scholarly journals LARVICIDAL ACTIVITY OF BACILLUS THURINGIENSIS ISOLATED FROM Bt COTTON RHIZOSPHERE SOIL AGAINST ANOPHELES MOSQUITO LARVAE (CULICIDAE)

2018 ◽  
Vol 11 (9) ◽  
pp. 456
Author(s):  
Janani Rajendran ◽  
Nathiya Subramanian ◽  
Rajesh Kannan Velu
Keyword(s):  
Bacillus Thuringiensis ◽  
16S Rrna ◽  
Larvicidal Activity ◽  
Rhizosphere Soil ◽  
Anopheles Mosquito ◽  
Cotton Field ◽  
Mosquito Larvae ◽  
Bt Cotton ◽  
Cry Proteins ◽  
Sds Page

Objective: The objective of the study was to isolate and identify Bacillus thuringiensis (Bt) from Bt cotton rhizosphere soil and analyze its larvicidal activity against Anopheles mosquito larvae.Methods: Soil samples were collected from Bt cotton field, and B. thuringiensis was isolated and characterized by biochemical and microscopical characterization. Crystal (Cry) proteins were extracted and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and its larvicidal activity was checked by mortality analysis. Effective Bt isolates were identified by 16S rRNA sequencing.Results: A total of 24 isolates were characterized as Bacillus sp. by biochemical characterization. Further, parasporal inclusion and Cry proteins were extracted, and it was quantified by Bradford assay. The precipitated Cry proteins were analyzed by SDS-PAGE and the results have indicates Cry I protein at 100kDa, Cry3 protein at 44kDa, and cytolytic protein (Cyt) at 29kDa in most of the isolates. Larvicidal activity was checked by the 4th instar Anopheles mosquito larvae. Among the tested isolates, RBL10 and RBL20 have shown the highest percentage of larvicidal activity at 96 and 83%, respectively. Further, the two isolates RBL10 and RBL20 were identified as Bt by 16S rRNA sequencing.Conclusion: B. thuringiensis producing Cry and Cyt proteins posses potential larvicidal activity against Anopheles mosquito larvae which has biological and economic importance in mosquito control.

scholarly journals LARVICIDAL ACTIVITY OFTITHONIA DIVERSIFOLIALEAF EXTRACT ONPERI-URBAN MOSQUITO LARVEA INABAKALIKI; ALTERNATIVE TO INSECTICIDE DEVELOPMENT.

2015 ◽  
Vol 7 (1) ◽  
pp. 1225-1228
Author(s):  
UHUO CA ◽  
OKEREKE CN ◽  
NWELE ED ◽  
OGBONNA S.U ◽  
NWANCHOR K.C ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Adverse Effects ◽  
Bioactive Compounds ◽  
Larvicidal Activity ◽  
Urban Areas ◽  
Insect Pests ◽  
Anopheles Mosquito ◽  
Mosquito Population ◽  
Mosquito Larvae ◽  
Dose Dependent

The bioassay activitiesofTithonia diversifolia leave extract was conducted on the larvae of Anopheles mosquito collected at peri-urban areas of Abakaliki Ebonyi State, using the concentrations of the extract in dilutions at 50/100ml, 40/100ml, 30/100ml and 20/100ml introduced with 10 Anopheles mosquito larvae each in four replicates and allowed for 3hrs. Mean mortality rate of the larvae were observed after the first hour, thus 30%, 10%, 05% and 0% respectively while in the 2nd hour were 60%, 40%, 20% and 10% and in the 3rd hour were 80%, 60%, 50% & 30% respectively. The result thus revealed that the treatment is dose dependent and that the studied specie has some bioactive compounds that can be exploited for insect pests control hence observed to be sensitive in anopheles mosquito larvae. Therefore Tithonia diversifolialeaf extract could be used as a bioassay for the control of mosquito due to its active properties as this has exhibited adverse effects on the larvae thereby reducing the mosquito population and thus reducing the malarious infection associated with the bite of mosquito.

Friendly Foes: The Bio-control Agents

2018 ◽  
Vol 2 (01) ◽  
Author(s):  
Kalpana Singh
Keyword(s):  
United States ◽  
Biological Control ◽  
Bacillus Thuringiensis ◽  
United States Of America ◽  
Control Agent ◽  
Mosquito Larvae ◽  
Bt Cotton ◽  
Economic Threshold ◽  
Pest Population ◽  
Natural Way

The bio-control agents are those organisms that manage the pest population in natural way and keep them below the economic threshold and are thus applied by the agency of man. This process is known as bio-control or biological control. They are foes to the pests and are thus beneficial and a friend for us. There are many pathogens (Bacillus thuringiensis, Bt cotton), parasites (parasitoids, ex. Parasitic wasps, tachinid flies) and predators (ex. Gambusia fish against mosquito larvae) that can be applied as bio-control agents. Many are being used as effective pest control agent in Europe and United States of America. There is lots of potential in this field and more explorations and researches need to be done in an agricultural country like India.

scholarly journals Toxicity intraperitoneal and intragastric route of Bacillus thuringiensis and Melia azedarach in mice

2012 ◽  
Vol 79 (4) ◽  
pp. 511-517 ◽  
Author(s):  
D.L. Berlitz ◽  
M. Giovenardi ◽  
J.-F. Charles ◽  
L.M. Fiúza
Keyword(s):  
Bacillus Thuringiensis ◽  
Aqueous Extract ◽  
Culture Supernatant ◽  
Stomach Contents ◽  
Melia Azedarach ◽  
Bacterial Suspension ◽  
Cry Proteins ◽  
In Vivo Assays ◽  
Sds Page

The aim of this investigation was the assessment of toxicity of two new isolates of Bacillus thuringiensis, and the aqueous extract of Melia azedarach through in vivo assays in CF1 mice. Bt 1958-2, Bt 2014-2 and the BTh Thuricide 63 standard isolates were grown in liquid usual glicosed medium, and Cry proteins were purified by centrifugation on a sucrose gradient. The supernatant was autoclaved at 121º C, 15min. to maintain the exotoxins. Dehydrated leaves of M. azedarach were used to prepare a 10% aqueous extract. Mice were treated either orally or intraperitoneally with a whole bacterial suspension (1.10(10) UFC/mL), a culture supernatant or purified crystal protein (50 µg/mL), and with the plant extract (50 µg/mL). The stomachs of the mice were collected and observed in stereomicroscopy, and the stomach contents were analyzed in 10% SDS-PAGE. Results showed that none of the oral treatments were toxic to mice, but intraperitoneal bacterial suspensions were lethal to the animals 6 - 24 hours after injection. In conclusion, the Cry proteins of the new B. thuringiensis isolates must be evaluated for their use as tools in the biotechnology field, since they do not show toxicity against mammals, intragastrically or peritoneally, just like the M. azedarach aqueous extract (10%), with those being indicated for the biological control of pest insects.

scholarly journals Interaction of Bacillus thuringiensis Toxins with Larval Midgut Binding Sites of Helicoverpa armigera (Lepidoptera: Noctuidae)

2004 ◽  
Vol 70 (3) ◽  
pp. 1378-1384 ◽  
Author(s):  
Anna Estela ◽  
Baltasar Escriche ◽  
Juan Ferr�
Keyword(s):  
Bacillus Thuringiensis ◽  
Concanavalin A ◽  
Helicoverpa Armigera ◽  
Binding Sites ◽  
Inhibitory Effect ◽  
Toxin Gene ◽  
Bt Cotton ◽  
Cry1ab Protein ◽  
Cry Proteins ◽  
Helicoverpa Armígera

ABSTRACT In 1996, Bt-cotton (cotton expressing a Bacillus thuringiensis toxin gene) expressing the Cry1Ac protein was commercially introduced to control cotton pests. A threat to this first generation of transgenic cotton is the evolution of resistance by the insects. Second-generation Bt-cotton has been developed with either new B. thuringiensis genes or with a combination of cry genes. However, one requirement for the “stacked” gene strategy to work is that the stacked toxins bind to different binding sites. In the present study, the binding of 125I-labeled Cry1Ab protein (125I-Cry1Ab) and 125I-Cry1Ac to brush border membrane vesicles (BBMV) of Helicoverpa armigera was analyzed in competition experiments with 11 nonlabeled Cry proteins. The results indicate that Cry1Aa, Cry1Ab, and Cry1Ac competed for common binding sites. No other Cry proteins tested competed for either 125I-Cry1Ab or 125I-Cry1Ac binding, except Cry1Ja, which competed only at the highest concentrations used. Furthermore, BBMV from four H. armigera populations were also tested with 125I-Cry1Ac and Cry1Ab to check the influence of the insect population on the binding results. Finally, the inhibitory effect of selected sugars and lectins was also determined. 125I-Cry1Ac binding was strongly inhibited by N-acetylgalactosamine, sialic acid, and concanavalin A and moderately inhibited by soybean agglutinin. In contrast, 125I-Cry1Ab binding was only significantly inhibited by concanavalin A. These results show that Cry1Ac and Cry1Ab use different epitopes for binding to BBMV.

scholarly journals Assessment of Some Bacteria from Panteka Stream, Kaduna, Nigeria, for their Larvicidal Activity Against Anopheles gambiae

2019 ◽  
Vol 3 (12) ◽  
pp. 149-154
Author(s):  
Thankgod Ositadinma Ndibe ◽  
Nancy Erika Nwabufo ◽  
Johnson John Usman ◽  
Winnie Chuno Eugene
Keyword(s):  
Anopheles Gambiae ◽  
Larvicidal Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Protein Profiling ◽  
Mosquito Larvae ◽  
Bacterial Isolates ◽  
Sample Collection ◽  
Sds Page ◽  
Biochemical Identification

It is obvious that malaria is one of the commonest diseases in Africa, hence the need to embark on a study to reduce its transmission by eliminating the vector. Some microorganisms are known to have larvicidal activity leading to destruction of mosquito larvae, thereby, preventing them from metamorphosing into adult mosquitoes that can transmit Plasmodium spp. Panteka stream, Kaduna, Nigeria, is a dumping site for refuse and automobile waste and thus, a potential source of bacteria. This present investigation was aimed at screening bacterial isolates for their larvicidal activity against Anopheles gambiae. Standard methods were employed in sample collection, isolation, morphological, biochemical identification and protein profiling of these bacteria isolates. Five different types of bacteria were identified; Bacillus thuringiensis, Staphylococcus aureus, Micrococcus sedentarius, Enterococcus faecalis and Streptococcus pneumonia. Among these bacteria, B. thuringiensis exhibited the most larvicidal activity, followed by M. sedentarius. On the basis of lethal concentration (LC50), B. thuringiensis exhibited the highest lethal activity against Anopheles gambiae larvae at 48 hour duration of exposure. Results showed that concentration of bacterial isolates and duration of exposure of larvae to the bacterial isolates, determine the mortality rate of larvae. Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) revealed variable bands between B. thuringiensis and M. sedentarius, which might have accounted for their differences in larvicidal activity. The use of bacteria for the control of mosquito larvae is highly recommended. Further research should be conducted to search for more bacteria and possibly fungi which have potentials for larvicidal activity.

scholarly journals Effect of Chlorine and Temperature on Larvicidal Activity of Cuban Bacillus thuringiensis Isolates

2019 ◽  
Author(s):  
Aileen González-Rizo ◽  
Camilo E Castañet ◽  
Ariamys Companioni ◽  
Zulema Menéndez ◽  
Hilda Hernández ◽  
...  
Keyword(s):  
Water Quality ◽  
High Temperature ◽  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Larvicidal Activity ◽  
Influence Of Temperature ◽  
Sds Page ◽  
Different Temperatures ◽  
Bioassay Data ◽  
Effect Of Chlorine

Background: The efficacy of biolarvicides may be influenced by species of mosquito, larval age and density, tem­perature, water quality, bacterial formulation, and others. The aim of this study was to evaluate the influence of tem­perature and chlorine on larvicidal activity of Bacillus thuringiensis Cuban isolates against Aedes aegypti. Methods: The influence of temperature (25, 30, 35 °C) and chlorine (2.25mg/L) on the larvicidal activity of eleven B. thuringiensis Cuban isolates (collected between 2007 and 2009) were tested under laboratory conditions following WHO protocols. Bioassay data were analyzed by Probit program. The effect of chlorine and temperature (25, 30, 35 and 40 °C) on the Cry and Cyt proteins of these isolates was determined by SDS-PAGE polyacrylamide gel electro­phoresis. Results: The pathogenicity of the isolates U81, X48 was affected at 35 °C. However, A21, A51, L910, and R89 isolates increase their entomopathogen activity at 35 °C. No differences were observed in toxicity of M29, R84, R85 and R87 isolates at different temperatures. The Cry 4, Cry 10 and Cry 11 proteins were reduced in A21, X48, R85 isolates at 35 and 40 °C. The Cyt proteins were reduced at 35 and 40 °C in A21, X48, R85, and A51 isolates. In L910 and R84 isolates, the Cyt toxin was degraded only at 40 °C. In chlorinated water, the lethal concentrations 50 and 90 in A21, A51, M29, R84, U81, and X48 isolates were increase. Conclusion: A21, A51, L910, R85, and X48 isolates have a strong larvicidal activity for the treatment of Ae. aegypti breeding’s sites exposed to high temperature and chlorine

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