Mosquito adulticidal activity of a biosurfactant produced by Bacillus subtilis subsp. subtilis

Abstract

BACKGROUND: A biosurfactant, surfactin, produced by a strain of Bacillus subtilis subsp. subtilis (VCRC B471), was effective in killing mosquito larval and pupal stages. As it was lethal to the non‐feeding pupal stage, it was presumed that it could kill the adult mosquitoes also. In this study, the adulticidal effect of the biosurfactant was assessed in the laboratory against a malaria vector, Anopheles stephensi.RESULTS: The biosurfactant surfactin, separated from the culture supernatant of the production strain, showed mosquito adulticidal activity when tested as ultralow‐volume (ULV) spray in a Peet‐Grady chamber. Knockdown activity and mortality were found to increase with increasing surfactin dosage. Knockdown dosage (KD) and lethal dosage (LD) were calculated by statistical analysis. The KD50 and KD90 dosages were 10.73 and 26.39 mg m−3 respectively. The LD50 and LD90 dosages were 16.13 and 39.21 mg m−3. The average droplet size of B. subtilis surfactin was 17.5 ± 1.07 µm.CONCLUSION: The present study indicates that the biosurfactant surfactin, produced by B. subtilis subsp. subtilis (VCRC B471), is a potential bioadulticide for ULV spray against malaria‐transmitting Anopheles stephensi mosquitoes. This is the first report of a mosquito adulticide from a microbial source. Copyright © 2012 Society of Chemical Industry

Swift Fabrication of Silver Nanoparticles Using Bougainvillea glabra: Potential Against the Japanese Encephalitis Vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae)

“…Also, the bio-surfactant products released by Bacillus subtilis subsp. subtilis (VCRC B471), are a potential bio adulticide for ULV spray against A. stephensi [88]. The adult mortality exterted by ethanol extract of C. sinensis showed LC 50 [89].…”

Characterization of biosurfactants as insecticidal metabolites produced by Bacillus subtilis Y9

“…Recently, biosurfactants have been introduced as alternatives to synthetic chemicals to control insects. For example, the mosquito adulticidal activity of a biosurfactant produced by a Bacillus strain has been reported to penetrate cuticles or spiracular openings, killing the mosquitoes (Geetha et al 2012). Rhamnolipids and orfamide A, biosurfactants produced by Pseudomonas strains, have shown insecticidal activity against aphids (Kim et al 2010;Jang et al 2013).…”

Controle biológico de Spodoptera frugiperda Smith, 1797 (Lepidoptera: Noctuidae) por bactérias

“…Por outro lado, a atividade inseticida já foi caracterizada, o que pode explicar as maiores taxas de mortalidade ocasionadas no estágio de pupa de S. frugiperda (Tabela 1). Esses dados reforçam a importância de estudos mais aprofundados sobre os efeitos dos metabólitos produzidos por bactérias sobre artrópodes pragas (GEETHA et al,2012;PARREIRA et al, 2013;SILVA et al,2015). Como por exemplo, os estudos realizados por Khedher et al (2017), que demonstraram a capacidade inseticida do biossurfactante produzido por B. amyloliquefaciens no controle de populações de S. littoralis.…”

“…Esta bactéria Gram positiva, isolada do solo, tem capacidade de produzir endotoxinas que afetam severamente o sistema digestivo das lagartas, levando-as a morte (HORTA et al, 2017). Foi relatado que bactérias do gênero Bacillus e Pseudomonas isoladas de solos contaminados por hidrocarbonetos do petróleo, com capacidade de produzir metabólitos bioativos, denominados biossurfactantes, também apresentaram ação inseticida, larvicida e repelente contra mosquitos (GEETHA et al, 2012;SILVA et al, 2015).…”