Isolation and identification of an exopolysaccharide producer Streptococcus thermophilus strain from Turkish yogurt

Starter Laktik Asit Bakterileri (LAB) tarafından ekzopolisakkarit (EPS) üretimi bu doğal polimerlerin teknolojik rollerinden dolayı son yıllarda önem kazanmıştır. Bu çalışmada yoğurt örnekleri yerel kaynaklardan toplanmış, bakteriler izole edilmiş ve bu türlerin EPS üretimi test edilmiştir. EPS üretim potansiyeli gösteren suşlar 16S rRNA sekanslama tekniği ile suş seviyesine kadar tanımlanmıştır. Bu çalışmalar neticesinde EPS üretimi gösteren bir Streptecoccus thermophilus suşu tanımlanmıştır. EPS S. thermophilusun kültür süpernatantından ekstrakte edilmiş, kısmi olarak safaştırılmış ve FTIR spektreskopi ile gerçekleştirilen yapısal analiz ekstraktın ekzopolisakkaritler ile alakalı tipik fonksiyonel grupları içerdiğini göstermiştir. Bu çalışma yoğurt üretimi için EPS üretme kabiliyetinde olan potansiyel bir starter kültürün tanımlanmasını açıklamaktadır.

Yoğurttan ekzopolisakkarit üreten streptococcus thermophilus suşunun izolasyonu ve tanımlanması

Production of exopolysaccharides (EPS) by starter Lactic acid bacteria (LAB) gained special interest due to technological role of these natural polymers. Yogurt samples were collected from diferent households in Turkey and bacterial strains were isolated and evaluated for EPS production. Strains potentially producing EPS were then identified to species level with 16S rRNA sequencing. An EPS producer Streptecoccus thermophilus strain was identified from yogurt samples. EPS was extracted from culture supernatants of S. thermophilus and partially purified and structural analysis of the crude EPS by FTIR spectroscopy revealed the presence of typical functional groups related to exopolysaccharides. This study explains the identification of a potential starter culture for yogurt production with EPS production.

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1. De Vuyst L, Degeest B: Heteropolysaccharides from lactic acid bacteria. FEMS Microbiol Rev, 23 (2): 153-177, 1999.
2. Delcour J, Ferain T, Deghorain M, Palumbo E, Hols P: The biosynthesis and functionality of the cell-wall of lactic acid bacteria. Antonie Van Leeuwenhoek , 76 (1-4): 159-184,1999. DOI: 10.1007/978-94-017-2027-4_7
3. Badel S, Bernardi T, Michaud P: New perspectives for Lactobacilli exopolysaccha rides. Biotechnol Adv, 29 (1): 54-66,2011. DOI : 10.1016/j. biotechadv.2010.08.011
4. Guzel-Seydim ZB, Sezgin E, Seydim AC: Infuences of exopolysaccharide producing cultures on the quality of plain set type yogurt. Food Control, 16 (3): 205-209, 2005. DOI : 10.1016/j.foodcont.2004.02.002
5. Doleyres Y, Schaub L, Lacroix C: Comparison of the functionality of exopolysaccharides produced in situ or added as bioingredients on yogurt properties. J Dairy Sci, 88 (12): 4146-4156, 2005. DOI : 10.3168/jds.S0022- 0302(05)73100-3
6. Aslim B, Onbasili D, Yuksekdag ZN: Determination of lactic acid production and antagonistic activity against Helicobacter pylori of L. delbrueckii subsp. bulgaricus and S. thermophilus strains. Kafkas Univ Vet Fak Derg , 17 (4): 609-614, 2011.
7. Ruas-Madiedo PCG, de los Reyes-Gavilan: Invited review: Methods for the screening, isolation, and characterization of exopolysaccharides produced by lactic acid bacteria. J Dairy Sci, 88 (3): 843-856, 2005. DOI : 10.3168/jds.S0022-0302(05)72750-8
8. Baker GC, Smith JJ, Cowan DA: Review and re-analysis of domain- specific 16S primers. J Microbiol Methods, 55 (3): 541-555, 2003. DOI : 10.1016/j.mimet.2003.08.009
9. Cole JR, Chai1 B, Farris RJ, Wang Q, Kulam SA, McGarrell DM, Garrity GM J. M. Tiedjeet JM: The ribosomal database project (RDP-II): Sequences and tools for high-throughput rRNA analysis. Nucleic Acids Res, 33 (Suppl. 1): D294-D296, 2005. DOI : 10.1093/nar/gki038
10. Horn N, Wegmann U, Dertli E, Mulholland F, Collins SR, Waldron KW, Bongaerts RJ, Mayer MJ, Narbad A: Spontaneous mutation reveals infuence of exopolysaccharide on Lactobacillus johnsonii surface characteristics. PLoS One , 8 (3): e59957, 2013. DOI: 10.1371/journal. pone.0059957
11. Bauer R, Bekker JP, Wyk N, du Toit C, Dicks LMT, Kossmann J: Exopolysaccharide production by lactose-hydrolyzing bacteria isolated from traditionally fermented milk. Int J Food Microbiol, 131 (2-3): 260- 264, 2009. DOI : 10.1016/j.ijfoodmicro.2009.02.020
12. Kanmani P, Satish Kumar R, Yuvaraj N, Paari KA, Pattukumar V, Arul V: Production and purification of a novel exopolysaccharide from lactic acid bacterium Streptococcus phocae PI80 and its functional characteristics activity in vitro. Bioresour Technol, 102 (7): 4827-4833, 2011. DOI : 10.1016/j. biortech.2010.12.118
13. Wang Y, Ahmed Z, Feng W, Li C, Song S: Physicochemical properties of exopolysaccharide produced by Lactobacillus kefiranofaciens ZW3 isolated from Tibet kefir. Int J Biol Macromol, 43 (3): 283-288, 2008. DOI : 10.1016/j.ijbiomac.2008.06.011
14. Yuan SJ, Sun M, Sheng GP, Li Y, Li WW, Yao RS, Yu HQ: Identification of key constituents and structure of the extracellular polymeric substances excreted by Bacillus megaterium TF10 for their focculation capacity. Environ Sci Technol, 45 (3): 1152-1157, 2011. DOI: 10.1021/es1030905
15. Lemoine J, Chirat F, Wieruszeski JM, Strecker G, Favre N, Neeser JR: Structural characterization of the exocellular polysaccharides produced by Streptococcus thermophilus SFi39 and SFi12. Appl Environ Microbiol, 63 (9): 3512-3518, 1997.
16. Petersen BL, Dave RI, McMahon DJ, Oberg CJ, Broadbent JR: Infuence of capsular and ropy exopolysaccharide-producing Streptococcus thermophilus on mozzarella cheese and cheese whey. J Dairy Sci, 83 (9): 1952-1956, 2000. DOI : 10.3168/jds.S0022-0302(00)75071-5
17. Stingele F, Neeser JR, Mollet B: Identification and characterization of the eps (Exopolysaccharide) gene cluster from Streptococcus thermophilus Sfi6. J Bacteriol, 178 (6): 1680-1690, 1996.
18. Bubb WA, Urashima T, Fujiwara R, Shinnai T, Ariga H: Structural characterisation of the exocellular polysaccharide produced by Streptococcus thermophilus OR 901. Carbohydrate Res, 301 (1-2): 41-50, 1997. DOI : 10.1016/ S0008-6215(97)00083-9
19. Doco T, Wieruszeski JM, Fournet B, Carcano D, Ramos P, Loones A: Structure of an exocellular polysaccharide produced by S treptococcus thermophilus. Carbohydr Res, 198 (2): 313-321, 1990. DOI : 10.1016/0008- 6215(90)84301-A
20. Low D, Ahlgren JA, Horne D, McMahon DJ, Oberg CJ, Broadbent JR: Role of Streptococcus thermophilus MR-1C capsular exopolysaccharide in cheese moisture retention. Appl Environ Microbiol, 64 (6): 2147-2151, 1998.