Growth, Sporulation, δ-Endotoxins Synthesis, and Toxicity During Culture of Bacillus thuringiensis H14

Sarrafzadeh, Mohammad‐Hossein; Guiraud, Joseph-Pierre; Lagneau, Christophe; Gaven, B.; Carron, Alexandre; Navarro, Jean-Marie

doi:10.1007/s00284-005-4463-3

Cited by 31 publications

(27 citation statements)

References 20 publications

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“…For the first protocol, the optical density at 600 nm (OD 600 ) of the culture was monitored at 24, 48, 72, and 96 h, a measurement that reflects the density of the particles in suspension. Since spores are less dense than vegetative cells, the OD 600 should decrease as the bacilli in the culture become spores (20,21). For the second technique, samples were obtained at the time points listed above and assessed by phase microscopy for sporulation.…”

Section: Methodsmentioning

confidence: 99%

Bacillus anthracis Exosporium Protein BclA Affects Spore Germination, Interaction with Extracellular Matrix Proteins, and Hydrophobicity

et al. 2007

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Bacillus collagen-like protein of anthracis (BclA) is the immunodominant glycoprotein on the exosporium of Bacillus anthracis spores. Here, we sought to assess the impact of BclA on spore germination in vitro and in vivo, surface charge, and interaction with host matrix proteins. For that purpose, we constructed a markerless bclA null mutant in B. anthracis Sterne strain 34F2. The growth and sporulation rates of the ⌬bclA and parent strains were nearly indistinguishable, but germination of mutant spores occurred more rapidly than that of wild-type spores in vitro and was more complete by 60 min. Additionally, the mean time to death of A/J mice inoculated subcutaneously or intranasally with mutant spores was lower than that for the wild-type spores even though the 50% lethal doses of the two strains were similar. We speculated that these in vitro and in vivo differences between mutant and wild-type spores might reflect the ease of access of germinants to their receptors in the absence of BclA. We also compared the hydrophobic and adhesive properties of ⌬bclA and wild-type spores. The ⌬bclA spores were markedly less water repellent than wild-type spores, and, probably as a consequence, the extracellular matrix proteins laminin and fibronectin bound significantly better to mutant than to wild-type spores. These studies suggest that BclA acts as a shield to not only reduce the ease with which spores germinate but also change the surface properties of the spore, which, in turn, may impede the interaction of the spore with host matrix substances.Bacillus anthracis is a gram-positive, spore-forming bacillus that can cause anthrax (15). The spore is the form of the organism found in its natural habitat, the soil, and is also the infectious form for herbivores, the typical vertebrate host for the bacterium, and humans (15). The B. anthracis spore is covered by a loose balloon-like membranous structure called the exosporium (8). BclA (for bacillus collagen-like protein of anthracis) was first described by Sylvestre et al. (23), who constructed an insertional bclA mutant and compared it to its wild-type parent. These investigators and, subsequently, others found that BclA is a glycoprotein and a major component of the hair-like projections that cover the exosporium (16,22,23,25). BclA is also an immunodominant marker on the outside of the spore (22). The finding that BclA does not play a significant role in the virulence of a Sterne-like strain for mice was first reported by Sylvestre et al. (23). Sterne strains contain pXO1 but not pX02 and are attenuated in humans and many other animals except certain mouse strains (26). In support of the findings of Sylvestre and colleagues, Bozue and coworkers recently constructed a bclA mutant of the fully virulent B. anthracis Ames strain and showed that the absence of BclA had no impact on the lethality of that strain for guinea pigs or mice (5). Whether BclA, the substance on the spore with which the host cells probably first interact, plays a more subtle role in B. anthracis patho...

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Section: Methodsmentioning

confidence: 99%

Bacillus anthracis Exosporium Protein BclA Affects Spore Germination, Interaction with Extracellular Matrix Proteins, and Hydrophobicity

et al. 2007

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“…The molecular mass of proteins was estimated by comparison with the Wide Molecular Weight Range Sigmamarker TM (from 6.5 to 205 kDa, Sigma). It was ensured that the observed proteins were not proteins from vegetative cells or spores, as described previously (Sarrafzadeh et al 2005b).…”

Section: Sds-page Analysismentioning

confidence: 99%

The effect of oxygen on the sporulation, δ-endotoxin synthesis and toxicity of Bacillus thuringiensis H14

Sarrafzadeh

Navarro

2005

World J Microbiol Biotechnol

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The sporulation and toxicity of Bacillus thuringiensis H14 were studied as a function of aeration. The fed-batch cultures carried out in the similar aeration conditions were followed in four different oxygen transfer rates containing 0, 20, 100 and 250 mmol/l/h. The percentage of total cells which had formed refractile spores in these four oxygen transfer rates were 100, 93, 84 and 48%, respectively. The highest rate of sporulation was observed in the absence of oxygen and the mature spores were the only population present under this condition at the end of culture. Sporulation in a large portion of cells failed under saturated oxygenation and either mature spores or vegetative cells were present at the end of culture. In the intermediate conditions, cells in different physiological states could be observed at the end of culture. It was found that the optimal conditions for spore yield and for d-endotoxin yield were not the same, even though sporulation and d-endotoxin formation proceed simultaneously during the fermentation process. The 130-kDa d-endotoxin seemed to be more sensitive to aeration conditions. The higher toxicity against Culex pipiens was obtained under the saturated condition.

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“…However, little information is available about some physiological and kinetic growth aspects of the fermentation process involving this microorganism. Moreover, the literature data suggested that the effect of operational conditions and media composition on fermentation results depends on the B. thuringiensis (Bt) variety or on the strain used [5,7,19,22]. There are, for example, contradictions concerning the type and the substrate concentration for the process, variables that affect the cell, spores and toxin production by Bt.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of Bacillus thuringiensis var. israelensis growth on high glucose concentrations

Berbert-Molina

Prata

Pessanha

et al. 2008

J Ind Microbiol Biotechnol

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The kinetic and general growth features of Bacillus thuringiensis var. israelensis were evaluated. Initial glucose concentration (S0) in fermentation media varied from 10 to 152 g/l. The results afforded to characterize four morphologically and physiologically well-defined culture phases, independent of S0 values: Phase I, vegetative growth; Phase II, transition to sporulation; Phase III, sporulation; and Phase IV, spores maturation and cell lysis. Important process parameters were also determined. The maximum specific growth rates (microX,m) were not affected with S0 up to 75 g/l (1.0-1.1 per hour), but higher glucose concentrations resulted in growth inhibition by substrate, revealed by a reduction in microX,m values. These higher S0 values led to longer Phases III and IV and delayed sporulation. Similar biomass concentrations (Xm=15.2-15.9 g/l) were achieved with S0 over 30.8 g/l, with increasing residual substrate, suggesting a limitation in some other nutrients and the use of glucose to form other metabolites. In this case, with S0 from 30.8 to 152 g/l, cell yield (YX/S) decreased from 0.58 to 0.41 g/g. On the other hand, with S0=10 g/l growth was limited by substrate, and YX/S has shown its maximum value (0.83 g/g).

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Growth, Sporulation, δ-Endotoxins Synthesis, and Toxicity During Culture of Bacillus thuringiensis H14

Cited by 31 publications

References 20 publications

Bacillus anthracis Exosporium Protein BclA Affects Spore Germination, Interaction with Extracellular Matrix Proteins, and Hydrophobicity

Bacillus anthracis Exosporium Protein BclA Affects Spore Germination, Interaction with Extracellular Matrix Proteins, and Hydrophobicity

The effect of oxygen on the sporulation, δ-endotoxin synthesis and toxicity of Bacillus thuringiensis H14

Kinetics of Bacillus thuringiensis var. israelensis growth on high glucose concentrations

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