copepoda),Daphnia pulexandD. longispina(Cladocera),Notodromas monachaandCypria ophthalmica(Ostracoda) andLebistes reticulatus(guppy).Bufo bufo(Amphibia) andPlanaria lugubris(Turbellaria) interfered significantly, presumably by secreting cercaricidal toxins. Several other organisms apparently produced no interference. The interferent effect of the plant speciesCeratophyllum demersum, Elodea canadensis, Lemna minor, Ranunculus aquaticus, Holcus lanatus(grass) andBotryococcus brauniiwas particularly pronounced when they were confined to the surface layer of the water. Several other species did not interfere with host-finding.


2015 ◽  
Vol 66 (3) ◽  
pp. 189-195 ◽  
Author(s):  
Mert Gürkan ◽  
Sibel Hayretdağ

Abstract Pesticides used in agriculture can have hazardous effects on aquatic organisms, and amphibians are even more threatened than other aquatic vertebrates. Maneb is widely used to control fungal diseases on crops, fruits, and vegetables. The aim of this study was to investigate the acute toxic effects of maneb on the common (Bufo bufo) and green toad (Pseudepidalea viridis) tadpoles. Tadpoles at the development stage 21 were exposed to maneb (0-5 mg L-1) for 120 h. Maneb LC50 values at hour 120 were 1.966 mg L-1 for B. bufo and 0.332 mg L-1 for P. viridis. To the best of our knowledge, these are the first published LC50 findings for the two species. Visceral oedema and tail deformations were observed in both species. We also observed liver necrosis, pronephric tubule deformations, somite deteriorations, and visceral oedema at maneb concentrations ≥0.1 mg L-1 for B. bufo and ≥0.05 mg L-1 for P. viridis. Our results show that B. bufo tadpoles have a much higher resilience to maneb than P. viridis tadpoles. This resilience seems to be related to the larger size of the B. bufo tadpoles and their ability to metamorphose faster in adverse conditions. Future research should look into the mechanisms of toxic action of maneb in anurans.


Author(s):  
Char'Mane Robinson ◽  
Andrew Mason

Cocos Lagoon is located on the southwestern end of the coast of Guam, and contains extensive coral reefs and an array of fish species. Within the Lagoon is a former US Coast Guard LORAN station on Cocos Island. Hazardous materials appear to have been disposed of on land and in near shore waters during the operation of the LORAN station, between the years of 1944 and 1963, exposing surrounding waters, sediment, fish species and humans to these materials. As part of a project to quantify chemical contaminants in Cocos Lagoon, and to address local and agency human health concerns, approximately 190 chemical contaminants were analyzed in sediments from 25 sites, along with 27 fish tissue samples from 16 sites. Higher levels of chemical contaminants were found in fish tissues collected from around Cocos Island, the site of the former LORAN station. Concentrations of polychlorinated biphenyls (PCBs), for example, were above an EPA recreational fishers’ screening value (SV) in some fish species from around Cocos Island, indicating risk to humans consuming fish from this area. PCBs at high concentrations are known to cause negative effects on resident marine aquatic organisms and human health concerns include cancer. Characterizing contaminant impacts to aquatic marine organisms and possible human health results from this project will provide resource managers with key information needed to make effective decisions for the health of Cocos Lagoon and also gauge the efficacy of restoration activities. The results show high levels of PCBs in the fish species from Coco Lagoon. This indicates that there is a high risk of adverse health effects such as cancer if consumed by humans.


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