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Delanthabettu A, Narasimhappa NS, Ramaswamy A, Mallesh MH, Nagarajappa N, Govind G. Molecular Characterization of Native Bacillus thuringiensis Strains from Root Nodules with Toxicity Against the Fall Armyworm (FAW, Spodoptera frugiperda) and Brinjal Ash Weevil (Myllocerus subfasciatus). Curr Microbiol 2022; 79:274. [PMID: 35907079 DOI: 10.1007/s00284-022-02951-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 06/24/2022] [Indexed: 11/28/2022]
Abstract
The fall armyworm is an exotic pest which destroys a wide variety of crops Querywhereas the brinjal ash weevil is a serious pest of eggplant and other solanaceous vegetables. The goal of this research is to find a sustainable and ecologically friendly bio-control agent for managing FAW and brinjal ash weevils. Twelve natural Bacillus thuringiensis strains were isolated from cowpea root nodules, and the Gram-positive cells with characteristic Bt crystal structures were discovered using phase contrast and scanning electron microscopy. There were bipyramidal, cuboidal, rhombus, and spherical crystals. The Bt cry gene content was characterized by PCR analysis, which revealed the presence of cry1, cry1I, cry3, cry7, cry7,8, cry14, cry26, and cry55 genes. The identity of Bt was confirmed by cloning and sequencing the cry genes. In the nucleotide sequences, no pseudo genes or indels were found in cry sequences. SDS-PAGE examination indicated the presence of bands ranging in size from 13 to 130 kDa, with 50-60 kDa being the most common. When compared to the control, the new native Bt strains were lethal, with pathogenicity ranging from 93 to 100% against S. frugiperda larvae and M. subfasciatus adults. The studies revealed that the native strains with conserved regions of 16S rRNA genes were compared to NCBI database sequences and classified as native Bt strains with 99-100% similarity to known Bt strains. In conclusion, native Bt strains from cowpea root nodules were shown to have bio-insecticidal activity against fall armyworm larvae and brinjal ash weevil adults.
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Affiliation(s)
| | | | - Asokan Ramaswamy
- Division of Basic Sciences, ICAR-Indian Institute of Horticultural Research, Hesaraghatta Lake Post, Bangalore, 560089, India
| | | | - Nethra Nagarajappa
- Seed Technology Research Unit, AICRP on Seeds (Crops), UAS, GKVK, Bangalore, 560065, India
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Ramasamy A, Suresh M, Mallesh MSH. Toxicity evaluation of Aphidicidal crystalliferous toxins from Bacillus thuringiensis strains: a molecular study. ANN MICROBIOL 2020. [DOI: 10.1186/s13213-020-01594-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Purpose
Aphis gossypii and A. punicae are the most damaging pests. The emergence of large populations has created concern among farmers because this pest complex is considered critical as it has a significant effect on major crops around the globe. The lack of new technologies for the control of A. gossypii and A. punicae is also worrying due to the indiscriminate use of chemical insecticides. Besides, this leads to the rapid development of resistance, which strangles their control in the field. Hence, there is a dire need to find the effective biocontrol agent for the management of Aphis gossypii and A. punicae.
Methods
The present investigation emphasizes the isolation and characterization of Aphidicidal Bacillus thuringiensis from the Andaman and Nicobar Islands, Karnataka, Assam, Arunachal Pradesh, and Sikkim soil samples. Phase contrast and scanning electron microscopy analysis used to characterize and identify the crystal morphology. Molecular profiling of Bt cry genes was determined by PCR using aphidicidal cry gene-specific primers, and molecular cloning and sequencing were carried out. Protein profiling by SDS–PAGE analysis was further studied. Finally, a qualitative bioassay of insecticidal activity was carried out against A. gossypii and A. punicae.
Results
A total of 65 Bacillus-like colonies were screened; 15 putative Aphidicidal B. thuringiensis isolates were identified based on morphological as well as through microbiological studies. Spherical and amorphous crystal inclusion was predominantly present in 34.28% of the Bt isolates. Crystal protein profiling of Bt isolates by SDS–PAGE analysis showed the presence 130, 73, 34, 25, and 13 kDa bands, among which 50−66 kDa bands were present abundantly. The detection of the cry gene of these isolates was done by PCR analysis, which indicated that cry1, cry2A, cry3A, and cry11A were on plasmid DNA. All cry genes were 80–100% homologous when aligned on alignment tool NCBI-BLASTn and BLASTp. All isolates of Bt were tested for their insecticidal activity against aphids. Three of the 15 isolates are Aphidicidal toxin specific by PCR analysis which were observed to be toxic to Aphis gossypii and A. punicae at a concentration of 35 μg/mL. The observed physical changes were induced by B. thuringiensis infection; these strains had been re-isolated from the dead aphids, and the presented results fulfilled Koch’s postulates.
Conclusion
The present study brought promising Bt isolates, primarily capable of creating an efficient biocontrol agent for Aphis gossypii and A. punicae and various sucking pests soon.
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Djenane Z, Nateche F, Amziane M, Gomis-Cebolla J, El-Aichar F, Khorf H, Ferré J. Assessment of the Antimicrobial Activity and the Entomocidal Potential of Bacillus thuringiensis Isolates from Algeria. Toxins (Basel) 2017; 9:E139. [PMID: 28406460 PMCID: PMC5408213 DOI: 10.3390/toxins9040139] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 03/29/2017] [Accepted: 04/11/2017] [Indexed: 11/23/2022] Open
Abstract
This work represents the first initiative to analyze the distribution of B. thuringiensis in Algeria and to evaluate the biological potential of the isolates. A total of 157 isolates were recovered, with at least one isolate in 94.4% of the samples. The highest Bt index was found in samples from rhizospheric soil (0.48) and from the Mediterranean area (0.44). Most isolates showed antifungal activity (98.5%), in contrast to the few that had antibacterial activity (29.9%). A high genetic diversity was made evident by the finding of many different crystal shapes and various combinations of shapes within a single isolate (in 58.4% of the isolates). Also, over 50% of the isolates harbored cry1, cry2, or cry9 genes, and 69.3% contained a vip3 gene. A good correlation between the presence of chitinase genes and antifungal activity was observed. More than half of the isolates with a broad spectrum of antifungal activity harbored both endochitinase and exochitinase genes. Interestingly, 15 isolates contained the two chitinase genes and all of the above cry family genes, with some of them harboring a vip3 gene as well. The combination of this large number of genes coding for entomopathogenic proteins suggests a putative wide range of entomotoxic activity.
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Affiliation(s)
- Zahia Djenane
- Microbiology Group, Laboratory of Cellular and Molecular Biology, Faculty of Biological Sciences, University of Science and Technology Houari Boumediene (USTHB), BP 32, EL ALIA, Bab Ezzouar, 16111 Algiers, Algeria.
- ERI BIOTECMED and Department of Genetics, Universitat de València, Dr. Moliner, 50, BURJASSOT, 46100 Valencia, Spain.
- Department of Science and Technology, Faculty of Science, University Dr Yahia Frès, 26000 Médéa, Algeria.
| | - Farida Nateche
- Microbiology Group, Laboratory of Cellular and Molecular Biology, Faculty of Biological Sciences, University of Science and Technology Houari Boumediene (USTHB), BP 32, EL ALIA, Bab Ezzouar, 16111 Algiers, Algeria.
| | - Meriam Amziane
- Microbiology Group, Laboratory of Cellular and Molecular Biology, Faculty of Biological Sciences, University of Science and Technology Houari Boumediene (USTHB), BP 32, EL ALIA, Bab Ezzouar, 16111 Algiers, Algeria.
| | - Joaquín Gomis-Cebolla
- ERI BIOTECMED and Department of Genetics, Universitat de València, Dr. Moliner, 50, BURJASSOT, 46100 Valencia, Spain.
| | - Fairouz El-Aichar
- Microbiology Group, Laboratory of Cellular and Molecular Biology, Faculty of Biological Sciences, University of Science and Technology Houari Boumediene (USTHB), BP 32, EL ALIA, Bab Ezzouar, 16111 Algiers, Algeria.
| | - Hassiba Khorf
- Microbiology Group, Laboratory of Cellular and Molecular Biology, Faculty of Biological Sciences, University of Science and Technology Houari Boumediene (USTHB), BP 32, EL ALIA, Bab Ezzouar, 16111 Algiers, Algeria.
| | - Juan Ferré
- ERI BIOTECMED and Department of Genetics, Universitat de València, Dr. Moliner, 50, BURJASSOT, 46100 Valencia, Spain.
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Zothansanga R, Senthilkumar N, Gurusubramanian G. Diversity and Toxicity of Bacillus thuringiensis from Shifting Cultivation (Jhum) Habitat. Biocontrol Sci 2016; 21:99-111. [PMID: 27350428 DOI: 10.4265/bio.21.99] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Bacillus thuringiensis (Bt) strains were isolated from jhum-agriculture, jhum-forest, aquatic and fallow soil samples from Mizoram by acetate selection method. Isolates were characterized for biochemical typing, cry gene and protein profiling, growth curve study and toxicity against Culex tritaeniorhynchus. Bt frequency was high in jhum-agriculture land (69.56%) whereas low in jhum-forest soils (31.57%). Bt was found to be abundant in jhum shifting cultivation soil with an index ranging between 0.010 and 0.015. Majority of the isolates from jhum soils produced oval and spherical crystals and showed eleven types of crystal proteins groups. PCR analysis revealed predominance of dipteran-active cry genes (cry4 and cry9). The variations in crystal morphology, cry genes and Cry protein (s) from the isolates of Bt revealed molecular diversity. Higher mortality, lower lethal dose, and lesser time to kill were observed in Bt isolates from jhum soils than aquatic and fallow habitats. Based on the toxicity test, SC1 and HP7 isolates containing cry 4 and cry 9 genes showed higher activity. Growth curve analysis showed significant variations among Bt isolates to reach the sporulating stage. Higher growth index and lower mean generation time were observed in SC1 and HP7 Bt isolates. Bt strains express different endotoxin genes and crystal proteins and their harvesting time also varied from strain to strain. Significant variation was found in Bt isolates from jhum habitats in relation to the cry gene composition, protein profiling and toxicity. Results from this study suggest that novel Bt entomopathogens may complement for regulating mosquito vectors.
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Cloning, characterization and expression of a novel haplotype cry2A-type gene from Bacillus thuringiensis strain SWK1, native to Himalayan valley Kashmir. J Invertebr Pathol 2016; 136:1-6. [DOI: 10.1016/j.jip.2016.02.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 02/17/2016] [Accepted: 02/18/2016] [Indexed: 11/21/2022]
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The Use of Polystyrene Beads to Prepare Arrayed Samples of Bacillus thuringiensis for Microscopic Examination. Curr Microbiol 2015; 71:412-4. [DOI: 10.1007/s00284-015-0870-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Accepted: 05/23/2015] [Indexed: 11/26/2022]
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Jia Y, Zhou JY, He JX, Du W, Bu YQ, Liu CH, Dai CC. Distribution of the Entomopathogenic Fungus Beauveria bassiana in Rice Ecosystems and Its Effect on Soil Enzymes. Curr Microbiol 2013; 67:631-6. [DOI: 10.1007/s00284-013-0414-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 05/19/2013] [Indexed: 11/24/2022]
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