National Repository of Grey Literature 6 records found  Search took 0.01 seconds. 
Microalgae Chlorella sp. as an Alternative Source of Fermentable Sugars
Maršálková, B. ; Širmerová, M. ; Kuřec, M. ; Brányik, T. ; Brányiková, Irena ; Melzoch, K. ; Zachleder, Vilém
The aim of this work was to optimize the enzymatic hydrolysis of starch originating from microalgae (34.0 +/- 1.2% wt. starch in the dry algal biomass) grown on flue gas from waste incineration plant and to study the influence cell disintegration method on the yield of hydrolysis. Apart from the starch, the possibility of cellulose usage from microalgae cell wall as a further source of fermentable sugars was studied and preliminary results are presented.
Selekce kmenů zelené řasy Scenedesmus quadricauda rezistentních vůči selenu
Umysová, Dáša ; Hlavová, Monika ; Vítová, Milada ; Doušková, Irena ; Bišová, Kateřina ; Zachleder, Vilém
Three mutant strains of the green alga Scenedesmus quadricauda were selected to be specifically resistant to the presence of high concentration of inofganic Se. The growth curves at the presence of various concentrations of selenite, selenate or misture of both compounds were monitored.
Řasy jako surovina pro výrobu bioetanolu
Doucha, Jiří ; Lívanský, Karel ; Doušková, Irena ; Zachleder, Vilém
Many countries are actively developing biofuels program. Leading in this field is Brazil whose present need of gasoline is supplied with 30 % by ethanol produced relatively cheaply from sugarcane. In developed countries bioethanol (3-5 % of present gasoline need) is produced mostly from corn (USA) or wheat (EU). However, ethanol production from cereals is expensive. Promising feedstock are microalgae. Some of them can surpass yields of classical crop 10-15 times. Technology of growth of unicellular Chlorella in very thin layer on inclined areas is compared with the technology of world-wide mode of cultivation in open ponds. It was found, that due to higher yields and lower energy needs, the cost of biomass production in thin-layer bioractores is only 20 % compared with ponds
Aktivita thioredoxin reduktázy v divokém a selen rezistentích kmenech řasy Scenedesmus quadricauda rostoucích v přítomnosti anorganických sloučenin selenu
Vítová, Milada ; Umysová, Dáša ; Doušková, Irena ; Rucki, M. ; Zachleder, Vilém
We have selected resistant strains of Scenedesmus quadricauda able to tolerate high selenium concentration up to 400 mg/L added either as selenate Na2SeO4 (strain SeVI) or selenite Na2SeO3 (strain SeIV). We have investigated activity of selenoprotein thioredoxin reductase (TR) in both wild type and Se-resistant strains. Concomitantly, a total amount of organically bound selenium was evaluated in biomass dry weight. We have found that activity of TR rapidly increases in the SeVI resistant strain in the presence of selenate, while no effect on TR activity was found in SeIV resistant strain and only slight increase in wild type in the presence of selenite
Odstranění CO2 ze spalin pocházejících ze spalovny komunálního odpadu a produkce biomasy pomocí mikroskopických řas
Doušková, Irena ; Doucha, Jiří ; Novák, P. ; Umysová, Dáša ; Vítová, Milada ; Zachleder, Vilém
A municipal waste incinerator flue gas was used as a source of CO2 for cultivation of the alga Chlorella vulgaris, in order to decrease production costs of the biomass and to bioremediate CO2 simultaneously. The following results were obtained during the experiments: The utilization of the flue gas for a photobioreactor agitation and CO2 supply was proved to be convenient. A growth rate of algal cultures on the flue gas was even higher when comparing with the control (pure CO2 in air). The toxicological analysis of the produced biomass showed only a slight excess of mercury while all the others compounds (other heavy metals, PAHs, PCDD/Fs and PCBs) were below the limits required by foodstuff legislation
Cirkadiální hodiny se neúčastní načasování buněčného dělení v řase Chlamydomonas reinhardtii
Vítová, Milada ; Bišová, Kateřina ; Hendrychová, Jana ; Čížková, Mária ; Zachleder, Vilém
To determine whether the circadian clock functions in control the entry of algal cells into the cell cycle, we have tested the green alga Chlamydomonas reinhardtii in a wide range of growth conditions both light intensity and temperature. We monitored the course of the cell cycles in asynchronous as well as in synchronized cultures. The cultures were grown either at the continuous light or at alternating light/dark periods. The length of the cell cycle was monitored also at different temperatures and in “circadian” mutant. We have evidenced that the length of the cell cycle corresponding to circadian times can be attained only under relatively narrow range of growth conditions and even in this case the “circadian time” is a result of given growth conditions and not of any circadian gating. These results suggest that the intrinsic circadian clock does not play any role in timing of the cell cycle division in the green alga Chlamydomonas

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