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Kim SK, Park JE, Oh JM, Kim H. Molecular Characterization of Four Alkaline Chitinases from Three Chitinolytic Bacteria Isolated from a Mudflat. Int J Mol Sci 2021; 22:ijms222312822. [PMID: 34884628 PMCID: PMC8658002 DOI: 10.3390/ijms222312822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/25/2021] [Accepted: 11/25/2021] [Indexed: 11/24/2022] Open
Abstract
Four chitinases were cloned and characterized from three strains isolated from a mudflat: Aeromonas sp. SK10, Aeromonas sp. SK15, and Chitinibacter sp. SK16. In SK10, three genes, Chi18A, Pro2K, and Chi19B, were found as a cluster. Chi18A and Chi19B were chitinases, and Pro2K was a metalloprotease. With combinatorial amplification of the genes and analysis of the hydrolysis patterns of substrates, Chi18A and Chi19B were found to be an endochitinase and exochitinase, respectively. Chi18A and Chi19B belonged to the glycosyl hydrolase family 18 (GH18) and GH19, with 869 and 659 amino acids, respectively. Chi18C from SK15 belonged to GH18 with 864 amino acids, and Chi18D from SK16 belonged to GH18 with 664 amino acids. These four chitinases had signal peptides and high molecular masses with one or two chitin-binding domains and, interestingly, preferred alkaline conditions. In the activity staining, their sizes were determined to be 96, 74, 95, and 73 kDa, respectively, corresponding to their expected sizes. Purified Chi18C and Chi18D after pET expression produced N,N′-diacetylchitobiose as the main product in hydrolyzing chitooligosaccharides and colloidal chitin. These results suggest that Chi18A, Chi18C, and Chi18D are endochitinases, that Chi19B is an exochitinase, and that these chitinases can be effectively used for hydrolyzing natural chitinous sources.
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Affiliation(s)
- Sung Kyum Kim
- Department of Agricultural Chemistry, Sunchon National University, Suncheon 57922, Korea;
| | - Jong Eun Park
- Department of Pharmacy, and Research Institute of Life Pharmaceutical Sciences, Sunchon National University, Suncheon 57922, Korea; (J.E.P.); (J.M.O.)
| | - Jong Min Oh
- Department of Pharmacy, and Research Institute of Life Pharmaceutical Sciences, Sunchon National University, Suncheon 57922, Korea; (J.E.P.); (J.M.O.)
| | - Hoon Kim
- Department of Pharmacy, and Research Institute of Life Pharmaceutical Sciences, Sunchon National University, Suncheon 57922, Korea; (J.E.P.); (J.M.O.)
- Correspondence: ; Tel.: +82-61-750-3751
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Pasin TM, de Oliveira TB, Scarcella ASDA, Polizeli MDLTDM, Guazzaroni ME. Perspectives on Expanding the Repertoire of Novel Microbial Chitinases for Biological Control. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:3284-3288. [PMID: 33720714 DOI: 10.1021/acs.jafc.1c00219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Interest in chitin-degrading enzymes has grown over the years, and microbial chitinases are the most attractive and promising candidates for the control of plant pests (fungi and insects). Currently, there are many studies on chitinases produced by cultivable microorganisms; however, almost none of them have achieved acceptable applicability as a biopesticide in the field. Approximately 99% of the microorganisms from soil cannot be isolated by conventional culture-dependent methods, thus having an enormous biotechnological/genetic potential to be explored. On the basis of this, the present paper aims to provide a brief overview of the metagenomic opportunities that have been emerging and allowing access to the biochemical potential of uncultivable microorganisms through the direct mining of DNA sequences recovered from the environment. This work also shortly discussed the future perspectives of functional and sequence-based metagenomic approaches for the identification of new chitinase-coding genes with potential for applications in several agricultural and biotechnological industries, especially in biological control.
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Affiliation(s)
- Thiago Machado Pasin
- Department of Biochemistry and Immunology, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo 14040-900, Brazil
| | - Tássio Brito de Oliveira
- Department of Biology, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo 14040-900, Brazil
| | - Ana Sílvia de Almeida Scarcella
- Department of Biochemistry and Immunology, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo 14040-900, Brazil
| | - Maria de Lourdes Teixeira de Moraes Polizeli
- Department of Biochemistry and Immunology, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo 14040-900, Brazil
- Department of Biology, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo 14040-900, Brazil
| | - María-Eugenia Guazzaroni
- Department of Biology, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo 14040-900, Brazil
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Hui C, Jiang H, Liu B, Wei R, Zhang Y, Zhang Q, Liang Y, Zhao Y. Chitin degradation and the temporary response of bacterial chitinolytic communities to chitin amendment in soil under different fertilization regimes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 705:136003. [PMID: 31846813 DOI: 10.1016/j.scitotenv.2019.136003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 10/20/2019] [Accepted: 12/06/2019] [Indexed: 06/10/2023]
Abstract
Chitin amendment is a promising agricultural management strategy to control fungal and nematodal plant diseases and to improve crop yield. Chitin degradation in the soil contributes significantly to carbon and nitrogen cycling in terrestrial ecosystems. However, little is known about chitin degradation and bacterial chitinolytic communities in agricultural soil under different fertilization regimes. Thus, in the present study, a 42-day soil incubation experiment was conducted, in which soil under four fertilization regimes (i.e., no fertilization (CK), chemical fertilizer (CF), pig manure plus 50% chemical fertilizer (PMCF), and rice straw plus 100% chemical fertilizer (SRCF)) were amended or not with chitin or its monomer, N-acetylglucosamine (NAG). Different nitrogen forms and CO2 and N2O emission were measured to evaluate chitin degradation and its environmental implications. SRCF soil had the highest CO2 emission, chitin N mineralization, and fungal abundance. NAG and chitin were enriched to exploit the chitin degraders. High-throughput sequencing analyses reveled that Streptomycetaceae, Oxalobacteraceae, Gemmatimonadaceae, and Acidobacteria were generally increased upon chitin amendment in CK, CF, and PMCF soil, whereas Streptomycetaceae dominated chitin-amended SRCF soil. Herpetosiphonaceae was enriched only in chitin-amended CK soil. LEfSe and network analysis were used to predict chitinolytic and opportunistic species, and revealed that most previously reported chitinolytic bacteria were detected in the present study and new potential chitin degraders, including unidentified_Solibacterales, Gemmatimonadaceae, and Herpetosiphonaceae, were identified. Some members of Firmicutes, Actinobacteria, and Proteobacteria, including Bacillus, and Kitasatospora, were speculated to be opportunistic species. The findings improve our understanding of the effects of chitin degradation on carbon and nitrogen cycling in agricultural soil under different fertilization regimes and help to identify chitinolytic bacteria.
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Affiliation(s)
- Cai Hui
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Hui Jiang
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Bing Liu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Ran Wei
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yiping Zhang
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Qichun Zhang
- Ministry of Education Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yongchao Liang
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, Zhejiang University, Hangzhou 310058, China
| | - Yuhua Zhao
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
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Konada RSR, Krishnapati LS, Ashapogu V, Lin CH, Nadimpalli SK. Comparative analysis of β-hexosaminidase and acid phosphatase from Hydra vulgaris Ind-Pune, H. vulgaris Naukuchiatal and H. magnipapillata sf-1: Localization studies of acid phosphatase and β-hexosaminidase from H. vulgaris Ind-Pune. Comp Biochem Physiol B Biochem Mol Biol 2019; 239:110365. [PMID: 31629812 DOI: 10.1016/j.cbpb.2019.110365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 09/08/2019] [Accepted: 09/18/2019] [Indexed: 11/25/2022]
Abstract
The present report describes a comprehensive study on comparative biochemical characterization of two lysosomal enzymes, acid phosphatase and β-hexosaminidase in three different strains of Hydra; Hydra vulgaris Ind-Pune, H. vulgaris Naukuchiatal and H. magnipapillata sf-1 (self-feeder-1). Since morphology and habitat of Hydra effect lysosomal enzymes and their response to environmental pollutants, it would be interesting to identify them in different Hydra strains so as to use them as toxicity testing. Preliminary studies revealed a differential expression of acid phosphatase, β-hexosaminidase and β-glucuronidase in three Hydra strains. Expression of all three lysosomal enzymes in H. vulgaris Ind-Pune was low in comparison to H. vulgaris Naukuchiatal and H. magnipapillata sf-1, while their expression is comparable in H. vulgaris Naukuchiatal and H. magnipapillata sf-1. The Michaelis-Menten (KM) values for lysosomal β-hexosaminidase using 4-nitrophenyl N-acetyl-β-D-glucosaminide as substrate were found to be 1.3 mM, 1.1 mM and 0.8 mM, respectively for H. vulgaris Ind-Pune, H. vulgaris Naukuchiatal and H. magnipapillata sf-1. For acid phosphatase using 4-nitrophenyl-phosphate as substrate, the KM values were 0.38 mM, 1.2 mM and 0.52 mM respectively, for H. vulgaris Ind-Pune, H. vulgaris Naukuchiatal and sf-1 strains. The optimum temperature for β-hexosaminidase was 60 °C for H. vulgaris Ind-Pune, while 50 °C was observed for H. vulgaris Naukuchiatal and sf-1 strains. The optimum pH for β-hexosaminidase was found to be 6.0 for H. vulgaris Ind-Pune and H. vulgaris Naukuchiatal, and 5.0 for sf-1. The optimum temperature and pH of acid phosphatase was similar in all three strains, viz., 40 °C and 3.0, respectively. Preliminary localization studies using whole mount in situ hybridization revealed predominant endodermal expression of three enzymes in H. vulgaris Ind-Pune. Our results thus support the conservation of lysosomal hydrolases in Hydra.
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Affiliation(s)
- Rohit Sai Reddy Konada
- Protein Biochemistry and Glycobiology Laboratory, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Lakshmi Surekha Krishnapati
- Protein Biochemistry and Glycobiology Laboratory, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Venugopal Ashapogu
- Protein Biochemistry and Glycobiology Laboratory, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Chung-Hung Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Siva Kumar Nadimpalli
- Protein Biochemistry and Glycobiology Laboratory, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
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Wright RJ, Gibson MI, Christie-Oleza JA. Understanding microbial community dynamics to improve optimal microbiome selection. MICROBIOME 2019; 7:85. [PMID: 31159875 PMCID: PMC6547603 DOI: 10.1186/s40168-019-0702-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/21/2019] [Indexed: 05/20/2023]
Abstract
BACKGROUND Artificial selection of microbial communities that perform better at a desired process has seduced scientists for over a decade, but the method has not been systematically optimised nor the mechanisms behind its success, or failure, determined. Microbial communities are highly dynamic and, hence, go through distinct and rapid stages of community succession, but the consequent effect this may have on artificially selected communities is unknown. RESULTS Using chitin as a case study, we successfully selected for microbial communities with enhanced chitinase activities but found that continuous optimisation of incubation times between selective transfers was of utmost importance. The analysis of the community composition over the entire selection process revealed fundamental aspects in microbial ecology: when incubation times between transfers were optimal, the system was dominated by Gammaproteobacteria (i.e. main bearers of chitinase enzymes and drivers of chitin degradation), before being succeeded by cheating, cross-feeding and grazing organisms. CONCLUSIONS The selection of microbiomes to enhance a desired process is widely used, though the success of artificially selecting microbial communities appears to require optimal incubation times in order to avoid the loss of the desired trait as a consequence of an inevitable community succession. A comprehensive understanding of microbial community dynamics will improve the success of future community selection studies.
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Affiliation(s)
- Robyn J. Wright
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Matthew I. Gibson
- Department of Chemistry, University of Warwick, Coventry, UK
- Medical School, University of Warwick, Coventry, UK
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Edwardson CF, Hollibaugh JT. Composition and Activity of Microbial Communities along the Redox Gradient of an Alkaline, Hypersaline, Lake. Front Microbiol 2018; 9:14. [PMID: 29445359 PMCID: PMC5797777 DOI: 10.3389/fmicb.2018.00014] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 01/05/2018] [Indexed: 11/21/2022] Open
Abstract
We compared the composition of microbial communities obtained by sequencing 16S rRNA gene amplicons with taxonomy derived from metatranscriptomes from the same samples. Samples were collected from alkaline, hypersaline Mono Lake, California, USA at five depths that captured the major redox zones of the lake during the onset of meromixis. The prokaryotic community was dominated by bacteria from the phyla Proteobacteria, Firmicutes, and Bacteroidetes, while the picoeukaryotic chlorophyte Picocystis dominated the eukaryotes. Most (80%) of the abundant (>1% relative abundance) OTUs recovered as amplicons of 16S rRNA genes have been reported in previous surveys, indicating that Mono Lake's microbial community has remained stable over 12 years that have included periods of regular, annual overturn interspersed by episodes of prolonged meromixis that result in extremely reducing conditions in bottom water. Metatranscriptomic sequences binned predominately to the Gammaproteobacteria genera Thioalkalivibrio (4–13%) and Thioalkalimicrobium (0–14%); and to the Firmicutes genera Dethiobacter (0–5%) and Clostridium (1–4%), which were also abundant in the 16S rRNA gene amplicon libraries. This study provides insight into the taxonomic affiliations of transcriptionally active communities of the lake's water column under different redox conditions.
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Affiliation(s)
- Christian F Edwardson
- Department of Marine Sciences, University of Georgia, Athens, GA, United States.,Department of Microbiology, University of Georgia, Athens, GA, United States
| | - James T Hollibaugh
- Department of Marine Sciences, University of Georgia, Athens, GA, United States
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Abdul Rahman N, Parks DH, Vanwonterghem I, Morrison M, Tyson GW, Hugenholtz P. A Phylogenomic Analysis of the Bacterial Phylum Fibrobacteres. Front Microbiol 2016; 6:1469. [PMID: 26779135 PMCID: PMC4704652 DOI: 10.3389/fmicb.2015.01469] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 12/07/2015] [Indexed: 12/13/2022] Open
Abstract
The Fibrobacteres has been recognized as a bacterial phylum for over a decade, but little is known about the group beyond its environmental distribution, and characterization of its sole cultured representative genus, Fibrobacter, after which the phylum was named. Based on these incomplete data, it is thought that cellulose hydrolysis, anaerobic metabolism, and lack of motility are unifying features of the phylum. There are also contradicting views as to whether an uncultured sister lineage, candidate phylum TG3, should be included in the Fibrobacteres. Recently, chitin-degrading cultured representatives of TG3 were isolated from a hypersaline soda lake, and the genome of one species, Chitinivibrio alkaliphilus, sequenced and described in detail. Here, we performed a comparative analysis of Fibrobacter succinogenes, C. alkaliphilus and eight near or substantially complete Fibrobacteres/TG3 genomes of environmental populations recovered from termite gut, anaerobic digester, and sheep rumen metagenomes. We propose that TG3 should be amalgamated with the Fibrobacteres phylum based on robust monophyly of the two lineages and shared character traits. Polymer hydrolysis, using a distinctive set of glycoside hydrolases and binding domains, appears to be a prominent feature of members of the Fibrobacteres. Not all members of this phylum are strictly anaerobic as some termite gut Fibrobacteres have respiratory chains adapted to the microaerophilic conditions found in this habitat. Contrary to expectations, flagella-based motility is predicted to be an ancestral and common trait in this phylum and has only recently been lost in F. succinogenes and its relatives based on phylogenetic distribution of flagellar genes. Our findings extend current understanding of the Fibrobacteres and provide an improved basis for further investigation of this phylum.
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Affiliation(s)
- Nurdyana Abdul Rahman
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland Brisbane, QLD, Australia
| | - Donovan H Parks
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland Brisbane, QLD, Australia
| | - Inka Vanwonterghem
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of QueenslandBrisbane, QLD, Australia; Advanced Water Management Center, The University of QueenslandBrisbane, QLD, Australia
| | - Mark Morrison
- Microbial Biology and Metagenomics, The University of Queensland Diamantina Institute, Translational Research Institute Brisbane, QLD, Australia
| | - Gene W Tyson
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland Brisbane, QLD, Australia
| | - Philip Hugenholtz
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of QueenslandBrisbane, QLD, Australia; Genomics and Computational Biology, Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia
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Ufarté L, Potocki-Veronese G, Laville É. Discovery of new protein families and functions: new challenges in functional metagenomics for biotechnologies and microbial ecology. Front Microbiol 2015; 6:563. [PMID: 26097471 PMCID: PMC4456863 DOI: 10.3389/fmicb.2015.00563] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 05/21/2015] [Indexed: 12/30/2022] Open
Abstract
The rapid expansion of new sequencing technologies has enabled large-scale functional exploration of numerous microbial ecosystems, by establishing catalogs of functional genes and by comparing their prevalence in various microbiota. However, sequence similarity does not necessarily reflect functional conservation, since just a few modifications in a gene sequence can have a strong impact on the activity and the specificity of the corresponding enzyme or the recognition for a sensor. Similarly, some microorganisms harbor certain identified functions yet do not have the expected related genes in their genome. Finally, there are simply too many protein families whose function is not yet known, even though they are highly abundant in certain ecosystems. In this context, the discovery of new protein functions, using either sequence-based or activity-based approaches, is of crucial importance for the discovery of new enzymes and for improving the quality of annotation in public databases. This paper lists and explores the latest advances in this field, along with the challenges to be addressed, particularly where microfluidic technologies are concerned.
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Affiliation(s)
- Lisa Ufarté
- Université de Toulouse, Institut National des Sciences Appliquées (INSA), Université Paul Sabatier (UPS), Institut National Polytechnique (INP), Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (LISBP) , Toulouse, France ; INRA - UMR792 Ingénierie des Systèmes Biologiques et des Procédés , Toulouse, France ; CNRS, UMR5504 , Toulouse, France
| | - Gabrielle Potocki-Veronese
- Université de Toulouse, Institut National des Sciences Appliquées (INSA), Université Paul Sabatier (UPS), Institut National Polytechnique (INP), Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (LISBP) , Toulouse, France ; INRA - UMR792 Ingénierie des Systèmes Biologiques et des Procédés , Toulouse, France ; CNRS, UMR5504 , Toulouse, France
| | - Élisabeth Laville
- Université de Toulouse, Institut National des Sciences Appliquées (INSA), Université Paul Sabatier (UPS), Institut National Polytechnique (INP), Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (LISBP) , Toulouse, France ; INRA - UMR792 Ingénierie des Systèmes Biologiques et des Procédés , Toulouse, France ; CNRS, UMR5504 , Toulouse, France
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Cretoiu MS, Berini F, Kielak AM, Marinelli F, van Elsas JD. A novel salt-tolerant chitobiosidase discovered by genetic screening of a metagenomic library derived from chitin-amended agricultural soil. Appl Microbiol Biotechnol 2015; 99:8199-215. [PMID: 26040993 PMCID: PMC4561078 DOI: 10.1007/s00253-015-6639-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 04/21/2015] [Accepted: 04/24/2015] [Indexed: 12/04/2022]
Abstract
Here, we report on the construction of a metagenomic library from a chitin-amended disease-suppressive agricultural soil and its screening for genes that encode novel chitinolytic enzymes. The library, constructed in fosmids in an Escherichia coli host, comprised 145,000 clones containing inserts of sizes of 21 to 40 kb, yielding a total of approximately 5.8 GB of cloned soil DNA. Using genetic screenings by repeated PCR cycles aimed to detect gene sequences of the bacterial chitinase A-class (hereby named chi A genes), we identified and characterized five fosmids carrying candidate genes for chitinolytic enzymes. The analysis thus allowed access to the genomic (fosmid-borne) context of these genes. Using the chiA-targeted PCR, which is based on degenerate primers, the five fosmids all produced amplicons, of which the sequences were related to predicted chitinolytic enzyme-encoding genes of four different host organisms, including Stenotrophomonas maltophilia. Sequencing and de novo annotation of the fosmid inserts confirmed that each one of these carried one or more open reading frames that were predicted to encode enzymes active on chitin, including one for a chitin deacetylase. Moreover, the genetic contexts in which the putative chitinolytic enzyme-encoding genes were located were unique per fosmid. Specifically, inserts from organisms related to Burkholderia sp., Acidobacterium sp., Aeromonas veronii, and the chloroflexi Nitrolancetus hollandicus and/or Ktedonobacter racemifer were obtained. Remarkably, the S. maltophilia chiA-like gene was found to occur in two different genetic contexts (related to N. hollandicus/K. racemifer), indicating the historical occurrence of genetic reshufflings in this part of the soil microbiota. One fosmid containing the insert composed of DNA from the N. hollandicus-like organism (denoted 53D1) was selected for further work. Using subcloning procedures, its putative gene for a chitinolytic enzyme was successfully brought to expression in an E. coli host. On the basis of purified protein preparations, the produced protein was characterized as a chitobiosidase of 43.6 kDa, with a pI of 4.83. Given its activity spectrum, it can be typified as a halotolerant chitobiosidase.
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Affiliation(s)
- Mariana Silvia Cretoiu
- />Department of Microbial Ecology, CEES, University of Groningen, Groningen, The Netherlands
- />Department of Marine Microbiology, Royal Netherlands Institute for Sea Research, Yerseke, The Netherlands
| | - Francesca Berini
- />Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
- />“The Protein Factory” Research Center, Politecnico of Milano, ICRM CNR Milano and University of Insubria, Varese, Italy
| | - Anna Maria Kielak
- />Department of Microbial Ecology, The Netherlands Institute of Ecology (NIOO), Wageningen, The Netherlands
| | - Flavia Marinelli
- />Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
- />“The Protein Factory” Research Center, Politecnico of Milano, ICRM CNR Milano and University of Insubria, Varese, Italy
| | - Jan Dirk van Elsas
- />Department of Microbial Ecology, CEES, University of Groningen, Groningen, The Netherlands
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Li H, Fei Z, Gong J, Yang T, Xu Z, Shi J. Screening and characterization of a highly active chitosanase based on metagenomic technology. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.molcatb.2014.11.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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11
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Hjort K, Presti I, Elväng A, Marinelli F, Sjöling S. Bacterial chitinase with phytopathogen control capacity from suppressive soil revealed by functional metagenomics. Appl Microbiol Biotechnol 2014; 98:2819-28. [PMID: 24121932 PMCID: PMC3936118 DOI: 10.1007/s00253-013-5287-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 09/08/2013] [Accepted: 09/12/2013] [Indexed: 12/16/2022]
Abstract
Plant disease caused by fungal pathogens results in vast crop damage globally. Microbial communities of soil that is suppressive to fungal crop disease provide a source for the identification of novel enzymes functioning as bioshields against plant pathogens. In this study, we targeted chitin-degrading enzymes of the uncultured bacterial community through a functional metagenomics approach, using a fosmid library of a suppressive soil metagenome. We identified a novel bacterial chitinase, Chi18H8, with antifungal activity against several important crop pathogens. Sequence analyses show that the chi18H8 gene encodes a 425-amino acid protein of 46 kDa with an N-terminal signal peptide, a catalytic domain with the conserved active site F175DGIDIDWE183, and a chitinase insertion domain. Chi18H8 was expressed (pGEX-6P-3 vector) in Escherichia coli and purified. Enzyme characterization shows that Chi18H8 has a prevalent chitobiosidase activity with a maximum activity at 35 °C at pH lower than 6, suggesting a role as exochitinase on native chitin. To our knowledge, Chi18H8 is the first chitinase isolated from a metagenome library obtained in pure form and which has the potential to be used as a candidate agent for controlling fungal crop diseases. Furthermore, Chi18H8 may also answer to the demand for novel chitin-degrading enzymes for a broad range of other industrial processes and medical purposes.
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Affiliation(s)
- Karin Hjort
- School of Natural Sciences and Environmental Studies, Södertörn University, 141 89 Huddinge, Sweden
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Ilaria Presti
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, 21100 Italy
| | - Annelie Elväng
- School of Natural Sciences and Environmental Studies, Södertörn University, 141 89 Huddinge, Sweden
| | - Flavia Marinelli
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, 21100 Italy
- The Protein Factory Research Center, Politecnico of Milano, ICRM CNR and University of Insubria, Varese, 21100 Italy
| | - Sara Sjöling
- School of Natural Sciences and Environmental Studies, Södertörn University, 141 89 Huddinge, Sweden
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Loni PP, Patil JU, Phugare SS, Bajekal SS. Purification and characterization of alkaline chitinase fromPaenibacillus pasadenensisNCIM 5434. J Basic Microbiol 2014; 54:1080-9. [DOI: 10.1002/jobm.201300533] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 12/06/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Prasad P. Loni
- Department of Microbiology; Yashwantrao Chavan College of Science; Karad India
| | - Jaysing U. Patil
- Department of Microbiology; Yashwantrao Chavan College of Science; Karad India
| | - Swapnil S. Phugare
- Department of Biotechnology; Yashwantrao Chavan College of Science; Karad India
| | - Shaym S. Bajekal
- Department of Microbiology; Yashwantrao Chavan College of Science; Karad India
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13
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Jacquiod S, Franqueville L, Cécillon S, M. Vogel T, Simonet P. Soil bacterial community shifts after chitin enrichment: an integrative metagenomic approach. PLoS One 2013; 8:e79699. [PMID: 24278158 PMCID: PMC3835784 DOI: 10.1371/journal.pone.0079699] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 09/25/2013] [Indexed: 11/19/2022] Open
Abstract
Chitin is the second most produced biopolymer on Earth after cellulose. Chitin degrading enzymes are promising but untapped sources for developing novel industrial biocatalysts. Hidden amongst uncultivated micro-organisms, new bacterial enzymes can be discovered and exploited by metagenomic approaches through extensive cloning and screening. Enrichment is also a well-known strategy, as it allows selection of organisms adapted to feed on a specific compound. In this study, we investigated how the soil bacterial community responded to chitin enrichment in a microcosm experiment. An integrative metagenomic approach coupling phylochips and high throughput shotgun pyrosequencing was established in order to assess the taxonomical and functional changes in the soil bacterial community. Results indicate that chitin enrichment leads to an increase of Actinobacteria, γ-proteobacteria and β-proteobacteria suggesting specific selection of chitin degrading bacteria belonging to these classes. Part of enriched bacterial genera were not yet reported to be involved in chitin degradation, like the members from the Micrococcineae sub-order (Actinobacteria). An increase of the observed bacterial diversity was noticed, with detection of specific genera only in chitin treated conditions. The relative proportion of metagenomic sequences related to chitin degradation was significantly increased, even if it represents only a tiny fraction of the sequence diversity found in a soil metagenome.
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Affiliation(s)
- Samuel Jacquiod
- Environmental Microbial Genomics Group, Ecole Centrale de Lyon, Laboratoire Ampère UMR5005 CNRS, Ecully, France
- Microbial Molecular Ecology Group, Section of Microbiology, København Universitat, København, Denmark
| | - Laure Franqueville
- Environmental Microbial Genomics Group, Ecole Centrale de Lyon, Laboratoire Ampère UMR5005 CNRS, Ecully, France
| | - Sébastien Cécillon
- Environmental Microbial Genomics Group, Ecole Centrale de Lyon, Laboratoire Ampère UMR5005 CNRS, Ecully, France
| | - Timothy M. Vogel
- Environmental Microbial Genomics Group, Ecole Centrale de Lyon, Laboratoire Ampère UMR5005 CNRS, Ecully, France
| | - Pascal Simonet
- Environmental Microbial Genomics Group, Ecole Centrale de Lyon, Laboratoire Ampère UMR5005 CNRS, Ecully, France
- * E-mail:
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14
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Sorokin DY, Gumerov VM, Rakitin AL, Beletsky AV, Damsté JSS, Muyzer G, Mardanov AV, Ravin NV. Genome analysis of Chitinivibrio alkaliphilus gen. nov., sp. nov., a novel extremely haloalkaliphilic anaerobic chitinolytic bacterium from the candidate phylum Termite Group 3. Environ Microbiol 2013; 16:1549-65. [PMID: 24112708 DOI: 10.1111/1462-2920.12284] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 07/29/2013] [Accepted: 09/09/2013] [Indexed: 11/30/2022]
Abstract
Anaerobic enrichments from hypersaline soda lakes with chitin as substrate yielded five closely related anaerobic haloalkaliphilic isolates growing on insoluble chitin by fermentation at pH 10 and salinities up to 3.5 M. The chitinolytic activity was exclusively cell associated. To better understand the biology and evolutionary history of this novel bacterial lineage, the genome of the type strain ACht1 was sequenced. Analysis of the 2.6 Mb draft genome revealed enzymes of chitin-degradation pathways, including secreted cell-bound chitinases. The reconstructed central metabolism revealed pathways enabling the fermentation of polysaccharides, while it lacks the genes needed for aerobic or anaerobic respiration. The Rnf-type complex, oxaloacetate decarboxylase and sodium-transporting V-type adenosine triphosphatase were identified among putative membrane-bound ion pumps. According to 16S ribosomal RNA analysis, the isolates belong to the candidate phylum Termite Group 3, representing its first culturable members. Phylogenetic analysis using ribosomal proteins and taxonomic distribution analysis of the whole proteome supported a class-level classification of ACht1 most probably affiliated to the phylum Fibribacteres. Based on phylogenetic, phenotypic and genomic analyses, the novel bacteria are proposed to be classified as Chitinivibrio alkaliphilus gen. nov., sp. nov., within a novel class Chitinivibrione.
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Affiliation(s)
- Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-let Oktyabrya, bld. 7-2, 117312, Moscow, Russia; Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
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15
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Beier S, Bertilsson S. Bacterial chitin degradation-mechanisms and ecophysiological strategies. Front Microbiol 2013; 4:149. [PMID: 23785358 PMCID: PMC3682446 DOI: 10.3389/fmicb.2013.00149] [Citation(s) in RCA: 227] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 05/28/2013] [Indexed: 11/13/2022] Open
Abstract
Chitin is one the most abundant polymers in nature and interacts with both carbon and nitrogen cycles. Processes controlling chitin degradation are summarized in reviews published some 20 years ago, but the recent use of culture-independent molecular methods has led to a revised understanding of the ecology and biochemistry of this process and the organisms involved. This review summarizes different mechanisms and the principal steps involved in chitin degradation at a molecular level while also discussing the coupling of community composition to measured chitin hydrolysis activities and substrate uptake. Ecological consequences are then highlighted and discussed with a focus on the cross feeding associated with the different habitats that arise because of the need for extracellular hydrolysis of the chitin polymer prior to metabolic use. Principal environmental drivers of chitin degradation are identified which are likely to influence both community composition of chitin degrading bacteria and measured chitin hydrolysis activities.
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Affiliation(s)
- Sara Beier
- Department of Ecology and Genetics, Limnology, Uppsala University Uppsala, Sweden ; Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, UPMC Paris 06, UMR 7621 Banyuls sur mer, France ; Laboratoire d'Océanographie Microbienne, Observatoire Océanologique Centre National de la Recherche Scientifique, UMR 7621 Banyuls sur mer, France
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16
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Paul Antony C, Kumaresan D, Hunger S, Drake HL, Murrell JC, Shouche YS. Microbiology of Lonar Lake and other soda lakes. THE ISME JOURNAL 2013; 7:468-76. [PMID: 23178675 PMCID: PMC3578565 DOI: 10.1038/ismej.2012.137] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 09/17/2012] [Accepted: 09/28/2012] [Indexed: 11/08/2022]
Abstract
Soda lakes are saline and alkaline ecosystems that are believed to have existed throughout the geological record of Earth. They are widely distributed across the globe, but are highly abundant in terrestrial biomes such as deserts and steppes and in geologically interesting regions such as the East African Rift valley. The unusual geochemistry of these lakes supports the growth of an impressive array of microorganisms that are of ecological and economic importance. Haloalkaliphilic Bacteria and Archaea belonging to all major trophic groups have been described from many soda lakes, including lakes with exceptionally high levels of heavy metals. Lonar Lake is a soda lake that is centered at an unusual meteorite impact structure in the Deccan basalts in India and its key physicochemical and microbiological characteristics are highlighted in this article. The occurrence of diverse functional groups of microbes, such as methanogens, methanotrophs, phototrophs, denitrifiers, sulfur oxidizers, sulfate reducers and syntrophs in soda lakes, suggests that these habitats harbor complex microbial food webs that (a) interconnect various biological cycles via redox coupling and (b) impact on the production and consumption of greenhouse gases. Soda lake microorganisms harbor several biotechnologically relevant enzymes and biomolecules (for example, cellulases, amylases, ectoine) and there is the need to augment bioprospecting efforts in soda lake environments with new integrated approaches. Importantly, some saline and alkaline lake ecosystems around the world need to be protected from anthropogenic pressures that threaten their long-term existence.
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Affiliation(s)
| | | | - Sindy Hunger
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Harold L Drake
- Department of Ecological Microbiology, University of Bayreuth, Bayreuth, Germany
| | - J Colin Murrell
- School of Environmental Sciences, University of East Anglia, Norwich, UK
| | - Yogesh S Shouche
- Microbial Culture Collection, National Centre for Cell Science, Pune, India
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17
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Kielak AM, Cretoiu MS, Semenov AV, Sørensen SJ, van Elsas JD. Bacterial chitinolytic communities respond to chitin and pH alteration in soil. Appl Environ Microbiol 2013; 79:263-72. [PMID: 23104407 PMCID: PMC3536121 DOI: 10.1128/aem.02546-12] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 10/21/2012] [Indexed: 01/21/2023] Open
Abstract
Chitin amendment is a promising soil management strategy that may enhance the suppressiveness of soil toward plant pathogens. However, we understand very little of the effects of added chitin, including the putative successions that take place in the degradative process. We performed an experiment in moderately acid soil in which the level of chitin, next to the pH, was altered. Examination of chitinase activities revealed fast responses to the added crude chitin, with peaks of enzymatic activity occurring on day 7. PCR-denaturing gradient gel electrophoresis (DGGE)-based analyses of 16S rRNA and chiA genes showed structural changes of the phylogenetically and functionally based bacterial communities following chitin addition and pH alteration. Pyrosequencing analysis indicated (i) that the diversity of chiA gene types in soil is enormous and (i) that different chiA gene types are selected by the addition of chitin at different prevailing soil pH values. Interestingly, a major role of Gram-negative bacteria versus a minor one of Actinobacteria in the immediate response to the added chitin (based on 16S rRNA gene abundance and chiA gene types) was indicated. The results of this study enhance our understanding of the response of the soil bacterial communities to chitin and are of use for both the understanding of soil suppressiveness and the possible mining of soil for novel enzymes.
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Affiliation(s)
- Anna M. Kielak
- Department of Microbial Ecology, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
| | - Mariana Silvia Cretoiu
- Department of Microbial Ecology, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
| | - Alexander V. Semenov
- Department of Microbial Ecology, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
| | - Søren J. Sørensen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jan Dirk van Elsas
- Department of Microbial Ecology, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
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18
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Bacterial chitin utilisation at extremely haloalkaline conditions. Extremophiles 2012; 16:883-94. [PMID: 23007247 DOI: 10.1007/s00792-012-0484-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 09/09/2012] [Indexed: 10/27/2022]
Abstract
Chitin is produced in large amounts in hypersaline habitats with neutral pH due to the high biomass production of brine shrimp Artemia. Recently, a high abundance of Artemia was also noticed in hypersaline soda lakes in the Kulunda Steppe (Altai, Russia), which prompted us to survey the possibility of microbial chitin utilization at extremely haloalkaline conditions in soda brines. Most active chitin utilisation-supporting microbial growth was found at anaerobic conditions at pH 10 and up to 3.5 M total Na(+). At aerobic conditions, the degradation of chitin was slower, mostly incomplete and active at <2 M total Na(+), although very slow partial degradation was possible up to 4 M Na(+). Anaerobic enrichments at pH 10 yielded two different groups of obligately haloalkaliphilic fermentative anaerobes, exclusively specialized to utilise insoluble chitin as the only growth substrate. One group was represented by a single strain growing at moderate salinity, and another comprised multiple isolates growing up to 3.5 M Na(+). These groups represent two novel bacterial phyla not closely related to any other cultured bacteria. Aerobic enrichments from the lake sediments were dominated by several obligately haloalkaliphilic members of the genus Marinimicrobium in the Gammaproteobacteria. They were less specialised than the anaerobes and grew with chitin and its monomer and oligomers at a pH of 10 up to 2.5 M Na(+). Furthermore, several strains of haloalkaliphilic Gram-positive chitinolytics belonging to bacilli and actinobacteria were isolated from soda lake sediments and surrounding soda soils. In general, the results indicate the presence of an active and diverse haloalkaliphilic chitinolytic microbial community in hypersaline soda habitats.
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19
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Ekkers DM, Cretoiu MS, Kielak AM, van Elsas JD. The great screen anomaly--a new frontier in product discovery through functional metagenomics. Appl Microbiol Biotechnol 2011; 93:1005-20. [PMID: 22189864 PMCID: PMC3264863 DOI: 10.1007/s00253-011-3804-3] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 11/27/2011] [Accepted: 11/29/2011] [Indexed: 11/25/2022]
Abstract
Functional metagenomics, the study of the collective genome of a microbial community by expressing it in a foreign host, is an emerging field in biotechnology. Over the past years, the possibility of novel product discovery through metagenomics has developed rapidly. Thus, metagenomics has been heralded as a promising mining strategy of resources for the biotechnological and pharmaceutical industry. However, in spite of innovative work in the field of functional genomics in recent years, yields from function-based metagenomics studies still fall short of producing significant amounts of new products that are valuable for biotechnological processes. Thus, a new set of strategies is required with respect to fostering gene expression in comparison to the traditional work. These new strategies should address a major issue, that is, how to successfully express a set of unknown genes of unknown origin in a foreign host in high throughput. This article is an opinionating review of functional metagenomic screening of natural microbial communities, with a focus on the optimization of new product discovery. It first summarizes current major bottlenecks in functional metagenomics and then provides an overview of the general metagenomic assessment strategies, with a focus on the challenges that are met in the screening for, and selection of, target genes in metagenomic libraries. To identify possible screening limitations, strategies to achieve optimal gene expression are reviewed, examining the molecular events all the way from the transcription level through to the secretion of the target gene product.
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Affiliation(s)
- David Matthias Ekkers
- Department of Microbial Ecology, Centre for Ecological and Evolutionary Studies, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Mariana Silvia Cretoiu
- Department of Microbial Ecology, Centre for Ecological and Evolutionary Studies, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Anna Maria Kielak
- Department of Microbial Ecology, Centre for Ecological and Evolutionary Studies, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Jan Dirk van Elsas
- Department of Microbial Ecology, Centre for Ecological and Evolutionary Studies, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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20
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Souza CP, Almeida BC, Colwell RR, Rivera ING. The importance of chitin in the marine environment. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2011; 13:823-830. [PMID: 21607543 DOI: 10.1007/s10126-011-9388-1] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Accepted: 02/15/2011] [Indexed: 05/30/2023]
Abstract
Chitin is the most abundant renewable polymer in the oceans and is an important source of carbon and nitrogen for marine organisms. The process of chitin degradation is a key step in the cycling of nutrients in the oceans and chitinolytic bacteria play a significant role in this process. These bacteria are autochthonous to both marine and freshwater ecosystems and produce chitinases that degrade chitin, an insoluble polysaccharide, to a biologically useful form. In this brief review, a description of the structure of chitin and diversity of chitinolytic bacteria in the oceans is provided, in the context of the significance of chitin degradation for marine life.
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Affiliation(s)
- Claudiana P Souza
- Instituto de Ciências Biomédicas, Universidade de São Paulo, 1374, Prof. Lineu Prestes Av., 05508-000, São Paulo, Brazil
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21
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Alkaliphilic bacteria: applications in industrial biotechnology. J Ind Microbiol Biotechnol 2011; 38:769-90. [DOI: 10.1007/s10295-011-0968-x] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 03/26/2011] [Indexed: 11/26/2022]
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22
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Fu C, Hu Y, Xie F, Guo H, Ashforth EJ, Polyak SW, Zhu B, Zhang L. Molecular cloning and characterization of a new cold-active esterase from a deep-sea metagenomic library. Appl Microbiol Biotechnol 2011; 90:961-70. [PMID: 21336688 DOI: 10.1007/s00253-010-3079-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 12/15/2010] [Accepted: 12/15/2010] [Indexed: 10/18/2022]
Abstract
A clone which conferred lipolytic activity at low temperature was identified from a fosmid library constructed from a South China Sea marine sediment sample. The gene responsible, estF, consisted of 1,080 bp that encoded 359 amino acid residues, with a typical N-terminal signal peptide of 28 amino acid residues. A phylogenetic analysis of amino acid sequence with other lipolytic enzymes revealed that EstF and seven closely related putative lipolytic enzymes comprised a unique clade in the phylogenetic tree. Moreover, these hypothetic esterases showed unique conservative sites in the amino acid sequence. The recombinant EstF was overexpressed and purified, and its biochemical properties were partially characterized. The optimal substrate for EstF to hydrolyze among a panel of p-nitrophenyl esters (C2 to C16) was p-nitrophenyl butyrate (C4), with a K(m) of 0.46 mM. Activity quickly decreased with substrates containing an acyl chain length longer than 10 carbons. We found that EstF was active in the temperature range of 0-60°C, showed the best activity at 50°C, but was unstable at 60°C. It exhibited a high level of activity in the pH range of 7.0-10.0 showing the highest activity at pH 9.0.
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Affiliation(s)
- Chengzhang Fu
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, 100101, Beijing, People's Republic of China
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23
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Wang Q, Wu H, Wang A, Du P, Pei X, Li H, Yin X, Huang L, Xiong X. Prospecting metagenomic enzyme subfamily genes for DNA family shuffling by a novel PCR-based approach. J Biol Chem 2010; 285:41509-16. [PMID: 20962349 DOI: 10.1074/jbc.m110.139659] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
DNA family shuffling is a powerful method for enzyme engineering, which utilizes recombination of naturally occurring functional diversity to accelerate laboratory-directed evolution. However, the use of this technique has been hindered by the scarcity of family genes with the required level of sequence identity in the genome database. We describe here a strategy for collecting metagenomic homologous genes for DNA shuffling from environmental samples by truncated metagenomic gene-specific PCR (TMGS-PCR). Using identified metagenomic gene-specific primers, twenty-three 921-bp truncated lipase gene fragments, which shared 64-99% identity with each other and formed a distinct subfamily of lipases, were retrieved from 60 metagenomic samples. These lipase genes were shuffled, and selected active clones were characterized. The chimeric clones show extensive functional and genetic diversity, as demonstrated by functional characterization and sequence analysis. Our results indicate that homologous sequences of genes captured by TMGS-PCR can be used as suitable genetic material for DNA family shuffling with broad applications in enzyme engineering.
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Affiliation(s)
- Qiuyan Wang
- Center for Biomedicine and Health, Hangzhou Normal University, Hangzhou 310012, China
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24
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Math RK, Islam SMA, Hong SJ, Cho KM, Kim JM, Yun MG, Cho JJ, Kim EJ, Lee YH, Yun HD. Metagenomic characterization of oyster shell dump reveals predominance of Firmicutes bacteria. Microbiology (Reading) 2010. [DOI: 10.1134/s0026261710040132] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Metagenomic analysis of apple orchard soil reveals antibiotic resistance genes encoding predicted bifunctional proteins. Appl Environ Microbiol 2010; 76:4396-401. [PMID: 20453147 DOI: 10.1128/aem.01763-09] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To gain insight into the diversity and origins of antibiotic resistance genes, we identified resistance genes in the soil in an apple orchard using functional metagenomics, which involves inserting large fragments of foreign DNA into Escherichia coli and assaying the resulting clones for expressed functions. Among 13 antibiotic-resistant clones, we found two genes that encode bifunctional proteins. One predicted bifunctional protein confers resistance to ceftazidime and contains a natural fusion between a predicted transcriptional regulator and a beta-lactamase. Sequence analysis of the entire metagenomic clone encoding the predicted bifunctional beta-lactamase revealed a gene potentially involved in chloramphenicol resistance as well as a predicted transposase. A second clone that encodes a predicted bifunctional protein confers resistance to kanamycin and contains an aminoglycoside acetyltransferase domain fused to a second acetyltransferase domain that, based on nucleotide sequence, was predicted not to be involved in antibiotic resistance. This is the first report of a transcriptional regulator fused to a beta-lactamase and of an aminoglycoside acetyltransferase fused to an acetyltransferase not involved in antibiotic resistance.
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26
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Tuffin M, Anderson D, Heath C, Cowan DA. Metagenomic gene discovery: how far have we moved into novel sequence space? Biotechnol J 2010; 4:1671-83. [PMID: 19946882 DOI: 10.1002/biot.200900235] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Metagenomics emerged in the late 1990s as a tool for accessing and studying the collective microbial genetic material in the environment. The advent of the technology generated great excitement, as it has provided new opportunities and technologies for studying the wealth of microbial genetic diversity in the environment. Metagenomics has been widely predicted to access new dimensions of protein sequence space. A decade on, we review how far we have actually moved into new sequence space (and other aspects of protein space) using metagenomic tools. While several novel enzyme activities and protein structures have been identified through metagenomic strategies, the greatest advancement has been made in the isolation of novel protein sequences, some of which have no close relatives, form deeply branched lineages and even represent novel families. This is particularly true for glycosyl hydrolases and lipase/esterases, despite the fact that these activities are frequently screened for in metagenomic studies. However, there is much room for improvement in the methods employed and they will need to be addressed so that access to novel biocatalytic activities can be widened.
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Affiliation(s)
- Marla Tuffin
- Institute for Microbial Biotechnology and Metagenomics, Department of Biotechnology, University of Western Cape, Cape town, South Africa
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27
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Hjort K, Bergström M, Adesina MF, Jansson JK, Smalla K, Sjöling S. Chitinase genes revealed and compared in bacterial isolates, DNA extracts and a metagenomic library from a phytopathogen-suppressive soil. FEMS Microbiol Ecol 2009; 71:197-207. [PMID: 19922433 DOI: 10.1111/j.1574-6941.2009.00801.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Soil that is suppressive to disease caused by fungal pathogens is an interesting source to target for novel chitinases that might be contributing towards disease suppression. In this study, we screened for chitinase genes, in a phytopathogen-suppressive soil in three ways: (1) from a metagenomic library constructed from microbial cells extracted from soil, (2) from directly extracted DNA and (3) from bacterial isolates with antifungal and chitinase activities. Terminal restriction fragment length polymorphism (T-RFLP) of chitinase genes revealed differences in amplified chitinase genes from the metagenomic library and the directly extracted DNA, but approximately 40% of the identified chitinase terminal restriction fragments (TRFs) were found in both sources. All of the chitinase TRFs from the isolates were matched to TRFs in the directly extracted DNA and the metagenomic library. The most abundant chitinase TRF in the soil DNA and the metagenomic library corresponded to the TRF(103) of the isolate Streptomyces mutomycini and/or Streptomyces clavifer. There were good matches between T-RFLP profiles of chitinase gene fragments obtained from different sources of DNA. However, there were also differences in both the chitinase and the 16S rRNA gene T-RFLP patterns depending on the source of DNA, emphasizing the lack of complete coverage of the gene diversity by any of the approaches used.
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Affiliation(s)
- Karin Hjort
- Södertörn University, School of Life Sciences, Huddinge, Sweden
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28
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Islam SMA, Cho KM, Hong SJ, Math RK, Kim JM, Yun MG, Cho JJ, Heo JY, Lee YH, Kim H, Yun HD. Chitinase of Bacillus licheniformis from oyster shell as a probe to detect chitin in marine shells. Appl Microbiol Biotechnol 2009; 86:119-29. [DOI: 10.1007/s00253-009-2215-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 08/17/2009] [Accepted: 08/18/2009] [Indexed: 11/29/2022]
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29
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Temporal dynamics of South End tidal creek (Sapelo Island, Georgia) bacterial communities. Appl Environ Microbiol 2008; 75:1058-64. [PMID: 19114517 DOI: 10.1128/aem.01725-08] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial community dynamics in South End tidal creek, Sapelo Island, GA, were studied over a 74-h, five-tidal-cycle period. Observations were made hourly for the first consecutive 24 hours, every 3 hours on the second day, and every 6 hours on the third day. Tide most strongly influenced bacterial community composition (high-tide versus low-tide community analysis of similarities, R = 0.41, P < 0.03). Dissolved oxygen concentration and conductivity were important proximate drivers. However, after accounting for tide and environmental variables colinear with tide, cumulative time became more important in describing community variation. In-stream physical processes, including particulate suspension and sedimentation, may explain tide-associated trends in the bacterial community composition observed.
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Jankovic D, Collett MA, Lubbers MW, Rakonjac J. Direct selection and phage display of a Gram-positive secretome. Genome Biol 2008; 8:R266. [PMID: 18078523 PMCID: PMC2246268 DOI: 10.1186/gb-2007-8-12-r266] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2007] [Revised: 11/01/2007] [Accepted: 12/13/2007] [Indexed: 12/23/2022] Open
Abstract
A phage display system for direct selection, identification, expression and purification of bacterial secretome proteins has been developed. Surface, secreted and transmembrane protein-encoding open reading frames, collectively the secretome, can be identified in bacterial genome sequences using bioinformatics. However, functional analysis of translated secretomes is possible only if many secretome proteins are expressed and purified individually. We have now developed and applied a phage display system for direct selection, identification, expression and purification of bacterial secretome proteins.
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Affiliation(s)
- Dragana Jankovic
- Institute of Molecular Biosciences, Massey University, Palmerston North, New Zealand.
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Logue JB, Bürgmann H, Robinson CT. Progress in the Ecological Genetics and Biodiversity of Freshwater Bacteria. Bioscience 2008. [DOI: 10.1641/b580205] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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