Chapter 10 Hmdling and Culturing of Chlorella

Kuhl, Adolf; Lorenzen, Harald

doi:10.1016/s0091-679x(08)62092-0

Cited by 114 publications

(62 citation statements)

References 47 publications

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“…Scenedesmus dimorphus was cultivated in growth medium for unicellular green algae (Kuhl and Lorenzen, 1964) in 1-L round glass flasks at 23 ± 2 • C, under continuous aeration and artificial light from full-spectrum fluorescent lamps (75 uE/m 2 /s).…”

Section: Rearing Of Daphnia Magna Populationsmentioning

confidence: 99%

Chronic Responses ofDaphnia magnaUnder Dietary Exposure to Leaves of a Transgenic (Event MON810) Bt–Maize Hybrid and its Conventional Near-Isoline

Holderbaum

Cuhra

Wickson

et al. 2015

Journal of Toxicology and Environmental Health, Part A

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Insect resistance is the second most common trait globally in cultivated genetically modified (GM) plants. Resistance is usually obtained by introducing into the plant's genome genes from the bacterium Bacillus thuringiensis (Bt) coding for insecticidal proteins (Cry proteins or toxins) that target insect pests. The aim of this study was to examine the hypothesis that a chronic, high-dose dietary exposure to leaves of a Bt-maize hybrid (GM event MON810, expressing a transgenic or recombinant Cry1Ab toxin), exerted no adverse effects on fitness parameters of the aquatic nontarget organism Daphnia magna (water flea) when compared to an identical control diet based on leaves of the non-GM near-isoline. Cry1Ab was immunologically detected and quantified in GM maize leaf material used for Daphnia feed. A 69-kD protein near Bt's active core-toxin size and a 34-kD protein were identified. The D. magna bioassay showed a resource allocation to production of resting eggs and early fecundity in D. magna fed GM maize, with adverse effects for body size and fecundity later in life. This is the first study to examine GM-plant leaf material in the D. magna model, and provides of negative fitness effects of a MON810 maize hybrid in a nontarget model organism under chronic, high dietary exposure. Based upon these results, it is postulated that the observed transgenic proteins exert a nontarget effect in D. magna and/or unintended changes were produced in the maize genome/metabolome by the transformation process, producing a nutritional difference between GM-maize and non-GM near-isoline.

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Section: Rearing Of Daphnia Magna Populationsmentioning

confidence: 99%

Chronic Responses ofDaphnia magnaUnder Dietary Exposure to Leaves of a Transgenic (Event MON810) Bt–Maize Hybrid and its Conventional Near-Isoline

Holderbaum

Cuhra

Wickson

et al. 2015

Journal of Toxicology and Environmental Health, Part A

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“…The material used was Chlorella pyrenoidosa (strain 211/8b of the Algensammlung des Pflanzenphysiologischen Institut of the University of Gottingen, Germany) grown axenically in the medium described by Kuhl and Lorenzen [13] and synchronized by the method of Lorenzen [14]: alternating periods of 14 h light and 10 h darkness, illumination with 10000 lux and temperature of 30 "C. Lack of bacterial contamination was routinely tested by microscopic observation and culture on bacterial growth medium.…”

Section: Methodsmentioning

confidence: 99%

Heterogeneity and Complexity of Chlorella Chloroplastic DNA

Bayen

Rode

1973

European Journal of Biochemistry

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The heterogeneity and complexity of Chlorelb chloroplastic DNA has been investigated by means of thermal denaturation and renaturation kinetics.The chloroplastic DNA presents a Tm of 82.2 "C, a maximal hyperchromicity of 40.2 and a dispersion coefficient 4213 of 6 "C. The absorbance melting profiles display irregularities indicating an intramolecular heterogeneity of the DNA. The fist derivated curves of the melting profiles show the presence in the chloroplastic DNA of two main components of Tm 81 "C and 84.7 "C (which represent together about 80°/, of the total DNA) and possibly three other minor ones.Denatured and sheared DNAs renature rapidly as a fast and a slow-renaturing class with a kinetic complexity of 3-10' daltons and 2 . 3~1 0~ daltons respectively (assuming a value of 2.5. lo9daltons for Escherichia coli DNA). If correction is applied to account for the low d(G + C) content of the chloroplastic DNA, the kinetic complexity of the slow-renaturing component is found to be in the range of 1.2-1.3 -los daltom.Our results con-firm and extend the fact that chloroplastic DNAs are similar in terms of kinetic complexity and heterogeneity. This is in good agreement with a possible common origin for all the chloroplastic DNAs.From the discrepancy between analytical and kinetic complexities of Chlorella chloroplastic DNA, one can assume that this DNA is extensively reiterated and that the unique nucleotide sequence is present in about 20 copies in the chloroplastic genome.The presence of DNA in algal chloroplasts was first established by Ris and Plaut in 1962 [l]. Since then many algae and higher plants have been shown to possess chloroplastic DNA exhibiting a base composition different from nuclear DNA [2]. Furthermore chloroplastic DNA, unlike nuclear DNA, renatures rapidly to its native density after denaturation [3], thus indicating much less kinetic complexity.A few years ago, Wetmur and Davidson [4] demonstrated that the genetic complexity of a given DNA can be estimated from its rate of renaturation. The chloroplastic DNAs of both lettuce [5] and C h bmydamonas [6,7] appear to contain a fast and a slowrenaturing sequence, whereas chloroplastic DNA of pea leaves [8], Euglena gracilis [9] and tobacco leaves[lo] renature homogeneously as a single kinetic class.Nevertheless the genetic complexities of the main renaturating class of these organisms are very similar and are close to that of bacteriophage T4.On the other hand, denaturation analysis of chloroplastic DNA has shown considerable intramolecular heterogeneity as manifested by multiphasic melting curves [6,7,11].The question arises as to whether these particular properties of chloroplastic DNA represent a general fact. We have approached this question by investigating here the kinetic complexity of Chlorelb pyrenoidosa chloroplastic DNA, according to the theoretical findings of Wetmur and Davidson [4] and Britten and Kohne [12], and the intramolecular heterogeneity, using the first derivative of the melting profiles and the analytical CsCl equilibri...

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“…These cultures were fed three times a week with log-phase Desmodesmus subspicatus. The algae were harvested from batch cultures grown in the medium as described by Kuhl and Lorenzen (1964), centrifuged and resuspended in 80 mL Elendt M4 medium. Mothers belonged to two different clones (Table 1): clone 5 was reared under laboratory conditions, and clone Tonne originated from the field sampling near Aachen (Coors, 1999).…”

Section: Experimental Datasetmentioning

confidence: 99%

How do interactive maternal traits and environmental factors determine offspring size inDaphnia magna?

Gabsi

Glazier

Hammers‐Wirtz³

et al. 2014

Ann. Limnol. - Int. J. Lim.

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-In this study, we investigated variation in offspring size (OS) of Daphnia magna in relation to multiple maternal traits and environmental variables. Data originated from laboratory experiments conducted at different feeding scenarios. The mother daphnids had different life-history traits and were reared under various feeding and density conditions. OS showed linear relationships with maternal traits, varying positively with maternal body size, age and brood number, and negatively with brood size and with the amount of ingested carbon. OS increased exponentially with crowding. Using stepwise multiple regression analysis, we developed an empirical model for the OS variation with the relevant maternal and environmental variables. Density dependence was considered by multiplying the resulting model by a density-effect function. We found that the ingested carbon and the maternal body size were the strongest determinants of the observed variation in the OS, whereas the brood size had the least impact on OS. Additionally, the brood number had no significant effect in determining the variability in the OS. The validity of the multivariate model was tested against an independent dataset. The model accurately predicted the OS despite several genetic and environmental differences compared with the data used for parameterization.

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Chapter 10 Hmdling and Culturing of Chlorella

Cited by 114 publications

References 47 publications

Chronic Responses ofDaphnia magnaUnder Dietary Exposure to Leaves of a Transgenic (Event MON810) Bt–Maize Hybrid and its Conventional Near-Isoline

Chronic Responses ofDaphnia magnaUnder Dietary Exposure to Leaves of a Transgenic (Event MON810) Bt–Maize Hybrid and its Conventional Near-Isoline

Heterogeneity and Complexity of Chlorella Chloroplastic DNA

How do interactive maternal traits and environmental factors determine offspring size inDaphnia magna?

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