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Lysinibacillus sphaericus S-layer protein toxicity against Culex quinquefasciatus

Lucía C Lozano1, Juan A Ayala, Jenny Dussán

  • 1Centro de Investigaciones Microbiológicas-CIMIC, Departamento de Ciencias Biológicas, Universidad de los Andes, Cra 1E No. 18A-10 J207, Bogotá, Colombia. lulozano@uniandes.edu.co

Biotechnology Letters
|June 15, 2011
PubMed

Insights

Lysinibacillus sphaericus produces toxins to kill mosquito larvae. This study reveals the mosquito larvicidal potency of its S-layer protein, a novel finding for this bacterium used in pest control.

Area of Science:

  • Microbiology
  • Toxicology
  • Vector Control

Background:

  • Lysinibacillus sphaericus is a bacterium utilized for mosquito control.
  • Its primary toxicity mechanism involves a binary toxin produced during sporulation, with additional toxins (Mtx1, Mtx2, Mtx3) expressed in vegetative cells.

Purpose of the Study:

  • To determine the mosquito larvicidal potency of the S-layer protein expressed in vegetative cells of Lysinibacillus sphaericus.
  • To investigate the potential of S-layer proteins as a novel larvicidal agent.

Main Methods:

  • The S-layer protein from Lysinibacillus sphaericus strains (OT4b25, OT4b26, and III(3)7) was expressed in vegetative cells.
  • Mosquito larvicidal activity was assessed by determining the LC50 values against third-instar larvae of Culex quinquefasciatus.

Main Results:

  • The S-layer protein exhibited significant mosquito larvicidal activity.
  • LC50 values for strains OT4b25, OT4b26, and III(3)7 were 8.7, 24, and 0.68 μg/ml, respectively.
  • The S-layer protein is similar to those found in other mosquitocidal L. sphaericus strains.

Conclusions:

  • This study demonstrates for the first time the mosquito larvicidal potency of the S-layer protein from Lysinibacillus sphaericus.
  • The S-layer protein represents a potential new tool for mosquito control strategies.

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