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Han R, Baudrexl M, Ludwig C, Berezina OV, Rykov SV, Liebl W. Identification of a novel xanthan-binding module of a multi-modular Cohnella sp. xanthanase. Front Microbiol 2024; 15:1386552. [PMID: 38596379 PMCID: PMC11002231 DOI: 10.3389/fmicb.2024.1386552] [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: 02/15/2024] [Accepted: 03/14/2024] [Indexed: 04/11/2024] Open
Abstract
A new strain of xanthan-degrading bacteria identified as Cohnella sp. has been isolated from a xanthan thickener for food production. The strain was able to utilize xanthan as the only carbon source and to reduce the viscosity of xanthan-containing medium during cultivation. Comparative analysis of the secretomes of Cohnella sp. after growth on different media led to the identification of a xanthanase designated as CspXan9, which was isolated after recombinant production in Escherichia coli. CspXan9 could efficiently degrade the β-1,4-glucan backbone of xanthan after previous removal of pyruvylated mannose residues from the ends of the native xanthan side chains by xanthan lyase treatment (XLT-xanthan). Compared with xanthanase from Paenibacillus nanensis, xanthanase CspXan9 had a different module composition at the N- and C-terminal ends. The main putative oligosaccharides released from XLT-xanthan by CspXan9 cleavage were tetrasaccharides and octasaccharides. To explore the functions of the N- and C-terminal regions of the enzyme, truncated variants lacking some of the non-catalytic modules (CspXan9-C, CspXan9-N, CspXan9-C-N) were produced. Enzyme assays with the purified deletion derivatives, which all contained the catalytic glycoside hydrolase family 9 (GH9) module, demonstrated substantially reduced specific activity on XLT-xanthan of CspXan9-C-N compared with full-length CspXan9. The C-terminal module of CspXan9 was found to represent a novel carbohydrate-binding module of family CBM66 with binding affinity for XLT-xanthan, as was shown by native affinity polyacrylamide gel electrophoresis in the presence of various polysaccharides. The only previously known binding function of a CBM66 member is exo-type binding to the non-reducing fructose ends of the β-fructan polysaccharides inulin and levan.
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Affiliation(s)
- Rui Han
- Chair of Microbiology, School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Melanie Baudrexl
- Chair of Microbiology, School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Christina Ludwig
- Bavarian Center for Biomolecular Mass Spectrometry (BayBioMS), School of Life Sciences, Technical University of Munich, Freising, Germany
| | | | - Sergey V. Rykov
- National Research Centre “Kurchatov Institute”, Moscow, Russia
| | - Wolfgang Liebl
- Chair of Microbiology, School of Life Sciences, Technical University of Munich, Freising, Germany
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Berezina OV, Rykov SV, Schwarz WH, Liebl W. Xanthan: enzymatic degradation and novel perspectives of applications. Appl Microbiol Biotechnol 2024; 108:227. [PMID: 38381223 PMCID: PMC10881899 DOI: 10.1007/s00253-024-13016-6] [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: 01/04/2024] [Revised: 01/04/2024] [Accepted: 01/11/2024] [Indexed: 02/22/2024]
Abstract
The extracellular heteropolysaccharide xanthan, synthesized by bacteria of the genus Xanthomonas, is widely used as a thickening and stabilizing agent across the food, cosmetic, and pharmaceutical sectors. Expanding the scope of its application, current efforts target the use of xanthan to develop innovative functional materials and products, such as edible films, eco-friendly oil surfactants, and biocompatible composites for tissue engineering. Xanthan-derived oligosaccharides are useful as nutritional supplements and plant defense elicitors. Development and processing of such new functional materials and products often necessitate tuning of xanthan properties through targeted structural modification. This task can be effectively carried out with the help of xanthan-specific enzymes. However, the complex molecular structure and intricate conformational behavior of xanthan create problems with its enzymatic hydrolysis or modification. This review summarizes and analyzes data concerning xanthan-degrading enzymes originating from microorganisms and microbial consortia, with a particular focus on the dependence of enzymatic activity on the structure and conformation of xanthan. Through a comparative study of xanthan-degrading pathways found within various bacterial classes, different microbial enzyme systems for xanthan utilization have been identified. The characterization of these new enzymes opens new perspectives for modifying xanthan structure and developing innovative xanthan-based applications. KEY POINTS: • The structure and conformation of xanthan affect enzymatic degradation. • Microorganisms use diverse multienzyme systems for xanthan degradation. • Xanthan-specific enzymes can be used to develop xanthan variants for novel applications.
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Affiliation(s)
- Oksana V Berezina
- National Research Centre «Kurchatov Institute», Academician Kurchatov Sq. 1, 123182, Moscow, Russian Federation
| | - Sergey V Rykov
- National Research Centre «Kurchatov Institute», Academician Kurchatov Sq. 1, 123182, Moscow, Russian Federation
| | - Wolfgang H Schwarz
- Chair of Microbiology, Technical University of Munich, TUM School of Life Sciences, Emil-Ramann-Str. 4, 85354, Freising, Germany
| | - Wolfgang Liebl
- Chair of Microbiology, Technical University of Munich, TUM School of Life Sciences, Emil-Ramann-Str. 4, 85354, Freising, Germany.
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Comparative analysis of genome-based CAZyme cassette in Antarctic Microbacterium sp. PAMC28756 with 31 other Microbacterium species. Genes Genomics 2022; 44:733-746. [PMID: 35486322 DOI: 10.1007/s13258-022-01254-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 03/31/2022] [Indexed: 11/04/2022]
Abstract
BACKGROUND The genus Microbacterium belongs to the family Microbacteriaceae and phylum Actinobacteria. A detailed study on the complete genome and systematic comparative analysis of carbohydrate-active enzyme (CAZyme) among the Microbacterium species would add knowledge on metabolic and environmental adaptation. Here we present the comparative genomic analysis of CAZyme using the complete genome of Antarctic Microbacterium sp. PAMC28756 with other complete genomes of 31 Microbacterium species available. OBJECTIVE The genomic and CAZyme comparison of Microbacterium species and to rule out the specific features of CAZyme for the environmental and metabolic adaptation. METHODS Bacterial source were collected from NCBI database, CAZyme annotation of Microbacterium species was analyzed using dbCAN2 Meta server. Cluster of orthologous groups (COGs) analysis was performed using the eggNOG4.5 database. Whereas, KEGG database was used to compare and obtained the functional genome annotation information in carbohydrate metabolism and glyoxylate cycle. RESULTS Out of 32 complete genomes of Microbacterium species, strain No. 7 isolated from Activated Sludge showed the largest genomic size at 4.83 Mb. The genomic size of PAMC28756 isolated from Antarctic lichen species Stereocaulons was 3.54 Mb, the G + C content was 70.4% with 3,407 predicted genes, of which 3.36% were predicted CAZyme. In addition, while comparing the Glyoxylate cycle among 32 bacteria, except 10 strains, all other, including our strain have Glyoxylate pathway. PAMC28756 contained the genes that degrade cellulose, hemicellulose, amylase, pectinase, chitins and other exo-and endo glycosidases. Utilizing these polysaccharides can provides source of energy in an extreme environment. In addition, PAMC28756 assigned the (10.15%) genes in the carbohydrate transport and metabolism functional group closely related to the CAZyme for polysaccharides degradation. CONCLUSIONS The genomic content and CAZymes distribution was varied in Microbacterium species. There was the presence of more than 10% genes in the carbohydrate transport and metabolism functional group closely related to the CAZyme for polysaccharides degradation. In addition, occurrence of glyoxylate cycle for alternative utilization of carbon sources suggest the adaptation of PAMC28756 in the harsh microenvironment.
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Ostrowski MP, La Rosa SL, Kunath BJ, Robertson A, Pereira G, Hagen LH, Varghese NJ, Qiu L, Yao T, Flint G, Li J, McDonald SP, Buttner D, Pudlo NA, Schnizlein MK, Young VB, Brumer H, Schmidt TM, Terrapon N, Lombard V, Henrissat B, Hamaker B, Eloe-Fadrosh EA, Tripathi A, Pope PB, Martens EC. Mechanistic insights into consumption of the food additive xanthan gum by the human gut microbiota. Nat Microbiol 2022; 7:556-569. [PMID: 35365790 DOI: 10.1038/s41564-022-01093-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 02/24/2022] [Indexed: 12/13/2022]
Abstract
Processed foods often include food additives such as xanthan gum, a complex polysaccharide with unique rheological properties, that has established widespread use as a stabilizer and thickening agent. Xanthan gum's chemical structure is distinct from those of host and dietary polysaccharides that are more commonly expected to transit the gastrointestinal tract, and little is known about its direct interaction with the gut microbiota, which plays a central role in digestion of other dietary fibre polysaccharides. Here we show that the ability to digest xanthan gum is common in human gut microbiomes from industrialized countries and appears contingent on a single uncultured bacterium in the family Ruminococcaceae. Our data reveal that this primary degrader cleaves the xanthan gum backbone before processing the released oligosaccharides using additional enzymes. Some individuals harbour Bacteroides intestinalis that is incapable of consuming polymeric xanthan gum but grows on oligosaccharide products generated by the Ruminococcaceae. Feeding xanthan gum to germfree mice colonized with a human microbiota containing the uncultured Ruminococcaceae supports the idea that the additive xanthan gum can drive expansion of the primary degrader Ruminococcaceae, along with exogenously introduced B. intestinalis. Our work demonstrates the existence of a potential xanthan gum food chain involving at least two members of different phyla of gut bacteria and provides an initial framework for understanding how widespread consumption of a recently introduced food additive influences human microbiomes.
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Affiliation(s)
- Matthew P Ostrowski
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Sabina Leanti La Rosa
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway.,Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway
| | - Benoit J Kunath
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Andrew Robertson
- Life Sciences Institute: Natural Products Discovery Core, University of Michigan, Ann Arbor, MI, USA
| | - Gabriel Pereira
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Live H Hagen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | | | - Ling Qiu
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Tianming Yao
- Department of Food Science and Whistler Center for Carbohydrate Research, Purdue University, West Lafayette, IN, USA
| | - Gabrielle Flint
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - James Li
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sean P McDonald
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Duna Buttner
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Nicholas A Pudlo
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Matthew K Schnizlein
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Vincent B Young
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA.,Department of Internal Medicine, Infectious Diseases Division, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Harry Brumer
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Thomas M Schmidt
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Nicolas Terrapon
- Centre National de la Recherche Scientifique, Aix-Marseille Univ, Marseille, France.,Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement, Marseille, France
| | - Vincent Lombard
- Centre National de la Recherche Scientifique, Aix-Marseille Univ, Marseille, France.,Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement, Marseille, France
| | - Bernard Henrissat
- Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.,Technical University of Denmark, DTU Bioengineering, Lyngby, Denmark
| | - Bruce Hamaker
- Department of Food Science and Whistler Center for Carbohydrate Research, Purdue University, West Lafayette, IN, USA
| | | | - Ashootosh Tripathi
- Life Sciences Institute: Natural Products Discovery Core, University of Michigan, Ann Arbor, MI, USA
| | - Phillip B Pope
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway. .,Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway.
| | - Eric C Martens
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA.
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Yuan Y, Chen C, Wang X, Shen S, Guo X, Chen X, Yang F, Li X. A novel accessory protein ArCel5 from cellulose-gelatinizing fungus Arthrobotrys sp. CX1. BIORESOUR BIOPROCESS 2022; 9:27. [PMID: 38647580 PMCID: PMC10991334 DOI: 10.1186/s40643-022-00519-1] [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: 01/14/2022] [Accepted: 03/06/2022] [Indexed: 11/10/2022] Open
Abstract
Improved understanding of cellulose swelling mechanism is beneficial for increasing the hydrolysis efficiency of cellulosic substrates. Here, we report a family 5 glycoside hydrolase ArCel5 isolated from the cellulose-gelatinizing fungus Arthrobotrys sp. CX1. ArCel5 exhibited low specific hydrolysis activity and high cellulose swelling capability, which suggested that this protein might function as an accessory protein. Homology modeling glycosylation detection revealed that ArCel5 is a multi-domain protein including a family 1 carbohydrate-binding module, a glycosylation linker, and a catalytic domain. The adsorption capacity, structural changes and hydrature index of filter paper treated by different ArCel5 mutants demonstrated that CBM1 and linker played an essential role in recognizing, binding and decrystallizing cellulosic substrates, which further encouraged the synergistic action between ArCel5 and cellulases. Notably, glycosylation modification further strengthened the function of the linker region. Overall, our study provides insight into the cellulose decrystallization mechanism by a novel accessory protein ArCel5 that will benefit future applications.
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Affiliation(s)
- Yue Yuan
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian, 116034, People's Republic of China
| | - Chunshu Chen
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian, 116034, People's Republic of China
| | - Xueyan Wang
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian, 116034, People's Republic of China
| | - Shaonian Shen
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian, 116034, People's Republic of China
| | - Xiaoyu Guo
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian, 116034, People's Republic of China
| | - Xiaoyi Chen
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian, 116034, People's Republic of China
| | - Fan Yang
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian, 116034, People's Republic of China.
| | - Xianzhen Li
- School of Biological Engineering, Dalian Polytechnic University, Ganjingziqu, Dalian, 116034, People's Republic of China.
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