Evolution of the Bacillus cereus Group

Økstad, Ole Andreas; Kolstø, Anne‐Brit

doi:10.1007/978-94-007-3021-2_6

Cited by 4 publications

(5 citation statements)

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“…The starting point for selection of Bacillus strains envisaging future biotechnological application to control sugarcane pests is the taxonomical identification of the bacterial species mainly considering the difficulties to separate species within the Bacillus cereus and B. thuringiensis clade even when complete genomic sequences are compared ( Baek et al, 2019 ). Here, we use different molecular identification methods to separate B. thuringiensis species from closely related Bacillus cereus group ( Okstad and Kolsto, 2012 ). For example, we amplified repetitive regions within the genome, a technique that has been used to compare isolates and understand the relationship between strains ( Versalovic et al, 1994 ).…”

Section: Discussionmentioning

confidence: 99%

Endophytic Bacillus Bacteria Living in Sugarcane Plant Tissues and Telchin licus licus Larvae (Drury) (Lepidoptera: Castniidae): The Symbiosis That May Open New Paths in the Biological Control

et al. 2021

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Bacteria of the genus Bacillus can colonize endophytically and benefit several crops including the control of some pest orders. In view of the benefits provided by these microorganisms and in order to find out an efficient biotechnological control for the giant borer, our interest in studying the microorganisms in symbiosis with sugarcane and the giant borer has arisen, since there is no efficient chemical or biological control method for this pest. Therefore, endophytic Bacillus strains were isolated from three sugarcane niches (apoplast fluid, central internode cylinder and roots) and also from the giant borer larvae living inside sugarcane varieties grown in the Northeast region of Brazil. The taxonomical characterization (16S rRNA) of 157 Gram-positive isolates showed that 138 strains belonged to the Bacillus genus. The most representative species were phylogenetically closely related to B. megaterium (11.5%) followed by B. safensis (10.8%), B. cereus (8.9%), B. oleronius (8.9%), B. amyloliquefaciens (7.0%), and B. pacificus (6.4%). BOX-PCR analyses showed very distinct band pattern profiles suggesting a great diversity of Bacillus species within the sugarcane niches and the digestive tract, while the B. cereus group remained very closely clustered in the dendrogram. According to XRE biomarker analysis, eleven strains (FORCN005, 007, 008, 011, 012, 014, 067, 076, 092, 093, and 135) correspond to B. thuringiensis species. Additional studies using conserved genes (glp, gmk, pta, and tpi) indicated that most of these strains were phylogenetically closely related to B. thuringiensis and may be considered different subspecies. In conclusion, this study suggests that the culturable Bacillus species are greatly diversified within the plant niches and showed Bacillus species in the digestive tract of the giant borer for the first time. These results open new perspectives to understand the role and functions played by these microorganisms in symbiosis with this pest and also the possibility of developing an efficient biological control method for the giant borer using strains identified as the B. thuringiensis species.

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Section: Discussionmentioning

confidence: 99%

Endophytic Bacillus Bacteria Living in Sugarcane Plant Tissues and Telchin licus licus Larvae (Drury) (Lepidoptera: Castniidae): The Symbiosis That May Open New Paths in the Biological Control

et al. 2021

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“…It produces a varied array of entomopathogenic compounds effective against a broad range of arthropods. These include crystal proteins (Cry), cytolitic proteins (Cyt), vegetative insecticidal proteins (Vip), secreted insecticidal protein (Sip) and exotoxins -each with different characteristics, specificities and modes of action (de Maagd, Bravo, Berry, Crickmore, & Schnepf, 2003;Økstad & Kolstø, 2012;Schnepf et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Since its discovery over a hundred years ago, research into B. thuringiensis has been motivated primarily by its potential for pest control (Hilbeck & Otto, 2015;Økstad & Kolstø, 2012;Sanchis, 2010). Until the 1950s, B. thuringiensis was considered taxonomically to be a variety of Bacillus cereus, as was Bacillus anthracis (Oh, Ham, & Cox, 2012;Økstad & Kolstø, 2012). Based on their genetic analyses, Helgason et al (2000) still postulated that all three 'should be considered as belonging to one and the same species' since the principal difference between B. cereus, B. anthracis and B. thuringiensis is only that the latter produces plasmids encoding crystalline endotoxins.…”

Section: Introductionmentioning

confidence: 99%

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The distinct properties of natural and GM cry insecticidal proteins

Latham¹,

Love

Hilbeck³

2017

Biotechnology and Genetic Engineering Reviews

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The Cry toxins are a family of crystal-forming proteins produced by the bacterium Bacillus thuringiensis. Their mode of action is thought to be to create pores that disrupt the gut epithelial membranes of juvenile insects. These pores allow pathogen entry into the hemocoel, thereby killing the insect. Genes encoding a spectrum of Cry toxins, including Cry mutants, Cry chimaeras and other Cry derivatives, are used commercially to enhance insect resistance in genetically modified (GM) crops. In most countries of the world, such GM crops are regulated and must be assessed for human and environmental safety. However, such risk assessments often do not test the GM crop or its tissues directly. Instead, assessments rely primarily on historical information from naturally occurring Cry proteins and on data collected on Cry proteins (called 'surrogates') purified from laboratory strains of bacteria engineered to express Cry protein. However, neither surrogates nor naturally occurring Cry proteins are identical to the proteins to which humans or other nontarget organisms are exposed by the production and consumption of GM plants. To-date there has been no systematic survey of these differences. This review fills this knowledge gap with respect to the most commonly grown GM Cry-containing crops approved for international use. Having described the specific differences between natural, surrogate and GM Cry proteins this review assesses these differences for their potential to undermine the reliability of risk assessments. Lastly, we make specific recommendations for improving risk assessments.

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“…Apresenta um amplo complexo enzimático, o que lhe permite utilizar uma variedade de substratos, principalmente no solo (ÂNGELO et al, 2010). propriedades entomopatogênicas e presença do gene da toxina inseticida cristalina (Cry) (OKSTAD; KOLSTO, 2012).…”

Section: Bacillus Thuringiensisunclassified

Micro-organismos, quitina e quitosana no manejo de nematoides das galhas no tomateiro

Mota¹

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Palavras-chaves: indução de resistência, micro-organismos quitinolíticos, nematoide das galhas.xiii CHAPTER III: Chitin and chitosan in the management of Meloidogyne incognita and Meloidogyne javanica and activation of pathogenesis-related proteins in tomato ABSTRACTThe addition of chitin to soil and spraying abiotic elicitors, such as chitosan, have been used against plant-parasitic nematodes, to increase chitinolytic microorganisms in the soil and to induce systemic resistance in plants, respectively. In this context, products used in alternative management against plant-parasitic nematodes are being marketed. This study evaluated the efficacy of the products HYT-C (chitin) and HYT-D (chitosan) in the control of M. incognita and M. javanica. The experiment was conducted by applying the products at tomato seedlings transplanting, by foliar spray or soil amendment, previously infested or not with M. javanica or M. incognita. The experimental design was completely randomized (DIC) in a factorial 7 x 3 (combination of products x root-knot nematodes), with ten replications. Evaluations were done after 60 days, determining the reproduction rate, number of eggs, juveniles and adults per gram of fresh root, shoot height (cm), root length (cm), fresh and dry root and shoot mass (g), population of chitinolytic organisms in the soil (UFC g -1 soil) and the activity of chitinase enzyme in the leaves. Chitin added to the soil increased length and fresh root mass in plants inoculated with M. incognita. When combined with foliar chitosan, it also increased plant shoot length. The application of chitin to soil associated with leaf spraying of chitosan, reduced reproduction factor and population of M. javanica per root gram. No significant results were obtained for M. incognita. Chitin in the soil increased the population of soil chitinolytic microorganisms. The application of soil chitin, foliar chitosan and a combination of both, increased the activity of the enzyme chitinase in the leaves four days after application, regardless of nematode inoculated.

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Evolution of the Bacillus cereus Group

Cited by 4 publications

References 83 publications

Endophytic Bacillus Bacteria Living in Sugarcane Plant Tissues and Telchin licus licus Larvae (Drury) (Lepidoptera: Castniidae): The Symbiosis That May Open New Paths in the Biological Control

Endophytic Bacillus Bacteria Living in Sugarcane Plant Tissues and Telchin licus licus Larvae (Drury) (Lepidoptera: Castniidae): The Symbiosis That May Open New Paths in the Biological Control

The distinct properties of natural and GM cry insecticidal proteins

Micro-organismos, quitina e quitosana no manejo de nematoides das galhas no tomateiro

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