1
|
Zhang B, Gou K, Xu K, Li Z, Guo X, Wu X. De novo biosynthesis of β-arbutin in Corynebacterium glutamicum via pathway engineering and process optimization. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:88. [PMID: 38918796 PMCID: PMC11197339 DOI: 10.1186/s13068-024-02540-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 06/20/2024] [Indexed: 06/27/2024]
Abstract
BACKGROUND β-Arbutin, a hydroquinone glucoside found in pears, bearberry leaves, and various plants, exhibits antioxidant, anti-inflammatory, antimicrobial, and anticancer effects. β-Arbutin has wide applications in the pharmaceutical and cosmetic industries. However, the limited availability of high-performance strains limits the biobased production of β-arbutin. RESULTS This study established the β-arbutin biosynthetic pathway in C. glutamicum ATCC13032 by introducing codon-optimized ubiC, MNX1, and AS. Additionally, the production titer of β-arbutin was increased by further inactivation of csm and trpE to impede the competitive metabolic pathway. Further modification of the upstream metabolic pathway and supplementation of UDP-glucose resulted in the final engineered strain, C. glutamicum AR11, which achieved a β-arbutin production titer of 7.94 g/L in the optimized fermentation medium. CONCLUSIONS This study represents the first successful instance of de novo β-arbutin production in C. glutamicum, offering a chassis cell for β-arbutin biosynthesis.
Collapse
Affiliation(s)
- Bin Zhang
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China.
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China.
| | - Kexin Gou
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China
| | - Kexin Xu
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China
| | - Zhimin Li
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China
| | - Xiaoyan Guo
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China.
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China.
| | - Xiaoyu Wu
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China
| |
Collapse
|
2
|
Siziya IN, Jung JH, Seo MJ, Lim MC, Seo DH. Whole-cell bioconversion using non-Leloir transglycosylation reactions: a review. Food Sci Biotechnol 2023; 32:749-768. [PMID: 37041815 PMCID: PMC10082888 DOI: 10.1007/s10068-023-01283-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/06/2023] [Accepted: 02/10/2023] [Indexed: 03/06/2023] Open
Abstract
Microbial biocatalysts are evolving technological tools for glycosylation research in food, feed and pharmaceuticals. Advances in bioengineered Leloir and non-Leloir carbohydrate-active enzymes allow for whole-cell biocatalysts to curtail production costs of purified enzymes while enhancing glucan synthesis through continued enzyme expression. Unlike sugar nucleotide-dependent Leloir glycosyltransferases, non-Leloir enzymes require inexpensive sugar donors and can be designed to match the high value, yield and selectivity of the former. This review addresses the current state of bacterial cell-based production of glucans and glycoconjugates via transglycosylation, and describes how alterations made to microbial hosts to surpass purified enzymes as the preferred mode of catalysis are steadily being acquired through genetic engineering, rational design and process optimization. A comprehensive exploration of relevant literature has been summarized to describe whole-cell biocatalysis in non-Leloir glycosylation reactions with various donors and acceptors, and the characterization, application and latest developments in the optimization of their use.
Collapse
Affiliation(s)
- Inonge Noni Siziya
- Department of Food Science and Technology, College of Agriculture and Life Sciences, Jeonbuk National University, Jeonju, 54896 Republic of Korea
- Division of Bioengineering, Incheon National University, Incheon, 22012 Republic of Korea
| | - Jong-Hyun Jung
- Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, 56212 Republic of Korea
| | - Myung-Ji Seo
- Division of Bioengineering, Incheon National University, Incheon, 22012 Republic of Korea
| | - Min-Cheol Lim
- Research Group of Consumer Safety, Korea Food Research Institute (KFRI), Jeollabuk-do, 55365 Korea
| | - Dong-Ho Seo
- Department of Food Science and Technology, College of Agriculture and Life Sciences, Jeonbuk National University, Jeonju, 54896 Republic of Korea
- Department of Food Science and Biotechnology, Graduate School of Biotechnology and Institute of Life Science and Resources, Kyung Hee University, Yongin, 17104 Republic of Korea
| |
Collapse
|
3
|
Li J, Li Z, Gong H, Ma M, Li S, Yang H, Zhang H, Liu J. Identification and characterization of a novel high-activity amylosucrase from Salinispirillum sp. LH10-3-1. Appl Microbiol Biotechnol 2023; 107:1725-1736. [PMID: 36795143 DOI: 10.1007/s00253-023-12430-6] [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: 09/12/2022] [Revised: 01/17/2023] [Accepted: 01/30/2023] [Indexed: 02/17/2023]
Abstract
In this study, a novel high-activity amylosucrase from Salinispirillum sp. LH10-3-1 (SaAS) was identified and characterized. The recombinant enzyme was determined as a monomer with a molecular mass of 75 kDa. SaAS protein exhibited the maximum total and polymerization activities at pH 9.0 and maximum hydrolysis activity at pH 8.0. The optimum temperature for total, polymerization, and hydrolysis activities were 40, 40, and 45 °C, respectively. Under the optimal pH and temperature, SaAS had a specific activity of 108.2 U/mg. SaAS also showed excellent salt tolerance and could retain 77.4% of its original total activity at 4.0 M NaCl. The addition of Mg2+, Ba2+, and Ca2+ enhanced the total activity of SaAS. When the conversion of 0.1 M and 1.0 M sucrose was catalyzed at pH 9.0 and 40 °C for 24 h, the ratios of hydrolysis, polymerization, and isomerization reactions were 11.9:77.4:10.7 and 15.3:53.5:31.2, respectively. The α-arbutin yield of 60.3% was achieved from 20 mM sucrose and 5 mM hydroquinone catalyzed by SaAS. KEY POINTS: • A novel amylosucrase from Salinispirillum sp. LH10-3-1 (SaAS) was characterized. • SaAS has the highest specific enzyme activity among all known amylosucrase. • SaAS has hydrolysis, polymerization, isomerization, and glucosyltransferase activities.
Collapse
Affiliation(s)
- Jing Li
- Centre for Bioengineering and Biotechnology, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Ziyi Li
- Centre for Bioengineering and Biotechnology, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Hui Gong
- Centre for Bioengineering and Biotechnology, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Mengyi Ma
- Centre for Bioengineering and Biotechnology, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Shuolei Li
- Centre for Bioengineering and Biotechnology, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Huilin Yang
- Centre for Bioengineering and Biotechnology, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Hailin Zhang
- Centre for Bioengineering and Biotechnology, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China
| | - Jianguo Liu
- Centre for Bioengineering and Biotechnology, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China.
| |
Collapse
|
4
|
Ni D, Chen Z, Tian Y, Xu W, Zhang W, Kim BG, Mu W. Comprehensive utilization of sucrose resources via chemical and biotechnological processes: A review. Biotechnol Adv 2022; 60:107990. [PMID: 35640819 DOI: 10.1016/j.biotechadv.2022.107990] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/20/2022] [Accepted: 05/24/2022] [Indexed: 11/30/2022]
Abstract
Sucrose, one of the most widespread disaccharides in nature, has been available in daily human life for many centuries. As an abundant and cheap sweetener, sucrose plays an essential role in our diet and the food industry. However, it has been determined that many diseases, such as obesity, diabetes, hyperlipidemia, etc., directly relate to the overconsumption of sucrose. It arouses many explorations for the conversion of sucrose to high-value chemicals. Production of valuable substances from sucrose by chemical methods has been studied since a half-century ago. Compared to chemical processes, biotechnological conversion approaches of sucrose are more environmentally friendly. Many enzymes can use sucrose as the substrate to generate functional sugars, especially those from GH68, GH70, GH13, and GH32 families. In this review, enzymatic catalysis and whole-cell fermentation of sucrose for the production of valuable chemicals were reviewed. The multienzyme cascade catalysis and metabolic engineering strategies were addressed.
Collapse
Affiliation(s)
- Dawei Ni
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Ziwei Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Yuqing Tian
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Wei Xu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Wenli Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Byung-Gee Kim
- School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Wanmeng Mu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China.
| |
Collapse
|
5
|
Xu KX, Xue MG, Li Z, Ye BC, Zhang B. Recent Progress on Feasible Strategies for Arbutin Production. Front Bioeng Biotechnol 2022; 10:914280. [PMID: 35615473 PMCID: PMC9125391 DOI: 10.3389/fbioe.2022.914280] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
Arbutin is a hydroquinone glucoside and a natural product present in various plants. Arbutin potently inhibits melanin formation. This property has been exploited in whitening cosmetics and pharmaceuticals. Arbutin production relies mainly on chemical synthesis. The multi-step and complicated process can compromise product purity. With the increasing awareness of sustainable development, the current research direction prioritizes environment-friendly, biobased arbutin production. In this review, current strategies for arbutin production are critically reviewed, with a focus on plant extraction, chemical synthesis, biotransformation, and microbial fermentation. Furthermore, the bottlenecks and perspectives for future direction on arbutin biosynthesis are discussed.
Collapse
Affiliation(s)
- Ke-Xin Xu
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resource, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China
| | - Meng-Ge Xue
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resource, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China
| | - Zhimin Li
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resource, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China
| | - Bang-Ce Ye
- College of Bioengineering, East China University of Science and Technology, Shanghai, China
| | - Bin Zhang
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resource, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China
| |
Collapse
|
6
|
Hatem S, Elkheshen SA, Kamel AO, Nasr M, Moftah NH, Ragai MH, Elezaby RS, El Hoffy NM. Functionalized chitosan nanoparticles for cutaneous delivery of a skin whitening agent: an approach to clinically augment the therapeutic efficacy for melasma treatment. Drug Deliv 2022; 29:1212-1231. [PMID: 35403519 PMCID: PMC9004510 DOI: 10.1080/10717544.2022.2058652] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The increase in the production of melanin level inside the skin prompts a patient-inconvenient skin color disorder namely; melasma. This arouses the need to develop efficacious treatment modalities, among which are topical nano-delivery systems. This study aimed to formulate functionalized chitosan nanoparticles (CSNPs) in gel form for enhanced topical delivery of alpha-arbutin as a skin whitening agent to treat melasma. Ionic gelation method was employed to prepare α-arbutin-CSNPs utilizing a 24 full factorial design followed by In vitro, Ex vivo and clinical evaluation of the nano-dispersions and their gel forms. Results revealed that the obtained CSNPs were in the nanometer range with positive zeta potential, high entrapment efficiency, good stability characteristics and exhibited sustained release of α-arbutin over 24 h. Ex vivo deposition of CSNPs proved their superiority in accumulating the drug in deep skin layers with no transdermal delivery. DSC and FTIR studies revealed the successful amorphization of α-arbutin into the nanoparticulate system with no interaction between the drug and the carrier system. The comparative split-face clinical study revealed that α-arbutin loaded CSNPs hydrogels showed better therapeutic efficacy compared to the free drug hydrogel in melasma patients, as displayed by the decrease in: modified melasma area and severity index (mMASI) scores, epidermal melanin particle size surface area (MPSA) and the number of epidermal monoclonal mouse anti–melanoma antigen recognized by T cells-1 (MART-1) positive cells which proved that the aforementioned system is a promising modality for melasma treatment.
Collapse
Affiliation(s)
- Shymaa Hatem
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Future University in Egypt, New Cairo, Egypt
| | - Seham A. Elkheshen
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Amany O. Kamel
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Maha Nasr
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Noha H. Moftah
- Department of Dermatology, STD's and Andrology, Faculty of Medicine, Minia University, Al-Minya, Egypt
| | - Maha H Ragai
- Department of Dermatology, STD's and Andrology, Faculty of Medicine, Minia University, Al-Minya, Egypt
| | - Reham S. Elezaby
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Nada M. El Hoffy
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Future University in Egypt, New Cairo, Egypt
| |
Collapse
|
7
|
Agarwal N, Rai AK, Singh SP. Biotransformation of hydroquinone into α-arbutin by transglucosylation activity of a metagenomic amylosucrase. 3 Biotech 2021; 11:362. [PMID: 34295607 DOI: 10.1007/s13205-021-02909-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 06/24/2021] [Indexed: 11/28/2022] Open
Abstract
Arbutin is a naturally occurring glycosylated product of hydroquinone. With the ability to interrupt melanin biosynthesis in epidermal cells, it is a promising cosmetic ingredient. In this study, a novel amylosucrase, Asmet, identified from a thermal spring metagenome, has been characterized for arbutin biosynthesis. Asmet was able to catalyze transglucosylation of hydroquinone to arbutin, taking sucrose as glycosyl donor, in the temperature range of 20 °C to 40 °C and pH 5.0 to 6.0, with the relative activity of 80% or more. The presence of chloride salts of Li, K, and Na at 1 mM concentration did not exhibit any notable effect on the enzyme's activity, unlike Cu, Ni, and Mn, which were observed to be detrimental. The hydroquinone (20 mM) to sucrose ratio of 1:1 to 1:10 was appropriate for the catalytic biosynthesis of arbutin. The maximum hydroquinone to arbutin conversion of 70% was obtained in 24 h of Asmet led catalysis, at 30 °C and pH 6.0. Arbutin production was also demonstrated using low-cost feedstock, table sugar, muscovado, and sweet sorghum stalk extract, as a replacement for sucrose. Whole-cell catalysis of hydroquinone to arbutin transglucosylation was also established.
Collapse
Affiliation(s)
- Neera Agarwal
- Center of Innovative and Applied Bioprocessing (DBT-CIAB), Sector-81 (Knowledge City), Mohali, S.A.S. Nagar, 140 306 Punjab India
- Department of Biotechnology, Panjab University, Chandigarh, Punjab India
| | - Amit K Rai
- Institute of Bioresources and Sustainable Development (DBT-IBSD), Sikkim Centre, Tadong, Sikkim India
| | - Sudhir P Singh
- Center of Innovative and Applied Bioprocessing (DBT-CIAB), Sector-81 (Knowledge City), Mohali, S.A.S. Nagar, 140 306 Punjab India
| |
Collapse
|
8
|
Special Issue “Biocatalysts: Design and Application”. Catalysts 2021. [DOI: 10.3390/catal11070778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The use of biocatalysts in chemical reactions is of great interest because reactions can be carried out under very mild and green conditions [...]
Collapse
|
9
|
Moulis C, Guieysse D, Morel S, Séverac E, Remaud-Siméon M. Natural and engineered transglycosylases: Green tools for the enzyme-based synthesis of glycoproducts. Curr Opin Chem Biol 2020; 61:96-106. [PMID: 33360622 DOI: 10.1016/j.cbpa.2020.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/16/2020] [Accepted: 11/19/2020] [Indexed: 01/22/2023]
Abstract
An increasing number of transglycosylase-based processes provide access to oligosaccharides or glycoconjugates, some of them reaching performance levels compatible with industrial developments. Nevertheless, the full potential of transglycosylases has not been explored because of the challenges in transforming a glycoside hydrolase into an efficient transglycosylase. Advances in studying enzyme structure/function relationships, screening enzyme activity, and generating synthetic libraries guided by computational protein design or machine learning methods should considerably accelerate the development of these catalysts. The time has now come for researchers to uncover their possibilities and learn how to design and precisely refine their activity to respond more rapidly to the growing demand for well-defined glycosidic structures.
Collapse
Affiliation(s)
- Claire Moulis
- Toulouse Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRAE, INSA, 135, Avenue de Rangueil, Toulouse, Cedex 04, F-31077, France.
| | - David Guieysse
- Toulouse Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRAE, INSA, 135, Avenue de Rangueil, Toulouse, Cedex 04, F-31077, France
| | - Sandrine Morel
- Toulouse Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRAE, INSA, 135, Avenue de Rangueil, Toulouse, Cedex 04, F-31077, France
| | - Etienne Séverac
- Toulouse Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRAE, INSA, 135, Avenue de Rangueil, Toulouse, Cedex 04, F-31077, France
| | - Magali Remaud-Siméon
- Toulouse Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRAE, INSA, 135, Avenue de Rangueil, Toulouse, Cedex 04, F-31077, France.
| |
Collapse
|
10
|
Zhu L, Xu M, Lu C, Chen L, Xu A, Fang J, Chen H, Lu Y, Fan Y, Chen X. Optimization of whole-cell biotransformation for scale-up production of α-arbutin from hydroquinone by the use of recombinant Escherichia coli. AMB Express 2019; 9:94. [PMID: 31254161 PMCID: PMC6598918 DOI: 10.1186/s13568-019-0820-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 06/19/2019] [Indexed: 11/25/2022] Open
Abstract
α-Arbutin is an effective skin-whitening cosmetic ingredient and hyperpigmentation therapy agent. It can be synthesized by one-step enzymatic glycosylation of hydroquinone (HQ), but limited by the low yield. Amylosucrase (Amy-1) from Xanthomonas campestris pv. campestris 8004 was recently identified with high HQ glycosylation activity. In this study, whole-cell transformation by Amy-1 was optimized and process scale-up was evaluated in 5000-L reactor. In comparison with purified Amy-1, whole-cell catalyst of recombinant E. coli displays better tolerance against inhibitors (oxidized products of HQ) and requires lower molar ratio of sucrose and HQ to reach high conversion rate (> 99%). Excess accumulation of glucose (0.6–1.0 M) derived from sucrose hydrolysis inhibits HQ glycosylation rate by 46–60%, which suggests the importance of balancing HQ glycosylation rate and sucrose hydrolysis rate by adjusting the activity of whole-cell catalyst and HQ-fed rate. Using optimal conditions, 540 mM of final concentration and 95% of molar conversion rate were obtained within 13–18 h in laboratory scale. For industrial scale-up production, 398 mM and 375 mM of final concentration with high conversion rates (~ 95%) were obtained in 3500-L and 4000-L of reaction volume, respectively. These yields and productivities (4.5–4.9 kg kL−1 h−1) were the highest by comparing to the best we known. Hence, high-yield production of α-arbutin by batch-feeding whole-cell biotransformation was successfully achieved in the 5000-L reaction scale.
Collapse
|