Identification and characterization of a novel marine Bacillus cereus for mosquito control

Abstract

Entomopathogenic bacteria to control mosquitoes are a promising environmentally friendly alternative to synthetic pesticides. In the present study, a novel mosquitocidal bacterium was isolated from marine soil collected from east coastal areas at Pondicherry (India). 16S rRNA gene sequence alignment depicted that this isolate belonged to Bacillus cereus VCRC-B520 (NCBI: KC-119192). Biochemical studies on bacterial growth, biomass, and toxin production have revealed that this strain could possibly be helpful in the production of a biopesticide in mosquito control. Toxicity assay with B. cereus against mosquito larvae has shown that the filariasis vector, Culex quinquefasciatus, is more susceptible than the other two species (Anopheles stephensi and Aedes aegypti). The LC50 and LC90 values for C. quinquefasciatus were 0.30 and 2.21 mg/L, respectively. No effect of B. cereus was found on nontargeted organisms. SDS-PAGE analysis and protein purification result from the cell mass of B. cereus have shown that a well-perceptible polypeptide was the dependable factor (85 kDa) for mosquitocidal action. Protein characterization (M/S MALDI-TOF) has shown that it is an endotoxin-specific insecticidal protein, namely "Cry4Aa". Phylogenetic analyses of 16S rDNA gene sequence from this marine isolate have revealed the presence of homology among closely related Bacillus strains. Therefore, considerable interest has been shown on the identification of a potential mosquitocidal bacterium from marine environment (B. cereus), which was not reported earlier in view of the current scenario of the rapid development of resistance to Bacillus sphaericus in mosquito vector control program.

Bacillus cereus strain S2 shows high nematicidal activity against Meloidogyne incognita by producing sphingosine

“…Six B. cereus strains are reported to produce several small, nonproteinaceous insecticidal exotoxins 21 22 23 . A novel mosquitocidal Bacillus cereus VCRC-B520 isolated from marine soil can produce an endotoxin-specific insecticidal protein of Cry4Aa 24 .…”

Marine Natural Products: The Important Resource of Biological Insecticide

“…Enterobacter cloacae VCRC−B519 obtained from marine soil was regarded as effective mosquitocidal bacterium, three peptides [114] isolated are thought to be related to the insecticidal activity of this bacteria. Study among marine soil collected from Pondicherry found a unique mosquitocidal bacterium and identified to be Bacillus cereus VCRC‐B520, isolation guided by its insecticidal activity discovered an insecticidal protein, namely “Cry4Aa”, [115] which can cause mosquito susceptibility of Culex quinquefasciatus. Mustapha et al.…”

Vector-Focused Approaches to Curb Malaria Transmission in the Brazilian Amazon: An Overview of Current and Future Challenges and Strategies

“…Mosquitocidal microorganisms, including viruses, fungi and bacteria have been investigated as potential ecologically friendly alternatives to chemical insecticides [170][171][172][173]. Bacillus thuringiensis var.…”