{"title":"Black-carrot drink şalgam as a habitat for spoilage yeasts","authors":"Dilek Safkan , Bilal Agirman , Bekir Safkan , Yesim Soyer , Huseyin Erten","doi":"10.1016/j.funbio.2024.01.002","DOIUrl":null,"url":null,"abstract":"<div><div><em>Şalgam</em><span> is a traditional drink produced via the lactic-acid fermentation of vegetables (black carrot and turnip), sourdough, and bulgur<span> flour; with rock salt also added. During storage, an additional yeast-mediated fermentation can occur, causing changes in organoleptic properties, as evidenced by the microbe-mediated release of gases. Here, we characterise </span></span><em>şalgam</em> as a microbial habitat, identify the yeasts that cause spoilage, and characterise yeast-induced changes of the <em>şalgam</em>. The total acidity of the spoiled <em>şalgam</em>, in terms of lactic acid, ranged from 5.33 to 8.36 g/L with pH values from 3.86 to 4.10. Nine different spoilage fungi were isolated and then identified using molecular techniques (combination of PCR-RFLP of the 5.8 S-rRNA region and sequencing of the D1/D2 domain of the 26 S-rRNA gene). The highest frequencies of species were for the (apparently dominant) <span><em>Saccharomyces cerevisiae</em></span>, <span><em>Galactomyces</em><em> candidum</em></span>, and <span><span>Pichia kudriavzevii</span></span>. Notably, two of these yeasts—<em>P. kudriavzevii</em> and <em>Saccharomyces cerevisiae</em><span>—are known to be acid-tolerant, have a robust stress biology, and can dominate various microbial habitats including those of fermented foods and drinks. </span><em>Şalgam</em> is a nutrient-rich, high-water-activity habitat that can favour the growth of various microbes and becomes less acidic (so more ecologically open) after the proliferation of yeasts.</div></div>","PeriodicalId":12683,"journal":{"name":"Fungal biology","volume":"128 8","pages":"Pages 2471-2478"},"PeriodicalIF":2.9000,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Fungal biology","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1878614624000023","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MYCOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Şalgam is a traditional drink produced via the lactic-acid fermentation of vegetables (black carrot and turnip), sourdough, and bulgur flour; with rock salt also added. During storage, an additional yeast-mediated fermentation can occur, causing changes in organoleptic properties, as evidenced by the microbe-mediated release of gases. Here, we characterise şalgam as a microbial habitat, identify the yeasts that cause spoilage, and characterise yeast-induced changes of the şalgam. The total acidity of the spoiled şalgam, in terms of lactic acid, ranged from 5.33 to 8.36 g/L with pH values from 3.86 to 4.10. Nine different spoilage fungi were isolated and then identified using molecular techniques (combination of PCR-RFLP of the 5.8 S-rRNA region and sequencing of the D1/D2 domain of the 26 S-rRNA gene). The highest frequencies of species were for the (apparently dominant) Saccharomyces cerevisiae, Galactomyces candidum, and Pichia kudriavzevii. Notably, two of these yeasts—P. kudriavzevii and Saccharomyces cerevisiae—are known to be acid-tolerant, have a robust stress biology, and can dominate various microbial habitats including those of fermented foods and drinks. Şalgam is a nutrient-rich, high-water-activity habitat that can favour the growth of various microbes and becomes less acidic (so more ecologically open) after the proliferation of yeasts.
期刊介绍:
Fungal Biology publishes original contributions in all fields of basic and applied research involving fungi and fungus-like organisms (including oomycetes and slime moulds). Areas of investigation include biodeterioration, biotechnology, cell and developmental biology, ecology, evolution, genetics, geomycology, medical mycology, mutualistic interactions (including lichens and mycorrhizas), physiology, plant pathology, secondary metabolites, and taxonomy and systematics. Submissions on experimental methods are also welcomed. Priority is given to contributions likely to be of interest to a wide international audience.