Presence of endotoxin in vegetative cells of Bacillus thuringiensis var. sotto

1970 ◽  
Vol 16 (9) ◽  
pp. 905-906 ◽  
Author(s):  
P. Luthy ◽  
Y. Hayashi ◽  
T. A. Angus
Keyword(s):  
Bacillus Thuringiensis ◽  
Vegetative Cell ◽  
Vegetative Cells ◽  
Cell Extracts

Endotoxin was found in vegetative cell extracts of Bacillus thuringiensis var. sotto. The distribution of the toxin in fractions obtained by centrifugation at different speeds indicates an association with cell particles, most likely membranes.

Soluble reduced nicotinamide adenine dinucleotide oxidase from Bacillus cereus T spores and vegetative cells. I. Purification

1969 ◽  
Vol 15 (11) ◽  
pp. 1309-1312 ◽  
Author(s):  
D. H. Ashton ◽  
L. C. Blankenship
Keyword(s):  
Bacillus Cereus ◽  
Nicotinamide Adenine Dinucleotide ◽  
Gel Electrophoresis ◽  
Oxidase Activity ◽  
Vegetative Cell ◽  
Nicotinamide Adenine ◽  
Vegetative Cells ◽  
Cell Extracts ◽  
Cell Enzyme ◽  
Reduced Nicotinamide Adenine Dinucleotide

Spores and vegetative cells of Bacillus cereus T were disrupted by two procedures and soluble extracts prepared from the ruptured cells. Reduced nicotinamide adenine dinucleotide (NADH2) oxidases were purified from the extracts by ammonium sulfate fractionation, ion exchange on hydroxylapatite, and preparative acrylamide gel electrophoresis. The electrophoresis step revealed the presence of two distinct components with NADH2 oxidase activity in soluble extracts of spores while vegetative cell extracts contained only one. The faster moving component in spore extracts constituted about 30% of the NADH2 oxidase activity recovered and was identical with the vegetative cell enzyme in electrophoretic mobility on acrylamide gel. The slower moving spore component accounted for 70% of recovered activity and was found in soluble extracts regardless of the procedure used to rupture spores.

scholarly journals Behavior of the Biological Control Agent Bacillus thuringiensis subsp. aizawai ABTS-1857 and Salmonella enterica on Spinach Plants and Cut Leaves

2021 ◽  
Vol 12 ◽  
Author(s):  
Xingchen Zhao ◽  
Marcelo Belchior Rosendo da Silva ◽  
Inge Van der Linden ◽  
Bernadette D. G. M. Franco ◽  
Mieke Uyttendaele
Keyword(s):  
Biological Control ◽  
Bacillus Thuringiensis ◽  
Salmonella Enterica ◽  
Biological Control Agent ◽  
Fresh Produce ◽  
Agricultural Field ◽  
Vegetative Cells ◽  
Post Harvest ◽  
Cut Leaves ◽  
Spinach Leaves

Fresh produce has been identified as an important vehicle for the transmission of foodborne pathogens. This study evaluated the behavior of vegetative cells and spores of Bacillus thuringiensis, one of the main biological control agents (BCAs) used in the world, and Salmonella enterica on spinach plants (pre-harvest) and spinach cut leaves (post-harvest) at 12°C, experimentally inoculated as single or co-cultures. The results evidenced that spray-inoculated commercial BCA containing Bacillus thuringiensis subsp. aizawai ABTS-1857 (BTa ABTS-1857) spores persisted well on spinach leaves in both pre- and post-harvest simulations. However, when BTa ABTS-1857 vegetative cells were spray-inoculated, more than 2 log reductions in the counts of B. thuringiensis were observed during 20 days pre- and 5 days post-harvest simulations, respectively. The counts of S. Montevideo on the spinach cut leaves during post-harvest storage at 12°C for 5 days remained unchanged, whereas 1 log reduction was noted during pre-harvest. Moreover, during pre-harvest simulation, when co-inoculated with BTa ABTS-1857 vegetative cells or spores, additional 0.5 or 1.0 log reductions were detected on the counts of S. Montevideo in the spinach leaves on the 10th day. These results were obtained under laboratory conditions, and further findings in longitudinal studies from farm (in the agricultural field) to retail (end of shelf life) will contribute to understanding of the role of B. thuringiensis as a BCA on growth/survival of Salmonella spp. in fresh produce.

EFFECT OF TEMPERATURE ON THE PATHOGENESIS OF BACILLUS THURINGIENSIS BERLINER IN LARVAE OF THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA CLEM. (LEPIDOPTERA: TORTRICIDAE)

1994 ◽  
Vol 126 (4) ◽  
pp. 1061-1065 ◽  
Author(s):  
Kees van Frankenhuyzen
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacterial Growth ◽  
Choristoneura Fumiferana ◽  
Larval Mortality ◽  
Lethal Dose ◽  
Spruce Budworm ◽  
Effect Of Temperature ◽  
Vegetative Cells ◽  
Time Required ◽  
Peak Abundance

AbstractThe relationship between temperature and pathogenesis of Bacillus thuringiensis Berliner var. kurstaki in infected larvae of the eastern spruce budworm, Choristoneura fumiferana Clem., was investigated to determine if more rapid death of larvae with an increase in temperature could be accounted for by enhanced bacterial growth. Cumulative mortality of larvae force-fed with a lethal dose of HD-1-S-1980 peaked within 2 days at 25 °C, 3 days at 19 °C, 7 days at 16 °C, and 21 days at 13 °C. The progress of bacterial growth in the larvae was followed from spore germination to cell lysis, and was completed within 4 days at 25 °C, 6 days at 22 °C, 12 days at 19 °C, 14 days at 16 °C, and > 28 days at 13 °C. Peak abundance of vegetative cells in the larvae was observed after 1 day at 25 °C, 2 days at 22 °C, 3 days at 19 °C, 7 days at 16 °C, and 21 days at 13 °C, and thus coincided almost exactly with the time required for maximum larval mortality. This correlation suggests that the observed effect of temperature on progression of larval mortality was due to its effect on the proliferation of vegetative cells in the infected larvae, and that bacterial septicemia makes an important contribution to death.

Basal Body and Flagellar Development During the Vegetative Cell Cycle and the Sexual Cycle of Chlamydomonas Reinhardii

1974 ◽  
Vol 16 (3) ◽  
pp. 529-556 ◽  
Author(s):  
T. CAVALIER-SMITH
Keyword(s):  
Basal Body ◽  
Vegetative Cell ◽  
Amorphous Material ◽  
Sexual Cycle ◽  
Transitional Region ◽  
Basal Bodies ◽  
Vegetative Cells ◽  
Chlamydomonas Reinhardii ◽  
Body Development ◽  
Microtubular Roots

Basal body development and flagellar regression and growth in the unicellular green alga Chlamydomonas reinhardii were studied by light and electron microscopy during the vegetative cell cycle in synchronous cultures and during the sexual life cycle. Flagella regress by gradual shortening prior to vegetative cell division and also a few hours after cell fusion in the sexual cycle. In vegetative cells basal bodies remain attached to the plasma membrane by their transitional fibres and do not act as centrioles at the spindle poles during division. In zygotes the basal bodies and associated microtubular roots and cross-striated connexions all dissolve, and by 6.5 h after mating all traces of flagellar apparatus and associated structures have disappeared. They remain absent for 6 days throughout zygospore maturation and then are reassembled during zygospore germination, after meiosis has begun. Basal body assembly in developing zygospores occurs close to the plasma membrane (in the absence of pre-existing basal bodies) via an intermediate stage consisting of nine single A-tubules surrounding a central ‘cartwheel’. Assembly is similar in vegetative cells (and occurs prior to cell division), except that new basal bodies are physically attached to old ones by amorphous material. In vegetative cells, amorphous disks, which may possibly be still earlier stages in basal-body development occur in the same location as 9-singlet developing basal bodies. After the 9-singlet structure is formed, B and C fibres are added and the basal body elongates to its mature length. Microtubular roots, striated connexions and flagella are then assembled. Both flagellar regression and growth are gradual and sequential, the transitional region at the base of the flagellum being formed first and broken down last. The presence of amorphous material at the tip of the axoneme of growing and regressing flagella suggests that the axoneme grows or shortens by the sequential assembly or disassembly at its tip. In homogenized cells basal bodies remain firmly attached to each other by their striated connexions. The flagellar transitional region, and parts of the membrane and of the 4 microtubular roots, also remain attached; so also do new developing basal bodies, if present. These structures are well preserved in homogenates and new fine-structural details can be seen. These results are discussed, and lend no support to the idea that basal bodies have genetic continuity. It is suggested that basal body development can be best understood if a distinction is made between the information needed to specify the structure of a basal body and that needed to specify its location and orientation.

Actin During Pollen Germination

1986 ◽  
Vol 86 (1) ◽  
pp. 1-8
Author(s):  
J. HESLOP-HARRISON ◽  
Y. HESLOP-HARRISON ◽  
M. CRESTI ◽  
A. TIEZZI ◽  
F. CIAMPOLINI
Keyword(s):  
Medium Release ◽  
Pollen Tube ◽  
Vegetative Cell ◽  
Pollen Germination ◽  
Pollen Grain ◽  
Actin Microfilaments ◽  
Vegetative Cells ◽  
Stage Of Development ◽  
Angiosperm Species

The cytoplasm of the vegetative cell of the ungerminated pollen grain of Endymton non-scriplus and other angiosperm species contains numerous fusiform bodies sometimes exceeding 15μm in length and 2.5 μm in width, which bind fluorescent-labelled phalloidin and are likely therefore to constitute a storage form of actin. The bodies are dispersed during the activation of the pollen, being replaced by aggregates of slender phalloidin-binding fibrils, which converge towards the germination apertures and are present in the emerging pollen tube. The storage bodies appear to be homologous with crystalline-fibrillar structures, shown in an earlier paper to be abundantly present in the vegetative cells of Nicotiana pollen. These are composed of massive aggregates of linearly disposed units with individual widths of 4–7 nm, probably to be interpreted as actin microfilaments. Vegetative-cell protoplasts from mature but ungerminated pollen disrupted in osmotically balancing medium release extended phalloidin-binding fibrils of a kind not observed in the intact grain. It is suggested that these are derived by the rapid dissociation of the compact actin storage bodies present in the vegetative cell at this stage of development.

scholarly journals DNA demethylation by ROS1a in rice vegetative cells promotes methylation in sperm

2019 ◽  
Vol 116 (19) ◽  
pp. 9652-9657 ◽  
Author(s):  
M. Yvonne Kim ◽  
Akemi Ono ◽  
Stefan Scholten ◽  
Tetsu Kinoshita ◽  
Daniel Zilberman ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Vegetative Cell ◽  
Seed Viability ◽  
Dna Demethylation ◽  
Central Cell ◽  
Dna Glycosylase ◽  
Rice Seed ◽  
Vegetative Cells ◽  
Active Dna Demethylation ◽  
Cell Genome

Epigenetic reprogramming is required for proper regulation of gene expression in eukaryotic organisms. In Arabidopsis, active DNA demethylation is crucial for seed viability, pollen function, and successful reproduction. The DEMETER (DME) DNA glycosylase initiates localized DNA demethylation in vegetative and central cells, so-called companion cells that are adjacent to sperm and egg gametes, respectively. In rice, the central cell genome displays local DNA hypomethylation, suggesting that active DNA demethylation also occurs in rice; however, the enzyme responsible for this process is unknown. One candidate is the rice REPRESSOR OF SILENCING1a (ROS1a) gene, which is related to DME and is essential for rice seed viability and pollen function. Here, we report genome-wide analyses of DNA methylation in wild-type and ros1a mutant sperm and vegetative cells. We find that the rice vegetative cell genome is locally hypomethylated compared with sperm by a process that requires ROS1a activity. We show that many ROS1a target sequences in the vegetative cell are hypomethylated in the rice central cell, suggesting that ROS1a also demethylates the central cell genome. Similar to Arabidopsis, we show that sperm non-CG methylation is indirectly promoted by DNA demethylation in the vegetative cell. These results reveal that DNA glycosylase-mediated DNA demethylation processes are conserved in Arabidopsis and rice, plant species that diverged 150 million years ago. Finally, although global non-CG methylation levels of sperm and egg differ, the maternal and paternal embryo genomes show similar non-CG methylation levels, suggesting that rice gamete genomes undergo dynamic DNA methylation reprogramming after cell fusion.

scholarly journals Bacillus thuringiensis Spores and Vegetative Bacteria: Infection Capacity and Role of the Virulence Regulon PlcR Following Intrahaemocoel Injection of Galleria mellonella

Insects ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 129 ◽  
Author(s):  
Christophe Buisson ◽  
Michel Gohar ◽  
Eugénie Huillet ◽  
Christina Nielsen-LeRoux
Keyword(s):  
Bacillus Thuringiensis ◽  
Galleria Mellonella ◽  
Lethal Dose ◽  
Intestinal Barrier ◽  
Oral Route ◽  
Infection Model ◽  
Wild Type ◽  
Response Curves ◽  
Vegetative Cells ◽  
Crystal Toxins

Bacillus thuringiensis is an invertebrate pathogen that produces insecticidal crystal toxins acting on the intestinal barrier. In the Galleria mellonella larvae infection model, toxins from the PlcR virulence regulon contribute to pathogenicity by the oral route. While B. thuringiensis is principally an oral pathogen, bacteria may also reach the insect haemocoel following injury of the cuticle. Here, we address the question of spore virulence as compared to vegetative cells when the wild-type Bt407cry- strain and its isogenic ∆plcR mutant are inoculated directly into G. mellonella haemocoel. Mortality dose-response curves were constructed at 25 and 37 °C using spores or vegetative cell inocula, and the 50% lethal dose (LD50) in all infection conditions was determined after 48 h of infection. Our findings show that (i) the LD50 is lower for spores than for vegetative cells for both strains, while the temperature has no significant influence, and (ii) the ∆plcR mutant is four to six times less virulent than the wild-type strain in all infection conditions. Our results suggest that the environmental resistant spores are the most infecting form in haemocoel and that the PlcR virulence regulon plays an important role in toxicity when reaching the haemocoel from the cuticle and not only following ingestion.

Differences in formation of vegetative cells and their walls in Trebouxia and Pseudotrebouxia as further evidence for the classification of these genera

1985 ◽  
Vol 17 (3) ◽  
pp. 281-287 ◽  
Author(s):  
E. Peveling ◽  
J. König
Keyword(s):  
Vegetative Cell ◽  
Cell Walls ◽  
Vegetative Cells

AbstractThe formation of vegetative cells from zoospores and the morphogenesis of the multilayered cell walls during this process was observed in some Trebouxia and Pseudotrebouxia species. In Trebouxia species, e.g. Trebouxia erici, the wall of the vegetative cell is formed around the zoospore while in Pseudotrebouxia species, e.g. Pseudotrebouxia corticola, firstly an autosporangium with its wall is formed then the autosporangium further divides.

A SEROLOGICAL COMPARISON OF VEGETATIVE CELL AND ASCUS WALLS AND THE SPORE COAT OF SACCHAROMYCES CEREVISIAE

1966 ◽  
Vol 12 (3) ◽  
pp. 485-488 ◽  
Author(s):  
I. J. Snider ◽  
J. J. Miller
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Structure ◽  
Vegetative Cell ◽  
Proteolytic Enzyme ◽  
Spore Coat ◽  
Vegetative Cells

Cross-agglutination tests with sera obtained by injection of vegetative cells, asci, and spores into rabbits revealed no immunological distinction between the walls of vegetative cells and asci, whereas the spore coats were found to be serologically distinct from cell and ascus walls. Treatment of vegetative cells and asci with periodate or a proteolytic enzyme before agglutination tests gave results which suggest that the critical antigen is a protein structure.

Fate of Bacillus thuringiensis in soil: effect of soil pH and organic amendment

1970 ◽  
Vol 16 (8) ◽  
pp. 677-680 ◽  
Author(s):  
S. M. Saleh ◽  
R. F. Harris ◽  
O. N. Allen
Keyword(s):  
Bacillus Thuringiensis ◽  
Incubation Period ◽  
Soil Ph ◽  
Organic Amendment ◽  
Acid Soils ◽  
Microbial Populations ◽  
Vegetative Cells ◽  
Soil Microbial ◽  
Neutral Ph

Bacillus thuringiensis spores germinated, grew, and sporulated in soils of neutral pH amended with alfalfa or casein. Numbers of viable spores of B. thuringiensis increased 100-fold and more than one million spores/g soil were maintained throughout a 3-month incubation period. B. thuringiensis spores apparently germinated but the resulting vegetative cells did not survive in acid soils amended with alfalfa or casein. It appears that B. thuringiensis spores can remain viable for long periods of time in soil and that the organism can compete successfully under conditions favoring the bacillus component of soil microbial populations.

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