Characterization of Bacillus thuringiensis parasporal crystals using laser speckle technique: effect of crystal concentration and dimension

Nassif, Rana; Nader, Christelle Abou; Rahbany, Jihane; Pellen, Fabrice; Salameh, Dominique; Lteif, Roger; Brun, Guy Le; Jeune, Bernard; Awad, Mireille Kallassy; Abboud, Maher

doi:10.1364/ao.54.003725

Cited by 13 publications

(7 citation statements)

References 21 publications

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“…These three strains carry Cry protein coding genes from the same families, with small variations in the amino acid compositions of the proteins. This includes four Cry1 coding genes, whose produced proteins are responsible for the bipyramid-shaped crystals, and two Cry2 coding genes, producing a cubic crystal [9,20].…”

Section: Anti-lepidopteran Strains: Collection Of Bipyramidal and Cubic Crystalsmentioning

confidence: 99%

“…One of the most recent techniques used to monitor the growth kinetics and production of B. thuringiensis spores and crystals is laser speckle imaging, a reliable and non-invasive technique based on light scattered by an illuminated medium [18]. In order to have accurate results and to understand the interaction between the light and the bacterial density, the size and shape of the scatterers in question should be known, along with whether these scatterers are in suspensions [19] or embedded in agar plates [20]. In the case of B. thuringiensis spores and crystals, their size and morphology vary according to the culture conditions and the presence of additional chaperone proteins.…”

Section: Introductionmentioning

confidence: 99%

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Morphological Study of Bacillus thuringiensis Crystals and Spores

et al. 2020

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In this paper, we report a morphological study of the crystals and spores of different shapes synthesized by seven different strains of Bacillus thuringiensis. Crystals and spores were separated after 48 h of culture on T3 agar medium and imaged under a scanning electron microscope (SEM). Sizes of the crystals and spores were determined using Image J software. The results showed that crystal and spore sizes were normally distributed. In addition, the volumes and aspect ratios of the crystals and spores were calculated. The statistical analysis of the data showed the variability of the size distribution and morphological data of the crystals produced by the analyzed strains. Furthermore, variations in spore size and shape within the same serovar were observed, indicating that, perhaps, there are still some unexplored differences between strains of this serovar, making them less identical than what was believed so far.

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Section: Anti-lepidopteran Strains: Collection Of Bipyramidal and Cubic Crystalsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Morphological Study of Bacillus thuringiensis Crystals and Spores

et al. 2020

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“…This is accomplished by using a logistic vector function (f i ), called the softmax function, Eq. (8), which takes a vector h i of real-valued scores for each of the classes i = 1, . .…”

Section: Stacked Sparse Autoencoder For Classification Of Concentrationmentioning

confidence: 99%

“…1. There is a substantial literature linking the statistics of the speckle pattern with the size, refractive index and concentration of the scattering particles, or more generally with the properties of the phase screen generating the speckle; see, e.g., [1][2][3][4][5][6][7][8][9] and the references therein. While there are many alternative optical methods for the estimation of properties of particle ensembles [10,11], in this paper we focus on speckle measurement.…”

Section: Introductionmentioning

confidence: 99%

Autoencoder-aided measurement of concentration from a single line of speckle

Šehić¹,

Dammann²,

Suljagić³

et al. 2019

Opt. Express

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“…Despite the multiple advantages offered by these methods for monitoring bacterial growth kinetics, their disadvantage is that they are relatively expensive or they require lengthy results processing; furthermore, they need highly qualified personnel. To overcome these drawbacks, the biospeckle, an optical method based on the scattered light, has been extensively implemented in different fields [9][10][11] , particularly for characterizing fermentation products 12 or investigating bacterial colony growth [13][14][15][16] . Reported studies were all performed on bacterial colonies growing on solid media (e.g., on an agar plate).…”

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confidence: 99%

Real-time monitoring of bacterial growth kinetics in suspensions using laser speckle imaging

Loutfi

Pellen

Jeune

et al. 2020

Sci Rep

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In microbiology, monitoring the growth of any microorganism in culture is important for studying and optimizing the growth kinetics, the biomass and the metabolite production. In this work, we show that laser speckle imaging is a reliable technique that can be used to perform real-time monitoring of bacteria growth kinetic in liquid culture media. Speckle parameters, specifically speckle grain size and the spatial contrast of the speckle images, and standard analytical parameters (optical density, pH and colony forming units) were measured during the culture of different strains of Bacillus thuringiensis. Our results show that both speckle grain size and spatial contrast decrease with bacterial growth. Furthermore, speckle parameters are sensitive to the fermentation conditions. Statistical analysis revealed a relatively high correlation between speckle and analytical parameters.

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Characterization of Bacillus thuringiensis parasporal crystals using laser speckle technique: effect of crystal concentration and dimension

Cited by 13 publications

References 21 publications

Morphological Study of Bacillus thuringiensis Crystals and Spores

Morphological Study of Bacillus thuringiensis Crystals and Spores

Autoencoder-aided measurement of concentration from a single line of speckle

Real-time monitoring of bacterial growth kinetics in suspensions using laser speckle imaging

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