<i>Candida tropicalis </i>as a Promising Oleaginous Yeast for Olive Mill Wastewater Bioconversion
Olive mill wastewater (OMW), which is generated during olive oil production, has detrimental effects on the environment due to its high organic load and phenolic compounds content. OMW is difficult to biodegrade, but represents a valuable resource of nutrients for microbial growth. In this study, ye...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-01-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/14/3/640 |
| _version_ | 1797406884333879296 |
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| author | Bruna Dias Marlene Lopes Renata Ramôa Ana S. Pereira Isabel Belo |
| author_facet | Bruna Dias Marlene Lopes Renata Ramôa Ana S. Pereira Isabel Belo |
| author_sort | Bruna Dias |
| collection | DOAJ |
| description | Olive mill wastewater (OMW), which is generated during olive oil production, has detrimental effects on the environment due to its high organic load and phenolic compounds content. OMW is difficult to biodegrade, but represents a valuable resource of nutrients for microbial growth. In this study, yeast strains were screened for their growth on phenolic compounds usually found in OMW and responsible for antimicrobial effects. <i>Candida tropicalis </i>ATCC 750 demonstrated an extraordinary capacity to grow in phenolics and was chosen for further experiments with OMW-based medium. The effects of nitrogen supplementation, the pH, and the stirring rate on cellular growth, OMW-components consumption, and added-value compounds production were studied in batch cultures in Erlenmeyer flasks and in a bioreactor. <i>Candida tropicalis </i>was able to reduce 68% of the organic load (chemical oxygen demand) and 39% of the total phenols of OMW in optimized conditions in bioreactor experiments, producing lipase (203 U·L<sup>−1</sup>) and protease (1105 U·L<sup>−1</sup>). Moreover, intracellular lipids were accumulated, most significantly under nitrogen-limited conditions, which is common in this type of wastewater. The high potential of <i>C. tropicalis </i>to detoxify OMW and produce added-value compounds from it makes this process an alternative approach to other conventional processes of OMW treatment. |
| first_indexed | 2024-03-09T03:32:06Z |
| format | Article |
| id | doaj.art-0c1248c0fb3f4ea88b61c71a6da8315a |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-09T03:32:06Z |
| publishDate | 2021-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-0c1248c0fb3f4ea88b61c71a6da8315a2023-12-03T14:52:38ZengMDPI AGEnergies1996-10732021-01-0114364010.3390/en14030640<i>Candida tropicalis </i>as a Promising Oleaginous Yeast for Olive Mill Wastewater BioconversionBruna Dias0Marlene Lopes1Renata Ramôa2Ana S. Pereira3Isabel Belo4Centre of Biological Engineering, University of Minho, 4710-057 Braga, PortugalCentre of Biological Engineering, University of Minho, 4710-057 Braga, PortugalCentre of Biological Engineering, University of Minho, 4710-057 Braga, PortugalCentre of Biological Engineering, University of Minho, 4710-057 Braga, PortugalCentre of Biological Engineering, University of Minho, 4710-057 Braga, PortugalOlive mill wastewater (OMW), which is generated during olive oil production, has detrimental effects on the environment due to its high organic load and phenolic compounds content. OMW is difficult to biodegrade, but represents a valuable resource of nutrients for microbial growth. In this study, yeast strains were screened for their growth on phenolic compounds usually found in OMW and responsible for antimicrobial effects. <i>Candida tropicalis </i>ATCC 750 demonstrated an extraordinary capacity to grow in phenolics and was chosen for further experiments with OMW-based medium. The effects of nitrogen supplementation, the pH, and the stirring rate on cellular growth, OMW-components consumption, and added-value compounds production were studied in batch cultures in Erlenmeyer flasks and in a bioreactor. <i>Candida tropicalis </i>was able to reduce 68% of the organic load (chemical oxygen demand) and 39% of the total phenols of OMW in optimized conditions in bioreactor experiments, producing lipase (203 U·L<sup>−1</sup>) and protease (1105 U·L<sup>−1</sup>). Moreover, intracellular lipids were accumulated, most significantly under nitrogen-limited conditions, which is common in this type of wastewater. The high potential of <i>C. tropicalis </i>to detoxify OMW and produce added-value compounds from it makes this process an alternative approach to other conventional processes of OMW treatment.https://www.mdpi.com/1996-1073/14/3/640olive mill wastewaterphenolic compounds<i>Candida tropicalis</i>microbial lipidslipaseprotease |
| spellingShingle | Bruna Dias Marlene Lopes Renata Ramôa Ana S. Pereira Isabel Belo <i>Candida tropicalis </i>as a Promising Oleaginous Yeast for Olive Mill Wastewater Bioconversion Energies olive mill wastewater phenolic compounds <i>Candida tropicalis</i> microbial lipids lipase protease |
| title | <i>Candida tropicalis </i>as a Promising Oleaginous Yeast for Olive Mill Wastewater Bioconversion |
| title_full | <i>Candida tropicalis </i>as a Promising Oleaginous Yeast for Olive Mill Wastewater Bioconversion |
| title_fullStr | <i>Candida tropicalis </i>as a Promising Oleaginous Yeast for Olive Mill Wastewater Bioconversion |
| title_full_unstemmed | <i>Candida tropicalis </i>as a Promising Oleaginous Yeast for Olive Mill Wastewater Bioconversion |
| title_short | <i>Candida tropicalis </i>as a Promising Oleaginous Yeast for Olive Mill Wastewater Bioconversion |
| title_sort | i candida tropicalis i as a promising oleaginous yeast for olive mill wastewater bioconversion |
| topic | olive mill wastewater phenolic compounds <i>Candida tropicalis</i> microbial lipids lipase protease |
| url | https://www.mdpi.com/1996-1073/14/3/640 |
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