HA, MDC, TGST efficiently detected 15, 17 and 14 biosurfactant producers respectively. Five hemolytic cultures did not show any biosurfactant production in MDC, TGST, and/or OSM. The emulsification of kerosene was also poorer. These results suggest that HA is not totally reliable. Six bacterial isolates produced biosurfactant in OSM, and MDC as well as TGST. MDC and TGS tests demonstrated good activity for nine isolates and proved to be the essential methods. None of the bacteria produced glycolipid on BAP. Cultures showing >30% of emulsification with kerosene were found to be positive in at least one of the above mentioned screening methods. The reference strains, Gram negative bacterium MM73b produced 68% the highest emulsification and demonstrated biosurfactant production in modified drop collapse, tilted glass slide test with highest emulsification units of 213.8 (EU/ml) for petrol.