摘要:

SUMMARYGrowth rate as well as rate of glucose uptake ofC. crypticadepends on glucose concentration in the medium according to saturation kinetics. TheKgfor growth is 1.9 × 10−5M, and theKt, for glucose transport is 5.8 × 10−5M. The maximum growth rate in the dark on glucose is considerably slower than the light‐saturated growth rate at the same temperature, and does not appear to be determined by the capacity of the cell for glucose uptake.The glucose transport process is highly specific, and depends on energy metabolism. TheQ10for the process is 2.2 (15–2.5 C). Glucose taken up by the cells is almost, quantitatively phosphorylated within 10 min, either through the transport process itself or by a high affinity kinase system in

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1971.tb01469.x

出版商:Blackwell Science Inc    

年代:1971

数据来源: WILEY

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1971.tb02433.x

出版商:Blackwell Science Inc    

年代:1971

数据来源: WILEY

摘要:

SUMMARYThe toxic principle of dermatitis‐producingLyngbya majusculaGomont has been purified by extraction of dried alga with organic solvents followed by column and thin‐layer adsorption chromatography. The toxin is readily soluble in methanol, chloroform, acetone, diethyl ether, and ethanol; it is insoluble in water and slightly soluble in petroleum ether. Qualitative tests have shown no free alpha amino groups, phosphate, sugar, sterol, or quaternary amine. Sulfur and halogen are also absent. The infrared absorption spectrum indicates the presence of hydroxyl groups, CH, CC, and probably CN bonds. Ultraviolet irradiation results in a decrease in toxic activity as well as in bleaching of the pigment. The toxin is also inactivated by heat and by reduction or oxidation. A quantitative test for assay of toxicity has been developed with human amnion cells grown in tissue cult

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1971.tb01470.x

出版商:Blackwell Science Inc    

年代:1971

数据来源: WILEY

摘要:

SUMMARYThe course of the reaction produced by intracutaneous injection of the toxin ofLyngbya majusculaGomont is that of a severe acute inflammatory reaction. No protective or sensitizing effect is induced by a previous exposure. The response from intravenous injection into a rat indicates that the toxin acts as a general cell toxin. The protozoanTetrahymena pyriformisand rabbit erythrocytes are lysed by the toxic principle, which also possesses antibacterial activity. Of the organisms tested,Mycobacteriumspecies are markedly inhibited, whileBacillus cereus, Gaffkya tetragena, andSarcina luteaare slightly to moderately inhibited. Other components of the alga, which are steam distillable, have been found to have antibacterial activity but are not involved in the skin reaction.

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1971.tb01471.x

出版商:Blackwell Science Inc    

年代:1971

数据来源: WILEY

摘要:

SUMMARYA microscope was adapted for immersion in natural aquatic habitats to make direct observations of attaching microorganisms. Using this technique the growth of several types of algae was followed. The algae observed exhibited a diurnal growth pattern. Most of the size increase occurred during the daylight hours, whereas most cellular division occurred during the night. Growth rates determined by size measurements varied from 1.3 to 1.8 doublings per day.

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1971.tb01472.x

出版商:Blackwell Science Inc    

年代:1971

数据来源: WILEY

摘要:

SUMMARYSome metabolic analogs, including azaguanine, azathymine, azauracil, caffeine, 4‐azaleucine,dl‐ethionine, anddl‐p‐fluorophenylanlanine, were examined for their ability to repress the multiplication of algae from natural aquatic sources grown in defined or semidefined media.dl‐ethionine,dl‐p‐fluorophenylalanine, and 4‐azaleucine, in that order, inhibited the multiplication of blue‐green but not other algal groups. The purine and pyrimidine analogs were not inhibitory. In chemically defined axenic media,dl‐ethionine was about 100 times more inhibitory to the blue‐green algaeSynechococcus cedrorumandAnabaena cylindricathan to the eucaryotic algaeOchromonas danicaandEuglena gracilis.The ciliateTetrahymena pyriformis was at least 100‐fold more resistant to ethionine than the algae. The unusual sensitivity of blue‐green algae to ethionine and other amino acid analogs represents an exceptional phylelic character and may be useful in the control of these algae when they become a nuisance. Amino acid analogs such as ethionine may also serve to remove blue‐green algae from cultures one

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1971.tb01473.x

出版商:Blackwell Science Inc    

年代:1971

数据来源: WILEY

摘要:

SUMMARYNonproliferating zooxanthellae fromAnthopleura elegantissimawere incubated with3H‐amino acids for 4–16 hr to uniformly label cell protein. Radioactive proteins from the nuclear membrane were extracted and solubilized for electrophoresis in polyacrylamide gels. Four major electrophoretic species of polypeptides were observed at pH 5.0, 7.0, and 9.0 in an SDS‐urea‐glutathione system. Their molecular weights were estimated to be 32,000, 44,000, 56,000, and 140,000 daltons. All 4 polypeptides are common to the outer as well as inner nuclear en

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1971.tb01474.x

出版商:Blackwell Science Inc    

年代:1971

数据来源: WILEY

摘要:

SUMMARYTrebouxiasp., the phycobiont of the lichenRamalina menziesiiTuck., was examined with the electron microscope. Its pyrenoid is characterized structurally as being permeated by interconnected vesiculate membrane systems associated with osmiophilic globules termed pyrenoglobuli. The variety of membrane structure associated with the pyrenoid has been documented with electron micrographs. A model based on serial sections was constructed to show the extent of vesiculation, to demonstrate that the pyrenoglobuli within the pyrenoid matrix are invariably adjacent to the thylakoid membranes within that, matrix, and to emphasize the recurrent thylakoid membrane to pyrenoglobuli relationship. A comparison of the glutaraldehyde‐osmium fixation image of the pyrenoglobuli and pyrenoid matrix with the permanganate fixation image has been included. The structure of the pyrenoid matrix in thin section was examined and appears essentially granula

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1971.tb01475.x

出版商:Blackwell Science Inc    

年代:1971

数据来源: WILEY

摘要:

SUMMARYConjugation inClosteriumhas been studied using sectioned material prepared for light and electron microscopy. Prior to conjugation, cells become dense and accumulate lipid droplets. Conjugation commences in paired cells with the formation through a point of mutual contact of a circumferential strip of papilla wall material which is not necessarily centrally situated in each cell. Some microtubules are initially present, near this specialized wall which grows all around each cell but asymmetrically so that the area of papillae in contact increases and each papilla balloons out toward the other, kinking the semicells. Vesicles probably contribute material to this wall. Microtubules disappear from near the papilla as it expands; they are then often found around the older semicell wall immediately adjacent to the papilla. An enlarging vacuole is always formed in each papilla. Cytoplasmic shrinkage is first evident from an accumulation of mucilage between the plasmalemma and wall at the tip of each semicell; the terminal vacuoles collapse and disappear. During further shrinkage of the protoplast, alveolate structures are common on the plasmalemma, and the papilla wall material separating the protoplasts thins out and disappears. Meanwhile, a profound general change renders the cytoplasm far less osmiophilic and stainable for both light and electron microscopy, as it becomes relatively homogeneous and granular, revealing a considerable loss in minor cytoplasmic structures; grana in the chloroplasts become bloated. These changes are not considered processing artefacts, but may result from a breakdown of vegetative cell structures no longer needed for zygote formation. After fusion, the zygote protoplast tends to round up. Zygote maturation commences with deposition of a multilayered wall and shrinkage of the protoplast. Then the very thick zygote wall proper is slowly secreted; meanwhile, very considerable cytoplasmic condensation now renders the cell increasingly osmiophilic and dense until ultrastructural detail becomes totally obscured. Fairly consistent changes in the appearance and probably in the function of the golgi bodies were noted. The results are discussed in terms of the possible function of cell organelles and their role in the mechanics of conjugation.

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1971.tb01476.x

出版商:Blackwell Science Inc    

年代:1971

数据来源: WILEY

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1971.tb01477.x

出版商:Blackwell Science Inc    

年代:1971

数据来源: WILEY