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Mei X, Zhang Y, Jiang X, Liu G, Shen J, Xue C, Xiao H, Chang Y. Discovery and characterization of a novel carbohydrate-binding module: a favorable tool for investigating agarose. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2024; 104:2792-2797. [PMID: 38010608 DOI: 10.1002/jsfa.13164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 11/21/2023] [Accepted: 11/24/2023] [Indexed: 11/29/2023]
Abstract
BACKGROUND Agarose, mainly composed of 3,6-anhydro-α-l-galactopyranose (LA) and β-d-galactopyranose (G) units, is an important polysaccharide with wide applications in food, biomedical and bioengineering industries. Carbohydrate-binding modules (CBMs) are favorable tools for the investigations of polysaccharides. Few agarose-binding CBMs have been hitherto reported, and their binding specificity is unclear. RESULTS An unknown domain with a predicted β-sandwich fold was discovered from a β-agarase of the marine bacterium Wenyingzhuangia fucanilytica CZ1127T . The expressed protein WfCBM101 could bind to agarose and exhibited relatively weak affinity for porphyran, with no affinity for the other seven examined polysaccharides. The protein binds to the tetrasaccharide (LA-G)2 , but not to the major tetrasaccharide contained in porphyran. The sequence novelty and well-defined binding function of WfCBM101 shed light on a novel CBM family (CBM101). Furthermore, the feasibility of WfCBM101 for visualizing agarose in situ was confirmed. CONCLUSION A novel CBM, WfCBM101, with a desired specificity for agarose was discovered and characterized, which represents a new CBM family. The CBM could be utilized as a promising tool for studies of agarose. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Xuanwei Mei
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Yuying Zhang
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Xiaoxiao Jiang
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Guanchen Liu
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Jingjing Shen
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Changhu Xue
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Hang Xiao
- Department of Food Science, University of Massachusetts, Amherst, MA, USA
| | - Yaoguang Chang
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
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Mei X, Zhang Y, Liu G, Shen J, Han J, Xue C, Xiao H, Chang Y. Characterization of a novel carbohydrate-binding module specifically binding to the major structural units of porphyran. Int J Biol Macromol 2023; 253:127106. [PMID: 37769778 DOI: 10.1016/j.ijbiomac.2023.127106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/07/2023] [Accepted: 09/25/2023] [Indexed: 10/03/2023]
Abstract
Porphyran is a promising bioactive polysaccharide majorly composed of 4-linked α-l-galactopyranose-6-sulfate (L6S) and 3-linked β-d-galactopyranose (G) disaccharide repeating units. Carbohydrate-binding modules (CBMs) have been verified to be essential tools for investigating polysaccharides. However, no confirmed CBM binding to porphyran has been hitherto reported. In this study, an unknown domain with a predicted β-sandwich fold from a potential GH86 porphyranase was discovered, and further recombinantly expressed. The CBM protein (named FvCBM99) presented a desired specificity for porphyran tetrasaccharide with an affinity constant of 1.9 × 10-4 M, while it could not bind to agarose tetrasaccharide. The sequence novelty and well-defined function of FvCBM99 and its homologs reveal a new CBM family, CBM99. Besides, the application potential of FvCBM99 in in situ visualization of porphyran was demonstrated. The discovery of FvCBM99 provides a favorable tool for future studies of porphyran.
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Affiliation(s)
- Xuanwei Mei
- College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China
| | - Yuying Zhang
- College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China
| | - Guanchen Liu
- College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China
| | - Jingjing Shen
- College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China
| | - Jin Han
- College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China
| | - Changhu Xue
- College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China
| | - Hang Xiao
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
| | - Yaoguang Chang
- College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China.
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Mei X, Chang Y, Shen J, Zhang Y, Han J, Xue C. Characterization of a Novel Carrageenan-Specific Carbohydrate-Binding Module: a Promising Tool for the In Situ Investigation of Carrageenan. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:9066-9072. [PMID: 35830544 DOI: 10.1021/acs.jafc.2c03139] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Carrageenan is a commercially important polysaccharide widely applied in the food industry. Specific probes are critical tools for the in situ investigation of polysaccharides, whereas the carrageenan-specific probes are limited at present. Carbohydrate-binding modules (CBMs) could serve as specific probes for the in situ investigation of polysaccharides. In the present study, an unknown function module from the κ-carrageenase Cgk16A was cloned and expressed in Escherichia coli. The expressed protein Cgk16A-CBM92 could specifically bind to carrageenan. Its novelty sheds light on a new CBM family (CBM92) as the founding member. Furthermore, a fluorescent probe was successfully constructed by fusing Cgk16A-CBM92 with a green fluorescent protein. The application potential of Cgk16A-CBM92 as a probe served in the in situ visualization of carrageenan was evaluated. The discovery of Cgk16A-CBM92 provided a promising tool for the in situ investigation of carrageenan.
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Affiliation(s)
- Xuanwei Mei
- College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Yaoguang Chang
- College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Jingjing Shen
- College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Yuying Zhang
- College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Jin Han
- College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Changhu Xue
- College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
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Novy V, Nielsen F, Cullen D, Sabat G, Houtman CJ, Hunt CG. The characteristics of insoluble softwood substrates affect fungal morphology, secretome composition, and hydrolytic efficiency of enzymes produced by Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:105. [PMID: 33902680 PMCID: PMC8074412 DOI: 10.1186/s13068-021-01955-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 04/11/2021] [Indexed: 05/04/2023]
Abstract
BACKGROUND On-site enzyme production using Trichoderma reesei can improve yields and lower the overall cost of lignocellulose saccharification by exploiting the fungal gene regulatory mechanism that enables it to continuously adapt enzyme secretion to the substrate used for cultivation. To harness this, the interrelation between substrate characteristics and fungal response must be understood. However, fungal morphology or gene expression studies often lack structural and chemical substrate characterization. Here, T. reesei QM6a was cultivated on three softwood substrates: northern bleached softwood Kraft pulp (NBSK) and lodgepole pine pretreated either by dilute-acid-catalyzed steam pretreatment (LP-STEX) or mild alkaline oxidation (LP-ALKOX). With different pretreatments of similar starting materials, we presented the fungus with systematically modified substrates. This allowed the elucidation of substrate-induced changes in the fungal response and the testing of the secreted enzymes' hydrolytic strength towards the same substrates. RESULTS Enzyme activity time courses correlated with hemicellulose content and cellulose accessibility. Specifically, increased amounts of side-chain-cleaving hemicellulolytic enzymes in the protein produced on the complex substrates (LP-STEX; LP-ALKOX) was observed by secretome analysis. Confocal laser scanning micrographs showed that fungal micromorphology responded to changes in cellulose accessibility and initial culture viscosity. The latter was caused by surface charge and fiber dimensions, and likely restricted mass transfer, resulting in morphologies of fungi in stress. Supplementing a basic cellulolytic enzyme mixture with concentrated T. reesei supernatant improved saccharification efficiencies of the three substrates, where cellulose, xylan, and mannan conversion was increased by up to 27, 45, and 2800%, respectively. The improvement was most pronounced for proteins produced on LP-STEX and LP-ALKOX on those same substrates, and in the best case, efficiencies reached those of a state-of-the-art commercial enzyme preparation. CONCLUSION Cultivation of T. reesei on LP-STEX and LP-ALKOX produced a protein mixture that increased the hydrolytic strength of a basic cellulase mixture to state-of-the-art performance on softwood substrates. This suggests that the fungal adaptation mechanism can be exploited to achieve enhanced performance in enzymatic hydrolysis without a priori knowledge of specific substrate requirements.
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Affiliation(s)
- Vera Novy
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA.
- Department of Biology and Bioengineering, Division of Industrial Biotechnology, Chalmers University of Technology, Kemivägen 10, 412 96, Göteborg, Sweden.
| | - Fredrik Nielsen
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA
| | - Daniel Cullen
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA
| | - Grzegorz Sabat
- University of Wisconsin Biotechnology Center, Madison, WI, 53706, USA
| | - Carl J Houtman
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA
| | - Christopher G Hunt
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA
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Rohrbach JC, Luterbacher JS. Investigating the effects of substrate morphology and experimental conditions on the enzymatic hydrolysis of lignocellulosic biomass through modeling. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:103. [PMID: 33902675 PMCID: PMC8073973 DOI: 10.1186/s13068-021-01920-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 03/03/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Understanding how the digestibility of lignocellulosic biomass is affected by its morphology is essential to design efficient processes for biomass deconstruction. In this study, we used a model based on a set of partial differential equations describing the evolution of the substrate morphology to investigate the interplay between experimental conditions and the physical characteristics of biomass particles as the reaction proceeds. Our model carefully considers the overall quantity of cellulase present in the hydrolysis mixture and explores its interplay with the available accessible cellulose surface. RESULTS Exploring the effect of various experimental and structural parameters highlighted the significant role of internal mass transfer as the substrate size increases and/or the enzyme loading decreases. In such cases, diffusion of cellulases to the available cellulose surface limits the rate of glucose release. We notably see that increasing biomass loading, while keeping enzyme loading constant should be favored for both small- (R < 300 [Formula: see text]) and middle-ranged (300 < R < 1000 [Formula: see text]) substrates to enhance enzyme diffusion while minimizing the use of enzymes. In such cases, working at enzyme loadings exceeding the full coverage of the cellulose surface (i.e. eI>1) does not bring a significant benefit. For larger particles (R > 1000 [Formula: see text]), increases in biomass loading do not offset the significant internal mass transfer limitations, but high enzyme loadings improve enzyme penetration by maintaining a high concentration gradient within the particle. We also confirm the well-known importance of cellulose accessibility, which increases with pretreatment. CONCLUSIONS Based on the developed model, we are able to propose several design criteria for deconstruction process. Importantly, we highlight the crucial role of adjusting the enzyme and biomass loading to the wood particle size and accessible cellulose surface to maintain a strong concentration gradient, while avoiding unnecessary excess in cellulase loading. Theory-based approaches that explicitly consider the entire lignocellulose particle structure can be used to clearly identify the relative importance of bottlenecks during the biomass deconstruction process, and serve as a framework to build on more detailed cellulase mechanisms.
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Affiliation(s)
- Jessica C Rohrbach
- Laboratory of Sustainable and Catalytic Processing, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Jeremy S Luterbacher
- Laboratory of Sustainable and Catalytic Processing, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland.
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