Effect of Substituted Pyridazinone Herbicides and of Difunone (EMD-IT 5914) on Carotenoid Biosynthesis in Green Algae

1976 ◽  
Vol 31 (11-12) ◽  
pp. 652-655 ◽  
Author(s):  
D Urbach ◽  
M Suchanka ◽  
W Urbach
Keyword(s):  
Chlorophyll A ◽  
Green Algae ◽  
Green Alga ◽  
Phenyl Ring ◽  
Chemical Structure ◽  
Methoxy Group ◽  
Carotenoid Biosynthesis ◽  
Chlorophyll Level ◽  
Sublethal Doses ◽  
Pyridazinone Derivatives

Abstract The carotenoid biosynthesis of the green alga Ankistrodesmus braunii is blocked if these cells are cultured in presence of sublethal doses of pyridazinone herbicides (San 9789, San 6706, BASF 44521) or of the herbicide difunone (EMD-IT 5914). The amount of colored carotenoids normally found in these algae is reduced drastically and the precursors phytoene and phytofluene are accumulated. Furthermore a decrease in the chlorophyll level occurs in the treated cells, but there is a stronger loss of chlorophyll a, resulting in a lowering of the chlorophyll a/b ratio with time. Concerning the activity of substituted pyridazinones leading to inhibition of carotenoid biosynthesis this effect can be related to the chemical structure of these compounds: a trifluoromethyl substitution of the phenyl ring and a mono- or dimethyl substitution of the amine (San 9789, San 6706) or a methoxy group instead of the substituted amine (BASF 44521) are required both for this effect. Other pyridazinone derivatives with either a trifluoromethyl substitution of the phenyl ring (San 9774) or a dimethyl substitution of the amine (San 9785) or a methoxy group (BASF 13761) are without any effect on the pigment pattern of these algae.

The Inhibition of Carotenoid Biosynthesis in Green Algae by SANDOZ H 6706: Accumulation of Phytoene and Phytofluene in Chlorella fusca

1975 ◽  
Vol 30 (5-6) ◽  
pp. 333-336 ◽  
Author(s):  
H. W. Kümmel ◽  
L. H. Grimme
Keyword(s):  
Green Algae ◽  
Green Alga ◽  
Control Mechanism ◽  
Carotenoid Biosynthesis ◽  
Chlorella Fusca ◽  
Prolonged Cultivation ◽  
Green Alga Chlorella

Abstract Prolonged cultivation of the green alga Chlorella fusca under heterotrophic conditions and in the presence of sub-lethal concentrations of SAN H 6706 (4-chloro-5-(dimethylamino)-2-(α,α,α-tri-fluoro-m-tolyl)-3 (2H)-pyridazinone) leads to an accumulation of phytoene and phytofluene. The content of chlorophylls and coloured carotenoids of the cells treated with this herbicide, compared with normal untreated cells, is diminished by about 90% and 95% respectively, but the total amount of carotenoids, including colourless phytoene and phytofluene, is increased by 65%. This suggests that SAN H 6706 causes increased accumulation of carotenoids by eliminating a biosynthetic control mechanism, so that the endproducts of the biosynthetic chain no longer control the rate of precursor formation.

Cytokinin activity of some substituted ureas and thioureas

1966 ◽  
Vol 165 (999) ◽  
pp. 245-265 ◽  
Keyword(s):  
Biological Activity ◽  
Active Compound ◽  
Phenyl Ring ◽  
Chemical Structure ◽  
Lower Activity ◽  
Cytokinin Activity ◽  
Hydrogen Atoms ◽  
Detectable Activity ◽  
Low Activity

N , N '-Diphenylurea was shown to have reproducible cytokinin activity . Some 500 ureas, mainly of the N -monosubstituted and N , N '-disubstituted types, were tested an d about one half of these were active. Attempts were made to correlate chemical structure with biological activity. Although there are some exceptions to nearly every generalization it has been possible to formulate some principles. (1) Phenyl urea was the simplest active compound. (2) An HNCONH bridge conferred higher activity than an HNCSNH linkage and any other tested arrangement of the bridge gave inactive com pounds. (3) Compounds in which both amino hydrogen atoms on one or both sides of the bridge were substituted were of low activity or were inactive. (4) Many com pounds of the type R NHCONH 2 in which R = a substituted phenyl ring were tested. Ring substitution generally increased the activity and the highest activity was associated with meta substitution and the lowest with ortho . Compounds with electron-attracting substituents were generally more active than those with electron-donating substituents. Pyridyl compounds were active but com pounds with non-planar rings were inactive. (5) In compounds of the type R NHCONH R ' in which R and R ' were phenyl or substituted phenyl groups the highest activities were usually found in com pounds with one unsubstituted phenyl ring. Those with two substituted phenyl groups generally had lower activity. Some ureas showed detectable activity at 0.1 parts/10 6 . This was about four times less active than kinetin when tested in the tobacco pith assay.

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 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

scholarly journals Novel Cell-Virus-Virophage Tripartite Infection Systems Discovered in the Freshwater Lake Dishui Lake in Shanghai, China

2020 ◽  
Vol 94 (11) ◽  
Author(s):  
Shengzhong Xu ◽  
Liang Zhou ◽  
Xiaosha Liang ◽  
Yifan Zhou ◽  
Hao Chen ◽  
...  
Keyword(s):  
Green Algae ◽  
Green Alga ◽  
Phylogenetic Analyses ◽  
Freshwater Lake ◽  
Metagenomic Data ◽  
Data Sets ◽  
Data Set ◽  
Dna Viruses ◽  
Oligonucleotide Frequency ◽  
Dsdna Viruses

ABSTRACT Virophages are small parasitic double-stranded DNA (dsDNA) viruses of giant dsDNA viruses infecting unicellular eukaryotes. Except for a few isolated virophages characterized by parasitization mechanisms, features of virophages discovered in metagenomic data sets remain largely unknown. Here, the complete genomes of seven virophages (26.6 to 31.5 kbp) and four large DNA viruses (190.4 to 392.5 kbp) that coexist in the freshwater lake Dishui Lake, Shanghai, China, have been identified based on environmental metagenomic investigation. Both genomic and phylogenetic analyses indicate that Dishui Lake virophages (DSLVs) are closely related to each other and to other lake virophages, and Dishui Lake large DNA viruses are affiliated with the micro-green alga-infecting Prasinovirus of the Phycodnaviridae (named Dishui Lake phycodnaviruses [DSLPVs]) and protist (protozoan and alga)-infecting Mimiviridae (named Dishui Lake large alga virus [DSLLAV]). The DSLVs possess more genes with closer homology to that of large alga viruses than to that of giant protozoan viruses. Furthermore, the DSLVs are strongly associated with large green alga viruses, including DSLPV4 and DSLLAV1, based on codon usage as well as oligonucleotide frequency and correlation analyses. Surprisingly, a nonhomologous CRISPR-Cas like system is found in DSLLAV1, which appears to protect DSLLAV1 from the parasitization of DSLV5 and DSLV8. These results suggest that novel cell-virus-virophage (CVv) tripartite infection systems of green algae, large green alga virus (Phycodnaviridae- and Mimiviridae-related), and virophage exist in Dishui Lake, which will contribute to further deep investigations of the evolutionary interaction of virophages and large alga viruses as well as of the essential roles that the CVv plays in the ecology of algae. IMPORTANCE Virophages are small parasitizing viruses of large/giant viruses. To our knowledge, the few isolated virophages all parasitize giant protozoan viruses (Mimiviridae) for propagation and form a tripartite infection system with hosts, here named the cell-virus-virophage (CVv) system. However, the CVv system remains largely unknown in environmental metagenomic data sets. In this study, we systematically investigated the metagenomic data set from the freshwater lake Dishui Lake, Shanghai, China. Consequently, four novel large alga viruses and seven virophages were discovered to coexist in Dishui Lake. Surprisingly, a novel CVv tripartite infection system comprising green algae, large green alga viruses (Phycodnaviridae- and Mimiviridae-related), and virophages was identified based on genetic link, genomic signature, and CRISPR system analyses. Meanwhile, a nonhomologous CRISPR-like system was found in Dishui Lake large alga viruses, which appears to protect the virus host from the infection of Dishui Lake virophages (DSLVs). These findings are critical to give insight into the potential significance of CVv in global evolution and ecology.

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.

Comparison of Chlorophyll a Extractions with Ethanol and Dimethyl Sulfoxide/Acetone, and a Concern about Spectrophotometric Phaeopigment Correction

1992 ◽  
Vol 49 (11) ◽  
pp. 2331-2336 ◽  
Author(s):  
D. J. Webb ◽  
B. K. Burnison ◽  
A. M. Trimbee ◽  
E. E. Prepas
Keyword(s):  
High Pressure ◽  
Dimethyl Sulfoxide ◽  
Chlorophyll A ◽  
Green Algae ◽  
Natural Populations ◽  
Eutrophic Lakes ◽  
North Central ◽  
Chl A ◽  
Blue Green Algae ◽  
Hplc Analyses

Chlorophyll a (Chl a) in water samples from three mesotrophic to eutrophic lakes in north-central Alberta was extracted with one of three solvents (95% ethanol, 90% ethanol, or a 2:3 mixture of dimethyl sulfoxide and 90% acetone (DMSO/acetone)) and analyzed by two techniques (spectrophotometry and high pressure liquid chromatography (HPLC). The dominant phytoplankton were blue-green algae and diatoms. Total Chl a concentrations (i.e. no correction for phaeopigments (Pha)) were not significantly different among solvents (P > 0.5). Total Chl a concentrations from spectrophotometric analyses were significantly higher than those from HPLC analyses (4.2 ± 0.88 and 2.6 ± 0.50 μg∙L−1 respectively, P < 0.05). Pha concentrations derived by spectrophotometry were 64 times higher than those derived by HPLC (1.7 ± 0.52 and 0.025 ± 0.01 μg∙L−1 respectively, P < 0.005). Thus, spectrophotometry appears to dramatically overestimate Pha concentrations and may overestimate total Chl a (i.e. no correction for Pha). Therefore, ethanol and DMSO/acetone are equally suitable for Chl a extraction from natural populations dominated by blue-green algae and/or diatoms, but if information on Pha and/or accessory pigments is required, HPLC analyses are the appropriate route rather than spectrophotometry.

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