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Liu F, Xia K, Chen Y, Zhu L, Zhu L, Zhao X, Sha R, Huang J. Inhibition of hyphal formation together with biochar addition promotes erythritol production by Yarrowia lipolytica. Biotechnol Bioeng 2024; 121:1937-1949. [PMID: 38548668 DOI: 10.1002/bit.28704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 03/11/2024] [Accepted: 03/14/2024] [Indexed: 05/29/2024]
Abstract
This study aimed to investigate the effect of hyphal formation in Yarrowia lipolytica and biochar addition on erythritol production by submerged fermentation. Hyphal formation significantly inhibited erythritol production by Y. lipolytica. Transcriptome analysis suggested that the impaired erythritol synthesis of hyphal cells was associated with the differential expression of genes involved in amino acid metabolism, lipid metabolism, and cell wall stability. Deletion of RAS2 responsible for yeast-to-hypha transition and EYD1 included in erythritol degradation blocked hyphal formation and improved erythritol production. Biochar prepared from corncob, sugarcane bagasse (SB), corn straw, peanut shell, coconut shell, and walnut shell (WS) had a positive effect on erythritol production, of which WS pyrolyzed at 500°C (WSc) performed the best in flask fermentation. In a 3.7 L bioreactor, 220.20 ± 10 g/L erythritol with a productivity of 2.30 ± 0.10 g/L/h was obtained in the presence of 1.4% (w/v) WSc and 0.7% SBc (SB pyrolyzed at 500°C) within 96 h. These results suggest that inhibition of hyphal formation together with biochar addition is an efficient way to promote erythritol production.
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Affiliation(s)
- Fangmei Liu
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, China
| | - Kai Xia
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, China
- Key Laboratory of Chemical and Biological Processing Technology for Farm Products of Zhejiang Province, Zhejiang University of Science and Technology, Hangzhou, China
- Zhejiang Provincial Collaborative Innovation Center of Agricultural Biological Resources Biochemical Manufacturing, Zhejiang University of Science and Technology, Hangzhou, China
| | - Yuqing Chen
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, China
| | - Ling Zhu
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, China
| | - Lingzhi Zhu
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, China
| | - Xuequn Zhao
- Key Laboratory of Chemical and Biological Processing Technology for Farm Products of Zhejiang Province, Zhejiang University of Science and Technology, Hangzhou, China
| | - Ruyi Sha
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, China
- Key Laboratory of Chemical and Biological Processing Technology for Farm Products of Zhejiang Province, Zhejiang University of Science and Technology, Hangzhou, China
- Zhejiang Provincial Collaborative Innovation Center of Agricultural Biological Resources Biochemical Manufacturing, Zhejiang University of Science and Technology, Hangzhou, China
| | - Jun Huang
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, China
- Key Laboratory of Chemical and Biological Processing Technology for Farm Products of Zhejiang Province, Zhejiang University of Science and Technology, Hangzhou, China
- Zhejiang Provincial Collaborative Innovation Center of Agricultural Biological Resources Biochemical Manufacturing, Zhejiang University of Science and Technology, Hangzhou, China
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Ranieri R, Candeliere F, Sola L, Leonardi A, Rossi M, Amaretti A, Raimondi S. Production of arabitol from glycerol by immobilized cells of Wickerhamomyces anomalus WC 1501. Front Bioeng Biotechnol 2024; 12:1375937. [PMID: 38659644 PMCID: PMC11039890 DOI: 10.3389/fbioe.2024.1375937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 03/26/2024] [Indexed: 04/26/2024] Open
Abstract
Polyalcohols such as arabitol are among the main targets of biorefineries aiming to upcycle wastes and cheap substrates. In previous works Wickerhamomyces anomalus WC 1501 emerged as an excellent arabitol producer utilizing glycerol. Arabitol production by this strain is not growth associated, therefore, in this study, pre-grown cells were entrapped in calcium alginate beads (AB) and utilized for glycerol transformation to arabitol. Flasks experiments aimed to assess the medium composition (i.e., the concentration of inorganic and organic nitrogen sources and phosphates) and to establish the appropriate carrier-to-medium proportion. In flasks, under the best conditions of ammonium limitation and the carrier:medium ratio of 1:3 (w/v), 82.7 g/L glycerol were consumed in 168 h, yielding 31.2 g/L arabitol, with a conversion of 38% and volumetric productivity of 186 mg/mL/h. The process with immobilized cells was transferred to laboratory scale bioreactors with different configurations: stirred tank (STR), packed bed (PBR), fluidized bed (FBR), and airlift (ALR) bioreactors. The STR experienced oxygen limitation due to the need to maintain low stirring to preserve AB integrity and performed worse than flasks. Limitations in diffusion and mass transfer of oxygen and/or nutrients characterized also the PBR and the FBR and were partially relieved only in ALR, where 89.4 g/L glycerol were consumed in 168 h, yielding 38.1 g/L arabitol, with a conversion of 42% and volumetric productivity of 227 mg/mL/h. When the ALR was supplied with successive pulses of concentrated glycerol to replenish the glycerol as it was being consumed, 117 g/L arabitol were generated in 500 h, consuming a total of 285 g/L glycerol, with a 41% and 234 mg/L/h. The study strongly supports the potential of W. anomalus WC 1501 for efficient glycerol-to-arabitol conversion using immobilized cells. While the yeast shows promise by remaining viable and active for extended periods, further optimization is required, especially regarding mixing and oxygenation. Improving the stability of the immobilization process is also crucial for reusing pre-grown cells in multiple cycles, reducing dead times, biomass production costs, and enhancing the economic feasibility of the process.
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Affiliation(s)
- Raffaella Ranieri
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Francesco Candeliere
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Laura Sola
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Alan Leonardi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Maddalena Rossi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Biogest-Siteia, University of Modena and Reggio Emilia, Reggio Emilia, Italy
| | - Alberto Amaretti
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Biogest-Siteia, University of Modena and Reggio Emilia, Reggio Emilia, Italy
| | - Stefano Raimondi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Biogest-Siteia, University of Modena and Reggio Emilia, Reggio Emilia, Italy
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3
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Li X, Zabed HM, Yun J, Zhang Y, Zhao M, Zhang C, Ouyang Z, Li J, Qi X. Sustainable bio-manufacturing of D-arabitol through combinatorial engineering of Zygosaccharomyces rouxii, bioprocess optimization and downstream separation. BIORESOURCE TECHNOLOGY 2024; 393:130162. [PMID: 38065516 DOI: 10.1016/j.biortech.2023.130162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/04/2023] [Accepted: 12/04/2023] [Indexed: 01/18/2024]
Abstract
Biosynthesis of D-arabitol, a high value-added platform chemical, from renewable carbon sources provides a sustainable and eco-friendly alternative to the chemical industry. Here, a robust brewing yeast, Zygosaccharomyces rouxii, capable of naturally producing D-arabitol was rewired through genome sequencing-based metabolic engineering. The recombinant Z. rouxii obtained by reinforcing the native D-xylulose pathway, improving reductive power of the rate-limiting step, and inhibiting the shunt pathway, produced 73.61% higher D-arabitol than the parent strain. Subsequently, optimization of the fermentation medium composition for the engineered strain provided 137.36 g/L D-arabitol, with a productivity of 0.64 g/L/h in a fed-batch experiment. Finally, the downstream separation of D-arabitol from the complex fermentation broth using an ethanol precipitation method provided a purity of 96.53%. This study highlights the importance of D-xylulose pathway modification in D-arabitol biosynthesis, and pave a complete and efficient way for the sustainable manufacturing of this value-added compound from biosynthesis to preparation.
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Affiliation(s)
- Xiaolan Li
- School of Pharmacy, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Hossain M Zabed
- School of Life Sciences, Guangzhou University, Guangzhou 510006, Guangdong, PR China
| | - Junhua Yun
- School of Life Sciences, Guangzhou University, Guangzhou 510006, Guangdong, PR China
| | - Yufei Zhang
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Mei Zhao
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Cunsheng Zhang
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Zhen Ouyang
- School of Pharmacy, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Jia Li
- School of Life Sciences, Guangzhou University, Guangzhou 510006, Guangdong, PR China
| | - Xianghui Qi
- School of Life Sciences, Guangzhou University, Guangzhou 510006, Guangdong, PR China.
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4
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Wang D, He M, Zhang M, Yang H, Huang J, Zhou R, Jin Y, Wu C. Food yeasts: occurrence, functions, and stress tolerance in the brewing of fermented foods. Crit Rev Food Sci Nutr 2023; 63:12136-12149. [PMID: 35875880 DOI: 10.1080/10408398.2022.2098688] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
With the rapid development of systems biology technology, there is a deeper understanding of the molecular biological mechanisms and physiological characteristics of microorganisms. Yeasts are widely used in the food industry with their excellent fermentation performances. While due to the complex environments of food production, yeasts have to suffer from various stress factors. Thus, elucidating the stress mechanisms of food yeasts and proposing potential strategies to improve tolerance have been widely concerned. This review summarized the recent signs of progress in the variety, functions, and stress tolerance of food yeasts. Firstly, the main food yeasts occurred in fermented foods, and the taxonomy levels are demonstrated. Then, the main functions of yeasts including aroma enhancer, safety performance enhancer, and fermentation period reducer are discussed. Finally, the stress response mechanisms of yeasts and the strategies to improve the stress tolerance of cells are reviewed. Based on sorting out these related recent researches systematically, we hope that this review can provide help and approaches to further exert the functions of food yeasts and improve food production efficiency.
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Affiliation(s)
- Dingkang Wang
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Muwen He
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Min Zhang
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Huan Yang
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Jun Huang
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Rongqing Zhou
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Yao Jin
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Chongde Wu
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
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5
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Iwata K, Maeda M, Kashiwagi Y, Maehashi K, Yoshikawa J. Isolation of Zygosaccharomyces siamensis kiy1 as a novel arabitol-producing yeast and its arabitol production. AMB Express 2023; 13:76. [PMID: 37452923 DOI: 10.1186/s13568-023-01581-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 07/07/2023] [Indexed: 07/18/2023] Open
Abstract
Arabitol is gaining attention in the food industry as an alternative sweetener owing to its low-caloric and non-cariogenic characteristics. The yeast strain kiy1 was newly isolated from unpasteurized honey for arabitol production. Based on internal transcribed spacer sequence analysis, the isolated strain was identified as Zygosaccharomyces siamensis. In this study, the effects of different substrates and sugar concentrations on arabitol production were investigated. When three types of carbon sources (glycerol, fructose, and glucose) were used, glucose was the most suitable substrate for arabitol production (68.7 g/L). Maximum arabitol production (101.4 g/L) was observed at a glucose concentration of 30%, and the highest arabitol production yield was 0.34 g/g of initial glucose. In the time-course production of sugar alcohols by strain kiy1, glucose was completely consumed for 8 days. The concentration of arabitol exceeded that of glycerol after 3 days, and the final arabitol concentration reached 83.6 g/L after 10 days. The maximum production rate was 16.7 g/L/day. The yeast produced glycerol as an intracellular sugar alcohol in the early stage of culture and switched its metabolism to arabitol production after the middle stage. Z. siamensis kiy1 possessed an NADP+-dependent arabitol dehydrogenase, which indicated that it probably produces arabitol via ribulose from glucose. These results suggest that the novel yeast strain, Z. siamensis kiy1, is promising for arabitol production. The proposed arabitol production approach can contribute toward its production at the industrial scale.
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Affiliation(s)
- Kan Iwata
- Department of Fermentation Science and Technology, Graduate School of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-Ku, Tokyo, 156-8502, Japan
| | - Mayumi Maeda
- Department of Fermentation Science, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-Ku, Tokyo, 156-8502, Japan
| | - Yutaka Kashiwagi
- Department of Fermentation Science, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-Ku, Tokyo, 156-8502, Japan
| | - Kenji Maehashi
- Department of Fermentation Science and Technology, Graduate School of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-Ku, Tokyo, 156-8502, Japan
- Department of Fermentation Science, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-Ku, Tokyo, 156-8502, Japan
| | - Jun Yoshikawa
- Department of Fermentation Science, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-Ku, Tokyo, 156-8502, Japan.
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Bodnár V, Király A, Orosz E, Miskei M, Emri T, Karányi Z, Leiter É, de Vries RP, Pócsi I. Species-specific effects of the introduction of Aspergillus nidulans gfdB in osmophilic aspergilli. Appl Microbiol Biotechnol 2023; 107:2423-2436. [PMID: 36811707 PMCID: PMC10033484 DOI: 10.1007/s00253-023-12384-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 02/24/2023]
Abstract
Industrial fungi need a strong environmental stress tolerance to ensure acceptable efficiency and yields. Previous studies shed light on the important role that Aspergillus nidulans gfdB, putatively encoding a NAD+-dependent glycerol-3-phosphate dehydrogenase, plays in the oxidative and cell wall integrity stress tolerance of this filamentous fungus model organism. The insertion of A. nidulans gfdB into the genome of Aspergillus glaucus strengthened the environmental stress tolerance of this xerophilic/osmophilic fungus, which may facilitate the involvement of this fungus in various industrial and environmental biotechnological processes. On the other hand, the transfer of A. nidulans gfdB to Aspergillus wentii, another promising industrial xerophilic/osmophilic fungus, resulted only in minor and sporadic improvement in environmental stress tolerance and meanwhile partially reversed osmophily. Because A. glaucus and A. wentii are phylogenetically closely related species and both fungi lack a gfdB ortholog, these results warn us that any disturbance of the stress response system of the aspergilli may elicit rather complex and even unforeseeable, species-specific physiological changes. This should be taken into consideration in any future targeted industrial strain development projects aiming at the fortification of the general stress tolerance of these fungi. KEY POINTS: • A. wentii c' gfdB strains showed minor and sporadic stress tolerance phenotypes. • The osmophily of A. wentii significantly decreased in the c' gfdB strains. • Insertion of gfdB caused species-specific phenotypes in A. wentii and A. glaucus.
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Affiliation(s)
- Veronika Bodnár
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- Doctoral School of Nutrition and Food Sciences, University of Debrecen, Debrecen, Hungary
| | - Anita Király
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Erzsébet Orosz
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Márton Miskei
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
| | - Zsolt Karányi
- Department of Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Utrecht, the Netherlands
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary.
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary.
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7
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Li X, Zhang Y, Zabed HM, Yun J, Zhang G, Zhao M, Ravikumar Y, Qi X. High-level production of d-arabitol by Zygosaccharomyces rouxii from glucose: Metabolic engineering and process optimization. BIORESOURCE TECHNOLOGY 2023; 367:128251. [PMID: 36334865 DOI: 10.1016/j.biortech.2022.128251] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/27/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
d-Arabitol is a top value-added compound with wide applications in the food, pharmaceutical and biochemical industries. Nevertheless, sustainable biosynthesis of d-arabitol is limited by lack of efficient strains and suitable fermentation process. Herein, metabolic engineering and process optimization were performed in Zygosaccharomyces rouxii to overcoming these limitations. Adopting systems metabolic engineering include enhancement of innate biosynthetic pathway, supply of precursor substrate d-ribulose-5P and cofactors regeneration, a novel recombinant strain ZR-5A with good performance was obtained, which boosted d-arabitol production up to 29.01 g/L, 59.31 % higher than the parent strain. Further with the optimum medium composition and fed-batch fermentation, the strain ZR-5A finally produced 149.10 g/L d-arabitol with the productivity of 1.04 g/L/h, which was the highest titer ever reported by Z.rouxii system. This is the first report on the use of metabolic engineering to construct Z. rouxii chassis for the sustainable production of d-arabitol.
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Affiliation(s)
- Xiaolan Li
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Yufei Zhang
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Hossain M Zabed
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Junhua Yun
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Guoyan Zhang
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Mei Zhao
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Yuvaraj Ravikumar
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Xianghui Qi
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, China.
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8
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Raimondi S, Foca G, Ulrici A, Destro L, Leonardi A, Buzzi R, Candeliere F, Rossi M, Amaretti A. Improved fed-batch processes with Wickerhamomyces anomalus WC 1501 for the production of D-arabitol from pure glycerol. Microb Cell Fact 2022; 21:179. [PMID: 36058916 PMCID: PMC9442996 DOI: 10.1186/s12934-022-01898-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/11/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND D-Arabitol, a five-carbon sugar alcohol, represents a main target of microbial biorefineries aiming to valorize cheap substrates. The yeast Wickerhamomyces anomalus WC 1501 is known to produce arabitol in a glycerol-based nitrogen-limited medium and preliminary fed-batch processes with this yeast were reported to yield 18.0 g/L arabitol. RESULTS Fed-batch fermentations with W. anomalus WC 1501 were optimized using central composite design (CCD). Dissolved oxygen had not a significant effect, while optimum values were found for glycerol concentration (114.5 g/L), pH (5.9), and temperature (32.5 °C), yielding 29 g/L D-arabitol in 160 h, a conversion yield of 0.25 g of arabitol per g of consumed glycerol, and a volumetric productivity of 0.18 g/L/h. CCD optimal conditions were the basis for further improvement, consisting in increasing the cellular density (3✕), applying a constant feeding of glycerol, and increasing temperature during production. The best performing fed-batch fermentations achieved 265 g/L D-arabitol after 325 h, a conversion yield of 0.74 g/g, and a volumetric productivity of 0.82 g/L/h. CONCLUSION W. anomalus WC 1501 confirmed as an excellent producer of D-arabitol, exhibiting a remarkable capability of transforming pure glycerol. The study reports among the highest values ever reported for microbial transformation of glycerol into D-arabitol, in terms of arabitol titer, conversion yield, and productivity.
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Affiliation(s)
- Stefano Raimondi
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy.,Biogest-Siteia, University of Modena and Reggio Emilia, 42124, Reggio Emilia, Italy
| | - Giorgia Foca
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy.,Biogest-Siteia, University of Modena and Reggio Emilia, 42124, Reggio Emilia, Italy
| | - Alessandro Ulrici
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy.,Biogest-Siteia, University of Modena and Reggio Emilia, 42124, Reggio Emilia, Italy
| | - Lorenza Destro
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - Alan Leonardi
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - Raissa Buzzi
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121, Ferrara, Italy
| | - Francesco Candeliere
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - Maddalena Rossi
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy.,Biogest-Siteia, University of Modena and Reggio Emilia, 42124, Reggio Emilia, Italy
| | - Alberto Amaretti
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy. .,Biogest-Siteia, University of Modena and Reggio Emilia, 42124, Reggio Emilia, Italy.
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