Survival of a strain of Bacillus megaterium carrying a lepidopteran-specific gene of Bacillus thuringiensis in the phyllospheres of various economically important plants

1994 ◽  
Vol 167 (2) ◽  
pp. 321-324 ◽  
Author(s):  
N. Sudarsan ◽  
N. R. Suma ◽  
S. John Vennison ◽  
Vaithilingam Sekar
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacillus Megaterium ◽  
Specific Gene

scholarly journals Novel Cell Wall Hydrolase CwlC fromBacillus thuringiensisIs Essential for Mother Cell Lysis

2018 ◽  
Vol 84 (7) ◽  
Author(s):  
Xiaomin Chen ◽  
Tantan Gao ◽  
Qi Peng ◽  
Jie Zhang ◽  
Yunrong Chai ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bacillus Thuringiensis ◽  
Insecticidal Activity ◽  
Mother Cell ◽  
Uv Light ◽  
Point Mutations ◽  
Cell Lysis ◽  
Specific Gene ◽  
Content Type ◽  
Cell Wall Hydrolase

ABSTRACTIn this study, a sporulation-specific gene (tentatively namedcwlC) involved in mother cell lysis inBacillus thuringiensiswas characterized. The encoded CwlC protein consists of an N-terminalN-acetylmuramoyl-l-alanine amidase (MurNAc-LAA) domain and a C-terminal amidase02 domain. The recombinant histidine-tagged CwlC proteins purified fromEscherichia coliwere able to directly bind to and digest theB. thuringiensiscell wall. The CwlC point mutations at the two conserved glutamic acid residues (Glu-24 and Glu-140) shown to be critical for the catalytic activity in homologous amidases resulted in a complete loss of cell wall lytic activity, suggesting that CwlC is anN-acetylmuramoyl-l-alanine amidase. Results of transcriptional analyses indicated thatcwlCis transcribed as a monocistronic unit and that its expression is dependent on sporulation sigma factor K (σK). Deletion ofcwlCcompletely blocked mother cell lysis during sporulation without impacting the sporulation frequency, Cry1Ac protein production, and insecticidal activity. Taken together, our data suggest that CwlC is an essential cell wall hydrolase forB. thuringiensismother cell lysis during sporulation. EngineeredB. thuringiensisstrains targetingcwlC, which allows the crystal inclusion to remain encapsulated in the mother cell at the end of sporulation, may have the potential to become more effective biological control agents in agricultural applications since the crystal inclusion remains encapsulated in the mother cell at the end of sporulation.IMPORTANCEMother cell lysis has been well studied inBacillus subtilis, which involves three distinct yet functionally complementary cell wall hydrolases. In this study, a novel cell wall hydrolase, CwlC, was investigated and found to be essential for mother cell lysis inBacillus thuringiensis. CwlC ofB. thuringiensisonly shows 9 and 21% sequence identity with knownB. subtilismother cell hydrolases CwlB and CwlC, respectively, suggesting that mechanisms of mother cell lysis may differ betweenB. subtilisandB. thuringiensis. ThecwlCgene deletion completely blocked the release of spores and crystals from the mother cell without affecting insecticidal activity. This may provide a new effective strategy for crystal encapsulation against UV light inactivation.

scholarly journals Assessment of cry1 Gene Contents of Bacillus thuringiensis Strains by Use of DNA Microarrays

2005 ◽  
Vol 71 (9) ◽  
pp. 5391-5398 ◽  
Author(s):  
Jaroslaw Letowski ◽  
Alejandra Bravo ◽  
Roland Brousseau ◽  
Luke Masson
Keyword(s):  
Bacillus Thuringiensis ◽  
Dna Microarrays ◽  
Specific Gene ◽  
Sequence Alignments ◽  
Fast Screening ◽  
Strain Collection ◽  
Positive Hybridization ◽  
Excellent Tool ◽  
Positive Results ◽  
Cry1 Gene

ABSTRACT A single Bacillus thuringiensis strain can harbor numerous different insecticidal crystal protein (cry) genes from 46 known classes or primary ranks. The cry1 primary rank is the best known and contains the highest number of cry genes which currently totals over 130. We have designed an oligonucleotide-based DNA microarray (cryArray) to test the feasibility of using microarrays to identify the cry gene content of B. thuringiensis strains. Specific 50-mer oligonucleotide probes representing the cry1 primary and tertiary ranks were designed based on multiple cry gene sequence alignments. To minimize false-positive results, a consentaneous approach was adopted in which multiple probes against a specific gene must unanimously produce positive hybridization signals to confirm the presence of a particular gene. In order to validate the cryArray, several well-characterized B. thuringiensis strains including isolates from a Mexican strain collection were tested. With few exceptions, our probes performed in agreement with known or PCR-validated results. In one case, hybridization of primary- but not tertiary-ranked cry1I probes indicated the presence of a novel cry1I gene. Amplification and partial sequencing of the cry1I gene in strains IB360 and IB429 revealed the presence of a cry1Ia gene variant. Since a single microarray hybridization can replace hundreds of individual PCRs, DNA microarrays should become an excellent tool for the fast screening of new B. thuringiensis isolates presenting interesting insecticidal activity.

Gene dosage effect on the expression of the delta-endotoxin genes of Bacillus thuringiensis subsp. kurstaki in Bacillus subtilis and Bacillus megaterium

Gene ◽  
1989 ◽  
Vol 79 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Annapur G. Shivakumar ◽  
Rita I. Vanags ◽  
David R. Wilcox ◽  
Leonard Katz ◽  
Patricia S. Vary ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Bacillus Thuringiensis ◽  
Bacillus Megaterium ◽  
Gene Dosage ◽  
Dosage Effect ◽  
Gene Dosage Effect ◽  
Bacillus Thuringiensis Subsp ◽  
Delta Endotoxin

scholarly journals Utilización de bacillus megaterium y bacillus thuringiensis para la detección de hongos toxicogénicos

2019 ◽  
Vol 3 (4) ◽  
Author(s):  
Adriana Saubois O, ◽  
Juan Carlos Basílico G. ◽  
Ana María González P.
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacillus Megaterium ◽  
Aspergillus Ochraceus

Se estudió la respuesta de distintos hongos toxicogénicos frente a una cepa de Baclllus megaterium y Bacillus thuringiensis serotipo 1, mediante la técnica empleada por Basílico y col (1987).La actividad de las micotoxinas se expresó en función de los diámetros de las zonas de inhibición y mediante la medida de la longitud de las células bacterianas situadas en el borde de las mismas.La cepa de B. thuringiensis presentó mayores halos de inhibición frente a extractos conteniendo aflatoxinas, zearalenona. ocratoxina, esterigmatocistina, patulina y patulina conjuntamente con citrinina. También se observó inhibición frente a un extracto de Fusarium melanochlorum productor de toxina acetil T-2. Las mayores elongaciones celulares se obtuvieron con extractos conteniendo aflatoxinas.s, zearalenona y frente a un extracto de Aspergillus ochraceus productor de ocratoxina A.Con B. megaterium se obtuvieron halos menores o resultados negativos. Este microorganismo no presentó las elongaciones celulares características de B.thuringiensis serotipo 1

scholarly journals Caracterización de bioinsumos producidos artesanalmente en Nicaragua

2021 ◽  
Author(s):  
Johana O'Connor-Mendoza ◽  
Leandro Páramo-Aguilera ◽  
Griselda Martínez-Laguna ◽  
Laura Guillén-Rodríguez
Keyword(s):  
Bacillus Subtilis ◽  
Agrobacterium Tumefaciens ◽  
Bacillus Thuringiensis ◽  
Bacillus Cereus ◽  
Aspergillus Flavus ◽  
Bacillus Megaterium ◽  
Bacillus Pumilus ◽  
Bacillus Sp ◽  
Bacillus Flexus ◽  
Paenibacillus Sp

Para la caracterización microbiológica y molecular se aislaron e identificaron microorganismos cultivables de 4 bioinsumos comerciales provenientes del occidente y norte de Nicaragua. Esto involucró la tipificación morfológica a través de: tinción Gram para bacterias y observación de esporas para hongos filamentosos. Se realizó la extracción y secuenciación del ADN (gen ADNr 16S – bacterias, región ITS1- ITS4 hongos filamentosos) para obtener los arboles filogenéticos. Se logró la identificación molecular de 28 de 30 microorganismos aislados (23 bacterias: 12 especies, 11 géneros; 5 hongos filamentosos: 4 especies, 1 género). Encontrándose en los Bioisumos zona norte: muestra TS: 5 bacterias (Bacillus pumilus, Bacillus thuringiensis, 2 Bacillus sp. y Stenotrophomonas sp.) y 3 hongos filamentosos (Monascus pupureus, Neosartorya glabra y Aspergillus flavus- reportado como patógeno para cultivos); muestra LS: 6 bacterias (Bacillus megaterium, Bacillus subtilis, Bacillus sp., 2 Stenotrophomonas sp. y Paenibacillus sp.); muestra LL: 3 bacterias (Bacillus Megaterium, Staphylococcus succinus y Bacillus sp.) y 2 hongos filamentosos (Byssochlamys nívea – reportado como contaminante en fruta procesada y otro no identificado). Zona de occidente, muestra DCL: 9 bacterias (2 Lysinibacillus macroides, Bacillus subtilis, Bacillus flexus, Bacillus cereus – patógeno para el ser humano, Agrobacterium tumefaciens, 2 Bacillus sp. y una Stenotrophomonas sp.) y 1 hongo levaduriforme no identificado molecularmente. Lo anterior muestra gran diversidad microbiana y la presencia de patógenos en los bioinsumos que son perjudiciales para la planta y el ser humano. 

scholarly journals Bacillus halodurans Strain C125 Encodes and Synthesizes Enzymes from Both Known Pathways To Form dUMP Directly from Cytosine Deoxyribonucleotides

2015 ◽  
Vol 81 (10) ◽  
pp. 3395-3404 ◽  
Author(s):  
Christian Berg Oehlenschlæger ◽  
Monika Nøhr Løvgreen ◽  
Eva Reinauer ◽  
Emilia Lehtinen ◽  
Marie-Louise Lindberg Pind ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mycobacterium Tuberculosis ◽  
Bacillus Thuringiensis ◽  
Bacillus Megaterium ◽  
Cytidine Deaminase ◽  
Bacillus Halodurans ◽  
Whole Genome ◽  
Gene Encoding ◽  
Content Type ◽  
Regulatory Properties

ABSTRACTAnalysis of the genome ofBacillus haloduransstrain C125 indicated that two pathways leading from a cytosine deoxyribonucleotide to dUMP, used for dTMP synthesis, were encoded by the genome of the bacterium. The genes that were responsible, thecomEBgene and thedcdBgene, encoding dCMP deaminase and the bifunctional dCTP deaminase:dUTPase (DCD:DUT), respectively, were both shown to be expressed inB. halodurans, and both genes were subject to repression by the nucleosides thymidine and deoxycytidine. The latter nucleoside presumably exerts its repression after deamination by cytidine deaminase. BothcomEBanddcdBwere cloned, overexpressed inEscherichia coli, and purified to homogeneity. Both enzymes were active and displayed the expected regulatory properties: activation by dCTP for dCMP deaminase and dTTP inhibition for both enzymes. Structurally, theB. haloduransenzyme resembled theMycobacterium tuberculosisenzyme the most. An investigation of sequenced genomes from other species of the genusBacillusrevealed that not only the genome ofB. haloduransbut also the genomes ofBacillus pseudofirmus,Bacillus thuringiensis,Bacillus hemicellulosilyticus,Bacillus marmarensis,Bacillus cereus, andBacillus megateriumencode both the dCMP deaminase and the DCD:DUT enzymes. In addition, eightdcdBhomologs fromBacillusspecies within the genus for which the whole genome has not yet been sequenced were registered in the NCBI Entrez database.

Three Dimensional structure and organization of diploid chromosomes by optical section microscopy

1987 ◽  
Vol 45 ◽  
pp. 633-635
Author(s):  
David A. Agard ◽  
Yasushi Hiraoka ◽  
John W. Sedat
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Developmental State ◽  
Mitotic Cell ◽  
Biological Properties ◽  
Dimensional Structure ◽  
Specific Gene ◽  
Three Dimensional Structure ◽  
Complementary Techniques ◽  
Dynamic Structures

In an effort to understand the complex relationship between structure and biological function within the nucleus, we have embarked on a program to examine the three-dimensional structure and organization of Drosophila melanogaster embryonic chromosomes. Our overall goal is to determine how DNA and proteins are organized into complex and highly dynamic structures (chromosomes) and how these chromosomes are arranged in three dimensional space within the cell nucleus. Futher, we hope to be able to correlate structual data with such fundamental biological properties as stage in the mitotic cell cycle, developmental state and transcription at specific gene loci.Towards this end, we have been developing methodologies for the three-dimensional analysis of non-crystalline biological specimens using optical and electron microscopy. We feel that the combination of these two complementary techniques allows an unprecedented look at the structural organization of cellular components ranging in size from 100A to 100 microns.

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