Production of biosurfactant on crude date syrup under saline conditions by entrapped cells of Natrialba sp. strain E21, an extremely halophilic bacterium isolated from a solar saltern (Ain Salah, Algeria)
- 438 Downloads
A bacterial strain E21 was isolated from a sample of water collected in the salt lake located close to Ain Salah, Algeria. The analysis of 16S rRNA gene sequence had indicated that the strain had 93 % sequence similarity with the genus Natrialba sp. strain E21 (GenBank, FR750525.1) and was considered extremely halophilic. Production of biosurfactant by the strain E21 with free and entrapped cells was investigated using soluble starch in the saline conditions. Biosurfactant synthesis was followed by measuring the surface tension and emulsifying index 9 days under optimal conditions (40 °C, pH 7). Some diffusional limitations in alginate and agar beads affected the kinetics of biosurfactant production when compared to that obtained with free cells culture. The minimum values of surface tension were 27 and 30 mN m−1 achieved after 9 days with free and immobilized cells, respectively, while the corresponding maximum E24 values were 65.3 and 62.3 %, respectively. The re-use of bacterial cells along with the limited cell losses provided by the immobilized system might lead to significant reduction of the biosurfactant production cost.
KeywordsNatrialba sp. strain E21 Cells immobilization Alginate Biosurfactant production
This work was supported by the assistance of the Algerian Ministry of Education grant PNR project (14/u35/1360) http://www.nasr-dz.org/dprep/pnr2/projets-pnr/PNR_efghi.htm.
- Bodour AA, Drees KP, Maier RM (2003) Distribution of biosurfactant-producing bacteria in undisturbed and contaminated arid Southwestern soils. Appl Environ Microbiol 69:3280–3287Google Scholar
- Hezayen FF, Rehm BH, Tindall BJ, Steinbüchel A (2001) Transfer of Natrialba asiatica B1T to Natrialba taiwanensis sp. nov. and description of Natrialba aegyptiaca sp. nov., a novel extremely halophilic, aerobic, non-pigmented member of the Archaea from Egypt that produces extracellular poly (glutamic acid). Int J Syst Evol Microbiol 51:1133–1142PubMedCrossRefGoogle Scholar
- Ogugbue CJ, Akubuenyi F, Ibiene AA (2012) Bacterial decolourization of acid orange 10 in synthetic wastewater under saline conditions: effect of process parameters. Singap J Sci Res 2:1–13Google Scholar
- Stewart P, Robertson C (1989) Microbial growth in a fixed volume: studies with entrapped Escherichia coli. Appl Microbiol Biotechnol 30:10–12Google Scholar
- Tambekar DH, Gadakh PV (2013) Biochemical and molecular detection of biosurfactant producing bacteria from soil. Int. J. LifeSci Biotechnol Pharm. Res 2:204–211Google Scholar
- Tamura K, Peterson D, Peterson N, Stecher G, Nei M, Kumar S (2011) MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Mol Biol EvolGoogle Scholar