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Fan W, Li Z, Li C, Gu Z, Hong Y, Cheng L, Ban X. Catalytic activity enhancement of 1,4-α-glucan branching enzyme by N-terminal modification. Food Chem X 2023; 20:100888. [PMID: 38144803 PMCID: PMC10739917 DOI: 10.1016/j.fochx.2023.100888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 09/11/2023] [Accepted: 09/16/2023] [Indexed: 12/26/2023] Open
Abstract
The 1,4-α-glucan branching enzyme (GBE, EC 2.4.1.18) has garnered considerable attention for its ability to increase the degree of branching of starch and retard starch digestion, which has great industrial applications. Previous studies have reported that the N-terminal domain plays an important role in the expression and stability of GBEs. To further increase the catalytic ability of Gt-GBE, we constructed five mutants in the N-terminal domain: L19R, L19K, L25R, L25K, and L25A. Specific activities of L25R and L25A were increased by 28.46% and 23.46%, respectively, versus the wild-type Gt-GBE. In addition, the α-1,6-glycosidic linkage ratios of maltodextrin samples treated with L25R and L25A increased to 5.71%, which were significantly increased by 19.96% compared with that of the wild-type Gt-GBE. The results of this study suggest that the N-terminal domain selective modification can improve enzyme catalytic activity, thus further increasing the commercial application of enzymes in food and pharmaceutical industries.
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Affiliation(s)
- Wenjuan Fan
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Zhaofeng Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- National Engineering Laboratory for Cereal Fermentation Technology, Wuxi, Jiangsu 214122, China
| | - Caiming Li
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Zhengbiao Gu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- National Engineering Laboratory for Cereal Fermentation Technology, Wuxi, Jiangsu 214122, China
- Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Yan Hong
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Li Cheng
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Xiaofeng Ban
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
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Xu L, Wu D, Xu H, Zhao Z, Chen Q, Li H, Wei Z, Chen L. Characterization, production optimization, and fructanogenic traits of levan in a new Microbacterium isolate. Int J Biol Macromol 2023; 250:126330. [PMID: 37579898 DOI: 10.1016/j.ijbiomac.2023.126330] [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: 05/23/2023] [Revised: 08/07/2023] [Accepted: 08/11/2023] [Indexed: 08/16/2023]
Abstract
Levan is a high-valued β-(2,6)-linked fructan with promising physicochemical and physiological properties and has diverse potential applications in the food, nutraceutical, pharmaceutical and cosmetic industry, but its commercial availability is still restricted to the relatively high costs of production. In this study, a strain identified as Microbacterium sp. XL1 was isolated from soil and highly produced exopolysaccharide (EPS). HPLC, FTIR and NMR spectroscopy revealed XL1-EPS is a levan-type fructan connected by β-(2, 6) linkages. SEM, DLS and TGA-DSC analysis showed that XL1-EPS processed high morphological versatility, narrow size distribution in its solutions and excellent thermal stability. The levan yield reached 83.67 ± 4.06 g/L with corresponding productivity of 3.49 ± 0.17 g/L/h and a conversion yield of 39.8 ± 1.9 % using sucrose (210 g/L) as substrates under the optimal cultivation conditions concluded by the response surface methodology (RSM). More strikingly, the XL1 strain also has multi-type fructanases to generate levanbiose, kestose, DFA IV and other L-FOSs. These results suggest Microbacterium sp. XL1 is a promising strain to produce levan and can provide various levan/inulin-degrading enzymes to create a great diversity of FOSs.
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Affiliation(s)
- Linxiang Xu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, 59 Cangwu Road, Lianyungang 222005, China; Jiangsu Institute of Marine Resources Development, 59 Cangwu Road, Haizhou, Lianyungang 222005, China; School of Food Science and Engineering, South China University of Technology, Guangzhou, China.
| | - Dan Wu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang 222005, China
| | - Haiyang Xu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang 222005, China
| | - Ziyan Zhao
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang 222005, China
| | - Qianqian Chen
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang 222005, China
| | - Hanqi Li
- School of Ocean Engineering, Jiangsu Ocean University, 59 Cangwu Road, Lianyungang 222005, China
| | - Zhen Wei
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, 59 Cangwu Road, Lianyungang 222005, China; Jiangsu Institute of Marine Resources Development, 59 Cangwu Road, Haizhou, Lianyungang 222005, China.
| | - Li Chen
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, 59 Cangwu Road, Lianyungang 222005, China; Jiangsu Institute of Marine Resources Development, 59 Cangwu Road, Haizhou, Lianyungang 222005, China.
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Identification of a Thermostable Levansucrase from Pseudomonas orientalis That Allows Unique Product Specificity at Different Temperatures. Polymers (Basel) 2023; 15:polym15061435. [PMID: 36987215 PMCID: PMC10058814 DOI: 10.3390/polym15061435] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/09/2023] [Accepted: 03/09/2023] [Indexed: 03/17/2023] Open
Abstract
The biological production of levan by levansucrase (LS, EC 2.4.1.10) has aroused great interest in the past few years. Previously, we identified a thermostable levansucrase from Celerinatantimonas diazotrophica (Cedi-LS). A novel thermostable LS from Pseudomonas orientalis (Psor-LS) was successfully screened using the Cedi-LS template. The Psor-LS showed maximum activity at 65 °C, much higher than the other LSs. However, these two thermostable LSs showed significantly different product specificity. When the temperature was decreased from 65 to 35 °C, Cedi-LS tended to produce high-molecular-weight (HMW) levan. By contrast, Psor-LS prefers to generate fructooligosaccharides (FOSs, DP ≤ 16) rather than HMW levan under the same conditions. Notably, at 65 °C, Psor-LS would produce HMW levan with an average Mw of 1.4 × 106 Da, indicating that a high temperature might favor the accumulation of HMW levan. In summary, this study allows a thermostable LS suitable for HMW levan and levan-type FOSs production simultaneously.
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Zhang S, Ni D, Xu W, Zhang W, Mu W. Characterization of a processive inulosucrase from Lactobacillus mulieris for efficient biosynthesis of high-molecular-weight inulin. Enzyme Microb Technol 2023; 164:110186. [PMID: 36529060 DOI: 10.1016/j.enzmictec.2022.110186] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/10/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
Inulin has been determined to have many exceptional properties and functions and has been used in the food and pharmaceutical fields. Recently, microbial high-molecular-weight inulin synthesized from sucrose by inulosucrase attracted much attention. In this study, a novel inulosucrase from Lactobacillus mulieris was constructed, overexpressed, purified, and identified. The recombinant enzyme displayed the maximum activity at pH 6.0 and 55 °C, and it exhibited high thermostability below 45 °C. After optimizing the production conditions, the conversion rate from 100 g/L sucrose to inulin reached 31 %, meanwhile, the maximum molecular weight of produced inulin reached 3.21 × 106 g/mol. The truncated IS showed a "processive" transfructosylation process, only synthesizing a small number of short-chain oligosaccharides with polymerization degrees below 6, which was in favor of the accumulation of high-molecular-weight inulin. Given this, L. mulieris inulosucrase might be a good potential candidate for the industrial production of high-molecular-weight inulin.
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Affiliation(s)
- Shuqi Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Dawei Ni
- 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
| | - 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.
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Ni D, Zhang S, Huang Z, Xu W, Zhang W, Mu W. Directionally modulating the product chain length of an inulosucrase by semi-rational engineering for efficient production of 1-kestose. Enzyme Microb Technol 2022; 160:110085. [PMID: 35752090 DOI: 10.1016/j.enzmictec.2022.110085] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/26/2022] [Accepted: 06/11/2022] [Indexed: 11/16/2022]
Abstract
Microbial inulosucrase as a transfructosylation tool has been used to produce inulin and inulin-type fructooligosaccharides with various polymerization degrees. Tailor-made oligosaccharides could be generated by inulosucrase via chain length modulation. In this study, a semi-rational design based on the modeled structure of Lactobacillus reuteri 121 inulosucrase was carried out to screen and construct variants. The residues Arg541 and Arg544 were determined to be significant to the product chain elongation of L. reuteri 121 inulosucrase. The variant R544W altered the product specificity of inulosucrase and produced short-chain fructooligosaccharides with 1-kestose as the main component. Molecular dynamic simulations verified an increased binding free energy of variant R544W with 1-kestose than the wild-type enzyme with 1-kestose. After optimization, 1-kestose and total short-chain fructooligosaccharides production reached approximately 206 g/L and 307 g/L, respectively. This study suggests the great potential of variant R544W in the biotransformation from sucrose to functional sugar.
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Affiliation(s)
- Dawei Ni
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Shuqi Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Zhaolin Huang
- 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
| | - 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
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Structure–Function Relationship Studies of Multidomain Levansucrases from Leuconostocaceae Family. Microorganisms 2022; 10:microorganisms10050889. [PMID: 35630334 PMCID: PMC9142893 DOI: 10.3390/microorganisms10050889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/19/2022] [Accepted: 02/23/2022] [Indexed: 01/27/2023] Open
Abstract
Levansucrase LevS from Leuconostoc mesenteroides B-512F is a multidomain fructansucrase (MD-FN) that contains additional domains (ADs) to the catalytic domain. However, the understanding of the effect that these ADs have on enzyme activity remains vague. To this aim, structure-function relationship studies of these LevS ADs were performed by evaluating both biochemical properties and the enzymatic capacity of truncated versions of LevS. Joint participation of the N- and C-terminal domains is essential for stability, activity, specificity, and polymerization processes. Specifically, the N-terminal region is involved in stability, while the transition region plays an essential role in the transfructosylation reaction and polymer elongation. Based on our results, we suggest that ADs interact with each other, adopting a U-shaped topology. The importance of these ADs observed in the MD-FN of the Leuconostocaceae family is not shared by the Lactobacillaceae family. Phylogenetic analysis of LevS AD suggests that MD-FN from Lactobacillaceae and Leuconostocaceae have different evolutionary origins. This is the first study on the structure-function relationship of multidomain levansucrases from the Leuconostocaceae family. Our results point towards the functional role of AD in MD-FN and its involvement in fructan synthesis.
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