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Borowska M, Ispiryan L, Neylon E, Sahin AW, Murphy CP, Zannini E, Arendt EK, Coffey A. Screening and Application of Novel Homofermentative Lactic Acid Bacteria Results in Low-FODMAP Whole-Wheat Bread. FERMENTATION-BASEL 2023. [DOI: 10.3390/fermentation9040336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
FODMAPs are fermentable oligo-, di-, monosaccharides, and polyols. The application of homofermentative lactic acid bacteria (LAB) has been investigated as a promising approach for producing low-FODMAP whole-wheat bread. The low-FODMAP diet is recommended to treat irritable bowel syndrome (IBS). Wheat flour is staple to many diets and is a significant source of fructans, which are considered FODMAPs. The reduction of fructans via sourdough fermentation, generally associated with heterofermentative lactic acid bacteria (LAB), often leads to the accumulation of other FODMAPs. A collection of 244 wild-type LAB strains was isolated from different environments and their specific FODMAP utilisation profiles established. Three homofermentative strains were selected for production of whole-wheat sourdough bread. These were Lactiplantibacillus plantarum FST1.7 (FST1.7), Lacticaseibacillus paracasei R3 (R3), and Pediococcus pentosaceus RYE106 (RYE106). Carbohydrate levels in flour, sourdoughs (before and after 48 h fermentation), and resulting breads were analysed via HPAEC-PAD and compared with whole-wheat bread leavened with baker’s yeast. While strain R3 was the most efficient in FODMAP reduction, breads produced with all three test strains had FODMAP content below cut-off levels that would trigger IBS symptoms. Results of this study highlighted the potential of homofermentative LAB in producing low-FODMAP whole-wheat bread.
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Chen L, Hill A, Petit JL, Mariage A, de Berardinis V, Karboune S. Discovery and Enzymatic Screening of Genome-Mined Microbial Levanases to Produce Second-Generation β-(2,6)-Fructooligosaccharides: Catalytic Properties. ACS Chem Biol 2023; 18:465-475. [PMID: 36826427 DOI: 10.1021/acschembio.2c00728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Evidence suggests that β-(2,6)-levan-type fructooligosaccharides (FOSs) possess higher prebiotic potential and selectivity than their β-(2,1)-inulin-type counterparts. The focus of the present work was to develop an enzymatic approach for the synthesis of levan-type FOSs, employing levanases (EC 3.2.1.65), specifically those performing endo-hydrolysis on levans. To identify new levanases, a selection of candidates was obtained via in silico exploration of the levanase family biodiversity through a sequence-driven approach. A collection of 113 candidates was screened according to their specific activities on low- and high-molecular-weight (MW) levan as well as thermal stability. The most active levanases were able to hydrolyze both types of levan with similar efficiency. This ultimately revealed 10 active, highly evolutionary distant and diverse candidate levanases, which demonstrated preferential hydrolysis of levan over inulin. The end-product profile differed significantly depending on levanase with levanbiose, levantriose, and levantetraose being the major FOSs. Among them, the catalytic properties of 5 selected potential new levanases (LEV9 from Belliella Baltica, LEV36 from Dyadobacter fermentans, LEV37 from Capnocytophaga ochracea, LEV79 from Vibrio natriegens, LEV91 from Paenarthrobacter aurescens) were characterized, especially in terms of pH and temperature profiles, thermal stability, and kinetic parameters. The identification of these novel levanases is expected to contribute to the production of levan-type FOSs with properties surpassing those of commercial preparations.
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Affiliation(s)
- Lily Chen
- Department of Food Science and Agricultural Chemistry, Macdonald Campus, McGill University 21,111 Lakeshore Road Sainte Anne de Bellevue, Quebec H9X 3V9, Canada
| | - Andrea Hill
- Department of Food Science and Agricultural Chemistry, Macdonald Campus, McGill University 21,111 Lakeshore Road Sainte Anne de Bellevue, Quebec H9X 3V9, Canada
| | - Jean-Louis Petit
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Univ Paris-Saclay, Evry 91057, France
| | - Aline Mariage
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Univ Paris-Saclay, Evry 91057, France
| | - Véronique de Berardinis
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Univ Paris-Saclay, Evry 91057, France
| | - Salwa Karboune
- Department of Food Science and Agricultural Chemistry, Macdonald Campus, McGill University 21,111 Lakeshore Road Sainte Anne de Bellevue, Quebec H9X 3V9, Canada
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Lekakarn H, Bunterngsook B, Jaikaew P, Kuantum T, Wansuksri R, Champreda V. Functional Characterization of Recombinant Endo-Levanase (LevBk) from Bacillus koreensis HL12 on Short-Chain Levan-Type Fructooligosaccharides Production. Protein J 2022; 41:477-488. [PMID: 35931938 DOI: 10.1007/s10930-022-10069-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2022] [Indexed: 10/15/2022]
Abstract
Levan-type fructooligosaccharides (L-FOSs) are a prominent class of non-digestible oligosaccharides with potential as nutritional prebiotics. Endo-levanase, which randomly hydrolyzes β-(2,6)-linkages in fructans, is a promising enzyme for short-chain FOS production. In this work, a recombinant levanase (LevBk) from Bacillus koreensis strain HL12 was characterized. Soluble LevBk protein was produced in Escherichia coli BL21(DE3) system at 40 mg/L of culture medium. Based on sequence and structural analysis, LevBk was classified as a member of endo-levanase in GH32 family containing N-terminal substrate binding pocket and C-terminal β-sandwich domains. LevBk optimally worked at 45 °C, pH 6.0 with the specific activity of 2.43 U/mg. Based on enzymatic hydrolysis, short-chain L-FOSs with degree of polymerization (DP) of 2-4 were produced from hydrolysis of timothy grass levan under optimal conditions for 9-24 h. With its ability to produce L-FOSs with specific chain lengths, LevBk could be attractively applied for converting of levan containing material to high value-added sweetener in the biorefinery industry.
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Affiliation(s)
- Hataikarn Lekakarn
- Department of Biotechnology, Faculty of Science and Technology, Rangsit Campus, Thammasat University, Pathum Thani, 12120, Thailand
| | - Benjarat Bunterngsook
- Enzyme Technology Research Team, Biorefinery Technology and Bioproduct Research Group, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani, 12120, Thailand.
| | - Phuphiphat Jaikaew
- Department of Biotechnology, Faculty of Science and Technology, Rangsit Campus, Thammasat University, Pathum Thani, 12120, Thailand
| | - Thanyanun Kuantum
- Department of Biotechnology, Faculty of Science and Technology, Rangsit Campus, Thammasat University, Pathum Thani, 12120, Thailand
| | - Rungtiva Wansuksri
- Cassava and Starch Technology Research Team, Functional Ingredients and Food Innovation Research Group, National Center for Genetic Engineering and Biotechnology, Bangkok, 10900, Thailand
| | - Verawat Champreda
- Enzyme Technology Research Team, Biorefinery Technology and Bioproduct Research Group, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani, 12120, Thailand
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Jakob F, Quintero Y, Musacchio A, Estrada‐de los Santos P, Hernández L, Vogel RF. Acetic acid bacteria encode two levansucrase types of different ecological relationship. Environ Microbiol 2019; 21:4151-4165. [DOI: 10.1111/1462-2920.14768] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/24/2019] [Accepted: 07/31/2019] [Indexed: 01/10/2023]
Affiliation(s)
- Frank Jakob
- Lehrstuhl für Technische Mikrobiologie, Technische Universität München Gregor‐Mendel‐Straße 4, 85354 Freising Germany
| | - Yamira Quintero
- Grupo Tecnología de Enzimas, Centro de Ingeniería Genética y Biotecnología (CIGB) Ave 31 entre 158 y 190, Apartado Postal 6162, Habana 10600 Cuba
| | - Alexis Musacchio
- Departamento de Biología de Sistemas Centro de Ingeniería Genética y Biotecnología (CIGB) Ave 31 entre 158 y 190, Apartado Postal 6162, Habana 10600 Cuba
| | - Paulina Estrada‐de los Santos
- Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Prol. de Carpio y Plan de Ayala s/n Col. Santo Tomás C.P., 11340 Cd. de México Mexico
| | - Lázaro Hernández
- Grupo Tecnología de Enzimas, Centro de Ingeniería Genética y Biotecnología (CIGB) Ave 31 entre 158 y 190, Apartado Postal 6162, Habana 10600 Cuba
| | - Rudi F. Vogel
- Lehrstuhl für Technische Mikrobiologie, Technische Universität München Gregor‐Mendel‐Straße 4, 85354 Freising Germany
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Jiang Y, Lu J, Chen T, Yan W, Dong W, Zhou J, Zhang W, Ma J, Jiang M, Xin F. The Draft Genome Sequence of Clostridium sp. Strain NJ4, a Bacterium Capable of Producing Butanol from Inulin Through Consolidated Bioprocessing. Curr Microbiol 2018; 75:1221-1225. [PMID: 29796852 DOI: 10.1007/s00284-018-1513-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/19/2018] [Indexed: 12/21/2022]
Abstract
A novel butanogenic Clostridium sp. NJ4 was successfully isolated and characterized, which could directly produce relatively high titer of butanol from inulin through consolidated bioprocessing (CBP). The assembled draft genome of strain NJ4 is 4.09 Mp, containing 3891 encoded protein sequences with G+C content of 30.73%. Among these annotated genes, a levanase, a hypothetical inulinase, and two bifunctional alcohol/aldehyde dehydrogenases (AdhE) were found to play key roles in the achievement of ABE production from inulin through CBP.
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Affiliation(s)
- Yujia Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Jiasheng Lu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Tianpeng Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Wei Yan
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, People's Republic of China
| | - Jie Zhou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, People's Republic of China
| | - Jiangfeng Ma
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China.
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, People's Republic of China.
| | - Fengxue Xin
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063, Guangdong, People's Republic of China.
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China.
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, People's Republic of China.
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Prebiotic Oligosaccharides: Special Focus on Fructooligosaccharides, Its Biosynthesis and Bioactivity. Appl Biochem Biotechnol 2017; 183:613-635. [PMID: 28948462 DOI: 10.1007/s12010-017-2605-2] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 09/13/2017] [Indexed: 12/12/2022]
Abstract
The bacterial groups in the gut ecosystem play key role in the maintenance of host's metabolic and structural functionality. The gut microbiota enhances digestion processing, helps in digestion of complex substances, synthesizes beneficial bioactive compounds, enhances bioavailability of minerals, impedes growth of pathogenic microbes, and prevents various diseases. It is, therefore, desirable to have an adequate intake of prebiotic biomolecules, which promote favorable modulation of intestinal microflora. Prebiotics are non-digestible and chemically stable structures that significantly enhance growth and functionality of gut microflora. The non-digestible carbohydrate, mainly oligosaccharides, covers a major part of total available prebiotics as dietary additives. The review describes the types of prebiotic low molecular weight carbohydrates, i.e., oligosaccharides, their structure, biosynthesis, functionality, and applications, with a special focus given to fructooligosaccharides (FOSs). The review provides an update on enzymes executing hydrolytic and fructosyltransferase activities producing prebiotic FOS biomolecules, and future perspectives.
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7
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Ua-Arak T, Jakob F, Vogel RF. Influence of levan-producing acetic acid bacteria on buckwheat-sourdough breads. Food Microbiol 2017; 65:95-104. [DOI: 10.1016/j.fm.2017.02.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 02/02/2017] [Accepted: 02/03/2017] [Indexed: 11/28/2022]
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8
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Alméciga-Díaz CJ, Gutierrez ÁM, Bahamon I, Rodríguez A, Rodríguez MA, Sánchez OF. Computational analysis of the fructosyltransferase enzymes in plants, fungi and bacteria. Gene 2011; 484:26-34. [DOI: 10.1016/j.gene.2011.05.024] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 05/23/2011] [Indexed: 11/30/2022]
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Rodríguez MA, Sánchez OF, Alméciga-Díaz CJ. Gene cloning and enzyme structure modeling of the Aspergillus oryzae N74 fructosyltransferase. Mol Biol Rep 2010; 38:1151-61. [PMID: 20563857 DOI: 10.1007/s11033-010-0213-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Accepted: 06/11/2010] [Indexed: 10/19/2022]
Abstract
The fructooligosaccharides (FOS) represent an important source of prebiotic compounds that are widely used as an ingredient in functional foods. Recently, the strain Aspergillus oryzae N74 was reported as a potential microorganism for the industrial production of FOS, due to its high yields of FOS production. In this work, we used a PCR-cloning strategy to clone the A. oryzae N74 ftase gene as a previous step for recombinant enzyme production. Ftase showed a 1630 bp size with a 99% similarity with other A. oryzae strains and between 1 to 68% identities with other Aspergillus strains. This gene encodes for a 525 amino acids protein with 99% similarity with other A. oryzae strains and between 11 to 69% similarities with other Aspergillus strains. Finally, an A. oryzae N74 FTase tertiary structure model was predicted base on its similarity with other glycoside hydrolase 32 family members. The active site was located inside the β-propeller domain and was formed for non-charged polar and charged amino acids. In summary, these results shows the high level of sequence conservation between A. oryzae strains and represent a first step towards the development of a FOS production industrial process using recombinant microorganism carrying the ftase gene from A. oryzae N74.
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Affiliation(s)
- Mauro A Rodríguez
- Institute for the Study of Inborn Errors of Metabolism, School of Sciences, Pontificia Universidad Javeriana, Kra 7 No. 43-82 Building 53, Room 303, Bogota, Colombia
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10
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Cho KM, Hong SJ, Math RK, Islam SMA, Kim JO, Lee YH, Kim H, Yun HD. Cloning of two cellulase genes from endophytic Paenibacillus polymyxa GS01 and comparison with cel 44C-man 26A. J Basic Microbiol 2009; 48:464-72. [PMID: 18759236 DOI: 10.1002/jobm.200700281] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Endophytic bacteria are acknowledged as a new source of genes, proteins and other biochemical compounds, which are often used in biochemical processes. In this study, Paenibacillus polymyxa GS01 was isolated from the interior of the roots of Korean cultivars of ginseng (Panax ginseng C. A. Meyer). Two cellulase genes, cel 5A and cel 5B, were cloned from GS01, and encode 334 aa and 573 aa proteins, respectively. Cel5A and Cel5B each contain a glycosyl hydrolase family 5 (GH5) catalytic domain. The molecular mass of Cel5A and Cel5B were estimated to be 33 kDa and 61 kDa, respectively, by CMC-SDS-PAGE. When purified from Escherichia coli Cel5A and Cel5B both displayed cellulase activity with pH optima of 7.0 and 6.0, respectively and shared a temperature optimum of 50 degrees C. Neither enzyme had detectable xylanase, lichenase, or mannase activity, in contrast to the multifunctional Cel44C-Man26A enzyme of P. polymyxa which displays cellulase, xylanase, lichenase and mannanase activities. However, Cel5A and Cel5B exhibited higher specific cellulase activity than Cel44C-Man26A (120% and 140%, respectively). Cel5A and Cel5B mutants with alanine substitutions at a conserved glutamic acid in the GH5 domain (Glu 179 of Cel5A and Glu184 of Cel5B) lacked cellulase activity, suggesting that this residue is important for GH5 domain function.
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Affiliation(s)
- Kye Man Cho
- Division of Applied Life Science, Gyeongsang National University, Chinju, Korea
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11
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Transcriptional regulation and signal-peptide-dependent secretion of exolevanase (LsdB) in the endophyte Gluconacetobacter diazotrophicus. Appl Environ Microbiol 2009; 75:1782-5. [PMID: 19139238 DOI: 10.1128/aem.01887-08] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gluconacetobacter diazotrophicus utilizes plant sucrose with a constitutively expressed levansucrase (LsdA), producing extracellular levan, which may be degraded under energetically unfavored conditions. Reverse transcriptase-PCR analysis revealed that lsdA and the downstream exolevanase gene (lsdB) form an operon. lsdB transcription was induced during growth with low fructose concentrations (0.44 to 33 mM) and repressed by glucose. Transport of LsdB to the periplasm involved N-terminal signal peptide cleavage. Type II secretion mutants failed to transfer LsdB across the outer membrane, impeding levan hydrolysis.
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Lammens W, Le Roy K, Schroeven L, Van Laere A, Rabijns A, Van den Ende W. Structural insights into glycoside hydrolase family 32 and 68 enzymes: functional implications. JOURNAL OF EXPERIMENTAL BOTANY 2009; 60:727-40. [PMID: 19129163 DOI: 10.1093/jxb/ern333] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Glycoside hydrolases (GH) have been shown to play unique roles in various biological processes like the biosynthesis of glycans, cell wall metabolism, plant defence, signalling, and the mobilization of storage reserves. To date, GH are divided into more than 100 families based upon their overall structure. GH32 and GH68 are combined in clan GH-J, not only harbouring typical hydrolases but also non-Leloir type transferases (fructosyltransferases), involved in fructan biosynthesis. This review summarizes the recent structure-function research progress on plant GH32 enzymes, and highlights the similarities and differences compared with the microbial GH32 and GH68 enzymes. A profound analysis of ligand-bound structures and site-directed mutagenesis experiments identified key residues in substrate (or inhibitor) binding and recognition. In particular, sucrose can bind as inhibitor in Cichorium intybus 1-FEH IIa, whereas it binds as substrate in Bacillus subtilis levansucrase and Arabidopsis thaliana cell wall invertase (AtcwINV1). In plant GH32, a single residue, the equivalent of Asp239 in AtcwINV1, appears to be important for sucrose stabilization in the active site and essential in determining sucrose donor specificity.
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Affiliation(s)
- Willem Lammens
- Laboratorium voor Moleculaire Plantenfysiologie, Faculteit Wetenschappen, Departement Biologie, K. U. Leuven, Kasteelpark Arenberg 31, bus 2434, B-3001 Heverlee, Belgium
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13
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Lima AOS, Quecine MC, Fungaro MHP, Andreote FD, Maccheroni W, Araújo WL, Silva-Filho MC, Pizzirani-Kleiner AA, Azevedo JL. Molecular characterization of a β-1,4-endoglucanase from an endophytic Bacillus pumilus strain. Appl Microbiol Biotechnol 2004; 68:57-65. [PMID: 15538558 DOI: 10.1007/s00253-004-1740-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2004] [Revised: 08/14/2004] [Accepted: 08/31/2004] [Indexed: 10/26/2022]
Abstract
Endophytes comprise mainly microorganisms that colonize inner plant tissues, often living with the host in a symbiotic manner. Several ecological roles have been assigned to endophytic fungi and bacteria, such as antibiosis to phytopathogenic agents and plant growth promotion. Nowadays, endophytes are viewed as a new source of genes, proteins and biochemical compounds that may be used to improve industrial processes. In this study, the gene EglA was cloned from a citrus endophytic Bacillus strain. The EglA encodes a beta-1,4-endoglucanase capable of hydrolyzing cellulose under in vitro conditions. The predicted protein, EglA, has high homology to other bacterial cellulases and shows a modular structure containing a catalytic domain of the glycosyl hydrolase family 9 (GH9) and a cellulose-binding module type 3 (CBM3). The enzyme was expressed in Escherichia coli, purified to homogeneity, and characterized. EglA has an optimum pH range of 5-8, and remarkable heat stability, retaining more than 85% activity even after a 24-h incubation at pH 6-8.6. This characteristic is an important feature for further applications of this enzyme in biotechnological processes in which temperatures of 50-60 degrees C are required over long incubation periods.
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Affiliation(s)
- André O S Lima
- Departamento de Genética, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Av. Pádua Dias 11, Piracicaba, SP, 13418-900, Brazil.
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14
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Arrieta JG, Sotolongo M, Menéndez C, Alfonso D, Trujillo LE, Soto M, Ramírez R, Hernández L. A type II protein secretory pathway required for levansucrase secretion by Gluconacetobacter diazotrophicus. J Bacteriol 2004; 186:5031-9. [PMID: 15262940 PMCID: PMC451657 DOI: 10.1128/jb.186.15.5031-5039.2004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The endophytic diazotroph Gluconacetobacter diazotrophicus secretes a constitutively expressed levansucrase (LsdA, EC 2.4.1.10) to utilize plant sucrose. LsdA, unlike other extracellular levansucrases from gram-negative bacteria, is transported to the periplasm by a signal-peptide-dependent pathway. We identified an unusually organized gene cluster encoding at least the components LsdG, -O, -E, -F, -H, -I, -J, -L, -M, -N, and -D of a type II secretory system required for LsdA translocation across the outer membrane. Another open reading frame, designated lsdX, is located between the operon promoter and lsdG, but it was not identified in BLASTX searches of the DDBJ/EMBL/GenBank databases. The lsdX, -G, and -O genes were isolated from a cosmid library of strain SRT4 by complementation of an ethyl methanesulfonate mutant unable to transport LsdA across the outer membrane. The downstream genes lsdE, -F, -H, -I, -J, -L, -M, -N, and -D were isolated through chromosomal walking. The high G+C content (64 to 74%) and the codon usage of the genes identified are consistent with the G+C content and codon usage of the standard G. diazotrophicus structural gene. Sequence analysis of the gene cluster indicated that a polycistronic transcript is synthesized. Targeted disruption of lsdG, lsdO, or lsdF blocked LsdA secretion, and the bacterium failed to grow on sucrose. Replacement of Cys(162) by Gly at the C terminus of the pseudopilin LsdG abolished the protein functionality, suggesting that there is a relationship with type IV pilins. Restriction fragment length polymorphism analysis revealed conservation of the type II secretion operon downstream of the levansucrase-levanase (lsdA-lsdB) locus in 14 G. diazotrophicus strains representing 11 genotypes recovered from four different host plants in diverse geographical regions. To our knowledge, this is the first report of a type II pathway for protein secretion in the Acetobacteraceae.
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Affiliation(s)
- Juan G Arrieta
- Plant-Microbe Interactions Lab, Plant Division, Center for Genetic Engineering and Biotechnology, P.O. Box 6162, Havana 10600, Cuba.
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15
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Menéndez C, Hernández L, Banguela A, Paı́s J. Functional production and secretion of the Gluconacetobacter diazotrophicus fructose-releasing exo-levanase (LsdB) in Pichia pastoris. Enzyme Microb Technol 2004. [DOI: 10.1016/j.enzmictec.2003.11.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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16
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Barrangou R, Altermann E, Hutkins R, Cano R, Klaenhammer TR. Functional and comparative genomic analyses of an operon involved in fructooligosaccharide utilization by Lactobacillus acidophilus. Proc Natl Acad Sci U S A 2003; 100:8957-62. [PMID: 12847288 PMCID: PMC166420 DOI: 10.1073/pnas.1332765100] [Citation(s) in RCA: 184] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Lactobacillus acidophilus is a probiotic organism that displays the ability to use prebiotic compounds such as fructooligosaccharides (FOS), which stimulate the growth of beneficial commensals in the gastrointestinal tract. However, little is known about the mechanisms and genes involved in FOS utilization by Lactobacillus species. Analysis of the L. acidophilus NCFM genome revealed an msm locus composed of a transcriptional regulator of the LacI family, a four-component ATP-binding cassette (ABC) transport system, a fructosidase, and a sucrose phosphorylase. Transcriptional analysis of this operon demonstrated that gene expression was induced by sucrose and FOS but not by glucose or fructose, suggesting some specificity for nonreadily fermentable sugars. Additionally, expression was repressed by glucose but not by fructose, suggesting catabolite repression via two cre-like sequences identified in the promoter-operator region. Insertional inactivation of the genes encoding the ABC transporter substrate-binding protein and the fructosidase reduced the ability of the mutants to grow on FOS. Comparative analysis of gene architecture within this cluster revealed a high degree of synteny with operons in Streptococcus mutans and Streptococcus pneumoniae. However, the association between a fructosidase and an ABC transporter is unusual and may be specific to L. acidophilus. This is a description of a previously undescribed gene locus involved in transport and catabolism of FOS compounds, which can promote competition of beneficial microorganisms in the human gastrointestinal tract.
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Affiliation(s)
- Rodolphe Barrangou
- Genomic Sciences Program and Southeast Dairy Foods Research Center, North Carolina State University, Raleigh, NC 27695, USA
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