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Mukherjee S, Lodha TD, Madhuprakash J. Comprehensive Genome Analysis of Cellulose and Xylan-Active CAZymes from the Genus Paenibacillus: Special Emphasis on the Novel Xylanolytic Paenibacillus sp. LS1. Microbiol Spectr 2023; 11:e0502822. [PMID: 37071006 PMCID: PMC10269863 DOI: 10.1128/spectrum.05028-22] [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: 12/06/2022] [Accepted: 03/24/2023] [Indexed: 04/19/2023] Open
Abstract
Xylan is the most abundant hemicellulose in hardwood and graminaceous plants. It is a heteropolysaccharide comprising different moieties appended to the xylose units. Complete degradation of xylan requires an arsenal of xylanolytic enzymes that can remove the substitutions and mediate internal hydrolysis of the xylan backbone. Here, we describe the xylan degradation potential and underlying enzyme machinery of the strain, Paenibacillus sp. LS1. The strain LS1 was able to utilize both beechwood and corncob xylan as the sole source of carbon, with the former being the preferred substrate. Genome analysis revealed an extensive xylan-active CAZyme repertoire capable of mediating efficient degradation of the complex polymer. In addition to this, a putative xylooligosaccharide ABC transporter and homologues of the enzymes involved in the xylose isomerase pathway were identified. Further, we have validated the expression of selected xylan-active CAZymes, transporters, and metabolic enzymes during growth of the LS1 on xylan substrates using qRT-PCR. The genome comparison and genomic index (average nucleotide identity [ANI] and digital DNA-DNA hybridization) values revealed that strain LS1 is a novel species of the genus Paenibacillus. Lastly, comparative genome analysis of 238 genomes revealed the prevalence of xylan-active CAZymes over cellulose across the Paenibacillus genus. Taken together, our results indicate that Paenibacillus sp. LS1 is an efficient degrader of xylan polymers, with potential implications in the production of biofuels and other beneficial by-products from lignocellulosic biomass. IMPORTANCE Xylan is the most abundant hemicellulose in the lignocellulosic (plant) biomass that requires cooperative deconstruction by an arsenal of different xylanolytic enzymes to produce xylose and xylooligosaccharides. Microbial (particularly, bacterial) candidates that encode such enzymes are an asset to the biorefineries to mediate efficient and eco-friendly deconstruction of xylan to generate products of value. Although xylan degradation by a few Paenibacillus spp. is reported, a complete genus-wide understanding of the said trait is unavailable till date. Through comparative genome analysis, we showed the prevalence of xylan-active CAZymes across Paenibacillus spp., therefore making them an attractive option towards efficient xylan degradation. Additionally, we deciphered the xylan degradation potential of the strain Paenibacillus sp. LS1 through genome analysis, expression profiling, and biochemical studies. The ability of Paenibacillus sp. LS1 to degrade different xylan types obtained from different plant species, emphasizes its potential implication in lignocellulosic biorefineries.
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Affiliation(s)
- Saumashish Mukherjee
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, India
| | | | - Jogi Madhuprakash
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, India
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2
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Pisa JH, Hero JS, Romero HG, Martínez MA. A genome-proteome-based approach for xylan degradation by Cohnella sp. AR92. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:755-765. [PMID: 35940859 DOI: 10.1111/1758-2229.13113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Several members of Cohnella genus have been reported as xylanolytic bacteria with significant capacity as carbohydrate-active enzyme producers (CAZymes), whose mechanisms involving xylan degradation are a key goal for suitable applications in bio-based industries. Using Cohnella sp. AR92 bacterium, we ensembled a genomic-proteomic approach to assess plant biomass conversion targeting its xylanolytic set of enzymes. Also, the genomic traits of the strain AR92 were compared to other Cohnella spp., showing a significant variability in terms of genome sizes and content of genes that code CAZymes. The AR92 strain genome harbours 209 CAZymes encoding sequences active on different polysaccharides, particularly directed towards xylans. Concurrent proteomic data recovered from cultures containing three kinds of lignocellulosic-derived substrates showed a broad set of xylan-degrading enzymes. The most abundant CAZymes expressed in the different conditions assayed were endo-β-1,4-xylanases belonging to the GH11 and GH10 families, enzymes that were previously proved to be useful in the biotransformation of lignocellulosic biomass derived from sugarcane as well as onto xylan-enriched substrates. Therefore, considering the large reserve of CAZymes of Cohnella sp. AR92, a xylan processing model for AR92 strain is proposed.
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Affiliation(s)
- José Horacio Pisa
- PROIMI - CONICET (National Scientific and Technical Research Council), Tucumán, Argentina
| | - Johan Sebastian Hero
- PROIMI - CONICET (National Scientific and Technical Research Council), Tucumán, Argentina
| | - Héctor Gabriel Romero
- Department of Ecology and Evolution, Faculty of Sciences/CURE, University of the Republic, Montevideo, Uruguay
| | - María Alejandra Martínez
- PROIMI - CONICET (National Scientific and Technical Research Council), Tucumán, Argentina
- Faculty of Exact Sciences and Technology, National University of Tucuman, Tucumán, Argentina
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3
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Wu X, Zhang S, Zhao S, Dai L, Huang S, Liu X, Yu J, Wang L. Functional Specificity of Three α-Arabinofuranosidases from Different Glycoside Hydrolase Families in Aspergillus niger An76. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:5039-5048. [PMID: 35420820 DOI: 10.1021/acs.jafc.1c08388] [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: 05/15/2023]
Abstract
α-l-Arabinofuranosidase (Abf), a debranching enzyme that can remove arabinose substituents from arabinoxylan, promotes the hydrolysis of hemicellulose in plant biomass. However, the functional specificity of Abfs from different glycoside hydrolase (GH) families on the digestion of arabinoxylan and their synergistic interaction with xylanase have not been systematically studied. In this work, we characterized three Abfs (AxhA, AbfB, and AbfC) from GH62, GH54, and GH51 families in Aspergillus niger An76. Quantitative transcriptional analysis showed that expression of the axhA gene was upregulated as a result of induction by xylose substrates, whereas expression of the abfB gene was mainly induced by arabinose. Recombinant AxhA, AbfB, and AbfC exhibited different hydrolytic performances. AxhA showed the highest catalytic activity toward wheat arabinoxylan (WAX) and tended to hydrolyze monosubstituted arabinofuranose units, whereas AbfB had higher catalytic activity on AN and debranched arabinan (DAN), having the ability to cope with mono- and disubstituted arabinofuranose units. Furthermore, AbfC had greater arabinofuranosidase activity on p-nitrophenyl-α-l-arabinofuranoside (pNP-AraF) than on other substrates. Moreover, three Abfs displayed obvious synergistic action with GH11 xylanase XynB against WAX and barley husk residues. The elucidation of the degradation mechanisms of Abfs will lay a theoretical foundation for the efficient industrialized transformation of arabinoxylans.
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Affiliation(s)
- Xiuyun Wu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, Shandong, China
- State Key Laboratory of Biological Fermentation Engineering of Beer, Qingdao 266000, Shandong, China
| | - Shu Zhang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, Shandong, China
| | - Sha Zhao
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, Shandong, China
| | - Lin Dai
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, Shandong, China
| | - Shuxia Huang
- State Key Laboratory of Biological Fermentation Engineering of Beer, Qingdao 266000, Shandong, China
| | - Xinli Liu
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, Shandong, China
| | - Junhong Yu
- State Key Laboratory of Biological Fermentation Engineering of Beer, Qingdao 266000, Shandong, China
| | - Lushan Wang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, Shandong, China
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4
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Srivastava S, Dafale NA, Purohit HJ. Functional genomics assessment of lytic polysaccharide mono-oxygenase with glycoside hydrolases in Paenibacillus dendritiformis CRN18. Int J Biol Macromol 2020; 164:3729-3738. [PMID: 32835796 DOI: 10.1016/j.ijbiomac.2020.08.147] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/06/2020] [Accepted: 08/19/2020] [Indexed: 11/25/2022]
Abstract
Recently discovered Lytic Polysaccharide Mono-Oxygenase (LPMO) enhances the enzymatic deconstruction of complex polysaccharide by oxidation. The present study demonstrates the agricultural waste hydrolyzing capabilities of Paenibacillus dendritiformis CRN18, which exhibits the enzyme activity of exo-glucanase, β-glucosidase, β-glucuronidase, endo-1, 4 β-xylanases, arabinosidase, and α-galactosidase as 0.1U/ml, 0.3U/ml, 0.09U/ml, 0.1U/ml, 0.05U/ml, and 0.41U/ml, respectively. The genome analysis of strain reveals the presence of four LPMO genes, along with lignocellulolytic genes. The gene structure of LPMO and its phylogenetic analysis shows the evolutionary relatedness with the Bacillus LPMO gene. Gene position of LPMOs in the genome of strains shows the close association of two LPMOs with chitin active enzyme GH18, and the other two are associated with hemicellulases (GH39, GH23). Protein-protein interaction and gene networking of LPMO sheds light on the co-occurrence, neighborhood, and interaction of LPMOs with chitinase and xylanase enzymes. Structural prediction of LPMOs unravels the information of the LPMO's binding site. Although the LPMO has been explored for its oxidative mechanism, a little light has been shed on its gene structure. This study provides insights into the LPMO gene structure in P. dendritiformis CRN18 and its potential in lignocellulose hydrolysis.
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Affiliation(s)
- Shweta Srivastava
- Environmental Biotechnology & Genomics Division, CSIR-National Environmental Engineering Research Institute (NEERI), Nagpur 440 020, India; AcSIR-Academy for Scientific and Innovative Research, Ghaziabad 201 002, India
| | - Nishant A Dafale
- Environmental Biotechnology & Genomics Division, CSIR-National Environmental Engineering Research Institute (NEERI), Nagpur 440 020, India; AcSIR-Academy for Scientific and Innovative Research, Ghaziabad 201 002, India.
| | - Hemant J Purohit
- Environmental Biotechnology & Genomics Division, CSIR-National Environmental Engineering Research Institute (NEERI), Nagpur 440 020, India
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López-Mondéjar R, Algora C, Baldrian P. Lignocellulolytic systems of soil bacteria: A vast and diverse toolbox for biotechnological conversion processes. Biotechnol Adv 2019; 37:107374. [DOI: 10.1016/j.biotechadv.2019.03.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/06/2019] [Accepted: 03/21/2019] [Indexed: 12/12/2022]
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Pasari N, Gupta M, Eqbal D, Yazdani SS. Genome analysis of Paenibacillus polymyxa A18 gives insights into the features associated with its adaptation to the termite gut environment. Sci Rep 2019; 9:6091. [PMID: 30988376 PMCID: PMC6465253 DOI: 10.1038/s41598-019-42572-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 04/03/2019] [Indexed: 01/17/2023] Open
Abstract
Paenibacillus polymyxa A18 was isolated from termite gut and was identified as a potential cellulase and hemicellulase producer in our previous study. Considering that members belonging to genus Paenibacillus are mostly free-living in soil, we investigated here the essential genetic features that helped P. polymyxa A18 to survive in gut environment. Genome sequencing and analysis identified 4608 coding sequences along with several elements of horizontal gene transfer, insertion sequences, transposases and integrated phages, which add to its genetic diversity. Many genes coding for carbohydrate-active enzymes, including the enzymes responsible for woody biomass hydrolysis in termite gut, were identified in P. polymyxa A18 genome. Further, a series of proteins conferring resistance to 11 antibiotics and responsible for production of 4 antibiotics were also found to be encoded, indicating selective advantage for growth and colonization in the gut environment. To further identify genomic regions unique to this strain, a BLAST-based comparative analysis with the sequenced genomes of 47 members belonging to genus Paenibacillus was carried out. Unique regions coding for nucleic acid modifying enzymes like CRISPR/Cas and Type I Restriction-Modification enzymes were identified in P. polymyxa A18 genome suggesting the presence of defense mechanism to combat viral infections in the gut. In addition, genes responsible for the formation of biofilms, such as Type IV pili and adhesins, which might be assisting P. polymyxa A18 in colonizing the gut were also identified in its genome. In situ colonization experiment further confirmed the ability of P. polymyxa A18 to colonize the gut of termite.
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Affiliation(s)
- Nandita Pasari
- Microbial Engineering Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India.,DBT-ICGEB Centre for Advanced Bioenergy Research, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Mayank Gupta
- Microbial Engineering Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India.,DBT-ICGEB Centre for Advanced Bioenergy Research, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Danish Eqbal
- Microbial Engineering Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Syed Shams Yazdani
- Microbial Engineering Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India. .,DBT-ICGEB Centre for Advanced Bioenergy Research, International Centre for Genetic Engineering and Biotechnology, New Delhi, India.
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7
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Gong W, Dai L, Zhang H, Zhang L, Wang L. A Highly Efficient Xylan-Utilization System in Aspergillus niger An76: A Functional-Proteomics Study. Front Microbiol 2018; 9:430. [PMID: 29623069 PMCID: PMC5874446 DOI: 10.3389/fmicb.2018.00430] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 02/26/2018] [Indexed: 11/23/2022] Open
Abstract
Xylan constituted with β-1,4-D-xylose linked backbone and diverse substituted side-chains is the most abundant hemicellulose component of biomass, which can be completely and rapidly degraded into fermentable sugars by Aspergillus niger. This is of great value for obtaining renewable biofuels and biochemicals. To clarify the underlying mechanisms associated with highly efficient xylan degradation, assimilation, and metabolism by A. niger, we utilized functional proteomics to analyze the secreted proteins, sugar transporters, and intracellular proteins of A. niger An76 grown on xylan-based substrates. Results demonstrated that the complete xylanolytic enzyme system required for xylan degradation and composed of diverse isozymes was secreted in a sequential order. Xylan-backbone-degrading enzymes were preferentially induced by xylose or other soluble sugars, which efficiently produced large amounts of xylooligosaccharides (XOS) and xylose; however, XOS was more efficient than xylose in triggering the expression of the key transcription activator XlnR, resulting in higher xylanase activity and shortening xylanase-production time. Moreover, the substituted XOS was responsible for improving the abundance of side-chain-degrading enzymes, specific transporters, and key reductases and dehydrogenases in the pentose catabolic pathway. Our findings indicated that industries might be able to improve the species and concentrations of xylan-degrading enzymes and shorten fermentation time by adding abundant intermediate products of natural xylan (XOS) to cultures of filamentous fungi.
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Affiliation(s)
- Weili Gong
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Lin Dai
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Huaiqiang Zhang
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Lili Zhang
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Lushan Wang
- The State Key Laboratory of Microbial Technology, Shandong University, Jinan, China.,State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
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8
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Comtet-Marre S, Parisot N, Lepercq P, Chaucheyras-Durand F, Mosoni P, Peyretaillade E, Bayat AR, Shingfield KJ, Peyret P, Forano E. Metatranscriptomics Reveals the Active Bacterial and Eukaryotic Fibrolytic Communities in the Rumen of Dairy Cow Fed a Mixed Diet. Front Microbiol 2017; 8:67. [PMID: 28197133 PMCID: PMC5281551 DOI: 10.3389/fmicb.2017.00067] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 01/10/2017] [Indexed: 12/31/2022] Open
Abstract
Ruminants have a unique ability to derive energy from the degradation of plant polysaccharides through the activity of the rumen microbiota. Although this process is well studied in vitro, knowledge gaps remain regarding the relative contribution of the microbiota members and enzymes in vivo. The present study used RNA-sequencing to reveal both the expression of genes encoding carbohydrate-active enzymes (CAZymes) by the rumen microbiota of a lactating dairy cow and the microorganisms forming the fiber-degrading community. Functional analysis identified 12,237 CAZymes, accounting for 1% of the transcripts. The CAZyme profile was dominated by families GH94 (cellobiose-phosphorylase), GH13 (amylase), GH43 and GH10 (hemicellulases), GH9 and GH48 (cellulases), PL11 (pectinase) as well as GH2 and GH3 (oligosaccharidases). Our data support the pivotal role of the most characterized fibrolytic bacteria (Prevotella, Ruminocccus and Fibrobacter), and highlight a substantial, although most probably underestimated, contribution of fungi and ciliate protozoa to polysaccharide degradation. Particularly these results may motivate further exploration of the role and the functions of protozoa in the rumen. Moreover, an important part of the fibrolytic bacterial community remains to be characterized since one third of the CAZyme transcripts originated from distantly related strains. These findings are used to highlight limitations of current metatranscriptomics approaches to understand the functional rumen microbial community and opportunities to circumvent them.
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Affiliation(s)
| | - Nicolas Parisot
- EA4678 CIDAM, Clermont Université, Université d'Auvergne Clermont-Ferrand, France
| | - Pascale Lepercq
- UR454 Unité de Microbiologie, INRA Saint-Genès-Champanelle, France
| | | | - Pascale Mosoni
- UR454 Unité de Microbiologie, INRA Saint-Genès-Champanelle, France
| | - Eric Peyretaillade
- EA4678 CIDAM, Clermont Université, Université d'Auvergne Clermont-Ferrand, France
| | - Ali R Bayat
- Nutritional Physiology, Green Technology, Natural Resources Institute Finland (Luke) Jokioinen, Finland
| | - Kevin J Shingfield
- Nutritional Physiology, Green Technology, Natural Resources Institute Finland (Luke)Jokioinen, Finland; Institute of Biological, Environmental and Rural Sciences, Aberystwyth UniversityAberystwyth, UK
| | - Pierre Peyret
- EA4678 CIDAM, Clermont Université, Université d'Auvergne Clermont-Ferrand, France
| | - Evelyne Forano
- UR454 Unité de Microbiologie, INRA Saint-Genès-Champanelle, France
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Rhee MS, Sawhney N, Kim YS, Rhee HJ, Hurlbert JC, St John FJ, Nong G, Rice JD, Preston JF. GH115 α-glucuronidase and GH11 xylanase from Paenibacillus sp. JDR-2: potential roles in processing glucuronoxylans. Appl Microbiol Biotechnol 2016; 101:1465-1476. [PMID: 27766358 DOI: 10.1007/s00253-016-7899-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 09/13/2016] [Accepted: 09/25/2016] [Indexed: 01/26/2023]
Abstract
Paenibacillus sp. JDR-2 (Pjdr2) has been studied as a model for development of bacterial biocatalysts for efficient processing of xylans, methylglucuronoxylan, and methylglucuronoarabinoxylan, the predominant hemicellulosic polysaccharides found in dicots and monocots, respectively. Pjdr2 produces a cell-associated GH10 endoxylanase (Xyn10A1) that catalyzes depolymerization of xylans to xylobiose, xylotriose, and methylglucuronoxylotriose with methylglucuronate-linked α-1,2 to the nonreducing terminal xylose. A GH10/GH67 xylan utilization regulon includes genes encoding an extracellular cell-associated Xyn10A1 endoxylanase and an intracellular GH67 α-glucuronidase active on methylglucuronoxylotriose generated by Xyn10A1 but without activity on methylglucuronoxylotetraose generated by a GH11 endoxylanase. The sequenced genome of Pjdr2 contains three paralogous genes potentially encoding GH115 α-glucuronidases found in certain bacteria and fungi. One of these, Pjdr2_5977, shows enhanced expression during growth on xylans along with Pjdr2_4664 encoding a GH11 endoxylanase. Here, we show that Pjdr2_5977 encodes a GH115 α-glucuronidase, Agu115A, with maximal activity on the aldouronate methylglucuronoxylotetraose selectively generated by a GH11 endoxylanase Xyn11 encoded by Pjdr2_4664. Growth of Pjdr2 on this methylglucuronoxylotetraose supports a process for Xyn11-mediated extracellular depolymerization of methylglucuronoxylan and Agu115A-mediated intracellular deglycosylation as an alternative to the GH10/GH67 system previously defined in this bacterium. A recombinantly expressed enzyme encoded by the Pjdr2 agu115A gene catalyzes removal of 4-O-methylglucuronate residues α-1,2 linked to internal xylose residues in oligoxylosides generated by GH11 and GH30 xylanases and releases methylglucuronate from polymeric methylglucuronoxylan. The GH115 α-glucuronidase from Pjdr2 extends the discovery of this activity to members of the phylum Firmicutes and contributes to a novel system for bioprocessing hemicelluloses.
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Affiliation(s)
- Mun Su Rhee
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL, 32611, USA.,Xycrobe Therapeutics Inc., 3210 Merryfield Row, San Diego,, CA, 92121,, USA
| | - Neha Sawhney
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL, 32611, USA.,Department of Chemistry, Vanderbilt University, Nashville, TN, 37235,, USA
| | - Young Sik Kim
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL, 32611, USA
| | - Hyun Jee Rhee
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL, 32611, USA.,Department of Materials Science and Engineering, Massachusetts Institute of Technology, 6-113, Cambridge, MA, 02139,, USA
| | - Jason C Hurlbert
- Department of Chemistry, Physics and Geology, Winthrop University, Rock Hill, SC, 29733, USA
| | - Franz J St John
- Forest Products Laboratory, United States Forest Service, The United States Department of Agriculture, Madison, Madison,, WI, 53726, USA
| | - Guang Nong
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL, 32611, USA
| | - John D Rice
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL, 32611, USA
| | - James F Preston
- Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL, 32611, USA.
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Sawhney N, Crooks C, Chow V, Preston JF, St John FJ. Genomic and transcriptomic analysis of carbohydrate utilization by Paenibacillus sp. JDR-2: systems for bioprocessing plant polysaccharides. BMC Genomics 2016; 17:131. [PMID: 26912334 PMCID: PMC4765114 DOI: 10.1186/s12864-016-2436-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 02/05/2016] [Indexed: 11/12/2022] Open
Abstract
Background Polysaccharides comprising plant biomass are potential resources for conversion to fuels and chemicals. These polysaccharides include xylans derived from the hemicellulose of hardwoods and grasses, soluble β-glucans from cereals and starch as the primary form of energy storage in plants. Paenibacillus sp. JDR-2 (Pjdr2) has evolved a system for bioprocessing xylans. The central component of this xylan utilization system is a multimodular glycoside hydrolase family 10 (GH10) endoxylanase with carbohydrate binding modules (CBM) for binding xylans and surface layer homology (SLH) domains for cell surface anchoring. These attributes allow efficient utilization of xylans by generating oligosaccharides proximal to the cell surface for rapid assimilation. Coordinate expression of genes in response to growth on xylans has identified regulons contributing to depolymerization, importation of oligosaccharides and intracellular processing to generate xylose as well as arabinose and methylglucuronate. The genome of Pjdr2 encodes several other putative surface anchored multimodular enzymes including those for utilization of β-1,3/1,4 mixed linkage soluble glucan and starch. Results To further define polysaccharide utilization systems in Pjdr2, its transcriptome has been determined by RNA sequencing following growth on barley-derived soluble β-glucan, starch, cellobiose, maltose, glucose, xylose and arabinose. The putative function of genes encoding transcriptional regulators, ABC transporters, and glycoside hydrolases belonging to the corresponding substrate responsive regulon were deduced by their coordinate expression and locations in the genome. These results are compared to observations from the previously defined xylan utilization systems in Pjdr2. The findings from this study show that Pjdr2 efficiently utilizes these glucans in a manner similar to xylans. From transcriptomic and genomic analyses we infer a common strategy evolved by Pjdr2 for efficient bioprocessing of polysaccharides. Conclusions The barley β-glucan and starch utilization systems in Pjdr2 include extracellular glycoside hydrolases bearing CBM and SLH domains for depolymerization of these polysaccharides. Overlapping regulation observed during growth on these polysaccharides suggests they are preferentially utilized in the order of starch before xylan before barley β-glucan. These systems defined in Pjdr2 may serve as a paradigm for developing biocatalysts for efficient bioprocessing of plant biomass to targeted biofuels and chemicals. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2436-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Neha Sawhney
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA.
| | - Casey Crooks
- Institute for Microbial and Biochemical Technology, Forest Products Laboratory, USDA Forest Service, Madison, WI, 53726, USA.
| | - Virginia Chow
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA.
| | - James F Preston
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA.
| | - Franz J St John
- Institute for Microbial and Biochemical Technology, Forest Products Laboratory, USDA Forest Service, Madison, WI, 53726, USA.
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11
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A 1,3-1,4-β-Glucan Utilization Regulon in Paenibacillus sp. Strain JDR-2. Appl Environ Microbiol 2016; 82:1789-1798. [PMID: 26746717 DOI: 10.1128/aem.03526-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 12/25/2015] [Indexed: 11/20/2022] Open
Abstract
Paenibacillus sp. strain JDR-2 (Paenibacillus JDR-2) secretes a multimodular cell-associated glycoside hydrolase family 10 (GH10) endoxylanase (XynA10A1) that catalyzes the depolymerization of methylglucuronoxylan (MeGXn) and rapidly assimilates the products of depolymerization. Efficient utilization of MeGXn has been postulated to result from the coupling of the processes of exocellular depolymerization and assimilation of oligosaccharide products, followed by intracellular metabolism. Growth and substrate utilization patterns with barley glucan and laminarin similar to those observed with MeGXn as a substrate suggest similar processes for 1,3-1,4-β-glucan and 1,3-β-glucan depolymerization and product assimilation. The Paenibacillus JDR-2 genome includes a cluster of genes encoding a secreted multimodular GH16 β-glucanase (Bgl16A1) containing surface layer homology (SLH) domains, a secreted GH16 β-glucanase with only a catalytic domain (Bgl16A2), transporter proteins, and transcriptional regulators. Recombinant Bgl16A1 and Bgl16A2 catalyze the formation of trisaccharides, tetrasaccharides, and larger oligosaccharides from barley glucan and of mono-, di-, tri-, and tetrasaccharides and larger oligosaccharides from laminarin. The lack of accumulation of depolymerization products during growth and a marked preference for polymeric glucan over depolymerization products support a process coupling extracellular depolymerization, assimilation, and intracellular metabolism for β-glucans similar to that ascribed to the GH10/GH67 xylan utilization system in Paenibacillus JDR-2. Coordinate expression of genes encoding GH16 β-glucanases, transporters, and transcriptional regulators supports their role as a regulon for the utilization of soluble β-glucans. As in the case of the xylan utilization regulons, this soluble β-glucan regulon provides advantages in the growth rate and yields on polymeric substrates and may be exploited for the efficient conversion of plant-derived polysaccharides to targeted products.
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Zhu N, Yang J, Ji L, Liu J, Yang Y, Yuan H. Metagenomic and metaproteomic analyses of a corn stover-adapted microbial consortium EMSD5 reveal its taxonomic and enzymatic basis for degrading lignocellulose. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:243. [PMID: 27833656 PMCID: PMC5103373 DOI: 10.1186/s13068-016-0658-z] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 10/28/2016] [Indexed: 05/08/2023]
Abstract
BACKGROUND Microbial consortia represent promising candidates for aiding in the development of plant biomass conversion strategies for biofuel production. However, the interaction between different community members and the dynamics of enzyme complements during the lignocellulose deconstruction process remain poorly understood. We present here a comprehensive study on the community structure and enzyme systems of a lignocellulolytic microbial consortium EMSD5 during growth on corn stover, using metagenome sequencing in combination with quantitative metaproteomics. RESULTS The taxonomic affiliation of the metagenomic data showed that EMSD5 was primarily composed of members from the phyla Proteobacteria, Firmicutes and Bacteroidetes. The carbohydrate-active enzyme (CAZyme) annotation revealed that representatives of Firmicutes encoded a broad array of enzymes responsible for hemicellulose and cellulose deconstruction. Extracellular metaproteome analysis further pinpointed the specific role and synergistic interaction of Firmicutes populations in plant polysaccharide breakdown. In particular, a wide range of xylan degradation-related enzymes, including xylanases, β-xylosidases, α-l-arabinofuranosidases, α-glucuronidases and acetyl xylan esterases, were secreted by diverse members from Firmicutes during growth on corn stover. Using label-free quantitative proteomics, we identified the differential secretion pattern of a core subset of enzymes, including xylanases and cellulases with multiple carbohydrate-binding modules (CBMs). In addition, analysis of the coordinate expression patterns indicated that transport proteins and hypothetical proteins may play a role in bacteria processing lignocellulose. Moreover, enzyme preparation from EMSD5 demonstrated synergistic activities in the hydrolysis of pretreated corn stover by commercial cellulases from Trichoderma reesei. CONCLUSIONS These results demonstrate that the corn stover-adapted microbial consortium EMSD5 harbors a variety of lignocellulolytic anaerobic bacteria and degradative enzymes, especially those implicated in hemicellulose decomposition. The data in this study highlight the pivotal role and cooperative relationship of Firmicutes members in the biodegradation of plant lignocellulose by EMSD5. The differential expression patterns of enzymes reveal the strategy of sequential lignocellulose deconstruction by EMSD5. Our findings provide insights into the mechanism by which consortium members orchestrate their array of enzymes to degrade complex lignocellulosic biomass.
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Affiliation(s)
- Ning Zhu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Beijing, China
| | - Jinshui Yang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Beijing, China
| | - Lei Ji
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Beijing, China
| | - Jiawen Liu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Beijing, China
| | - Yi Yang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Beijing, China
| | - Hongli Yuan
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Beijing, China
- National Energy R & D Center for Non-food Biomass, China Agricultural University, Beijing, 100193 China
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Metabolic potential of Bacillus subtilis 168 for the direct conversion of xylans to fermentation products. Appl Microbiol Biotechnol 2015; 100:1501-1510. [PMID: 26559526 DOI: 10.1007/s00253-015-7124-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 09/30/2015] [Accepted: 10/20/2015] [Indexed: 10/22/2022]
Abstract
Methylglucuronoxylans (MeGXn) and methylglucuronoarabinoxylans (MeGAXn) respectively comprise most of the hemicellulose fractions in dicots and monocots and, next to cellulose, are the major resources for the production of fuels and chemicals from lignocellulosics. With either MeGXn or MeGAXn as a substrate, Bacillus subtilis 168 accumulates acidic methylglucuronoxylotriose as a limit product following the uptake and metabolism of neutral xylooligosaccharides. Secreted GH11 endoxylanase (Xyn11A), GH30 endoxylanase (Xyn30C), and GH43 arabinoxylan arabinofuranohydrolase (Axh43) respectively encoded by the xynA, xynC, and xynD genes collectively contribute to the depolymerization of MeGAXn. Studies here demonstrate the complementary roles of these enzymes in the digestion of MeGAXn. Coordinate expression of the xynD and xynC genes defines an operon accounting for the Axh43-catalyzed release of arabinose followed by Xyn30C and Xyn11A-catalyzed depolymerization of MeGAXn. Both sources generate acetate and lactate as the principal fermentation products, with yields of 26 % acetate and 32 % lactate from MeGXn compared to 22 % acetate and 21 % lactate from MeGAXn. These studies of the GH43/GH30/GH11 system in B. subtilis 168 provide a basis for the further development of B. subtilis and related species as biocatalysts for direct conversion of hemicellulose derived from energy crops as well as agricultural and forest residues to chemical feedstocks.
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Liao H, Zheng H, Li S, Wei Z, Mei X, Ma H, Shen Q, Xu Y. Functional diversity and properties of multiple xylanases from Penicillium oxalicum GZ-2. Sci Rep 2015. [PMID: 26224514 PMCID: PMC4519791 DOI: 10.1038/srep12631] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
A multiple xylanase system with high levels of xylanase activity produced from Penicillium oxalicum GZ-2 using agricultural waste as a substrate has been previously reported. However, the eco-physiological properties and origin of the multiplicity of xylanases remain unclear. In the present study, eight active bands were detected using zymography, and all bands were identified as putative xylanases using MALDI-TOF-MS/MS. These putative xylanases are encoded by six different xylanase genes. To evaluate the functions and eco-physiological properties of xylanase genes, xyn10A, xyn11A, xyn10B and xyn11B were expressed in Pichia pastoris. The recombinant enzymes xyn10A and xyn10B belong to the glycoside hydrolase (GH) family 10 xylanases, while xyn11A and xyn11B belong to GH11 xylanases. Biochemical analysis of the recombinant proteins revealed that all enzymes exhibited xylanase activity against xylans but with different substrate specificities, properties and kinetic parameters. These results demonstrated that the production of multiple xylanases in P. oxalicum GZ-2 was attributed to the genetic redundancy of xylanases and the post-translational modifications, providing insight into a more diverse xylanase system for the efficient degradation of complex hemicelluloses.
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Affiliation(s)
- Hanpeng Liao
- 1] National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, 210095, China [2] Ningbo Urban Environment Observation and Research Station-NUEORS, Institute of Urban Environment, Chinese Academy of Sciences, No. 88 Zhong Ke Road, Ningbo 315830, China
| | - Haiping Zheng
- National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shuixian Li
- National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhong Wei
- National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xinlan Mei
- National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hongyu Ma
- College of plant protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qirong Shen
- National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yangchun Xu
- National Engineering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, 210095, China
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