scholarly journals Effects of Phenolic Pollution on Interspecific Competition between Microcystis aeruginosa and Chlorella pyrenoidosa and their Photosynthetic Responses

Author(s):  
Xiao Tan ◽  
Kaiwen Dai ◽  
Keshab Parajuli ◽  
Xiaoshuai Hang ◽  
Zhipeng Duan ◽  
...  

The demand for phenolic compounds has been increasing rapidly, which has intensified the production and usage of phenol at a commercial scale. In some polluted water bodies, phenol has become one of the typical aromatic contaminants. Such water bodies are inescapably influenced by nutrients from human activities, and also suffer from nuisance cyanobacterial blooms. While phenolic pollution threatens water safety and ecological balance, algal cells are ubiquitous and sensitive to pollutants. Therefore, effects of phenolic pollution on interspecific competition between a bloom-forming cyanobacterium and other common alga merit quantitative investigation. In this study, the effects of phenol on Microcystis aeruginosa (M. aeruginosa, a bloom-forming cyanobacterium) and Chlorella pyrenoidosa (C. pyrenoidosa, a ubiquitous green alga) were analyzed in mono- and co-cultures. The two species were exposed to a series of phenol treatments (0, 2, 20, and 200 μg mL−1). Population dynamics were measured by a flow cytometer and analyzed by the Lotka-Volterra model. The results showed that M. aeruginosa was more sensitive to phenol (EC50 = 80.8 ± 0.16 μg mL−1) compared to C. pyrenoidosa (EC50 = 631.4 ± 0.41 μg mL−1) in mono-cultures. M. aeruginosa won in the co-cultures when phenol was below or equal to 20 μg mL−1, while C. pyrenoidosa became the dominant species in the 200 μg mL−1 treatment. Photosynthetic activity was measured by a fluometer. Results showed phenol significantly impacted the photosynthetic activity of M. aeruginosa by inhibiting the acceptor side of its photosystem II (PSII), while such inhibition in C. pyrenoidosa was only observed in the highest phenol treatment (200 μg mL−1). This study provides a better understanding for predicting the succession of algal community structure in water bodies susceptible to phenolic contamination. Moreover, it reveals the mechanism on photosynthetic responses of these two species under phenolic stress.

2001 ◽  
Vol 1 (2) ◽  
pp. 247-250 ◽  
Author(s):  
Z. Romanowska-Duda ◽  
M. Tarczyńska ◽  
M. Zalewski

The seasonal blooming of cyanobacteria in water bodies creates considerable medical and veterinary problems, because certain species are potential sources of toxins, principally neuro- and hepatotoxins. Much effort has been devoted to prevent them blooming. In this study, axenic cultures of Microcystis aeruginosa and Anabaena sp. were cultivated in medium Z supplemented with growth retardants. Cells were counted under a microscope each week for up to 8 weeks of culture. The growth retardants paclobutrazol, ancymidol and uniconazole greatly reduced the number of living cells, the effect already being striking after 24 hours of culture. Plant growth retardants can be effectively used in control of cyanobacterial blooms.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3013
Author(s):  
Larissa Souza Passos ◽  
Éryka Costa Almeida ◽  
Claudio Martin Pereira de Pereira ◽  
Alessandro Alberto Casazza ◽  
Attilio Converti ◽  
...  

Cyanobacterial blooms and strains absorb carbon dioxide, drawing attention to its use as feed for animals and renewable energy sources. However, cyanobacteria can produce toxins and have a low heating value. Herein, we studied a cyanobacterial strain harvested during a bloom event and analyzed it to use as animal feed and a source of energy supply. The thermal properties and the contents of total nitrogen, protein, carbohydrate, fatty acids, lipid, and the presence of cyanotoxins were investigated in the Microcystis aeruginosa LTPNA 01 strain and in a bloom material. Microcystins (hepatotoxins) were not detected in this strain nor in the bloom material by liquid chromatography coupled to mass spectrometry. Thermogravimetric analysis showed that degradation reactions (devolatilization) initiated at around 180 °C, dropping from approximately 90% to 20% of the samples’ mass. Our work showed that despite presenting a low heating value, both biomass and non-toxic M. aeruginosa LTPNA 01 could be used as energy sources either by burning or producing biofuels. Both can be considered a protein and carbohydrate source similar to some microalgae species as well as biomass fuel. It could also be used as additive for animal feed; however, its safety and potential adverse health effects should be further investigated.


Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1831
Author(s):  
Natalia Herrera ◽  
Fernando Echeverri

Although several theories have been postulated to explain cyanobacterial blooms, their biochemical origin has not yet been found. In this work, we explore the existence of bacterial communication, called quorum sensing, in Microcystis aeruginosa and Cylindrospermopsis raciborskii. Thus, the application of several known acylhomoserine lactones to cultures of both cyanobacteria causes profound metabolic. At 72 h post-application, some of them produced substantial increases in cell proliferation, while others were inhibitors. There was a correlation with colony-forming activity for most of them. According to ELISA analysis, the microcystin levels were increased with some lactones. However, there was a clear difference between M. aeruginosa and C. raciborskii culture since, in the first one, there was an inducing effect on cell proliferation, while in C. raciborskii, the effects were minor. Besides, there were compound inhibitors and inducers of microcystins production in M. aeruginosa, but almost all compounds were only inducers of saxitoxin production in C. raciborskii. Moreover, each lactone appears to be involved in a specific quorum sensing process. From these results, the formation of cyanobacterial blooms in dams and reservoirs could be explained since lactones may come from cyanobacteria and other sources as bacterial microflora-associated or exogenous compounds structurally unrelated to lactones, such as drugs, industrial effluents, and agrochemicals.


Author(s):  
E. Yu. Kulikova ◽  
Ju. A. Sergeeva

One of the problems of functioning of coal industry enterprises is the formation of mine waters, which are discharged into water bodies and cause their dangerous pollution. The total volume of water pumped by the enterprise includes up to 15 % for the recycling cycle, the remaining 85% is discharged to surface water bodies. As a result, the ecological balance of coal regions is disturbed, their sanitary and hygienic state on the environment worsens, and the quality of coal is reduced due to the intake of polluted water for technological operations. The volume of mine water contamination increases during mining operations at deeper horizons and in difficult mining and hydrogeological conditions. In turn, this leads to pollution and depletion of underground aquifers and the formation of environmental risk factors. In Kuzbass, all these factors contribute to the development of water crisis, since the state of surface reservoirs has already reached a critical limit. Especially dangerous is the process of liquidation of mines. Closing mines and sections disrupt natural water flows, resulting in all water from the aquifers going to deeper horizons. More pollutants enter the water, which poison the underground hydrosphere of the regions. The paper analyzes the pollutants entering the underground and surface hydro grid at coal-fired plants and offers a Conceptual model for minimizing the risk of water pollution.


2013 ◽  
Vol 10 (12) ◽  
pp. 8139-8157 ◽  
Author(s):  
M. W. Matthews ◽  
S. Bernard

Abstract. A two-layered sphere model is used to investigate the impact of gas vacuoles on the inherent optical properties (IOPs) of the cyanophyte Microcystis aeruginosa. Enclosing a vacuole-like particle within a chromatoplasm shell layer significantly altered spectral scattering and increased backscattering. The two-layered sphere model reproduced features in the spectral attenuation and volume scattering function (VSF) that have previously been attributed to gas vacuoles. This suggests the model is good at least as a first approximation for investigating how gas vacuoles alter the IOPs. Measured Rrs was used to provide a range of values for the central value of the real refractive index, 1 + ε, for the shell layer using measured IOPs and a radiative transfer model. Sufficient optical closure was obtained for 1 + ε between 1.1 and 1.14, which had corresponding Chl a-specific phytoplankton backscattering, bbφ*, between 3.9 and 7.2 × 10−3 m2 mg−1 at 510 nm. The bbφ* values are in close agreement with the literature and in situ particulate backscattering measurements. Rrs simulated for a population of vacuolate cells was greatly enlarged relative to a homogeneous population. A sensitivity analysis of empirical algorithms for estimating Chl a in eutrophic/hypertrophic waters suggests these are robust under variable constituent concentrations and likely to be species-sensitive. The study confirms that gas vacuoles cause significant increase in backscattering and are responsible for the high Rrs values observed in buoyant cyanobacterial blooms. Gas vacuoles are therefore one of the most important bio-optical substructures influencing the IOPs in phytoplankton.


Hydrobiologia ◽  
1996 ◽  
Vol 322 (1-3) ◽  
pp. 149-151 ◽  
Author(s):  
Boris V. Gromov ◽  
Alexey A. Vepritsky ◽  
Kira A. Mamkaeva ◽  
Lyudmila N. Voloshko

2021 ◽  
Vol 45 (37) ◽  
pp. 17483-17492
Author(s):  
Xuechun Wei ◽  
Hongxiang Zhu ◽  
Jianhua Xiong ◽  
Wenyu Huang ◽  
Ji Shi ◽  
...  

Fluorine-doped TiO2 was successfully synthesised and applied as algaecide. Studies on algae removal efficiencies and mechanisms illustrated that F-TiO2 was suitable for algae elimination in natural water bodies.


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