Seasonal Development of Phytoplankton in Fish Ponds

At the fish ponds under study the authors defined several types of plankton which have been frequently found during the season (April – October). These types are: Early-spring maximum of phytoplankton, Depression of phytoplankton, Bloom of Aphanizomenon, Maximum of Chlorococcales. The periods of “depression” seem to be typical for the managed carp ponds in the spring. They are characterized by the low density of rapidly reproducing algal populations (e. g. Cryptomonas) and by the dense populations of large cladocerans of the genus Daphnia. Chlorophyll in phytoplankton is less than 5μg/l, transparency is higher than 2 meters. Periods of the spring depression may be followed by the maxima of either Aphanizomenon or Chlorococcales, with concentrations of chlorophyll increasing to 100 μg/l and more. The change from the phase of “depression” to the “maximum of Chlorococcales” is accompanied by decrease in numbers of Daphnia and increase in numbers of the small cladoceran species, but all the mechanisms responsible for the transition are not yet fully understood.     

Effect of sodium humate on swelling and Germination of winter wheat

V práci byl studován vliv humátu sodného na bub?ení a klí?ení ozimé p? enice Py?elka (Triticum vulgare Vill.) a sledována změna intensity dýchání bub?ících obilek v prvých 24 hodinách bub?ení. Bylo zji?těno, ?e Na-humát v koncentraci 100 mg/ml urychluje v prvé fázi bub?oní p?íjem vody bub?ícími obilkami. Tím, ?e obilky p?ijmou d?ive dostate?né mno?ství vody, dochází u nich d?íve k aktivaci enzymatických systém?, zabezpe? ujících zdárný pr?běh klí?ení, co? se projeví zvý?ením intensity dý chání. Energie uvolněná dýcháním m??e být vyu?ita k rychlej?ímu r?stu embrya, co? se projeví morfologicky v rychlosti klí?ení.     

Cyclodextrin glucanotransferase production by cell biocatalysts of alkaliphilic bacilli

Cells of obligated alkaliphiles Bacillus pseudalcaliphilus 20RF and Bacillus pseudalcaliphilus 8SB isolated from Bulgarian habitats, producers of cyclodextrin glucanotransferase (CGTase, EC 2.4.1.19), were immobilized by three different techniques: on two types of polysulphone membranes; entrapped in agar-gel beads containing magnetite and by nano-particles of silanized magnetite covalently bound on the cell surface. The biocatalysts obtained demonstrated the opportunity for a significantly enhanced CGTase production compared to free cells for a long period of time (10 days semicontinuous cultivation) without impact on their mechanical stability. The cell membrane-biocatalysts exhibited the highest enzyme activity after 240 h repeated batch cultivation and retained 1.3–2.3-fold increase of the CGTase yield compared to free cells at the end of the process. Membrane biocatalysts were applied for a direct cyclodextrin (CD) production. The results obtained demonstrated the possibility of starch conversion into cyclodextrins by immobilized cells without using of crude or purified enzyme. The membrane biocatalysts of both obligated alkaliphiles formed mainly β- and γ-CDs after 6 h enzyme reaction at pH 9.0 of the reaction mixture. Under these conditions, the quantity of γ-CDs was a relative high, to 35–37% of the total CD amount.     

Failure to form antibodies following transfer of nucleoprotein fractions to chick embryos

В серии опытов, посвященных исследованиям роли нуклеопротеидов в процессе образования антител (Šterzl, Hrubešová 1955; Hrubešová, Askonas, Humphrey 1959; Šterzl, Hrubešová 1959; Hrubešová 1961) мы пользовались методом переноса фракций 3–5-дневным крольчатам. Для проверки результатов, полученных после переноса нуклеопротеидов, выделенных из селезенки взрослого кролика после его иммунизации одной дозой антигена Brucella suis (Hrubešová 1961), мы в настоящей работе в качестве реципиента применяли 18-дневные куриные эмбрионы, новорожденных цыплят и цыплят в возрасте 48 часов. Донорами клеток селезенки были взрослые куры, которых мы иммунизировали 1 мл антигена Brucella suis (7,5×10⁹ микробов), инактивированной протреванием за 24 или 48 час. до обескровливания. Приготовление и анализы нуклеопротеидов (РНП, ДНП) производились теми же методами, как и в предшествовавших работах. ДНК мы приготовляли по Schwander и Signer (1950), РНК—по Kirby (1956). После переноса ДНП, РНП, РНК и ДНК, выделенных через 24 и 48 час. после иммунизации взрослой курицы, нам не удавалось определить противобруцеллезные антитела в сыворотках реципиентов. Только в контрольном опыте переноса целых клеток селезенки, выделенных через 48 час. после иммунизации, мы находили антитела к Brucella suis с максимальным титром 1∶64. Обсуждается расхождение результатов при применении различных антигенов.      

Functional reconstitution of the solubilized Arabidopsis thaliana STP1 monosaccharide-H+ symporter in lipid vesicles and purification of the histidine tagged protein from transgenic Saccharomyces cerevisiae

Complete DNA sequences encoding the Arabidopsis thaliana STP1 monosaccharide/H⁺ symporter or a histidine-tagged STP1-His6 protein were expressed in baker's yeast Saccharomyces cerevisiae. Both wild-type STP1 and the recombinant his-tagged protein were located in the plasma membranes of transformed yeast cells. The C-terminal modification caused no loss of transport activity compared with the wild-type protein. Anti-STP1-antibodies were used to confirm the identity of the protein in yeast and to compare the apparent molecular weights of STP1 proteins in membrane extracts from yeast or Arabidopsis thaliana. Purified yeast plasma membranes were fused with proteoliposomes consisting of Escherichia coli lipids and beef heart cytochrome-c oxidase. Addition of ascorbate/TMPD/cytochrome-c to these fused vesicles caused an immediate formation of membrane potential (inside negative; monitored with [³H]tetraphenylphosphonium cations) and a simultaneous, uncoupler-sensitive influx of d -glucose into the energized vesicles. STP1-His6 protein is functionally active after solubilization with octyl-β-d -glucoside, which was shown by insertion of the protein into proteoliposomes by detergent dilution and determination of the resulting transport capacity. Detergent extracts from either total membranes or plasma membranes of transgenic yeast cells were used for one-step purification of the STP1-His6 protein on Ni²⁺-NTA columns. The identity of the purified protein was checked by immunoblotting and N-terminal sequencing.     

Die Schluchtwälder des Gebirges Hrubý Jeseník (Hohes Gesenke)

Im Rahmen der systematischen Erforschung derFagetalia-Gesellschaften der Tschechoslowakei bearbeitete die Verfasserin die Schlucht- und Hangwälder in den Durchbruchstälern und Querschluchten im mittleren und westlichen Teil des Gebirges Hrubý Jeseník (Hohes Gesenke) und im anliegenden Teil des Gebirges Rychlebské hory (Reichensteiner Gebirge). Es wurden hier folgende Syntaxa beschrieben:Arunco-Aceretum crepidetosum paludosae, A.-A. abietetosum undAceri-Fagetum, Polystichum lobatum Ausbildung. Diese Waldgesellschaften wurden von phytozönologischen und ökologischen Gesichtspunkt aus analysiert.     

Role of cell surface hydrophobicity in Candida albicans biofilm

Overall cell surface hydrophobicity (CSH) is predicted to play an important role during biofilm formation in Candida albicans but is the result of many expressed proteins. This study compares the CSH status and CSH1 gene expression in C. albicans planktonic cells, sessile biofilm, and dispersal cells. Greater percentages of hydrophobic cells were found in non-adhered (1.5 h) and dispersal forms (24 or 48 h) (41.34±4.17% and 39.52±7.45%, respectively), compared with overnight planktonic cultures (21.69±3.60%). Results from quantitative real-time PCR confirmed greater up-regulation of the CSH1 gene in sessile biofilm compared with both planktonic culture and dispersal cells. Up-regulation was also greater in dispersal cells compared with planktonic culture. The markedly increased CSH found both in C. albicans biofilm, and in cells released during biofilm formation could provide an advantage to dispersing cells building new biofilm.     

In vitro induction of polyploidy in yacon (<Emphasis Type="Italic">Smallanthus sonchifolius</Emphasis>)

In vitro chromosome doubling was induced in octoploid (2n = 58) yacon using oryzalin and colchicine as mitotic spindle inhibitors. Nodal segments of in vitro cultured plants, 5–15 mm long, were exposed to 20, 25, or 30 μM oryzalin and 1, 3, or 5 mM colchicine for 24 or 48 h. The resulting ploidy level was determined by chromosome counting and flow cytometry. Out of 240 nodal segments, 3.33% hexadecaploid (2n = 116) plants were regenerated after the application of oryzalin. The greatest proportions of hexadecaploid plants (1.6%) were obtained after 48 h of 25 μM oryzalin treatment. With the colchicine treatment, only 0.42% hexadecaploid plants were detected and their survival rate was significantly lower in comparison with the oryzalin treatment. In hexadecaploid yacon, significantly higher levels of saccharides were detected (FOS 13.9 g/100 g FM, fructose 4.6 g/100 g FM and glucose 2.1 g/100 g FM) compared to the octoploid control (FOS 5.3 g/100 g FM, fructose 2.9 g/100 g FM and glucose 1.0 g/100 g FM). These results indicate that in vitro treatment of nodal segments with oryzalin solution could be an effective procedure for chromosome doubling and the polyploidy breeding can help to increase the FOS content in the tuberous roots.     

Determination of alpha-amylase activity in dextran,ficoll and polyethylene glycol solutions

Summary A new insoluble chromolytic substrate for the spectrophotometric determination of alpha-amylase activity (starch cross-linked with 1,4-butanediol diglycidyl ether in the presence of black drawing ink; “black starch”) has been shown to work well also in the presence of dextran, Ficoll and polyethylene glycol; on the other hand these phase-forming polymers interfere with some commonly used alpha-amylase assays.     

Beitrag zur Samenmorphologie der FamilieFabaceae

Die Autorinnen legen drei neuen Fachausdrücke für die an Samen der FamilieFabaceae festgestellten Gebilde for. Macula cicatricularis—ein Makel um die Narbe (cicatricula), macula raphalis—ein Makel um die Sammennaht (raphe), und fissum hilare—eine linienförmige Vertiefung inmitten des Nabels (hilum).