1. Results and Discussion
Screening of biological surface active agent producer fungi from oil contaminated soil of Iran
Parvin Hasani Zadeh1,1, Hamid Moghimi1,2* and Javad Hamedi1,3
1 Msc in Microbial Biotechnology
2Assistant professor in Microbial Biotechnology
3Associate professor in Microbial Biotechnology
1Microbial Biotechnology Laboratory, Department of Microbiology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, , Tehran, Iran
Microbial Technology and Products Research Center, University of Tehran, , Tehran, Iran
Introduction
comparison to reports.
Figure 1: Addition supernatant of
G-13 has produced halo with 12.5
cm diameter in a plate contain water
covered with a layer of crude oil.
Morphological and molecular identification of this isolate by PCR of LSU gene and alignment of obtained sequence revealed that, this fungus has 99% similarity to Rhodotorula sp. and was released at university of Tehran Microorganisms Culture Collection by accession number UTMC 5046.
Biosurfactant production analysis was showed the maximum activity was occurred in 9 days after inoculation in mineral salt medium with 5% sunflower oil as sole carbon source.
Biosurfactants are ecofriendly surface active agents which produced as secondary metabolites by microorganisms. Variety of bacteria and few fungi are reported to produce biosurfactants using renewable sources. These compounds have many potential applications in various industries such as bioremediation of oil contamination and have lots of advantages in comparison to chemical ones. 
Materials and Methods
Here, we report yeast isolate with high potency to produce surface active agent from oil contaminated soil of Ghom, Iran. Isolation was done using crude oil enrichment method. The biosurfactant producing capability of the fungal isolates were screened using oil displacement activity, emulsification index assay and surface tension (SFT) measurement in a basal salt medium contains frying oil as carbon source. Molecular identification of selected isolate by PCR of LSU gene was done.
Results and Discussion
In this study, among 20 isolated fungi from crude oil contaminated soil of Iran, 4 isolates show biosurfactant production activity. G-13 was the best isolate by using oil spreading test, emulsification activity and Du Nouy ring method.
Table 1: Results of oil spreading test, emulsification activity test and measurment of reduction in surface tension for biosurfactant producing isolates
Figure 2: Microscopic scheme and colony morphology of Rhodotorula sp. UTMC 5046.
Figure 3: Biosurfactant production curve of Rhodotorula sp. UTMC 5046.
Conclusion
%EA
Surface tension (mN/m)
Diameter of halo in oil spreading test (cm)
Isolate 45
34.0±0.3
5.5
SH-1 30
.05±38.1 4
SH-12 40
.3±39.0
4.5
SH-50 80
.01±28.0 13
G-13
.23±44.57
control
According to the obtained results, Rhodotorula sp. UTMC 5046 showed high ability to biosurfactant production. High emusification activity of broth fermentation in this strain illustrates that it can be used as candidate for bioremediation of crude oil contaminated areas.
References
M. Bustamante, N. Durán, M. C. Diez , Biosurfactants are useful tools for the bioremediation of contaminated soil: a review 669 , Journal of Soil Science and Plant Nutrition 2012, 12 (4),
Nadielly R. Andrade Silva, Biosurfactant-and-Bioemulsifier Produced by a Promising Cunninghamella echinulata Isolated from Caatinga Soil in the Northeast of Brazil, Int. J. Mol. Sci. 2014, 15
Measurement of surface tension reduction by Du Nouy Ring method showed that G-13 isolate can reduce surface tension to 28.0 mN/m, which this amount of reduction is significant in