Al- Anbar Medical Journal

Abstract

Objectives: The aim of research is purification and characterization of surlactin produced by Lactobacillus acidophilus isolated from vaginal swabs of healthy women. Materials and Methods: The stationary growth phase for Lactobacillus acidophilus isolated from vaginal swabs of healthy women from (Kamal Al-Samaraei and Al-Alweia Maternity Hospitals) in Baghdad was adopted on production of surlactin, after separation of bacterial cells from the growth media (Man-Rogosa Sharpe, MRS), incubated in phosphate buffer (0.1 molar)or four hours at temperature of 25 oC to produce Surlactin. It was purified by using paper filtration, dialyses and concentration using sucrose. Purified Surlactin is characterized by the best pH, incubation temperature and time, inoculation volume per 10 milliter of the media, storage condition and total molecular weight obtained by gel filtration. Also it studies the importance of magnesium and manganese sulfate for the bacterial growth and for surlactin production.Results: Results of purified and characterized surlactin showed that the best pH was at 6.0, while the incubation temperature and time were 25؛C for four hours with inoculation volume of 600 µ liter (6×107 cell / milliter) per 10 milliter of the media. It is active at a temperature up to 75؛C for an hour and it keeps its activity for six months when storage it at -20 ؛C , while at 4 ؛C it remains active for only one month. Total molecular weight is obtained by gel filtration and found to be 60-80 K Dalton. Magnesium and manganese sulfate are important for the bacterial growth and for surlactin production consequently at concentration of 0.04 and 0.01%, respectively for isolates.Conclusion: Lactobacillus acidophilus was isolated from healthy women, who were capable of producing crude surlactin in stationary phase of growth, then purified and characterized. Some physical and chemical factors affecting the ability of the bacteria in the production of surlactin had been studied, later identified optimal conditions for growth and increase production of surlactin.Keywords: Lactobacillus acidophilus, Surlactin, Biosurfactants, Purification.