Next Article in Journal
PLA2 Inhibitor Varespladib as an Alternative to the Antivenom Treatment for Bites from Nikolsky’s Viper Vipera berus nikolskii
Next Article in Special Issue
The Cadherin Protein Is Not Involved in Susceptibility to Bacillus thuringiensis Cry1Ab or Cry1Fa Toxins in Spodoptera frugiperda
Previous Article in Journal
Post-Exposure Anti-Ricin Treatment Protects Swine against Lethal Systemic and Pulmonary Exposures
Previous Article in Special Issue
The Cytocidal Spectrum of Bacillus thuringiensis Toxins: From Insects to Human Cancer Cells
Open AccessArticle

Potential of Cry10Aa and Cyt2Ba, Two Minority δ-endotoxins Produced by Bacillus thuringiensis ser. israelensis, for the Control of Aedes aegypti Larvae

1
Departamento de Agronomía, Biotecnología y Alimentación, Universidad Pública de Navarra, 31006 Pamplona, Spain
2
Bioinsectis SL, Avda Pamplona 123, 31192 Mutilva, Spain
3
Instituto de Ecología AC, 91073 Xalapa, Mexico
4
Institute for Multidisciplinary Applied Biology Research (IMAB), Universidad Pública de Navarra, 31006 Mutilva, Spain
*
Author to whom correspondence should be addressed.
Toxins 2020, 12(6), 355; https://doi.org/10.3390/toxins12060355
Received: 17 April 2020 / Revised: 22 May 2020 / Accepted: 26 May 2020 / Published: 29 May 2020
Bacillus thuringiensis ser. israelensis (Bti) has been widely used as microbial larvicide for the control of many species of mosquitoes and blackflies. The larvicidal activity of Bti resides in Cry and Cyt δ-endotoxins present in the parasporal crystal of this pathogen. The insecticidal activity of the crystal is higher than the activities of the individual toxins, which is likely due to synergistic interactions among the crystal component proteins, particularly those involving Cyt1Aa. In the present study, Cry10Aa and Cyt2Ba were cloned from the commercial larvicide VectoBac-12AS® and expressed in the acrystalliferous Bt strain BMB171 under the cyt1Aa strong promoter of the pSTAB vector. The LC50 values for Aedes aegypti second instar larvae estimated at 24 hpi for these two recombinant proteins (Cry10Aa and Cyt2Ba) were 299.62 and 279.37 ng/mL, respectively. Remarkable synergistic mosquitocidal activity was observed between Cry10Aa and Cyt2Ba (synergistic potentiation of 68.6-fold) when spore + crystal preparations, comprising a mixture of both recombinant strains in equal relative concentrations, were ingested by A. aegypti larvae. This synergistic activity is among the most powerful described so far with Bt toxins and is comparable to that reported for Cyt1A when interacting with Cry4Aa, Cry4Ba or Cry11Aa. Synergistic mosquitocidal activity was also observed between the recombinant proteins Cyt2Ba and Cry4Aa, but in this case, the synergistic potentiation was 4.6-fold. In conclusion, although Cry10Aa and Cyt2Ba are rarely detectable or appear as minor components in the crystals of Bti strains, they represent toxicity factors with a high potential for the control of mosquito populations. View Full-Text
Keywords: Bacillus thuringiensis; Aedes aegypti; minor proteins; synergy; mosquito control; Bti Bacillus thuringiensis; Aedes aegypti; minor proteins; synergy; mosquito control; Bti
Show Figures

Graphical abstract

MDPI and ACS Style

Valtierra-de-Luis, D.; Villanueva, M.; Lai, L.; Williams, T.; Caballero, P. Potential of Cry10Aa and Cyt2Ba, Two Minority δ-endotoxins Produced by Bacillus thuringiensis ser. israelensis, for the Control of Aedes aegypti Larvae. Toxins 2020, 12, 355.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop