In this work,rhamnolipid production was investigated using waste frying oil as the sole carbon source. By culture in shaking flasks,a naturally isolated strain synthesized rhamnolipid at concentration of 12.47 g/L and...In this work,rhamnolipid production was investigated using waste frying oil as the sole carbon source. By culture in shaking flasks,a naturally isolated strain synthesized rhamnolipid at concentration of 12.47 g/L and its mutant after treatment by UV light increased this productivity to 24.61 g/L. Fermentation was also conducted in a 50 L bioreactor and the productivity reached over 20 g/L. Hence,with a stable and high productive mutant strain,it could be feasible to reuse waste frying oil for rhamnolipid production on industrial scale.展开更多
Rhamnolipid production by Pseudomonas aeruginosa ATCC 9027 with waste frying oil as sole carbon source was studied using response surface method. Cultures were incubated in shaking flask with temperature, NO3- and Mg2...Rhamnolipid production by Pseudomonas aeruginosa ATCC 9027 with waste frying oil as sole carbon source was studied using response surface method. Cultures were incubated in shaking flask with temperature, NO3- and Mg2+ concentrations as the variables. Meanwhile, fed-batch fermentation experiments were conducted. The results show that the three variables are closely related to rhamnolipid production. The optimal cultivation conditions are of 6.4 g/L NaNO3 , 3.1 g/L MgSO4 at 32 ℃, with the maximum rhamnolipid production of 6.6 g/L. The results of fed-batch fermentation experiments show that feeding the oil in two batches can enhance rhamnolipid production. The best time interval is 72 h with the maximum rhamnolipid production of 8.5 g/L. The data are potentially useful for mass production of rhamnolipid on oil waste with this bacterium.展开更多
In a time where surface active agents are capable of reducing the energy of the bonds between water molecules by interacting with them to reduce surface tension, it would be unwise not to be able to generate these in ...In a time where surface active agents are capable of reducing the energy of the bonds between water molecules by interacting with them to reduce surface tension, it would be unwise not to be able to generate these in masses. Different Pseudomonas species were grown in MSP （minimal sulphate phosphate） media containing salts, glycerol and glucose. P. aeruginosa grown aerobically in the presence of glycerol as carbon source showed the highest emulsion percentage （81.48%）, most significant decrease in surface tension （20 mN/m） and rhamnose production of 2.86 mg/mL. However, in anaerobic conditions there was no emulsion, rhamnolipid production or decrease in surface tension. The rhamnolipids were molecularly characterized using ESI-MS （electrospray ionization-mass spectrometry）, P. aeruginosa CVCM 411 is able to produce mono-rhamnolipids and di-rhamnolipids, being rhamnolipid RhC10C12.1 the predominant monomer. The specific growth rate for isolates ofP. aeruginosa and P.fluorescens in MSP are 0.6732 ht and 0.2181 h^-1, respectively. In conclusion, the formation of rhamnolipids by P. aeruginosa is linked to its growth （depending on μ）, and its ability to generate about 35% of the μmax in the presence of glucose （carbon source） and glycerol （applied as pulses）.展开更多
基金Project (No. 2006C100105) supported by the Ningbo Scientific Research Project, China
文摘In this work,rhamnolipid production was investigated using waste frying oil as the sole carbon source. By culture in shaking flasks,a naturally isolated strain synthesized rhamnolipid at concentration of 12.47 g/L and its mutant after treatment by UV light increased this productivity to 24.61 g/L. Fermentation was also conducted in a 50 L bioreactor and the productivity reached over 20 g/L. Hence,with a stable and high productive mutant strain,it could be feasible to reuse waste frying oil for rhamnolipid production on industrial scale.
基金Project(108100) supported by the Key Program for Science and Technology Research of Ministry of Education of ChinaProjects(50978087, 50908081) supported by the National Natural Science Foundation of China+1 种基金Project(531107011019) supported by the Hunan University Graduate Education Innovation Program, ChinaProject(CX2010B157) supported by the Hunan Provincial Innovation Foundation for Postgraduate students, China
文摘Rhamnolipid production by Pseudomonas aeruginosa ATCC 9027 with waste frying oil as sole carbon source was studied using response surface method. Cultures were incubated in shaking flask with temperature, NO3- and Mg2+ concentrations as the variables. Meanwhile, fed-batch fermentation experiments were conducted. The results show that the three variables are closely related to rhamnolipid production. The optimal cultivation conditions are of 6.4 g/L NaNO3 , 3.1 g/L MgSO4 at 32 ℃, with the maximum rhamnolipid production of 6.6 g/L. The results of fed-batch fermentation experiments show that feeding the oil in two batches can enhance rhamnolipid production. The best time interval is 72 h with the maximum rhamnolipid production of 8.5 g/L. The data are potentially useful for mass production of rhamnolipid on oil waste with this bacterium.
文摘In a time where surface active agents are capable of reducing the energy of the bonds between water molecules by interacting with them to reduce surface tension, it would be unwise not to be able to generate these in masses. Different Pseudomonas species were grown in MSP （minimal sulphate phosphate） media containing salts, glycerol and glucose. P. aeruginosa grown aerobically in the presence of glycerol as carbon source showed the highest emulsion percentage （81.48%）, most significant decrease in surface tension （20 mN/m） and rhamnose production of 2.86 mg/mL. However, in anaerobic conditions there was no emulsion, rhamnolipid production or decrease in surface tension. The rhamnolipids were molecularly characterized using ESI-MS （electrospray ionization-mass spectrometry）, P. aeruginosa CVCM 411 is able to produce mono-rhamnolipids and di-rhamnolipids, being rhamnolipid RhC10C12.1 the predominant monomer. The specific growth rate for isolates ofP. aeruginosa and P.fluorescens in MSP are 0.6732 ht and 0.2181 h^-1, respectively. In conclusion, the formation of rhamnolipids by P. aeruginosa is linked to its growth （depending on μ）, and its ability to generate about 35% of the μmax in the presence of glucose （carbon source） and glycerol （applied as pulses）.
