Evaluation of biosurfactant production potential of Lysinibacillus fusiformis MK559526 isolated from automobile-mechanic-workshop soil

Background Biosurfactants are amphipathic biological compounds with surface active potential and are produced by many microorganisms. Biosurfactant production by Lysinibacillus fusiformis MK559526 isolated from automobile-mechanic-shop soil was investigated with a view to assessing its potential for production and potential for optimization. Materials and methods Effects of carbon and nitrogen sources, pH, temperature and incubation periods on biosurfactant production were evaluated with a view to optimizing the processes. Fourier Transform Infra-Red absorption peaks and Gas chromatography mass spectrometry were used to determine the functional groups of the chemical make-up and the chemical profile of the biosurfactant respectively. Results Lysinibacillus fusiformis surfactant had emulsification index of 65.15 +/- 0.35 %, oil displacement of 2.7 +/- 0.26 mm, zone of haemolysis of 7.3 +/- 0.16 mm and a positive drop collapse test. Optimized culture conditions for biosurfactant production: temperature, 35 oC; pH, 7.0; starch solution, 40 g/L and urea, 1.5 g/L showed a reduction in surface tension to 28.46 +/- 1.11 mN/m and increased emulsification index to 93.80 +/- 0.41 %. Maximum biosurfactant production of 2.92 +/- 0.04 g/L was obtained after 72 h. The biosurfactant contained peptides and fatty acids. The predominant fatty acid was 9-Octadecenoic acid (80.80%). Conclusions The above results showing high emulsification potential and remarkable reduction in the surface tension are good biosurfactant attributes. Consequently, Lysinibacillus fusiformis MK559526 is a good candidate for biosurfactant production.

Automated summary

The biosurfactant produced by Lysinibacillus fusiformis demonstrated high emulsification potential and significant reduction in surface tension. After optimizing the culture conditions, both biosurfactant production and emulsification index were increased. The biosurfactant mainly consisted of peptides and fatty acids, with 9-Octadecenoic acid being the predominant fatty acid.