Integrated Process for Bioenergy Production and Water Recycling in the Dairy Industry: Selection of <i>Kluyveromyces</i> Strains for Direct Conversion of Concentrated Lactose-Rich Streams into Bioethanol
Dairy industries have a high environmental impact, with very high energy and water consumption and polluting effluents. To increase the sustainability of these industries it is urgent to implement technologies for wastewater treatment allowing water recycling and energy savings. In this study, dairy...
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-11-01
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| Series: | Microorganisms |
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| Online Access: | https://www.mdpi.com/2076-2607/7/11/545 |
| _version_ | 1818314820890394624 |
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| author | Maria José Leandro Susana Marques Belina Ribeiro Helena Santos César Fonseca |
| author_facet | Maria José Leandro Susana Marques Belina Ribeiro Helena Santos César Fonseca |
| author_sort | Maria José Leandro |
| collection | DOAJ |
| description | Dairy industries have a high environmental impact, with very high energy and water consumption and polluting effluents. To increase the sustainability of these industries it is urgent to implement technologies for wastewater treatment allowing water recycling and energy savings. In this study, dairy wastewater was processed by ultrafiltration and nanofiltration or ultrafiltration and reverse osmosis (UF/RO) and retentates from the second membrane separation processes were assessed for bioenergy production. Lactose-fermenting yeasts were tested in direct conversion of the retentates (lactose-rich streams) into bioethanol. Two <i>Kluyveromyces</i> strains efficiently fermented all the lactose, with ethanol yields higher than 90% (>0.47 g/g yield). Under severe oxygen-limiting conditions, the <i>K. marxianus</i> PYCC 3286 strain reached 70 g/L of ethanol, which is compatible with energy-efficient distillation processes. In turn, the RO permeate is suitable for recycling into the cleaning process. The proposed integrated process, using UF/RO membrane technology, could allow water recycling (RO permeate) and bioenergy production (from RO retentate) for a more sustainable dairy industry. |
| first_indexed | 2024-12-13T08:55:43Z |
| format | Article |
| id | doaj.art-09886d47de00466cae981b416bceeb46 |
| institution | Directory Open Access Journal |
| issn | 2076-2607 |
| language | English |
| last_indexed | 2024-12-13T08:55:43Z |
| publishDate | 2019-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Microorganisms |
| spelling | doaj.art-09886d47de00466cae981b416bceeb462022-12-21T23:53:16ZengMDPI AGMicroorganisms2076-26072019-11-0171154510.3390/microorganisms7110545microorganisms7110545Integrated Process for Bioenergy Production and Water Recycling in the Dairy Industry: Selection of <i>Kluyveromyces</i> Strains for Direct Conversion of Concentrated Lactose-Rich Streams into BioethanolMaria José Leandro0Susana Marques1Belina Ribeiro2Helena Santos3César Fonseca4Unidade de Bioenergia, Laboratório Nacional de Energia e Geologia, I.P. (LNEG), Estrada do Paço do Lumiar 22, 1649-038 Lisboa, PortugalUnidade de Bioenergia, Laboratório Nacional de Energia e Geologia, I.P. (LNEG), Estrada do Paço do Lumiar 22, 1649-038 Lisboa, PortugalUnidade de Bioenergia, Laboratório Nacional de Energia e Geologia, I.P. (LNEG), Estrada do Paço do Lumiar 22, 1649-038 Lisboa, PortugalInstituto de Tecnologia Química e Biológica António Xavier, Biology Division, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, PortugalUnidade de Bioenergia, Laboratório Nacional de Energia e Geologia, I.P. (LNEG), Estrada do Paço do Lumiar 22, 1649-038 Lisboa, PortugalDairy industries have a high environmental impact, with very high energy and water consumption and polluting effluents. To increase the sustainability of these industries it is urgent to implement technologies for wastewater treatment allowing water recycling and energy savings. In this study, dairy wastewater was processed by ultrafiltration and nanofiltration or ultrafiltration and reverse osmosis (UF/RO) and retentates from the second membrane separation processes were assessed for bioenergy production. Lactose-fermenting yeasts were tested in direct conversion of the retentates (lactose-rich streams) into bioethanol. Two <i>Kluyveromyces</i> strains efficiently fermented all the lactose, with ethanol yields higher than 90% (>0.47 g/g yield). Under severe oxygen-limiting conditions, the <i>K. marxianus</i> PYCC 3286 strain reached 70 g/L of ethanol, which is compatible with energy-efficient distillation processes. In turn, the RO permeate is suitable for recycling into the cleaning process. The proposed integrated process, using UF/RO membrane technology, could allow water recycling (RO permeate) and bioenergy production (from RO retentate) for a more sustainable dairy industry.https://www.mdpi.com/2076-2607/7/11/545dairy industry<i>kluyveromyces</i>lactose fermentationbioethanolwater recycling |
| spellingShingle | Maria José Leandro Susana Marques Belina Ribeiro Helena Santos César Fonseca Integrated Process for Bioenergy Production and Water Recycling in the Dairy Industry: Selection of <i>Kluyveromyces</i> Strains for Direct Conversion of Concentrated Lactose-Rich Streams into Bioethanol Microorganisms dairy industry <i>kluyveromyces</i> lactose fermentation bioethanol water recycling |
| title | Integrated Process for Bioenergy Production and Water Recycling in the Dairy Industry: Selection of <i>Kluyveromyces</i> Strains for Direct Conversion of Concentrated Lactose-Rich Streams into Bioethanol |
| title_full | Integrated Process for Bioenergy Production and Water Recycling in the Dairy Industry: Selection of <i>Kluyveromyces</i> Strains for Direct Conversion of Concentrated Lactose-Rich Streams into Bioethanol |
| title_fullStr | Integrated Process for Bioenergy Production and Water Recycling in the Dairy Industry: Selection of <i>Kluyveromyces</i> Strains for Direct Conversion of Concentrated Lactose-Rich Streams into Bioethanol |
| title_full_unstemmed | Integrated Process for Bioenergy Production and Water Recycling in the Dairy Industry: Selection of <i>Kluyveromyces</i> Strains for Direct Conversion of Concentrated Lactose-Rich Streams into Bioethanol |
| title_short | Integrated Process for Bioenergy Production and Water Recycling in the Dairy Industry: Selection of <i>Kluyveromyces</i> Strains for Direct Conversion of Concentrated Lactose-Rich Streams into Bioethanol |
| title_sort | integrated process for bioenergy production and water recycling in the dairy industry selection of i kluyveromyces i strains for direct conversion of concentrated lactose rich streams into bioethanol |
| topic | dairy industry <i>kluyveromyces</i> lactose fermentation bioethanol water recycling |
| url | https://www.mdpi.com/2076-2607/7/11/545 |
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