Vol. 3, Issue 2, Part A (2016)

Author(s): Dr. T Janaki

Abstract: Mosquito borne diseases are diseases caused by viruses, bacteria and parasitic organisms transmitted by mosquito vectors. The usage of chemical pesticides in the environment for controlling mosquitoes causes serious problem like bio-magnification of chemicals through food web. So, it is an alternative approach to find bio-pesticide from mangrove actinomycetes. Totally 25 actinomycetes were isolated by dry heat (70^oC) treatment method on SCA media, from the soil sample of the mangrove Avicennia marina from the back water area, Ariyankuppam, Puducherry (UT). Mosquito larvae used in this study was Culex quinquefasciatus (III instar). Among the 25 isolates, the isolate M20’s crude extract was found to better in controlling the larvae of Culex quinquefasciatus mosquitoes. 100% larval mortality was noted at the concentration 500 µl. The active isolate M20 was identified as Streptomyces cacaoi subsp cacaoi with 98.6% similarity with already reported sp (NRBC 12748(T)-AB184115. The isolate M20 was examined further for their physiological and biochemical characterization, the isolate M20 was chitinase positive. The partially purified compound fraction was used to confirm the bio insecticide activity of Culex quinquefasciatus further by VCRC, Puducherry. There was 98% of mortality recorded in 500µl/100ml partially purified compound fraction of M20 within 24 hours. UV-Vis spectral analysis of crude extract of isolate M20 revealed the compound belonged to nucleoside antibiotics. The GC-MS of partially purified compound fraction showed 5 compounds and these may responsible for inhibiting the growth and controlling the mosquito larvae effectively. It is evident that the mangrove actinomycetes are potential for controlling mosquito borne diseases through controlling of mosquito larva effectively for human welfare.

Related Graphics: Click here for more related graphics