Effect of light stress from phytoplankton on the relationship between aquatic vegetation and the propagule bank in shallow lakes

2012 ◽  
Vol 57 (4) ◽  
pp. 666-675 ◽  
Author(s):  
FLORENT ARTHAUD ◽  
MATHILDE MOUSSET ◽  
DOMINIQUE VALLOD ◽  
JOËL ROBIN ◽  
ALEXANDER WEZEL ◽  
...  
Keyword(s):  
Shallow Lakes ◽  
Aquatic Vegetation ◽  
Light Stress ◽  
Propagule Bank ◽  
The Relationship ◽  
Effect Of Light

scholarly journals Effects of Modification of Light Parameters on the Production of Cryptophycin, Cyanotoxin with Potent Anticancer Activity, in Nostoc sp.

Toxins ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 809
Author(s):  
Alexandros Polyzois ◽  
Diana Kirilovsky ◽  
Thi-hanh Dufat ◽  
Sylvie Michel
Keyword(s):  
Light Stress ◽  
Red Light ◽  
Major Effect ◽  
High Light Intensity ◽  
Efficient Production ◽  
Lower Growth ◽  
Noticeable Increase ◽  
Lower Growth Rate ◽  
Industrial Use ◽  
Effect Of Light

Cryptophycin-1 is a cyanotoxin produced by filamentous cyanobacteria. It has been evaluated as an anticancer agent with great potential. However, its synthesis provides insufficient yield for industrial use. An alternative solution for metabolite efficient production is to stress cyanobacteria by modifying the environmental conditions of the culture (Nostoc sp. ATCC 53789). Here, we examined the effects of light photoperiod, wavelength, and intensity. In light photoperiod, photoperiods 24:0 and 16:8 (light:dark) were tested while in wavelength, orange-red light was compared with blue. Medium, high, and very high light intensity experiments were performed to test the effect of light stress. For a 10-day period, growth was measured, metabolite concentration was calculated through HPLC, and the related curves were drawn. The differentiation of light wavelength had a major effect on the culture, as orange-red filter contributed to noticeable increase in both growth and doubled the cyanotoxin concentration in comparison to blue light. Remarkably, constant light provides higher cryptophycin yield, but slightly lower growth rate. Lastly, the microorganism prefers medium light intensities for both growth and metabolite expression. The combination of these optimal conditions would contribute to the further exploitation of cryptophycin.

scholarly journals A phytosociological survey of aquatic vegetation in the main freshwater lakes of Greece

2020 ◽  
Vol 1 ◽  
pp. 53-75
Author(s):  
Dimitrios Zervas ◽  
Ioannis Tsiripidis ◽  
Erwin Bergmeier ◽  
Vasiliki Tsiaoussi
Keyword(s):  
Plant Communities ◽  
Aquatic Plant ◽  
Aquatic Vegetation ◽  
Environmental Parameters ◽  
Hierarchical Cluster ◽  
Freshwater Lake ◽  
Vegetation Types ◽  
Freshwater Lakes ◽  
Lake Ecosystems ◽  
The Relationship

Aims: This study aims to contribute to the knowledge of European freshwater lake ecosystems with updated and new information on aquatic plant communities, by conducting national-scale phytosociological research of freshwater lake vegetation in Greece. Moreover, it investigates the relationship between aquatic plant communities and lake environmental parameters, including eutrophication levels and hydro-morphological conditions. Study area: Lakes in Greece, SE Europe. Methods: 5,690 phytosociological relevés of aquatic vegetation were sampled in 18 freshwater lake ecosystems during 2013–2016. The relevés were subjected to hierarchical cluster and indicator species analyses in order to identify associations and communities of aquatic vegetation, as well as to describe their syntaxonomy. Multiple regression analysis was applied to investigate the relationship between vegetation syntaxa and environmental parameters of lakes, i.e. physico-chemical parameters and water level fluctuation. Results: Ninety-nine plant taxa belonging to 30 different families were recorded. Forty-six vegetation types were identified and described by their ecological characteristics, diagnostic taxa and syntaxonomical status. Thirteen vegetation types, the largest number belonging to the vegetation class Charetea, are considered to be new records for Greece. The distribution of the vegetation types recorded in the 18 freshwater lakes was found to depend on environmental parameters and levels of eutrophication. Conclusions: An updated aquatic vegetation inventory was produced for Greek lakes, and primary results showed that the presence/absence of aquatic plant communities and the community composition in freshwater lakes can be utilized to assess the pressure of eutrophication on lake ecosystems. Taxonomic reference: Euro+Med (2006–). Abbreviations: MNT = Mean number of taxa; WFD = Water Framework Directive.

scholarly journals Physiological response of Monimopetalum chinense to light stress under habitat fragmentation

2010 ◽  
Vol 56 (No. 12) ◽  
pp. 551-556 ◽  
Author(s):  
C. Hao ◽  
R. Fan ◽  
X. Zhang ◽  
L. Wang ◽  
W. Chen ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Habitat Fragmentation ◽  
Light Intensity ◽  
Physiological Responses ◽  
Light Stress ◽  
Strong Light ◽  
Malondialdehyde Content ◽  
Antioxidant Enzymes Activities ◽  
Intense Light ◽  
Effect Of Light

To determine the effect of light stress under fragmental habitat on the physiology, this paper investigated the physiological responses of Monimopetalum chinense with different light intensities in the Xianyu Mountains (Anhui, China). The study showed that both weak and intense light brought about by habitat fragmentation could improve antioxidant enzymes activities, and promote electrical conductivity and malondialdehyde content of M. chinense leaves. However, too strong light could inhibit photosynthesis rates, superoxide dismutase, catalase, and ascorbate peroxidase activities. In addition, the characteristics of leaves were affected by light intensity at the fragmental habitat. Specifically, intense light was disadvantageous to photosynthesis and antioxidant enzymes of the species. Our results suggest that the biodiversity conservation of M. chinense is necessary, and that light intensity should be considered carefully when implementing conservation efforts.  

The Effect of Light Stress and Other Culture Conditions on Photoinhibition and Growth of Dunaliella tertiolecta

2015 ◽  
Vol 178 (2) ◽  
pp. 396-407 ◽  
Author(s):  
Jitpisut Seepratoomrosh ◽  
Prayad Pokethitiyook ◽  
Metha Meetam ◽  
Kittisak Yokthongwattana ◽  
Wenqiao Yuan ◽  
...  
Keyword(s):  
Light Stress ◽  
Culture Conditions ◽  
Dunaliella Tertiolecta ◽  
Effect Of Light

Zooplankton species distribution, richness and composition across tropical shallow lakes: A large scale assessment by biome, lake origin, and lake habitat

2020 ◽  
Vol 56 ◽  
pp. 25
Author(s):  
Camila Rodrigues Cabral ◽  
Leidiane Pereira Diniz ◽  
Alef Jonathan da Silva ◽  
Gustavo Fonseca ◽  
Luciana Silva Carneiro ◽  
...  
Keyword(s):  
Species Richness ◽  
Atlantic Forest ◽  
Species Distribution ◽  
Shallow Lakes ◽  
Aquatic Vegetation ◽  
Habitat Type ◽  
Northeastern Brazil ◽  
Similar Species ◽  
Zooplankton Species ◽  
Zooplankton Community Structure

Assessing zooplankton biodiversity is essential to support freshwater management/conservation programs. Here, we investigated the zooplankton community structure from 180 shallow lakes in northeastern Brazil and analyzed them according to biome (Atlantic Forest or Caatinga), the origin of ecosystems (natural or man-made lakes), and habitat type (pelagic or littoral). Additionally, we provided an updated list of zooplankton species. We registered 227 species (137 Rotifera, 65 Cladocera, 25 Copepoda). The most common species of each major group among all lakes were the cladoceran Ceriodaphina cornuta, the rotifers Brachionus havanaensis and Lecane bulla, and the copepod Termocyclops decipiens. Species related to aquatic vegetation, as the Lecanidae rotifers and phytophilous cladocerans, were more frequent along Atlantic Forest biome and natural lakes. On the other hand, species that are bioindicators of eutrophic waters were more common at the Caatinga biome and man-made lakes. Atlantic Forest and Caatinga biomes had similar species richness, but different community compositions for all zooplankton groups, reinforcing the Caatinga significance for the Brazilian aquatic biodiversity. The type of habitat was the most important factor structuring species richness, with higher richness in the littoral region when compared to the pelagic. A result of many unique species of Cladocera and Rotifera associated with the aquatic vegetation were observed. The findings demonstrated that conservation/management plans cannot generalize zooplankton species distribution across different biomes, origins and even within a single lake, between the pelagic and littoral zones.

scholarly journals The effect of light on N<sub>2</sub> fixation and net nitrogen release of field <i>Trichodesmium</i>

2017 ◽  
Author(s):  
Yangyang Lu ◽  
Zuozhu Wen ◽  
Dalin Shi ◽  
Mingming Chen ◽  
Yao Zhang ◽  
...  
Keyword(s):  
Light Intensity ◽  
Model Prediction ◽  
Carbon Fixation ◽  
Physiological State ◽  
Light Stress ◽  
Light Response ◽  
Light Change ◽  
Filamentous Cyanobacterium ◽  
Net Release ◽  
Effect Of Light

Abstract. Dinitrogen fixation (NF) by marine cyanobacteria is a crucial pathway to replenish the oceanic bioavailable nitrogen inventory. Light is the key to modulate NF, however, field studies regarding light response curve (NF-I curve) of NF rate and the effect of light on diazotroph derived nitrogen (DDN) net release are missing that may hamper an accurate nitrogen model prediction. Uncontaminated 15N2 gas dissolution method was applied to examine how the light change may influence the NF intensity and DDN net release in the oligotrophic ocean. Experiments were conducted at stations with diazotrophs dominated by filamentous cyanobacterium Trichodesmium spp. in the Western Pacific and the South China Sea. The light effect on carbon fixation (CF) was measured in parallel using the 13C labelling method specifically for a station characterized by Trichodesmium bloom. Both NF-I and CF-I curves showed Ik (light saturation coefficient) range of 328 to 509 μE m−2 s−1 with saturation light at around 600 μE m−2 s−1. The proportion of DDN net release ranged from ~6% to ~50% revealing an increasing trend as the light intensity decreased. At the Trichodesmium bloom station, we found CF/NF ratio was light-dependent and the ratio started to increase as light was lower than the carbon compensation point of 300 μE m−2 s−1. NF pathway was likely preferentially blocked under low light to conserve energy for photosynthesis, thus, there is a metabolism tradeoff between carbon and nitrogen fixation pathways under light stress. Results showed that short-term light change modulates the physiological state, which subsequently determined the C/N metabolism and DDN net release of field Trichodesmium. Energy reallocation associated with the variations of field light intensity would be helpful for model prediction of global biogeochemical cycle involved with Trichodesmium.

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