Isolation and Identification of Lactose-Degrading Yeasts and Characterisation of Their Fermentation-Related Ability to Produce Ethanol
Kefir is traditionally produced by fermenting cow’s milk using kefir grains as a starter culture. As the viability of microbes within kefir grains is limited and preparing the grains for kefir fermentation is laborious, here, a single starter that ferments lactose and produces ethanol is developed....
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-04-01
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| Series: | Fermentation |
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| Online Access: | https://www.mdpi.com/2311-5637/8/4/183 |
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| author | Murni Kurniawati Nurliyani Nurliyani Wiratni Budhijanto Widodo Widodo |
| author_facet | Murni Kurniawati Nurliyani Nurliyani Wiratni Budhijanto Widodo Widodo |
| author_sort | Murni Kurniawati |
| collection | DOAJ |
| description | Kefir is traditionally produced by fermenting cow’s milk using kefir grains as a starter culture. As the viability of microbes within kefir grains is limited and preparing the grains for kefir fermentation is laborious, here, a single starter that ferments lactose and produces ethanol is developed. For this purpose, it is important to isolate yeasts that can ferment lactose and subsequently produce alcohol. This study aimed to isolate and identify yeasts from kefir and characterise their ability as single starters to produce kefir. Based on morphological and physiological evaluations, 15 presumptive yeast isolates were obtained, 10 of which grew well on lactose-containing media. Those that were able to grow on lactose using only carbon sources were subjected to molecular identification based on the internal transcribed spacer (ITS) of the 5.8 rDNA using PCR technology. Molecular identification confirmed four isolates—namely, KFA 3, KFA 7, KFA 9 and KFB 1—as belonging to <i>Kluyveromyces marxianus</i>. The batch fermentation data of these strains were fitted on a logistic model to obtain the carrying capacity coefficients and strain performances were compared. The kinetic modelling revealed that KFA 9 had the highest values for the carrying capacity coefficient, biomass yield and product yield, indicating that, among the four <i>K. marxianus</i> strains, this was superior due to its relatively fast growth and good ethanol productivity. |
| first_indexed | 2024-03-09T10:37:58Z |
| format | Article |
| id | doaj.art-b54ce47677664959b6303bec42e3498a |
| institution | Directory Open Access Journal |
| issn | 2311-5637 |
| language | English |
| last_indexed | 2024-03-09T10:37:58Z |
| publishDate | 2022-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fermentation |
| spelling | doaj.art-b54ce47677664959b6303bec42e3498a2023-12-01T20:52:13ZengMDPI AGFermentation2311-56372022-04-018418310.3390/fermentation8040183Isolation and Identification of Lactose-Degrading Yeasts and Characterisation of Their Fermentation-Related Ability to Produce EthanolMurni Kurniawati0Nurliyani Nurliyani1Wiratni Budhijanto2Widodo Widodo3Department of Technology of Animal Products, Faculty of Animal Science, Universitas Gadjah Mada, Yogyakarta 55281, IndonesiaDepartment of Technology of Animal Products, Faculty of Animal Science, Universitas Gadjah Mada, Yogyakarta 55281, IndonesiaChemical Engineering Department, Faculty of Engineering, Universitas Gadjah Mada, Yogyakarta 55281, IndonesiaDepartment of Technology of Animal Products, Faculty of Animal Science, Universitas Gadjah Mada, Yogyakarta 55281, IndonesiaKefir is traditionally produced by fermenting cow’s milk using kefir grains as a starter culture. As the viability of microbes within kefir grains is limited and preparing the grains for kefir fermentation is laborious, here, a single starter that ferments lactose and produces ethanol is developed. For this purpose, it is important to isolate yeasts that can ferment lactose and subsequently produce alcohol. This study aimed to isolate and identify yeasts from kefir and characterise their ability as single starters to produce kefir. Based on morphological and physiological evaluations, 15 presumptive yeast isolates were obtained, 10 of which grew well on lactose-containing media. Those that were able to grow on lactose using only carbon sources were subjected to molecular identification based on the internal transcribed spacer (ITS) of the 5.8 rDNA using PCR technology. Molecular identification confirmed four isolates—namely, KFA 3, KFA 7, KFA 9 and KFB 1—as belonging to <i>Kluyveromyces marxianus</i>. The batch fermentation data of these strains were fitted on a logistic model to obtain the carrying capacity coefficients and strain performances were compared. The kinetic modelling revealed that KFA 9 had the highest values for the carrying capacity coefficient, biomass yield and product yield, indicating that, among the four <i>K. marxianus</i> strains, this was superior due to its relatively fast growth and good ethanol productivity.https://www.mdpi.com/2311-5637/8/4/183yeastkefirsingle starterbatch fermentation kinetics |
| spellingShingle | Murni Kurniawati Nurliyani Nurliyani Wiratni Budhijanto Widodo Widodo Isolation and Identification of Lactose-Degrading Yeasts and Characterisation of Their Fermentation-Related Ability to Produce Ethanol Fermentation yeast kefir single starter batch fermentation kinetics |
| title | Isolation and Identification of Lactose-Degrading Yeasts and Characterisation of Their Fermentation-Related Ability to Produce Ethanol |
| title_full | Isolation and Identification of Lactose-Degrading Yeasts and Characterisation of Their Fermentation-Related Ability to Produce Ethanol |
| title_fullStr | Isolation and Identification of Lactose-Degrading Yeasts and Characterisation of Their Fermentation-Related Ability to Produce Ethanol |
| title_full_unstemmed | Isolation and Identification of Lactose-Degrading Yeasts and Characterisation of Their Fermentation-Related Ability to Produce Ethanol |
| title_short | Isolation and Identification of Lactose-Degrading Yeasts and Characterisation of Their Fermentation-Related Ability to Produce Ethanol |
| title_sort | isolation and identification of lactose degrading yeasts and characterisation of their fermentation related ability to produce ethanol |
| topic | yeast kefir single starter batch fermentation kinetics |
| url | https://www.mdpi.com/2311-5637/8/4/183 |
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