Isolation of Fluoride Tolerant Bacillus spp (KT201599, KT201600) from the Midgut of Drosophila melanogaster: Their Probable Role in Fluoride Removal

Abstract

This is for the first time that two fluoride tolerant bacterial strains of Bacillus spp (KT201599 and KT201600) have been isolated from the mid-gut of third instar larvae of Drosophila melanogaster. They are characterized and identified using phenotypic characters and 16S rRNA gene based molecular phylogenetic analysis. Interestingly, KT201599 and KT201600 are able to survive at 2000-2500 lg/mL sodium fluoride (NaF) concentrations. The chronic lethal concentration 50 (LC 50 ) for NaF in Drosophila larvae is 125 lg/mL, whereas, the abovementioned Bacillus strains isolated from their mid-gut are found to be more tolerant to fluoride (F) in comparison to their host. In search for biological relevance of KT201599 and KT201600, we further deciphered that these strains not only survived at high F concentrations, but also were efficient in removing the fluoride ions from the medium by 16.66 and 24.71% respectively. Thus, the study indicates that resident gut flora of Drosophila having the property of reducing fluoride load from the medium, might be helping the host to thrive in a fluoridated environment.

Characterization of a novel Fluoride resistant bacterial isolate and its capability of Fluoride bioremediation

“…Two Fluoride tolerant bacterial strains, Bacillus sp . KT201599 and KT201600, were isolated from the mid-gut of third instar larvae of Drosophila melanogaster , which could survive at 2000–2500 µg/mL sodium Fluoride (NaF) concentrations and have the capability to remove Fluoride from the media by 16.66 and 24.71%, respectively [18] . Meanwhile, Fluoride resistant isolate H1 with high Fluoride resistance of 4 g/L in LB broth, purified in this study, showed 38.2% Fluoride removal activity from the media with NaF concentration of 250 mg·L −1 after incubation of 72 h at temperature 37 °C and initial pH 7.…”