scholarly journals Ultrasonic selectivity on depressing photosynthesis of cyanobacteria and green algae probed by chlorophyll-a fluorescence transient

2017 ◽  
Vol 76 (8) ◽  
pp. 2085-2094 ◽  
Author(s):  
Zhipeng Duan ◽  
Xiao Tan ◽  
Niegui Li
Keyword(s):  
Chlorophyll A ◽  
Green Algae ◽  
Electron Acceptor ◽  
Cell Concentration ◽  
Electron Flow ◽  
Chlorella Pyrenoidosa ◽  
Cyanobacterial Blooms ◽  
Cell Structures ◽  
Toxic Cyanobacteria ◽  
New Strategy

Ultrasound can inhibit cyanobacterial growth through rupturing cells, but this pathway frequently has the risk to release intercellular toxin (e.g., microcystin). Depressing photosynthesis without cell disruption may provide a new strategy to control cyanobacterial blooms using ultrasound, especially Microcystis blooms. In this work, Microcystis aeruginosa (toxic cyanobacteria) and Chlorella pyrenoidosa (typical green algae) were chosen as model microalgae to verify this hypothesis. Results showed that ultrasound has the ability to inhibit cyanobacterial photosynthesis significantly and selectively. Specifically, sonication damaged QA, a tightly bound one-electron acceptor, and blocked electron flow at QB, a two-electron acceptor, in the photosystem II (PSII) of M. aeruginosa when it was exposed for 60 s (35 kHz, 0.043 W/cm3). Moreover, 44.8% of the reaction centers (RCs) in the PSII of M. aeruginosa were transferred into inactive ones (RCsis), and the cell concentration decreased by 32.5% after sonication for 300 s. By contrast, only 7.9% of RCsi occurred in C. pyrenoidosa, and cell concentration and chlorophyll-a content reduced by 18.7% and 9.3%, respectively. Differences in both species (i.e., cell structures) might be responsible for the varying levels to sonication. This research suggests that cyanobacteria, especially Microcystis, could be controlled by ultrasound via damaging their PSIIs.

scholarly journals Phytoremediation of CYN, MC-LR and ANTX-a from Water by the Submerged Macrophyte Lemna trisulca

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 699
Author(s):  
Małgorzata Kucała ◽  
Michał Saładyga ◽  
Ariel Kaminski
Keyword(s):  
Electrical Conductivity ◽  
Chlorophyll A ◽  
Growth And Development ◽  
Cyanobacterial Blooms ◽  
Biotechnological Potential ◽  
Intracellular Pool ◽  
Ph Values ◽  
Bg11 Medium ◽  
Total Pool ◽  
Harmful Cyanobacterial Blooms

Cyanotoxins are harmful to aquatic and water-related organisms. In this study, Lemna trisulca was tested as a phytoremediation agent for three common cyanotoxins produced by bloom-forming cyanobacteria. Cocultivation of L. trisulca with Dolichospermum flos-aquae in BG11 medium caused a release of the intracellular pool of anatoxin-a into the medium and the adsorption of 92% of the toxin by the plant—after 14 days, the total amount of toxin decreased 3.17 times. Cocultivation with Raphidopsis raciborskii caused a 2.77-time reduction in the concentration of cylindrospermopsin (CYN) in comparison to the control (62% of the total pool of CYN was associated with the plant). The greatest toxin limitation was noted for cocultivation with Microcystis aeruginosa. After two weeks, the microcystin-LR (MC-LR) concentration decreased more than 310 times. The macrophyte also influenced the growth and development of cyanobacteria cells. Overall, 14 days of cocultivation reduced the biomass of D. flos-aquae, M. aeruginosa, and R. raciborskii by 8, 12, and 3 times, and chlorophyll a concentration in comparison to the control decreased by 17.5, 4.3, and 32.6 times, respectively. Additionally, the macrophyte stabilized the electrical conductivity (EC) and pH values of the water and affected the even uptake of cations and anions from the medium. The obtained results indicate the biotechnological potential of L. trisulca for limiting the development of harmful cyanobacterial blooms and their toxicity.

scholarly journals Hyperspectral Data and Machine Learning for Estimating CDOM, Chlorophyll a, Diatoms, Green Algae and Turbidity

2018 ◽  
Vol 15 (9) ◽  
pp. 1881 ◽  
Author(s):  
Sina Keller ◽  
Philipp Maier ◽  
Felix Riese ◽  
Stefan Norra ◽  
Andreas Holbach ◽  
...  
Keyword(s):  
Machine Learning ◽  
Water Quality ◽  
Chlorophyll A ◽  
Green Algae ◽  
Hyperspectral Data ◽  
Coefficient Of Determination ◽  
Inland Waters ◽  
Learning Approaches ◽  
River Elbe ◽  
Regression Framework

Inland waters are of great importance for scientists as well as authorities since they are essential ecosystems and well known for their biodiversity. When monitoring their respective water quality, in situ measurements of water quality parameters are spatially limited, costly and time-consuming. In this paper, we propose a combination of hyperspectral data and machine learning methods to estimate and therefore to monitor different parameters for water quality. In contrast to commonly-applied techniques such as band ratios, this approach is data-driven and does not rely on any domain knowledge. We focus on CDOM, chlorophyll a and turbidity as well as the concentrations of the two algae types, diatoms and green algae. In order to investigate the potential of our proposal, we rely on measured data, which we sampled with three different sensors on the river Elbe in Germany from 24 June–12 July 2017. The measurement setup with two probe sensors and a hyperspectral sensor is described in detail. To estimate the five mentioned variables, we present an appropriate regression framework involving ten machine learning models and two preprocessing methods. This allows the regression performance of each model and variable to be evaluated. The best performing model for each variable results in a coefficient of determination R 2 in the range of 89.9% to 94.6%. That clearly reveals the potential of the machine learning approaches with hyperspectral data. In further investigations, we focus on the generalization of the regression framework to prepare its application to different types of inland waters.

Extraction and quantification of chlorophyll a from freshwater green algae

1998 ◽  
Vol 32 (7) ◽  
pp. 2220-2223 ◽  
Author(s):  
David Simon ◽  
Stuart Helliwell
Keyword(s):  
Chlorophyll A ◽  
Green Algae

scholarly journals Persicivirga ulvanivorans sp. nov., a marine member of the family Flavobacteriaceae that degrades ulvan from green algae

2011 ◽  
Vol 61 (8) ◽  
pp. 1899-1905 ◽  
Author(s):  
Tristan Barbeyron ◽  
Yannick Lerat ◽  
Jean-François Sassi ◽  
Sophie Le Panse ◽  
William Helbert ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Green Algae ◽  
Electron Acceptor ◽  
Sequence Similarity ◽  
Rrna Gene ◽  
Strictly Aerobic ◽  
The Novel ◽  
The Family ◽  
Gliding Bacterium

A rod shaped, Gram-stain-negative, chemo-organotrophic, heterotrophic, strictly aerobic, non-gliding bacterium, designated strain PLRT, was isolated from faeces of the mollusc Aplysia punctata (Mollusca, Gastropoda) that had been fed with green algae belonging to the genus Ulva. The novel strain was able to degrade ulvan, a polysaccharide extracted from green algae (Chlorophyta, Ulvophyceae). The taxonomic position of strain PLRT was investigated by using a polyphasic approach. Strain PLRT was dark orange, oxidase-positive, catalase-positive and grew optimally at 25 °C, at pH 7.5 and in the presence of 2.5 % (w/v) NaCl with an oxidative metabolism using oxygen as the electron acceptor. Nitrate could not be used as the electron acceptor. Strain PLRT had a Chargaff’s coefficient (DNA G+C content) of 35.3 mol%. Phylogenetic analysis based on the sequence of the 16S rRNA gene placed the novel strain in the family Flavobacteriaceae (phylum ‘Bacteroidetes’), within a clade comprising Stenothermobacter spongiae, Nonlabens tegetincola, Sandarakinotalea sediminis, Persicivirga xylanidelens and Persicivirga dokdonensis. The closest neighbours of strain PLRT were P. xylanidelens and P. dokdonensis, sharing 95.2 and 95.5 % 16S rRNA gene sequence similarity, respectively. Phylogenetic inference and differential phenotypic characteristics demonstrated that strain PLRT represents a novel species of the genus Persicivirga, for which the name Persicivirga ulvanivorans sp. nov. is proposed. The type strain is PLRT ( = CIP 110082T = DSM 22727T).

scholarly journals Research of pigments of blue-green algae spirulina platensis for practical use in confectionery technology

2019 ◽  
Vol 81 (2) ◽  
pp. 170-176
Author(s):  
T. K. Kalenik ◽  
E. V. Dobrynina ◽  
V. M. Ostapenko ◽  
Y. Torii ◽  
J. Hiromi
Keyword(s):  
Chlorophyll A ◽  
Green Algae ◽  
Spirulina Platensis ◽  
Food Additives ◽  
Water Extract ◽  
Blue Pigment ◽  
Natural Food ◽  
Synthetic Dyes ◽  
Blue Green Algae ◽  
Synthetic Origin

The article presents a study of the process of isolation of natural blue pigment – phycocyanin from the biomass of blue-green algae Spirulina platensis by water extraction, followed using its water solution as a natural food colorant in the production of milk chocolate. Recently, modern food enterprises are pursuing their policy towards expanding the range of products, which is closely related to the increasing needs of the population in food of a new kind. One of the solutions to this problem is the use of food additives of both natural and synthetic origin. Among the similar components widespread found dyes synthetic origin, which have high coverage rates and relatively low cost. However, many of the permitted in our country synthetic food dyes are banned in several developed countries as potentially dangerous to health. Synthetic dyes of red, yellow and green color have many natural analogues – carotenoids, lutein, chlorophyll, etc., except for the blue dye, the analogue of which is only anthocyanins, which are unstable depending on the pH conditions. In this article were identified phycobiliproteins and chlorophyll a in a water extract of spirulina. The mass concentration of phycobiliproteins and chlorophyll a was determined by spectrophotometric method before and after the addition of ammonium sulfate. A comparative analysis of the effect of fractionation (salting out) on the degree of purification of the phycocyanin solution. Presented and described the technological scheme of extraction of phycocyanin which allows to use it in food technologies as an extract or a dry powder. Established the concentration of phycocyanin extract from blue-green algae spirulina to produce milk blue chocolate. Determined organoleptic and hygienic characteristics of the finished product

Photosystem I-abhängige Phosphorylierung isolierter Chloroplasten mit Ascorbat/2.6-Dichlorphenolindophenol als Elektronendonator und Methylviologen als Elektronenakzeptor / Photosystem I Dependent Phosphorylation of Isolated Chloroplasts with Ascorbate/2,6-Dichlorophenolindophenol as Electron Donor and Methylviologen as Electron Acceptor

1972 ◽  
Vol 27 (4) ◽  
pp. 445-455 ◽  
Author(s):  
Heinrich Strotmann ◽  
Christa Von Gösseln
Keyword(s):  
Electron Transport ◽  
Linear System ◽  
Photosystem I ◽  
Electron Acceptor ◽  
Electron Flow ◽  
Phosphorylation Site ◽  
Cyclic System ◽  
Atp Production ◽  
Proton Uptake ◽  
Isolated Chloroplasts

Photosystem I related phosphorylation of isolated chloroplasts was investigated with special reference to the stoichiometry between ATP production and electron transprt (ATP: 2e⊖). The system studied contained DCMU to inhibit electron flow from photosystem II, ascorbate and DPIP to supply electrons to photosystem I, and methylviologen as electron acceptor. The following results were obtained:1. Basal electron transport is stimulated by the addition of the phosphorylating system, indicating that phosphorylation is really coupled to non-cyclic electron flow. The ratio ATP: 2e⊖ is 1, when the increase of electron flow obtained by the addition of ADP and phosphate is correlated to phosphorylation. This ratio is constant upon varying several parameters including DPIP concentration and light intensity.2. In the absence of methylviologen a DPIP catalyzed cyclic phosphorylation takes place (cf. I. c.7, 11, 12). Phosphorylation is not increased by the addition of methylviologen, indicating that both, the cyclic DPIP mediated and the non-cyclic system are coupled to the same phosphorylation site and limited by the same reaction step.3. In the absence of oxygen a methylviologen supported cyclic phosphorylation occurs. Comparing optimum rates, phosphorylation under these conditions is about twice as high as in the noncyclic system. Therefore we conclude that two phosphorylation sites are involved in methylviologen catalyzed cyclic electron transport. This system is sensitive against trypsin treatment of the chloroplasts, whereas the linear system is not.4. The two cyclic systems as well as the non-cyclic system are coupled to reversible proton uptake. Furthermore the linear system exhibits an irreversible uptake of hydrogen ions, which is stoichiometric to electron flow. From the reversible and the irreversible components of the pH changes the ratio of the proton pump to electron transprt can be calculated. Under steady state conditions the ration H⨁ : e⊖ approaches 1.

Pre-treating algae-laden raw water by silver carp during Microcystis-dominated and non-Microcystis-dominated periods

2012 ◽  
Vol 65 (8) ◽  
pp. 1448-1453 ◽  
Author(s):  
Hua Ma ◽  
Fuyi Cui ◽  
Zhiquan Liu ◽  
Zhiwei Zhao
Keyword(s):  
Chlorophyll A ◽  
Green Algae ◽  
Total Phosphorus ◽  
Phytoplankton Community ◽  
Phosphorus Content ◽  
Silver Carp ◽  
Nutrient Level ◽  
Species Structure ◽  
Raw Water ◽  
Filter Feeding

Performance of pre-treating algae-laden raw water by silver carp during a non-Microcystis-dominated period (period I) and a Microcystis-dominated period (period II) was investigated in terms of algae cell concentration, total phosphorus content, chlorophyll a and phytoplankton species structure. During period I the ineffective filter-feeding for small green algae resulted in the increase of small single algae, which led to the negative removal of chlorophyll a, and when the biomass was higher, the negative was more significant. However, due to the effective filter-feeding of silver carp for Microcystis flos-aquae, the average removal efficiency exceeded 50% at all stocking biomass levels (20–120 g/m3) used in experiments during period II. Total phosphorus removal efficiencies could exceed 50% at silver carp biomass stocking levels of 60–80 g/m3 during both period I and period II. The experimental results indicated that silver carp stocking contributed to the removal of colony-forming cyanobacteria, but led to the increase of single-cell algae (mainly green algae and diatoms) during both period I and period II. The initial phytoplankton community structure and the control of nutrient level were important factors in the choice of silver carp stocking biomass when used to purify algae-loaded water.

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