1.A novel cost-effective medium for the production of Bacillus thuringiensis subsp. israelensis for mosquito control
Subbiah Poopathi ; Archana, B.
Tropical Biomedicine 2012;29(1):81-91
Abstract. Bacillus thuringiensis subsp. israelensis (Bti) has been used for mosquito-control
programmes the world-wide. Indeed, the large-scale production of Bti for mosquito control is
very expensive due to the high cost of its culture. In the present study, we attempted to widen
the scope in developing cost-effective culture medium for Bti production, based on the raw
materials available on the biosphere, including coconut cake powder, CCP (Cocos nucifera),
neem cake powder, NCP (Azadirachta indica) and groundnut cake powder, GCP (Arachis
hypogea). Among these raw materials, the biomass production of Bti, sporulation and toxin
synthesizing from ‘CCP’ in combination with mineral salt (MnCl2) was comfortably satisfactory.
Bioassays with mosquito species (Culex quinquefasciatus, Anopheles stephensi and Aedes
aegypti) and field trials were also satisfactory. The present investigation suggests that coconut
cake-based culture medium can be used as an alternative for industrial production of Bti in
mosquito-control programme. Therefore, the study is very important from the point of effective
production of Bti from cost-effective culture medium for the control of mosquito vectors.
2.An investigation on the diversity of mosquitocidal bacteria and its relationship with incidence of vector borne diseases
Subbiah Poopathi ; De Britto, R.L.J ; Thirugnanasambantham, K ; Ragul, K ; Mani, C ; Balagangadharan, K.
Tropical Biomedicine 2015;32(1):84-97
Control of mosquitoes is the most important aspect of public health, as mosquitoes
transmit many human diseases, including the fatal infection, Japanese encephalitis. This
paper addresses the isolation of new mosquitocidal bacteria from soil samples in the Union
Territory of Pondicherry, India, where, no clinical cases of vector borne infections have been
reported. Bacterial isolates from soil samples were screened for potential mosquitocidal
strains and bioassays against mosquito vectors (Culex quinquefasciatus, Anopheles stephensi
and Aedes aegypti) were carried out. Genomic DNA of potential mosquitocidal isolates was
amplified and species identification was carried out using BLASTn program (NCBI).
Phylogenetic analysis of 16S rRNA sequences of mosquitocidal bacteria revealed seven
potential isolates. SDS-PAGE results have shown that there was considerable difference in
the protein profiles. Numerical analysis revealed 4 distinct groups at similarity level 25%. The
relationship between VBDs and prevalence of soil mosquitocidal bacteria in the study sites
has elicited considerable interest in the diversity of mosquitocidal bacteria and their application
for mosquito borne diseases control.