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Wang H, Zhu B. Directed preparation of algal oligosaccharides with specific structures by algal polysaccharide degrading enzymes. Int J Biol Macromol 2024; 277:134093. [PMID: 39053825 DOI: 10.1016/j.ijbiomac.2024.134093] [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: 04/07/2024] [Revised: 07/15/2024] [Accepted: 07/20/2024] [Indexed: 07/27/2024]
Abstract
Seaweed polysaccharides have a wide range of sources and rich content, with various biological activities such as anti-inflammatory, anti-tumor, anticoagulant, and blood pressure lowering. They can be applied in fields such as food, agriculture, and medicine. However, the poor solubility of macromolecular seaweed polysaccharides limits their further application. Reports have shown that some biological activities of seaweed oligosaccharides are more extensive and superior to that of seaweed polysaccharides. Therefore, reducing the degree of polymerization of polysaccharides will be the key to the high value utilization of seaweed polysaccharide resources. There are three main methods for degrading algal polysaccharides into algal oligosaccharides, physical, chemical and enzymatic degradation. Among them, enzymatic degradation has been a hot research topic in recent years. Various types of algal polysaccharide hydrolases and related glycosidases are powerful tools for the preparation of algal oligosaccharides, including α-agarases, β-agaroses, α-neoagarose hydrolases and β-galactosidases that are related to agar, κ-carrageenases, ι-carrageenases and λ-carrageenases that are related to carrageenan, β-porphyranases that are related to porphyran, funoran hydrolases that are related to funoran, alginate lyases that are related to alginate and ulvan lyases related to ulvan. This paper describes the bioactivities of agar oligosaccharide, carrageenan oligosaccharide, porphyran oligosaccharide, funoran oligosaccharide, alginate oligosaccharide and ulvan oligosaccharide and provides a detailed review of the progress of research on the enzymatic preparation of these six oligosaccharides. At the same time, the problems and challenges faced are presented to guide and improve the preparation and application of algal oligosaccharides in the future.
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Affiliation(s)
- Hui Wang
- College of Food Science and Light Industry, Nanjing Tech University, 211086, China
| | - Benwei Zhu
- College of Food Science and Light Industry, Nanjing Tech University, 211086, China.
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Zeng X, Tian Y, Kong H, Li Z, Gu Z, Li C, Hong Y, Cheng L, Ban X. Catalytic Mode and Product Specificity of an α-Agarase Reveal Its Direct Catalysis for the Production of Agarooligosaccharides. Foods 2024; 13:2351. [PMID: 39123543 PMCID: PMC11311870 DOI: 10.3390/foods13152351] [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: 07/09/2024] [Revised: 07/21/2024] [Accepted: 07/24/2024] [Indexed: 08/12/2024] Open
Abstract
Many α-agarases have been characterized and are utilized for producing agarooligosaccharides through the degradation of agar and agarose, which are considered valuable for applications in the food and medicine industries. However, the catalytic mechanism and product transformation process of α-agarase remain unclear, limiting further enzyme engineering for industrial applications. In this study, an α-agarase from Catenovulum maritimus STB14 (Cm-AGA) was employed to degrade agarose oligosaccharides (AGOs) with varying degrees of polymerization (DPs) to investigate the catalytic mechanism of α-agarases. The results demonstrated that Cm-AGA could degrade agarose into agarotetraose and agarohexaose. The reducing ends of agarotetraose and agarohexaose spontaneously release unstable 3,6-anhydro-α-l-galactose molecules, which were further degraded into agarotriose and agaropentose. Cm-AGA cannot act on α-1,3-glucoside bonds in agarotriose, agarotetraose, neoagarobiose, and neoagarotetraose but can act on AGOs with a DP greater than four. The product analysis was further verified by β-galactosidase hydrolysis, which specifically cleaves the non-reducing glycosidic bond of agarooligosaccharides. Multiple sequence alignment results showed that two conserved residues, Asp994 and Glu1129, were proposed as catalytic residues and were further identified by site-directed mutagenesis. Molecular docking of Cm-AGA with agaroheptose revealed the potential substrate binding mode of the α-agarase. These findings enhance the understanding of Cm-AGA's catalytic mode and could guide enzyme engineering for modulating the production of agarooligosaccharides.
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Affiliation(s)
- Xiaofeng Zeng
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (X.Z.); (Y.T.); (H.K.); (Z.L.); (Z.G.); (C.L.); (Y.H.); (L.C.)
| | - Yixiong Tian
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (X.Z.); (Y.T.); (H.K.); (Z.L.); (Z.G.); (C.L.); (Y.H.); (L.C.)
| | - Haocun Kong
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (X.Z.); (Y.T.); (H.K.); (Z.L.); (Z.G.); (C.L.); (Y.H.); (L.C.)
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China
| | - Zhaofeng Li
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (X.Z.); (Y.T.); (H.K.); (Z.L.); (Z.G.); (C.L.); (Y.H.); (L.C.)
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China
| | - Zhengbiao Gu
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (X.Z.); (Y.T.); (H.K.); (Z.L.); (Z.G.); (C.L.); (Y.H.); (L.C.)
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China
| | - Caiming Li
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (X.Z.); (Y.T.); (H.K.); (Z.L.); (Z.G.); (C.L.); (Y.H.); (L.C.)
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China
| | - Yan Hong
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (X.Z.); (Y.T.); (H.K.); (Z.L.); (Z.G.); (C.L.); (Y.H.); (L.C.)
| | - Li Cheng
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (X.Z.); (Y.T.); (H.K.); (Z.L.); (Z.G.); (C.L.); (Y.H.); (L.C.)
| | - Xiaofeng Ban
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (X.Z.); (Y.T.); (H.K.); (Z.L.); (Z.G.); (C.L.); (Y.H.); (L.C.)
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China
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Zhang M, Tong X, Wang W, Wang J, Qu W. Agarose biodegradation by deep-sea bacterium Vibrio natriegens WPAGA4 with the agarases through horizontal gene transfer. J Basic Microbiol 2024; 64:e2300521. [PMID: 37988660 DOI: 10.1002/jobm.202300521] [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: 09/10/2023] [Revised: 10/10/2023] [Accepted: 11/01/2023] [Indexed: 11/23/2023]
Abstract
This study aimed to reveal the importance of horizontal gene transfer (HGT) for the agarose-degrading ability and the related degradation pathway of a deep-sea bacterium Vibrio natriegens WPAGA4, which was rarely reported in former works. A total of four agarases belonged to the GH50 family, including Aga3418, Aga3419, Aga3420, and Aga3472, were annotated and expressed in Escherichia coli cells. The agarose degradation products of Aga3418, Aga3420, and Aga3472 were neoagarobiose, while those of Aga3419 were neoagarobiose and neoagarotetraose. The RT-qPCR analysis showed that the expression level ratio of Aga3418, Aga3419, Aga3420, and Aga3472 was stable at about 1:1:1.5:2.5 during the degradation, which indicated the optimal expression level ratio of the agarases for agarose degradation by V. natriegens WPAGA4. Based on the genomic information, three of four agarases and other agarose-degrading related genes were in a genome island with a G + C content that was obviously lower than that of the whole genome of V. natriegens WPAGA4, indicating that these agarose-degrading genes were required through HGT. Our results demonstrated that the expression level ratio instead of the expression level itself of agarase genes was crucial for agarose degradation by V. natriegens WPAGA4, and HGT occurred in the deep-sea environment, thereby promoting the deep-sea carbon cycle and providing a reference for studying the evolution and transfer pathways of agar-related genes.
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Affiliation(s)
- Mengyuan Zhang
- Marine Science and Technology College, Zhejiang Ocean University, Zhoushan, China
- Zhejiang Ocean University-University of Pisa Marine Graduate School, Zhoushan, China
| | - Xiufang Tong
- Marine Science and Technology College, Zhejiang Ocean University, Zhoushan, China
| | - Wenxin Wang
- Zhejiang Ocean University-University of Pisa Marine Graduate School, Zhoushan, China
| | - Jianxin Wang
- Marine Science and Technology College, Zhejiang Ocean University, Zhoushan, China
| | - Wu Qu
- Marine Science and Technology College, Zhejiang Ocean University, Zhoushan, China
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Sun H, Lv Y, Zhang J, Zhou C, Su X. A dual-signal fluorometric and colorimetric sensing platform based on gold-platinum bimetallic nanoclusters for the determination of β-galactosidase activity. Anal Chim Acta 2023; 1252:341010. [PMID: 36935161 DOI: 10.1016/j.aca.2023.341010] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 02/21/2023] [Accepted: 02/23/2023] [Indexed: 02/25/2023]
Abstract
Herein, a novel dual-signal sensing system for the determination of β-galactosidase (β-Gal) activity was established, which was based on a dual-emission probe assembled from gold-platinum bimetallic nanoclusters (Au-Pt NCs) and rhodamine B. Under the catalysis of β-Gal, 4-nitrophenyl β-D-galactopyranoside (PNPG) was rapidly hydrolyzed to generate p-nitrophenol (PNP), which has an obvious UV absorption peak at 400 nm. The hydrolyzed product PNP can quench the fluorescence of Au-Pt NCs effectively by inner filter effect (IFE), and PNP had no impact on the fluorescence of rhodamine B, which will change the emission intensity ratio of Au-Pt NCs and rhodamine B. Therefore, the ratiometric fluorescent and colorimetric dual-signal sensor based on Au-Pt NCs and rhodamine B was successfully constructed for sensitive detection of β-Gal activity. The linear detection range for the ratiometric fluorescence and colorimetric methods were 2.5-25 U/L and 15-55 U/L with detection limits of 1.2 U/L and 5.2 U/L, respectively. The developed assay method has been used for quantitative detection of β-Gal in spiked serum samples and showed good performance. And the detection platform has high reliability and excellent selectivity, which opens a new avenue for the further application of Au-Pt NCs in chemical sensing and biological analysis.
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Affiliation(s)
- Huilin Sun
- Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Yuntai Lv
- Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Jiabao Zhang
- Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Chenyu Zhou
- Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Xingguang Su
- Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China.
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Tao S, Qingbin M, Zhiling L, Caiyu S, Lixin L, Lilai L. Comparative genomics reveals cellobiose hydrolysis mechanism of Ruminiclostridium thermocellum M3, a cellulosic saccharification bacterium. Front Microbiol 2023; 13:1079279. [PMID: 36687593 PMCID: PMC9852859 DOI: 10.3389/fmicb.2022.1079279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/07/2022] [Indexed: 01/08/2023] Open
Abstract
The cellulosome of Ruminiclostridium thermocellum was one of the most efficient cellulase systems in nature. However, the product of cellulose degradation by R. thermocellum is cellobiose, which leads to the feedback inhibition of cellulosome, and it limits the R. thermocellum application in the field of cellulosic biomass consolidated bioprocessing (CBP) industry. In a previous study, R. thermocellum M3, which can hydrolyze cellulosic feedstocks into monosaccharides, was isolated from horse manure. In this study, the complete genome of R. thermocellum M3 was sequenced and assembled. The genome of R. thermocellum M3 was compared with the other R. thermocellum to reveal the mechanism of cellulosic saccharification by R. thermocellum M3. In addition, we predicted the key genes for the elimination of feedback inhibition of cellobiose in R. thermocellum. The results indicated that the whole genome sequence of R. thermocellum M3 consisted of 3.6 Mb of chromosomes with a 38.9% of GC%. To be specific, eight gene islands and 271 carbohydrate-active enzyme-encoded proteins were detected. Moreover, the results of gene function annotation showed that 2,071, 2,120, and 1,246 genes were annotated into the Clusters of Orthologous Groups (COG), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, respectively, and most of the genes were involved in carbohydrate metabolism and enzymatic catalysis. Different from other R. thermocellum, strain M3 has three proteins related to β-glucosidase, and the cellobiose hydrolysis was enhanced by the synergy of gene BglA and BglX. Meanwhile, the GH42 family, CBM36 family, and AA8 family might participate in cellobiose degradation.
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Affiliation(s)
- Sheng Tao
- College of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, China,*Correspondence: Sheng Tao,
| | - Meng Qingbin
- College of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, China
| | - Li Zhiling
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, China,Li Zhiling,
| | - Sun Caiyu
- College of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, China
| | - Li Lixin
- College of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, China
| | - Liu Lilai
- College of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, China
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Li G, Guo R, Wu S, Cheng S, Li J, Liu Z, Xie W, Sun X, Zhang Q, Li Z, Xu J, Wu J, Wei Z, Hu F. Characterization of Agarolytic Pathway in a Terrestrial Bacterium Cohnella sp. LGH. Front Microbiol 2022; 13:828687. [PMID: 35432256 PMCID: PMC9008576 DOI: 10.3389/fmicb.2022.828687] [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: 01/07/2022] [Accepted: 02/17/2022] [Indexed: 11/13/2022] Open
Abstract
Previously, we have reported that an endo-type β-agarase AgaW was responsible for the hydrolysis of agarose into the major product neoagarotetraose in a terrestrial agar-degrading bacterium Cohnella sp. LGH. Here, we identify and characterize the following depolymerization pathway in strain LGH through the genomic and enzymatic analysis. In the pathway, neoagarotetraose was depolymerized by a novel α-neoagarooligosaccharide (NAOS) hydrolase CL5012 into 3,6-anhydro-α-L-galactose (L-AHG) and agarotriose; Agarotriose was further depolymerized by a novel agarolytic β-galactosidase CL4994 into D-galactose and neoagarobiose; Neoagarobiose was finally depolymerized by CL5012 into L-AHG and D-galactose. Although α-agarase has not been identified in strain LGH, the combined action of CL5012 and CL4994 unexpectedly plays a critical role in the depolymerization of agarotetraose, one theoretical product of α-agarase hydrolysis of agarose. In this pathway, agarotetraose was depolymerized by CL4994 into D-galactose and neoagarotriose; Neoagarotriose was then depolymerized by CL5012 into L-AHG and agarobiose. Furthermore, another novel endo-type β-agarase CL5055 was identified as an isozyme of AgaW with different pH preference in the hydrolysis of agarose into α-NAOSs. Strain LGH seemed to lack a common exo-type β-agarase responsible for the direct depolymerization of agarose or neoagarooligosaccharide into neoagarobiose. These results highlight the diversity of agarolytic manner in bacteria and provide a novel insight on the diversity of agarolytic pathways.
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Affiliation(s)
- Gen Li
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Key Lab of Plant Immunity, Nanjing, China
| | - Rui Guo
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Shuqi Wu
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Si Cheng
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Jiaqi Li
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Zhenzhen Liu
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Wangliang Xie
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Xiaolin Sun
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Qiuyi Zhang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Zihan Li
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - JiaZheng Xu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Jun Wu
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
- *Correspondence: Jun Wu,
| | - Zhong Wei
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Key Lab of Plant Immunity, Nanjing, China
| | - Feng Hu
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
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Yi Y, Li J, Zong Z, Liu X, Song H, Wang H, Zhang Z, Zhang H, Li Y. Cloning, expression, and characteristic analysis of the novel β-galactosidase from silkworm, Bombyx mori. Genesis 2021; 59:e23446. [PMID: 34449115 DOI: 10.1002/dvg.23446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/16/2021] [Accepted: 08/18/2021] [Indexed: 01/22/2023]
Abstract
β-Galactosidase is a critical exoglycosidase involved in the hydrolysis of lactose, the modification and degradation of glycoprotein in vivo. In this study, the β-galactosidase gene of silkworm (BmGal), whose cDNA comprises 11 exons and contains an intact ORF of 1,821 bp, was cloned. The protein sequence of BmGal showed high similarity with other known insect β-galactosidases. No activity of the BmGal expressed in Escherichia coli or Pichia pastoris was detected while it was successfully expressed with high enzyme activity in baculovirus expression system in silkworm, and the electrophoresis result revealed that the BmGal showed activity in oligomer mode. Enzyme activity assay showed that its optimum pH was 8.4 and its optimum temperature was 40 °C. What is more, we found that iron ions can stimulate the activity of the enzyme while cobalt, nickel, or lead ions can inhibit its activity significantly. Besides, the temporal-spatial transcription pattern of the BmGal mRNA level was analyzed, which showed that BmGal was transcribed at the highest level in the fifth larval instar but relatively low level in the pupal and adult stage, and the highest transcriptional level of BmGal was found in testis among all the tissues concerned.
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Affiliation(s)
- Yongzhu Yi
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China
| | - Jialei Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhipeng Zong
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xingjian Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Haozhi Song
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Haining Wang
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China
| | - Zhifang Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Huan Zhang
- Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Yinü Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
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Jiang C, Cheng D, Liu Z, Sun J, Mao X. Advances in agaro-oligosaccharides preparation and bioactivities for revealing the structure-function relationship. Food Res Int 2021; 145:110408. [PMID: 34112411 DOI: 10.1016/j.foodres.2021.110408] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 04/13/2021] [Accepted: 05/06/2021] [Indexed: 11/24/2022]
Abstract
Agaro-oligosaccharides originating from red algae have attracted increasing attention in both basic theoretical research and applied fields due to their excellent bioactivities, which indicates the wide prospects of agaro-oligosaccharides for application in the food, pharmaceutical and cosmetic industries. Thus, a considerable number of studies regarding functional agaro-oligosaccharides preparation as well as the bioactivities exploration have been carried out. Based on these studies, this review first introduced different methods that have been used in agar extraction from red algae, and further provided research progress on arylsulfatase. Then, different methods used for agaro-oligosaccharides production were summarized. Moreover, the abundant bioactivities of agaro-oligosaccharides were described in detail. Finally, this review has discussed current research problems and further provided critical aspects, which may be helpful for revealing the structure-function relationship of agaro-oligosaccharide.
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Affiliation(s)
- Chengcheng Jiang
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
| | - Danyang Cheng
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
| | - Zhen Liu
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
| | - Jianan Sun
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
| | - Xiangzhao Mao
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
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Agarose degradation for utilization: Enzymes, pathways, metabolic engineering methods and products. Biotechnol Adv 2020; 45:107641. [PMID: 33035614 DOI: 10.1016/j.biotechadv.2020.107641] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 09/27/2020] [Accepted: 10/03/2020] [Indexed: 12/14/2022]
Abstract
Red algae are important renewable bioresources with very large annual outputs. Agarose is the major carbohydrate component of many red algae and has potential to be of value in the production of agaro-oligosaccharides, biofuels and other chemicals. In this review, we summarize the degradation pathway of agarose, which includes an upstream part involving transformation of agarose into its two monomers, D-galactose (D-Gal) and 3,6-anhydro-α-L-galactose (L-AHG), and a downstream part involving monosaccharide degradation pathways. The upstream part involves agarolytic enzymes such as α-agarase, β-agarase, α-neoagarobiose hydrolase, and agarolytic β-galactosidase. The downstream part includes the degradation pathways of D-Gal and L-AHG. In addition, the production of functional agaro-oligosaccharides such as neoagarobiose and monosaccharides such as L-AHG with different agarolytic enzymes is reviewed. Third, techniques for the setup, regulation and optimization of agarose degradation to increase utilization efficiency of agarose are summarized. Although heterologous construction of the whole agarose degradation pathway in an engineered strain has not been reported, biotechnologies applied to improve D-Gal utilization efficiency and construct L-AHG catalytic routes are reviewed. Finally, critical aspects that may aid in the construction of engineered microorganisms that can fully utilize agarose to produce agaro-oligosaccharides or as carbon sources for production of biofuels or other value-adding chemicals are discussed.
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Li D, Li S, Wu Y, Jin M, Zhou Y, Wang Y, Chen X, Han Y. Cloning and Characterization of a New β-Galactosidase from Alteromonas sp. QD01 and Its Potential in Synthesis of Galacto-Oligosaccharides. Mar Drugs 2020; 18:md18060312. [PMID: 32545859 PMCID: PMC7344425 DOI: 10.3390/md18060312] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/10/2020] [Accepted: 06/10/2020] [Indexed: 12/11/2022] Open
Abstract
As prebiotics, galacto-oligosaccharides (GOSs) can improve the intestinal flora and have important applications in medicine. β-galactosidases could promote the synthesis of GOSs in lactose and catalyze the hydrolysis of lactose. In this study, a new β-galactosidase gene (gal2A), which belongs to the glycoside hydrolase family 2, was cloned from marine bacterium Alteromonas sp. QD01 and expressed in Escherichia coli. The molecular weight of Gal2A was 117.07 kDa. The optimal pH and temperature of Gal2A were 8.0 and 40 °C, respectively. At the same time, Gal2A showed wide pH stability in the pH range of 6.0–9.5, which is suitable for lactose hydrolysis in milk. Most metal ions promoted the activity of Gal2A, especially Mn2+ and Mg2+. Importantly, Gal2A exhibited high transglycosylation activity, which can catalyze the formation of GOS from milk and lactose. These characteristics indicated that Gal2A may be ideal for producing GOSs and lactose-reducing dairy products.
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Liu J, Liu Z, Jiang C, Mao X. Biochemical Characterization and Substrate Degradation Mode of a Novel α-Agarase from Catenovulum agarivorans. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:10373-10379. [PMID: 31453692 DOI: 10.1021/acs.jafc.9b03073] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Agarose can be hydrolyzed into agarooligosaccharides (AOSs) by α-agarase, which is an important enzyme for efficient saccharification of agarose or preparation of bioactive oligosaccharides from agarose. Although many β-agarases have been reported and characterized, there are only a few studies on α-agarases. Here, we cloned a novel α-agarase named CaLJ96 with a molecular weight of approximately 200 kDa belonging to glycoside hydrolase family 96 from Catenovulum agarivorans. CaLJ96 has good pH stability and exhibits maximum activity at 37 °C and pH 7.0. The hydrolyzed products of agarose by CaLJ96 are analyzed as agarobiose (A2), agarotetraose (A4), and agarohexaose (A6), in which A4 is the dominant product. CaLJ96 can hydrolyze agaropentaose (A5) into A2 and agarotriose (A3) and A6 into A2 and A4 but cannot act on A2, A3, or A4. This is the first report to characterize the α-agarase action on AOSs in detail. Therefore, CaLJ96 has potential for the manufacture of bioactive AOSs.
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Affiliation(s)
- Jie Liu
- College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
| | - Zhen Liu
- College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
| | - Chengcheng Jiang
- College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
| | - Xiangzhao Mao
- College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
- Laboratory for Marine Drugs and Bioproducts , Qingdao National Laboratory for Marine Science and Technology , Qingdao 266237 , China
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