Exopolysaccharide-Producing Halophilic and Halotolerant Microorganisms Isolated from the Saline Lakes Qarun (Egypt) and Elton (Russia)
Microorganisms inhabiting saline environments can produce compounds unique in structure and properties. This ability recently prompted researchers to study the biotechnological potential of halophiles. This work aimed at screening the exopolysaccharideproducing halophilic and halotolerant microorganisms of two saline lakes, one in in Egypt and the other in Russia. For strain isolation and characterization, we used microbiological and physico-chemical methods, as well as light and transmission electron microscopy. Taxonomy studies of the isolates was studied on the basis of analyses of cultural and morphological characteristics, biochemical properties and 16S rDNA sequencing data. Of 104 isolates adapted to saline environments we selected 49 exopolysaccharide-producing strains. The content of polysaccharides in the culture liquids of the isolated microorganisms reached 13.7 mg/ml-1. Sixteen isolates were identified to species.
1. Aneiros A., Garatei A. Bioactive peptides from marine sources. Pharmacological properties and isolation procedures // J. Chromatogr. B. Anal. Technol. Biomed. Life Sci. 2004. Vol. 15. P. 41–53.
2. Ma Y., Galinski E. A., Grant W. D., Oren A., Ventosa A. Halophiles 2010 : life in saline environments // Appl. Environ. Microbiol. 2010. Vol. 76(21). P. 6971–6981.
3. Gontia-Mishra I., Sapre S., Tiwari S. Diversiy of halophilic bacteria and actinobacteria from India and their biotechnological applications // Ind. J. Geo Marine Sci. 2017. Vol. 46 (8). P. 1575–1587.
4. Johnson A., Thurlow L., Zwenger R., Gillock E. Partial characterization of two moderately halophilic bacteria from a Kansas salt marsh // Prairie Nat. 2007. Vol. 39. P. 29–39.
5. Rodriguez-Valera F., Ruiz-Berraquero F., Ramos-Cormenzana A. Characteristics of the heterotrophic bacterial populations in hypersaline environments of different salt concentrations // Microb. Ecol. 1981. Vol. 7 (3). P. 235–243.
6. Rodriguez-Valera F. Characteristics and microbial ecology of hypersaline environments // Halophilic Bacteria / ed. F. Rodriguez-Valera. CRC Press, Boca Raton, Fla, USA, 1988. Vol. 1. P. 3–30.
7. Kushner D. J., Kamekura M. Physiology of halophilic eubacteria // Halophilic Bacteria / ed. F. RodriguezValera. CRC Press, Boca Raton, Fla, USA, 1988. Vol. 1. P. 109–138.
8. Elbanna K., Ibrahim I. M., Revol-Junelles A.-M. Purifi - cation and characterization of halo-alkali-thermophilic protease from Halobacterium sp. strain HP25 isolated from raw salt, Lake Qarun, Fayoum, Egypt // Extremophiles. 2015. Vol. 19 (4). P. 763–774.
9. Korany A. H., Ali A. E., Essam T. M., Megahed S. A. Optimization of cellulase production by Halobacillus sp. QLS 31 isolated from Lake Qarun, Egypt // Appl. Biochem. Biotechnol. 2017. Vol. 183 (1). P. 189–199.
10. Sutherland I. W. Bacterial exopolysaccharides // Adv. Microb. Physiol. 1972. Vol. 8. P. 143–213.
11. Ventosa A., Mellado E., Sa nchez-Porro C., Ma rquez M. C. Halophilic and halotolerant microorganisms from soils // Microbiology of extreme soils / eds. P. Dion, C. S. Nautiyal. Heidelberg : Springer, 2008. P. 85–11.
12. Litchfi eld C. D. Potential for industrial products from the halophilic Archaea // J. Ind. Microbiol. Biotechnol. 2012. Vol. 38. P. 1635–1647.
13. Biswas J., Paul A. K. Production of extracellular polymeric substances by halophilic bacterial diversity in multi-pond solar salterns // Chinese J. Biol. 2014. Vol. 12. https://doi.org/10.1155/2014/205731
14. Casillo A., Lanzetta R., Parrilli M., Corsaro M. M. Exopolysaccharides from marine and marine extremophilic bacteria: structures, properties, ecological roles and applications // Mar. Drugs. 2018. Vol. 16 (2). https://doi.org/10.3390/md16020069
15. Sutherland I. W. Microbial exopolysaccharides-structural subtleties and their consequences // Pure Appl. Chem. 1997. Vol. 69 (9). P. 1911–1917.
16. Dussault H. P. An improved technique for staining halophilic bacteria // J. Bacteriol. 1955. Vol. 70. P. 484–485.
17. Gerhardt P., Murray R. G. E., Wood W. A., Krieg N. R. Methods for general and molecular bacteriology / American Society for Microbiology, Washington, D.C., 1994. P. 607–654.
18. Nieto J., Fernandez-Castillo R., Marquez M., Ventosa A., Quesada E., Ruiz Berraquero F. Survey of metal tolerance in moderately halophilic eubacteria // Appl. Environ. Microbiol. 1989. Vol. 55. P. 2385–2390.
19. DuBois M., Gilles K. A., Hamilton J. K., Rebers P. A., Smith F. Calorimetric method for determination of sugars and related substances // Anal. Chem. 1956. Vol. 28. P. 350–356.
20. Hezayen F. F., Tindall B. J., Steinbuchel A., Rehm B. Characterization of a novel halophilic archaeon, Halobiforma haloterrestris gen. nov., sp. nov., and transfer of Natronobacterium nitratireducens to Halobiforma nitratireducens comb. nov. // Intern. J. Syst. Evol. Microbiol. 2002. Vol. 52. P. 2272–2280.
21. Weisburg W. G., Barns S. M., Pelletier D. A., Lane D. J. 16S ribosomal DNA amplification for phylogenetic study // J. Bacteriol. 1991. Vol. 173 (2). P. 697–703.
22. Fang Y., Ahmed S., Liu S., Wang S., Lu M., Jiao Y. Optimization of antioxidant exopolysaccharidess production by Bacillus licheniformis in solid state fermentation // Carbohydr. Polym. 2013. Vol. 98 (2). P. 1377–1382.
23. Hedi A., Sadfi N., Fardeau M. L., Rebib H., Cayol J. L. Ollivier B., Boudabous A. Studies on the biodiversity of halophilic microorganisms isolated from El-Djerid salt lake (Tunisia) under aerobic conditions // Intern. J. Microbiol. 2009. https://doi.org/10.1155/2009/731786
24. Jayachandra S. Y., Kumar S. A., Merley D. P., Sulochana M. B. Isolation and characterization of extreme halophilic bacterium Salinicoccus spp. JAS4 producing extracellular hydrolytic enzymes // Rec. Res. Sci. Technol. 2012. Vol. 4 (4). P. 46–49.