Adsorption of Toxic Metals and Control of Mosquitos-borne Disease by Lysinibacillus sphaericus: Dual Benefits for Health and Environment.
OBJECTIVE
Assessment of the bacterium L. sphaericus as a dual-action candidate for biological control of mosquito-borne diseases and bioremediation of toxic metals.


METHODS
Larvae of the mosquito, C. quinquefasciatus, were first evaluated for metal tolerance and then exposed to 5 ppm cadmium, chromium, arsenic, and lead in assays together with seven strains of L. sphaericus. A probit regression analysis was used to estimate the LC(50) of Cd, Cr, As, and Pb to C. quinquefasciatus. An analysis of covariance and multifactorial ANOVA examined the metal biosorption and larvicidal properties of the seven strains of L. sphaericus.


RESULTS
We found that L. sphaericus adsorbed the toxic metal ions and was toxic against mosquito larvae. The L. sphaericus strain III(3)7 resulted in a larvae mortality of over 80% for all the tested metals. This strain also exhibited the capacity to adsorb 76% of arsenic, 32% of lead, 25% of chromium, and 7% of cadmium.


CONCLUSIONS
This study found combined metal adsorption and larval toxicity associated with three strains of L. sphaericus [III(3)7, OT4b.31, and CBAM5]. This suggests that a combination of these strains shows strong dual potential for biological control of mosquitos in heavy metal-contaminated areas and remediate the heavy metal contamination as well.
Biological Sciences, Universidad De Los Andes, Bogotá 111711, Colombia.
Edo Vargas
EV
Javier
Biological Sciences, Universidad De Los Andes, Bogotá 111711, Colombia.
Dussán
D
Jenny
D000818:Animals; D001406:Bacillaceae / Q000502:physiology*; D009033:Culicidae / Q000382:microbiology*; D054884:Host-Pathogen Interactions; D007303:Insect Vectors; D007814:Larva / Q000382:microbiology; D019216:Metals, Heavy / Q000378:metabolism* / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000633:toxicity
D019216:Metals, Heavy; D014874:Water Pollutants, Chemical
Culex quinquefasciatus; Entomopathogen; Heath; Lysinibacillus sphaericus; Toxic metals