Chemical structures and biological activities of rhamnolipids produced by Pseudomonas aeruginosa B189 isolated from milk factory waste

101

The fermentative production of rhamnolipid biosurfactant from Pseudomonas aeruginosa MTCC 2297 was carried out by submerged fermentation using various cost-effective waste materials such as orange peelings, carrot peel waste, lime peelings, coconut oil cake, and banana waste. The orange peel was found to be the best substrate generating 9.18 g/l of rhamnolipid biosurfactant with a surface tension reduction up to 31.3 mN/m. The production was growth independent, and optimum conditions were standardized. The emulsifying activity was highest against kerosene (73.3%). Rhamnolipid components were purified and separated by ethyl acetate extraction, preparative silica gel column chromatography, high-performance liquid chromatography and thin-layer chromatography. The major rhamnolipid components were characterized, by fast atom bombardment mass spectrometry, as a mixture of dirhamnolipids and monorhamnolipids.

Section: Tlc Analysismentioning

confidence: 99%

“…Fast atom bombardment mass spectra (FAB-MS) [18,20] were recorded on a JEOL JMS 600 H mass spectrometer (Mass Spectrum Laboratory, NIST, Thiruvananthapuram). FAB positive ion mode was used and the matrix used was 4-nitro benzyl alcohol.…”

Section: Characterization Of Purified Rhamnolipidmentioning

confidence: 99%

Analysis of Rhamnolipid Biosurfactants Produced Through Submerged Fermentation Using Orange Fruit Peelings as Sole Carbon Source

Georgé

Jayachandran

2008

101

“…Therefore, attentions have been paid to the alternative environmental friendly manners for the production of these surface-active compounds especially microbiologically production of surfactants. The main reason is that biosurfactant take advantages over synthetic counterparts include lower toxicity, biodegradability, better environmental compatibility, higher foaming, high selectivity, specific activity at extreme temperatures, pH, and salinity [1,[5][6][7][8][9][10][11]. During the process of crude petroleum biodegradation, petroleum-degrading strains utilize petroleum hydrocarbons as sole source of carbon and energy.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization, and Oil Recovery Application of Biosurfactant Produced by Indigenous Pseudomonas aeruginosa WJ-1 Using Waste Vegetable Oils

Xia

Luo

Dong

et al. 2011

A bacterial strain was isolated and cultured from the oil excavation areas in tropical zone in northern China. The biochemical characteristics and partial sequenced 16S rRNA gene of isolate, WJ-1, was identical to those of cultured representatives of the species Pseudomonas aeruginosa. This bacterium was able to produce a type of biosurfactant. Compositional analysis revealed that the extracted biosurfactant was composed of high percentage lipid (∼74%, w/w) and carbohydrate (∼20%, w/w) in addition to a minor fraction of protein (∼6%, w/w). The best production of 50.2 g/l was obtained when the cells were grown on minimal salt medium containing 6.0% (w/v) glucose and 0.75% (w/v) sodium nitrate supplemented with 0.1% (v/v) element solution at 37 °C and 180 rpm after 96 h. The optimum biosurfactant production pH value was found to be 6.0-8.0. The biosurfactant of WJ-1, with the critical micelle concentration of 0.014 g/L, could reduce surface tension to 24.5 mN/m and emulsified kerosene up to EI(24) ≈95. The results obtained from time course study indicated that the surface tension reduction and emulsification potential was increased in the same way to cell growth. However, maximum biosurfactant production occurred and established in the stationary growth phase (after 90 h). Thin layer chromatography, Fourier transform infrared spectrum, and mass spectrum analysis indicate the extracted biosurfactant was affiliated with rhamnolipid. The core holder flooding experiments demonstrated that the oil recovery efficiency of strain and its biosurfactant was 23.02% residual oil.

“…The differences in rhamnolipids components depend on the bacterial strain and culture medium condition. It was reported that from two to 28 kinds of homologue were detected in rhamnolipids mixed samples [25,26]. The ratio of monorhamnolipids and dirhamnolipids produced by the strain GIM32 was about 1:3.27.…”

Section: Utilizing Molasses Distillery Wastewater As a Medium For Rhamentioning

confidence: 97%

Rhamnolipid Production by Pseudomonas Aeruginosa GIM 32 Using Different Substrates Including Molasses Distillery Wastewater

Liu

Sun

et al. 2010

A rhamnolipid production strain newly isolated from oil-contaminated soil was identified as Pseudomonas aeruginosa GIM32 by its morphology and 16S rDNA sequence analysis. The effect of carbon source and carbon to nitrogen (C/N) ratio on rhamnolipids production was investigated. Palm oil was favorable as a carbon source for rhamnolipid production. The maximum biomass and rhamnolipid concentration were 8.24 g/L and 30.4 g/L, respectively, with an optimization medium containing 50 g/L palm oil and 5 g/L sodium nitrate. Molasses distillery wastewater as an unconventional substrate for rhamnolipid production was investigated. It was found that 2.6 g/L of rhamnolipids was produced; this amount was higher than that of past reports using wastewater as a substrate. In addition, 44% of the chemical oxygen demand of wastewater was removed at the same time under the optimization condition. Eleven kinds of different molecular weight rhamnolipid homologues were identified in the rhamnolipids obtained from molasses distillery wastewater by P. aeruginosa GIM32 by LC-MS analysis.