Fructilactobacillus sanfranciscensis
Fructilactobacillus sanfranciscensis | |
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Species: | F. sanfranciscensis |
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Fructilactobacillus sanfranciscensis (Weiss and Schillinger 1984) Zheng et al. 2020 | |
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Fructilactobacillus sanfranciscensis is a heterofermentative species of lactic acid bacteria which, through the production mainly of lactic and acetic acids, helps give sourdough bread its characteristic taste. It is named after San Francisco, where sourdough was found to contain the variety, though it is dominant in Type I sourdoughs globally.[2][3] In fact, F. sanfranciscensis has been used in sourdough breads for thousands of years, and is used in 3 million tons of sourdough goods yearly.[4]
Sourdough starters are leavened by a mixture of yeast and lactobacilli in a ratio of about 1:100. The yeast is most commonly Kasachstania humilis (formerly Candida humilis or C. milleri). This yeast cannot metabolize the maltose found in the dough, while the Fructilactobacillus requires maltose.[5] They therefore act without conflict for substrate, with lactobacilli utilizing maltose and the yeast utilizing the other sugars, including the glucose produced by the F. sanfranciscensis.
External conditions such as acidity and temperature affect the growth rates of F. sanfranciscensis. A temperature of 33 °C (91 °F) leads to maximum growth rates, whereas temperatures over 41 °C (105 °F) completely inhibit the bacteria growth. Ideal and maximum growth temperatures of other organisms may be quite different; for instance a common yeast in sourdough, K. humilis prefers 27 °C (81 °F) and will not grow above 36 °C (97 °F).[6]
For commercial use, specific strains of F sanfranciscensis are grown on defined media, freeze-dried, and shipped to bakeries worldwide.
References
- ↑ Zheng, Jinshui; Wittouck, Stijn; Salvetti, Elisa; Franz, Charles M.A.P.; Harris, Hugh M.B.; Mattarelli, Paola; O’Toole, Paul W.; Pot, Bruno; Vandamme, Peter; Walter, Jens; Watanabe, Koichi (2020). "A taxonomic note on the genus Lactobacillus: Description of 23 novel genera, emended description of the genus Lactobacillus Beijerinck 1901, and union of Lactobacillaceae and Leuconostocaceae". International Journal of Systematic and Evolutionary Microbiology. 70 (4): 2782–2858. doi:10.1099/ijsem.0.004107. ISSN 1466-5026. PMID 32293557.
- ↑ Gänzle, Michael G.; Zheng, Jinshui (2019-08-02). "Lifestyles of sourdough lactobacilli - Do they matter for microbial ecology and bread quality?". International Journal of Food Microbiology. 302: 15–23. doi:10.1016/j.ijfoodmicro.2018.08.019. ISSN 1879-3460. PMID 30172443.
- ↑ De Vuyst, Luc; Van Kerrebroeck, Simon; Leroy, Frédéric (2017). "Microbial Ecology and Process Technology of Sourdough Fermentation". Advances in Applied Microbiology. 100: 49–160. doi:10.1016/bs.aambs.2017.02.003. ISBN 9780128120484. ISSN 0065-2164. PMID 28732554.
- ↑ Rudi F. Vogel; Melanie Pavlovic; Matthias A. Ehrmann; Arnim Wiezer; Heiko Liesegang; Stefanie Offschanka; Sonja Voget; Angel Angelov; Georg Bocker; Wolfgang Liebl (1 September 2011). "Genomic analysis reveals Lactobacillus sanfranciscensis as stable element in traditional sourdoughs". Microbial Cell Factories. 10 (Suppl 1): S6. doi:10.1186/1475-2859-10-S1-S6. PMC 3231932. PMID 21995419.
- ↑ Neubauer H, Glaasker E, Hammes WP, Poolman B, Konings WN (1994). "Mechanism of maltose uptake and glucose excretion in Lactobacillus sanfrancisco". J Bacteriol. 176 (10): 3007–12. doi:10.1128/jb.176.10.3007-3012.1994. PMC 205458. PMID 8188601.
- ↑ Ganzle MG, Ehmann M, Hammes WP (1998). "Modeling of Growth of Lactobacillus sanfranciscensis and Candida milleri in Response to Process Parameters of Sourdough Fermentation". Appl Environ Microbiol. 64 (7): 2616–2623. doi:10.1128/AEM.64.7.2616-2623.1998. PMC 106434. PMID 9647838.