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Biovalorisation of crude glycerol and xylose into xylitol by oleaginous yeast Yarrowia lipolytica
Vinod Kumar
Cranfield University
Corresponding Author
ORCiD: https://orcid.org/0000-0001-8967-6119
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background: Xylitol is a commercially important chemical with multiple applications in the food and pharmaceutical industries. According to the US Department of Energy, xylitol is one of the top twelve platform chemicals that can be produced from biomass. The chemical method for xylitol synthesis is however expensive and energy intensive. In contrast, the biological route using microbial cell factories offers a potential cost-effective alternative process. The bioprocess occurs under ambient conditions and makes use of biocatalysts and biomass which can be sourced from renewable carbon originating from a variety of cheap waste feedstocks.
Result: In this study, biotransformation of xylose to xylitol was investigated using Yarrowia lipolytica an oleaginous yeast which was firstly grown on a glycerol/glucose for screening of co-substrate, followed by media optimisation in shake flask, scale up in bioreactor and downstream processing of xylitol. A two-step medium optimization was employed using central composite design and artificial neural network coupled with genetic algorithm. The yeast amassed a concentration of 53.2 g/L xylitol using pure glycerol (PG) and xylose with a bioconversion yield of 0.97 g/g. Similar results were obtained when PG was substituted with crude glycerol (CG) from the biodiesel industry (titer: 50.5 g/L; yield: 0.92 g/g). Even when xylose from sugarcane bagasse hydrolysate was used as opposed to pure xylose, a xylitol yield of 0.54 g/g was achieved. Xylitol was successfully crystallized from PG/xylose and CG /xylose fermentation broths with a recovery of 39.5 and 35.3%, respectively.
Conclusion: To the best of the author’s knowledge, this study demonstrates for the first time the potential of using Y. lipolytica as a microbial cell factory for xylitol synthesis from inexpensive feedstocks. The results obtained are competitive with other xylitol producing organisms.
Keywords
Glycerol, Xylose, Yarrowia lipolytica, Biotransformation, Xylitol
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On 13 May, 2020
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On 12 May, 2020
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On 11 May, 2020
Editor invited
On 11 May, 2020
No comments provided
Review #2 received
Received 08 Apr, 2020
Review #1 received
Received 08 Apr, 2020
Editorial decision: Major Revision
On 08 Apr, 2020
Reviewer #2 agreed
On 26 Mar, 2020
Reviewer #1 agreed
On 25 Mar, 2020
Reviewers invited
Invitations sent on 24 Mar, 2020
Editor assigned
On 24 Mar, 2020
First submitted
On 23 Mar, 2020
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On 23 Mar, 2020
Editor invited
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Subject Areas
Applied & Industrial Microbiology
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This preprint is under consideration at Microbial Cell Factories. A preprint is a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Learn more about In Review
Research
Biovalorisation of crude glycerol and xylose into xylitol by oleaginous yeast Yarrowia lipolytica
Vinod Kumar
Cranfield University
Corresponding Author
ORCiD: https://orcid.org/0000-0001-8967-6119
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
Peer Review Timeline
CURRENT STATUS: Under Review
Version 2
Posted 21 May, 2020
No community comments so far
Review #1 received
Received 15 May, 2020
Reviewer #1 agreed
On 13 May, 2020
Editor assigned
On 12 May, 2020
Reviewers invited
Invitations sent on 12 May, 2020
Submission checks complete
On 11 May, 2020
Editor invited
On 11 May, 2020
No comments provided
Review #2 received
Received 08 Apr, 2020
Review #1 received
Received 08 Apr, 2020
Editorial decision: Major Revision
On 08 Apr, 2020
Reviewer #2 agreed
On 26 Mar, 2020
Reviewer #1 agreed
On 25 Mar, 2020
Reviewers invited
Invitations sent on 24 Mar, 2020
Editor assigned
On 24 Mar, 2020
First submitted
On 23 Mar, 2020
Submission checks complete
On 23 Mar, 2020
Editor invited
On 23 Mar, 2020
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Subject Areas
Applied & Industrial Microbiology
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background: Xylitol is a commercially important chemical with multiple applications in the food and pharmaceutical industries. According to the US Department of Energy, xylitol is one of the top twelve platform chemicals that can be produced from biomass. The chemical method for xylitol synthesis is however expensive and energy intensive. In contrast, the biological route using microbial cell factories offers a potential cost-effective alternative process. The bioprocess occurs under ambient conditions and makes use of biocatalysts and biomass which can be sourced from renewable carbon originating from a variety of cheap waste feedstocks.
Result: In this study, biotransformation of xylose to xylitol was investigated using Yarrowia lipolytica an oleaginous yeast which was firstly grown on a glycerol/glucose for screening of co-substrate, followed by media optimisation in shake flask, scale up in bioreactor and downstream processing of xylitol. A two-step medium optimization was employed using central composite design and artificial neural network coupled with genetic algorithm. The yeast amassed a concentration of 53.2 g/L xylitol using pure glycerol (PG) and xylose with a bioconversion yield of 0.97 g/g. Similar results were obtained when PG was substituted with crude glycerol (CG) from the biodiesel industry (titer: 50.5 g/L; yield: 0.92 g/g). Even when xylose from sugarcane bagasse hydrolysate was used as opposed to pure xylose, a xylitol yield of 0.54 g/g was achieved. Xylitol was successfully crystallized from PG/xylose and CG /xylose fermentation broths with a recovery of 39.5 and 35.3%, respectively.
Conclusion: To the best of the author’s knowledge, this study demonstrates for the first time the potential of using Y. lipolytica as a microbial cell factory for xylitol synthesis from inexpensive feedstocks. The results obtained are competitive with other xylitol producing organisms.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7