LACTOBACİLLUS SANFRANCİSCENSİS’İN GELİŞMESİNDE ETKİLİ BİYOPROSES PARAMETRELERİNİN BELİRLENMESİ VE OPTİMİZASYONU

Öz

Son yıllarda, eski bir ekmek üretim metodu olan ekşi hamur ekmeğine yönelik talep artmıştır. Lactobacillus sanfranciscensis, heterofermantatif laktik asit bakterisidir ve maltozu kullanarak yüksek miktarlarda laktik asit ve asetik asit üreterek hamurun ekşimesine sebep olmaktadır. Bu çalışmada, farklı parametrelerinin L. sanfranciscensis’in gelişmesi üzerine etkisi incelenmiştir. En uygun azot kaynağı olarak maya ekstraktı, en uygun karbon kaynağı ise, maltoz olarak belirlenmiştir. En yüksek optik yoğunluk değerine fermantasyonun 48. saatinde ulaşılmıştır. pH, maltoz, maya ekstraktı ve Tryptic Soy Broth konsantrasyonlarının bakteri gelişimine etkisi incelenmiş ve bu parametrelerin optimum değerleri sırasıyla pH 6.5, %2 (w/v), %1.7 (w/v), %0.6 (w/v) olarak belirlenmiştir. Belirlenen optimum koşullar altında maksimum optik yoğunluk değeri 1.120±0.007 (biyokütle konsantrasyonu: 1.818±0.002 g/L) olarak bulunmuştur.

Anahtar Kelimeler

• Lactobacillus sanfranciscensis,starter kültür,optimizasyon,optik yoğunluk,azot kaynağı

DETERMINATION AND OPTIMIZATION OF THE BIOPROCESS PARAMETERS EFFECTING GROWTH OF LACTOBACILLUS SANFRANCISCENSIS

Öz

In recent years, there is an increasing demand for sourdough bread, which is one of the oldest methods of bread production. Lactobacillus sanfranciscensis is a heterofermentative lactic acid bacteria which produce large amounts of lactic acid and acetic acid from maltose and thus it is responsible for souring activity in sourdough. In this study, the effect of different cultivation parameters on the growth of L. sanfranciscensis has been evaluated. Maximum optical density was obtained at the 48^th hour of the fermentation. Yeast extract was determined as the most appropriate nitrogen source and maltose was determined as the most appropriate carbon source. The optimum levels of pH, maltose, yeast extract and Tryptic Soy Broth were found as pH 6.5, 2% (w/v), 1.7% (w/v), 0.6% (w/v), respectively. Under optimized conditions, the optical density of 1.120±0.007 was obtained which corresponds to a biomass dry weight of 1.818±0.002 g/L.

Anahtar Kelimeler

• Lactobacillus sanfranciscensis,starter culture,optimization,optical density,nitrogen source

Kaynakça

1. Aeschlimann, A., Von Stockar, U. (1990). The effect of yeast extract supplementation on the production of lactic acid from whey permeate by Lactobacillus helveticus. Appl Microbiol Biotechnol, 32:398–402, doi: 10.1007/BF00903772.
2. Amrane, A., Prigent, Y. (1997). Growth and lactic acid production coupling for Lactobacillus helveticus cultivated on supplemented whey: Influence of peptidic nitrogen deficiency. J Biotechnol, 55(1): 1–8, doi:10.1016/S0168-1656(97)00041-2.
3. De Vuyst, L., Neysens, P. (2005). The sourdough microflora: biodiversity and metabolic interactions. Trends Food Sci Technol, 16:43-56, doi: 10.1016/j.tifs.2004.02.012.
4. De Vuyst, L., Van Kerrebroeck, S., Harth, H., Huys, G., Daniel, H.M., Weckx, S. (2014). Microbial ecology of sourdough fermentations: diverse or uniform?. Food Microbiol, 37:11-29, doi: 10.1016/j.fm.2013.06.002.
5. Decock, P., Cappelle, S. (2005). Bread technology and sourdough technology. Trends Food Sci Technol, 16(1–3): 113–120, doi:10.1016/j.tifs.2004.04.012.
6. Ercolini, D., Pontonio, E., De Filippis ,F., Minervini, F., La Storia, A., Gobbetti, M., Di Cagnob, R. (2013). Microbial ecology dynamics during rye and wheat sourdough preparation. Appl. Environ Microbiol, 79 (24):7827-7836, doi: 10.1128/AEM.02955-13.
7. Gobbetti, M., Corsetti, A. (1997). Lactobacillus sanfrancisco a key sourdough lactic acid bacterium: a review. Food Microbiol, 14:175–187.
8. Gobbetti, M., De Angelis, M., Corsetti, A., Cagno, R.D. (2005). Biochemistry and physiology of sourdough lactic acid bacteria. Trends Food Sci Technol, 16:57–69, doi: 10.1016/j.tifs.2004.02.013.

9. Gobbetti, M., Minervini, F., Pontonio, E., Di Cagno, R., De Angelis, M. (2016). Drivers for the establishment and composition of the sourdough lactic acid bacteria biota. Int J Food Microbiol, 239:3-18, doi:10.1016/j.ijfoodmicro.2016.05.022.
10. Göçmen, D. (2001). Ekşi hamur ve laktik asit starter kullanımının ekmekte aroma oluşumu üzerine etkileri. GIDA, 26(1):13-16.
11. Göksungur, Y. (1998). Melastan laktik asit üretiminde farklı üretim tekniklerinin kullanılabilirliği ve ortam şartlarının optimizasyonu. Ege Üniversitesi Fen Bilimleri Enstitüsü Gıda Mühendisliği Anabilim Dalı Doktora Tezi, İzmir, Türkiye, 155s.
12. Hammes, W.P., Brandt, M.J., Francis, K.L., Rosenheim, J., Seitter, M.F.H., Vogelmann, S.A. (2005). Microbial ecology of cereal fermentations. Trends Food Sci Technol, 16: 4-11, doi: 10.1016/j.tifs.2004.02.010.
13. Hendek Ertop, M., Hayta, M. (2016). Ekşi hamur fermantasyonunun ekmeğı̇ bı̇yoaktı̇f bı̇leşenlerı̇ ve bı̇yoyararlanim üzerı̇ndeki etkı̇lerı̇. GIDA, 41(2): 115-122, doi: 10.15237/gida.GD15053.
14. Kline, L., Sugihara, T.F. (1971). Microorganisms of the San Francisco sour dough bread process. II. Isolation and characterization of undescribed bacterial species responsible for the souring activity. Appl Microbiol, 21 (1971):459-465.
15. Leroy, F., De Vuyst, L. (2004). Lactic acid bacteria as functional starter cultures for the food fermentation industry. Trends Food Sci Technol, 15: 67–78, doi:10.1016/j.tifs.2003.09.004.
16. Messens, W., Neysens P., Vansieleghem, W., Vanderhoeven, J., De Vuyst, L. (2002). Modeling growth and bacteriocin production by Lactobacillus amylovorus dce 471 in response to temperature and ph values used for sourdough fermentations. Appl Environ Microbiol, 63:1431-1435, doi: 10.1128/AEM.68.3.1431–1435.2002.
17. Neubauer, H., Glaasker, E., Hammes, W.P., Poolman, B., Konings, W.I.L.N. (1994). Mechanism of maltose uptake and glucose excretion in Lactobacillus sanfrancisco. J. Bacteriol, 1(5): 3007–3012, doi: 0021-9193/94/$04.00+0.
18. Paramithiotis, S., Chouliaras, Y., Tsakalidou, E., Kalantzopoulos, G. (2005). Application of selected starter cultures for the production of wheat sourdough bread using a traditional three-stage procedure. Process Biochem, 40:2813–2819, doi:10.1016/j.procbio.2004.12.021.
19. Rehman, S., Paterson, A., Piggott, J.R. (2006). Flavour in sourdough breads : a review. Trends Food Sci Technol, 17: 557-566, doi:10.1016/j.tifs.2006.03.006.
20. Stolz, P., Böcker, G., Vogel, R.F., Hammes, W.P. (1993). Utilisation of isolated from maltose and glucose by sourdough Lactobacilli isolated from sourdough. FEMS Microbiol Lett, 109: 237-242.
21. Weiss, N., Schillinger, U. (1984). Lactobacillus sanfrancisco sp. Nov., nom. Rev. Syst Appl Microbiol., 5: 230-232.