MAHNAZ MAZAHERI ASSADJ, MAHSA ROSTAMZA, ASHRAFUL SADAT NOOHP, MOORIE LEVIN AND MANOOCHEHR SHAHAMATI
Abstract
A rhamnolipid producing bacterium, Pseudomonas aeruginosa MM1011 was previously isolated from soil contaminated with crude 'oil over years. Glycolipid production by isolated bacterium using sugar beet molasses as a carbon and energy source was investigated. Biosurfactant production was quantified by surface tension reduction, critical micelle dilution (CMD), Emulsification capacity (EC), and thin layer chromatography. Results at different agitation rates (100, 150, 200, 250 and 300 rpm) and incubation times (0-118) was examined. These parameters showed considerable effect on biosurfactant release. Biosurfactant production directly correlated with biomass production. After 72-96 h, the best growth of bacteria and highest rhamnolipid production was obtained when 2% sugar beet molasses was the carbon source. The rhamnolipid yield was 7.5 mg/mL and surface tension was reduced to 20 mN/m. This is the first report On a "wild type" biosurfactant producer on 2% sugar beet molasses.