HARSHA K., SHALIMA M.V. AND ASWATI R. NAIR
Abstract
Biosurfactants (BS) or green surfactants are amphiphilic compounds that enhance the bioavailability of hydrophobic organic compounds and also exhibit anti-phytopathogenic properties. BS-producing isolates thus find applications in soil remediation and development of biocontrol agents. Endophytes that confer several benefits to host plant constitute a good resource for prospecting BS-producing isolates. The present study screened the Z. zerumbet endophytes identified in earlier studies for BS production by hydrocarbon overlay agar method, CTAB- Methylene blue agar assay and determining Emulsification Index (EI24). EI24 was observed as the most desirable parameter to determine BS production compared to hydrocarbon overlay agar and CTAB- methylene blue agar plate assay. Isolate ZzADK4 (Bacillus spp) showed highest emulsification activity (58%) determined as EI% with kerosene. UV-vis spectral scans identified the endophytes as producing LP class of BS with absorbance maxima spanning 207- 216 nm. LP class of BS-producing endophytic isolates identified in the present study constitute potential solutions with applications in soil remediation and the development of biocontrol agents (BCAs).