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Sime AM, Kifle BA, Woldesemayat AA, Gemeda MT. Microbial carbohydrate active enzyme (CAZyme) genes and diversity from Menagesha Suba natural forest soils of Ethiopia as revealed by shotgun metagenomic sequencing. BMC Microbiol 2024; 24:285. [PMID: 39090559 PMCID: PMC11293184 DOI: 10.1186/s12866-024-03436-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 07/23/2024] [Indexed: 08/04/2024] Open
Abstract
BACKGROUND The global over-reliance on non-renewable fossil fuels has led to the emission of greenhouse gases, creating a critical global environmental challenge. There is an urgent need for alternative solutions like biofuels. Advanced biofuel is a renewable sustainable energy generated from lignocellulosic plant materials, which can significantly contribute to mitigating CO2 emissions. Microbial Carbohydrate Active Enzymes (CAZymes) are the most crucial enzymes for the generation of sustainable biofuel energy. The present study designed shotgun metagenomics approaches to assemble, predict, and annotate, aiming to gain an insight into the taxonomic diversity, annotate CAZymes, and identify carbohydrate hydrolyzing CAZymes from microbiomes in Menagesha suba forest soil for the first time. RESULTS The microbial diversity based on small subunit (SSU) rRNA analysis revealed the dominance of the bacterial domain representing 81.82% and 92.31% in the studied samples. Furthermore, the phylum composition result indicated the dominance of the phyla Proteobacteria (23.08%, 27.27%), Actinobacteria (11.36%, 20.51%), and Acidobacteria (10.26%, 15.91%). The study also identified unassigned bacteria which might have a unique potential for biopolymer hydrolysis. The metagenomic study revealed that 100,244 and 65,356 genes were predicted from the two distinct samples. A total number of 1806 CAZyme genes were identified, among annotated CAZymes, 758 had a known enzyme assigned to CAZymes. Glycoside hydrolases (GHs) CAZyme family contained most of the CAZyme genes with known enzymes such as β-glucosidase, endo-β-1,4-mannanase, exo-β-1,4-glucanase, α-L-arabinofuranosidase and oligoxyloglucan reducing end-specific cellobiohydrolase. On the other hand, 1048 of the identified CAZyme genes were putative CAZyme genes with unknown enzymatical activity and the majority of which belong to the GHs family. CONCLUSIONS In general, the identified putative CAZymes genes open up an opportunity for the discovery of new enzymes responsible for hydrolyzing biopolymers utilized for biofuel energy generation. This finding is used as a first-hand piece of evidence to serve as a benchmark for further and comprehensive studies to unveil novel classes of bio-economically valuable genes and their encoded products.
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Affiliation(s)
- Amsale Melkamu Sime
- Biotechnology Department, College of Natural and Applied Sciences, Addis Ababa Sciences and Technology University, Addis Ababa, Ethiopia
| | - Bezayit Amare Kifle
- Biotechnology Department, College of Natural and Applied Sciences, Addis Ababa Sciences and Technology University, Addis Ababa, Ethiopia
| | - Adugna Abdi Woldesemayat
- Biotechnology Department, College of Natural and Applied Sciences, Addis Ababa Sciences and Technology University, Addis Ababa, Ethiopia
- Biotechnology and Bioprocess Center of Excellence, Addis Ababa Science and Technology University, Addis Ababa, Ethiopia
| | - Mesfin Tafesse Gemeda
- Biotechnology Department, College of Natural and Applied Sciences, Addis Ababa Sciences and Technology University, Addis Ababa, Ethiopia.
- Biotechnology and Bioprocess Center of Excellence, Addis Ababa Science and Technology University, Addis Ababa, Ethiopia.
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Mon ML, Romano N, Farace PD, Tortone CA, Oriani DS, Picariello G, Zumárraga MJ, Gioffré AK, Talia PM. Exploring the cellulolytic activity of environmental mycobacteria. Tuberculosis (Edinb) 2024; 147:102516. [PMID: 38735123 DOI: 10.1016/j.tube.2024.102516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 05/07/2024] [Accepted: 05/07/2024] [Indexed: 05/14/2024]
Abstract
Although studies on non-tuberculous mycobacteria have increased in recent years because they cause a considerable proportion of infections, their cellulolytic system is still poorly studied. This study presents a characterization of the cellulolytic activities of environmental mycobacterial isolates derived from soil and water samples from the central region of Argentina, aimed to evaluate the conservation of the mechanism for the degradation of cellulose in this group of bacteria. The molecular and genomic identification revealed identity with Mycolicibacterium septicum. The endoglucanase and total cellulase activities were assessed both qualitatively and quantitatively and the optimal enzymatic conditions were characterized. A specific protein of around 56 kDa with cellulolytic activity was detected in a zymogram. Protein sequences possibly arising from a cellulase were identified by mass spectrometry-based shotgun proteomics. Results showed that M. septicum encodes for cellulose- and hemicellulose-related degrading enzymes, including at least an active β-1,4 endoglucanase enzyme that could be useful to improve its survival in the environment. Given the important health issues related to mycobacteria, the results of the present study may contribute to the knowledge of their cellulolytic system, which could be important for their ability to survive in many different types of environments.
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Affiliation(s)
- María Laura Mon
- Instituto de Agrobiotecnología y Biología Molecular IABIMO, UEDD INTA-CONICET, Dr. N. Repetto y Los Reseros s/n, (1686) Hurlingham, provincia de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
| | - Nelson Romano
- Instituto de Agrobiotecnología y Biología Molecular IABIMO, UEDD INTA-CONICET, Dr. N. Repetto y Los Reseros s/n, (1686) Hurlingham, provincia de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
| | - Pablo Daniel Farace
- Instituto de Agrobiotecnología y Biología Molecular IABIMO, UEDD INTA-CONICET, Dr. N. Repetto y Los Reseros s/n, (1686) Hurlingham, provincia de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
| | - Claudia A Tortone
- Cátedra de Bacteriología y Micología, Facultad de Ciencias Veterinarias, Universidad Nacional de La Pampa, General Pico, La Pampa, Argentina.
| | - Delia S Oriani
- Cátedra de Bacteriología y Micología, Facultad de Ciencias Veterinarias, Universidad Nacional de La Pampa, General Pico, La Pampa, Argentina.
| | - Gianluca Picariello
- Istituto di Scienze Dell'Alimentazione, Consiglio Nazionale Delle Ricerche, Via Roma 64, 83100, Avellino, Italy.
| | - Martín José Zumárraga
- Instituto de Agrobiotecnología y Biología Molecular IABIMO, UEDD INTA-CONICET, Dr. N. Repetto y Los Reseros s/n, (1686) Hurlingham, provincia de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
| | - Andrea Karina Gioffré
- Instituto de Agrobiotecnología y Biología Molecular IABIMO, UEDD INTA-CONICET, Dr. N. Repetto y Los Reseros s/n, (1686) Hurlingham, provincia de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
| | - Paola M Talia
- Instituto de Agrobiotecnología y Biología Molecular IABIMO, UEDD INTA-CONICET, Dr. N. Repetto y Los Reseros s/n, (1686) Hurlingham, provincia de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
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Tu X, Kang J, Zhang C, Qiu W, Guo Y, Ao G, Ge J, Ping W. Effect of combined bacteria on the flax dew degumming process: Substance degradation sequence and changes in functional bacteria taxa. Int J Biol Macromol 2024; 273:132877. [PMID: 38848847 DOI: 10.1016/j.ijbiomac.2024.132877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 05/16/2024] [Accepted: 06/01/2024] [Indexed: 06/09/2024]
Abstract
In this study, 16S rDNA high-throughput sequencing, Fourier transform infrared spectroscopy, and two-dimensional correlation spectroscopy techniques were used to analyze the mechanisms driving the sequence of degradation of gummy substances by the microbial community and hydrolytic enzymes during the flax dew degumming process. The results revealed that the inoculation of combined bacteria induced quorum sensing, modulated hydrolytic enzyme production, and reshaped the community structure. Lignin-degraded genera (Pseudomonas and Sphingobacterium) were enriched, and the relative abundances of pectin- and cellulose-degraded genera (Chryseobacterium) decreased in the early degumming stages. Hemicellulose-degraded genera (Brevundimonas) increased over the degumming time. Moreover, the abundance of lignin hydrolytic enzymes improved in the early stages, while the abundance of pectin hydrolytic enzymes increased at the end of degumming. Various types of functional bacteria taxa changed the sequence of substance degradation. Electron scanning microscopy and differential scanning calorimetry results indicated that the degumming, facilitated by the inoculation of combined bacteria, was nearly completed by 21 d. The fibers exhibited smoother and more intact properties, along with higher thermal stability, as indicated by a melting temperature of 71.54 °C. This study provides a reference for selecting precise degumming bacterial agents to enhance degumming efficiency.
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Affiliation(s)
- Xiujun Tu
- Engineering Research Center of Agricultural Microbiology Technology, Ministry of Education & Heilongjiang Provincial Key Laboratory of Plant Genetic Engineering and Biological Fermentation Engineering for Cold Region & Key Laboratory of Microbiology, College of Heilongjiang Province & School of Life Sciences, Heilongjiang University, Harbin 150080, China
| | - Jie Kang
- Engineering Research Center of Agricultural Microbiology Technology, Ministry of Education & Heilongjiang Provincial Key Laboratory of Plant Genetic Engineering and Biological Fermentation Engineering for Cold Region & Key Laboratory of Microbiology, College of Heilongjiang Province & School of Life Sciences, Heilongjiang University, Harbin 150080, China
| | - Chi Zhang
- Engineering Research Center of Agricultural Microbiology Technology, Ministry of Education & Heilongjiang Provincial Key Laboratory of Plant Genetic Engineering and Biological Fermentation Engineering for Cold Region & Key Laboratory of Microbiology, College of Heilongjiang Province & School of Life Sciences, Heilongjiang University, Harbin 150080, China
| | - Wei Qiu
- Engineering Research Center of Agricultural Microbiology Technology, Ministry of Education & Heilongjiang Provincial Key Laboratory of Plant Genetic Engineering and Biological Fermentation Engineering for Cold Region & Key Laboratory of Microbiology, College of Heilongjiang Province & School of Life Sciences, Heilongjiang University, Harbin 150080, China
| | - Yuhao Guo
- Engineering Research Center of Agricultural Microbiology Technology, Ministry of Education & Heilongjiang Provincial Key Laboratory of Plant Genetic Engineering and Biological Fermentation Engineering for Cold Region & Key Laboratory of Microbiology, College of Heilongjiang Province & School of Life Sciences, Heilongjiang University, Harbin 150080, China
| | - Guoxu Ao
- Engineering Research Center of Agricultural Microbiology Technology, Ministry of Education & Heilongjiang Provincial Key Laboratory of Plant Genetic Engineering and Biological Fermentation Engineering for Cold Region & Key Laboratory of Microbiology, College of Heilongjiang Province & School of Life Sciences, Heilongjiang University, Harbin 150080, China
| | - Jingping Ge
- Engineering Research Center of Agricultural Microbiology Technology, Ministry of Education & Heilongjiang Provincial Key Laboratory of Plant Genetic Engineering and Biological Fermentation Engineering for Cold Region & Key Laboratory of Microbiology, College of Heilongjiang Province & School of Life Sciences, Heilongjiang University, Harbin 150080, China; Hebei University of Environmental Engineering, Hebei Key Laboratory of Agroecological Safety, Qinhuangdao 066102, China.
| | - Wenxiang Ping
- Engineering Research Center of Agricultural Microbiology Technology, Ministry of Education & Heilongjiang Provincial Key Laboratory of Plant Genetic Engineering and Biological Fermentation Engineering for Cold Region & Key Laboratory of Microbiology, College of Heilongjiang Province & School of Life Sciences, Heilongjiang University, Harbin 150080, China; Hebei University of Environmental Engineering, Hebei Key Laboratory of Agroecological Safety, Qinhuangdao 066102, China.
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Becker MF, Klueken AM, Knief C. Effects of above ground pathogen infection and fungicide application on the root-associated microbiota of apple saplings. ENVIRONMENTAL MICROBIOME 2023; 18:43. [PMID: 37245023 DOI: 10.1186/s40793-023-00502-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 05/14/2023] [Indexed: 05/29/2023]
Abstract
BACKGROUND The root-associated microbiome has been of keen research interest especially in the last decade due to the large potential for increasing overall plant performance in agricultural systems. Knowledge about the impact of above ground plant disturbances on the root-associated microbiome remains limited. We addressed this by focusing on two potential impacts, foliar pathogen infection alone and in combination with the application of a plant health protecting product. We hypothesized that these lead to plant-mediated responses in the rhizosphere microbiota. RESULTS The effects of an infection of greenhouse grown apple saplings with either Venturia inaequalis or Podosphaera leucotricha as foliar pathogen, as well as the combined effect of P. leucotricha infection and foliar application of the synthetic plant health protecting product Aliette (active ingredient: fosetyl-aluminum), were studied on the root-associated microbiota. The bacterial community structure of rhizospheric soil and endospheric root material was characterized post-infection, using 16S rRNA gene amplicon sequencing. With increasing disease severity both pathogens led to changes in the rhizosphere and endosphere bacterial communities in comparison to uninfected plants (explained variance up to 17.7%). While the preventive application of Aliette on healthy plants two weeks prior inoculation did not induce changes in the root-associated microbiota, a second later application on the diseased plants decreased disease severity and resulted in differences of the rhizosphere bacterial community between infected and several of the cured plants, though differences were overall not statistically significant. CONCLUSIONS Foliar pathogen infections can induce plant-mediated changes in the root-associated microbiota, indicating that above ground disturbances are reflected in the below-ground microbiome, even though these become evident only upon severe leaf infection. The application of the fungicide Aliette on healthy plants itself did not induce any changes, but the application to diseased plants helped the plant to regain the microbiota of a healthy plant. These findings indicate that above ground agronomic management practices have implications for the root-associated microbiome, which should be considered in the context of microbiome management strategies.
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Affiliation(s)
- Maximilian Fernando Becker
- Institute of Crop Science and Resource Conservation - Molecular Biology of the Rhizosphere, University of Bonn, Nussallee 13, 53115, Bonn, Germany
| | - A Michael Klueken
- Crop Science Division, Disease Control Biology, Bayer AG, Alfred-Nobel-Str. 50, 40789, Monheim am Rhein, Germany
| | - Claudia Knief
- Institute of Crop Science and Resource Conservation - Molecular Biology of the Rhizosphere, University of Bonn, Nussallee 13, 53115, Bonn, Germany.
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Liu Y, Zhang B, Zhang Y, Shen Y, Cheng C, Yuan W, Guo P. Organic Matter Decomposition in River Ecosystems: Microbial Interactions Influenced by Total Nitrogen and Temperature in River Water. MICROBIAL ECOLOGY 2023; 85:1236-1252. [PMID: 35501499 DOI: 10.1007/s00248-022-02013-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 04/11/2022] [Indexed: 05/10/2023]
Abstract
Microbes contribute to the organic matter decomposition (OMD) in river ecosystems. This study considers two aspects of OMD in river ecosystems which have not been examined in scientific studies previously, and these are the microbial interactions in OMD and the influence of environmental factors on microbial interactions. Cotton strip (CS), as a substitute for organic matter, was introduced to Luanhe River Basin in China. The results of CS assay, microbial sequencing, and redundancy analysis (RDA) showed that CS selectively enriched bacterial and fungal groups related to cellulose decomposition, achieving cotton strip decomposition (CSD). Bacterial phylum Proteobacteria and fungal phyla Rozellomycota and Ascomycota were the dominant groups associated with CSD. Network analysis and Mantel test results indicated that bacteria and fungi on CS cooperatively formed an interaction network to achieve the CSD. In the network, modules 2 and 4 were significantly positively associated with CSD, which were considered as the key modules in this study. The key modules were mainly composed of phyla Proteobacteria and Ascomycota, indicating that microbes in key modules were the effective decomposers of CS. Although keystone taxa were not directly associated with CSD, they may regulate the genera in key modules to achieve the CSD, since some keystone taxa were linked with the microbial genera associated with CSD in the key modules. Total nitrogen (TN) and temperature in water were the dominant environmental factors positively influenced CSD. The key modules 2 and 4 were positively influenced by water temperature and TN in water, respectively, and two keystone taxa were positively associated with TN. This profoundly revealed that water temperature and TN influenced the OMD through acting on the keystone taxa and key modules in microbial interactions. The research findings help us to understand the microbial interactions influenced by environmental factors in OMD in river ecosystems.
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Affiliation(s)
- Yibo Liu
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of New Energy and Environment, Jilin University, Changchun, 130012, People's Republic of China
- Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun, 130012, People's Republic of China
| | - Baiyu Zhang
- Department of Civil Engineering, Faculty of Engineering and Applied Science, Memorial University, St. John' s, NL, A1B 3X5, Canada
| | - Yixin Zhang
- Department of Landscape Architecture, Gold Mantis School of Architecture, Soochow University, Suzhou, China
| | - Yanping Shen
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of New Energy and Environment, Jilin University, Changchun, 130012, People's Republic of China
- Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun, 130012, People's Republic of China
| | - Cheng Cheng
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of New Energy and Environment, Jilin University, Changchun, 130012, People's Republic of China
- Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun, 130012, People's Republic of China
| | - Weilin Yuan
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of New Energy and Environment, Jilin University, Changchun, 130012, People's Republic of China
- Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun, 130012, People's Republic of China
| | - Ping Guo
- Key Laboratory of Groundwater Resources and Environment Ministry of Education, College of New Energy and Environment, Jilin University, Changchun, 130012, People's Republic of China.
- Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun, 130012, People's Republic of China.
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Arunrat N, Sereenonchai S, Sansupa C, Kongsurakan P, Hatano R. Effect of Rice Straw and Stubble Burning on Soil Physicochemical Properties and Bacterial Communities in Central Thailand. BIOLOGY 2023; 12:biology12040501. [PMID: 37106702 PMCID: PMC10135879 DOI: 10.3390/biology12040501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/22/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023]
Abstract
Rice straw and stubble burning is widely practiced to clear fields for new crops. However, questions remain about the effects of fire on soil bacterial communities and soil properties in paddy fields. Here, five adjacent farmed fields were investigated in central Thailand to assess changes in soil bacterial communities and soil properties after burning. Samples of soil prior to burning, immediately after burning, and 1 year after burning were obtained from depths of 0 to 5 cm. The results showed that the pH, electrical conductivity, NH4-N, total nitrogen, and soil nutrients (available P, K, Ca, and Mg) significantly increased immediately after burning due to an increased ash content in the soil, whereas NO3-N decreased significantly. However, these values returned to the initial values. Chloroflexi were the dominant bacteria, followed by Actinobacteria and Proteobacteria. At 1 year after burning, Chloroflexi abundance decreased remarkably, whereas Actinobacteria, Proteobacteria, Verrucomicrobia, and Gemmatimonadetes abundances significantly increased. Bacillus, HSB OF53-F07, Conexibacter, and Acidothermus abundances increased immediately after burning, but were lower 1 year after burning. These bacteria may be highly resistant to heat, but grow slowly. Anaeromyxobacter and Candidatus Udaeobacter dominated 1 year after burning, most likely because of their rapid growth and the fact that they occupy areas with increased soil nutrient levels after fires. Amidase, cellulase, and chitinase levels increased with increased organic matter levels, whereas β-glucosidase, chitinase, and urease levels positively correlated with the soil total nitrogen level. Although clay and soil moisture strongly correlated with the soil bacterial community’s composition, negative correlations were found for β-glucosidase, chitinase, and urease. In this study, rice straw and standing stubble were burnt under high soil moisture and within a very short time, suggesting that the fire was not severe enough to raise the soil temperature and change the soil microbial community immediately after burning. However, changes in soil properties due to ash significantly increased the diversity indices, which was noticeable 1 year after burning.
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Kumar P, Verma A, Sundharam SS, Ojha AK, Krishnamurthi S. Exploring Diversity and Polymer Degrading Potential of Epiphytic Bacteria Isolated from Marine Macroalgae. Microorganisms 2022; 10:microorganisms10122513. [PMID: 36557766 PMCID: PMC9786321 DOI: 10.3390/microorganisms10122513] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/02/2022] [Accepted: 12/03/2022] [Indexed: 12/23/2022] Open
Abstract
The macroalgae surface allows specific bacterial communities to colonize, resulting in complex biological interactions. In recent years, several researchers have studied the diversity and function of the epiphytic bacteria associated with algal host, but largely these interactions remain underexplored. In the present study we analysed the cultivable diversity and polymer degradation potential of epiphytic bacteria associated with five different marine macroalgae (Sargassum, Ulva, Padina, Dictyota and Pterocladia sp.) sampled from the central west coast of India. Out of the total 360 strains isolated, purified and preserved, about 238 strains were identified through 16S rRNA gene sequence analysis and processed for polymer (cellulose, pectin, xylan and starch) degrading activities. Phylogeny placed the strains within the classes Actinobacteria, Bacilli, Alpha-proteobacteria, and Gamma-proteobacteria and clustered them into 45 genera, wherein Vibrio, Bacillus, Pseudoalteromonas, Alteromonas, Staphylococcus and Kocuria spp. were the most abundant with 20 strains identified as potentially novel taxa within the genera Bacillus, Cellulosimicrobium, Gordonia, Marinomonas, Vibrio, Luteimonas and Pseudoalteromonas. In terms of polymer hydrolysis potential, 61.3% had xylanase activity, while 59.7%, 58.8%, and 52.2% had amylase, cellulase, and pectinase activity, respectively. Overall, 75.6% of the strains degraded more than one polysaccharide, 24% degraded all polymers, while nine strains (3.8%) degraded raw sugarcane bagasse. This study showed great potential for seaweed-associated bacteria in the bio-remediation of agro-waste based raw materials, which can be employed in the form of green technology.
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Affiliation(s)
- Pravin Kumar
- Microbial Type Culture Collection and Gene Bank (MTCC), CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh 160036, India
| | - Ashish Verma
- Microbial Type Culture Collection and Gene Bank (MTCC), CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh 160036, India
| | - Shiva S. Sundharam
- Microbial Type Culture Collection and Gene Bank (MTCC), CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh 160036, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Anup Kumar Ojha
- Microbial Type Culture Collection and Gene Bank (MTCC), CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh 160036, India
| | - Srinivasan Krishnamurthi
- Microbial Type Culture Collection and Gene Bank (MTCC), CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh 160036, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
- Correspondence:
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Li L, Xia T, Yang H. Seasonal patterns of rhizosphere microorganisms suggest carbohydrate-degrading and nitrogen-fixing microbes contribute to the attribute of full-year shooting in woody bamboo Cephalostachyum pingbianense. Front Microbiol 2022; 13:1033293. [PMID: 36523824 PMCID: PMC9745117 DOI: 10.3389/fmicb.2022.1033293] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/11/2022] [Indexed: 10/15/2023] Open
Abstract
Compared with the ordinary single-season shooting among woody bamboos in Poaceae, the attribute of full-year shooting in Cephalostachyum pingbianense represents a unique shooting type or mechanism. Nevertheless, except for the overall physiological mechanism, the effect of ecological factors, especially soil microorganisms, on this full-year shooting characteristic remains unclear. In this study, 16S rRNA and ITS rRNA genes were sequenced using the Illumina platform. Our aims were to detect the seasonal changes in rhizospheric microbial communities of C. pingbianense and to discover the correlations of soil microbes with soil properties and bamboo shoot productivity. The results showed that seasonal change had no significant effect on bacterial alpha diversity, but significantly affected bacterial and fungal community structures as well as fungal richness. Among all soil properties examined, soil temperature, soil moisture and organic matter were the predominant factors affecting bacterial community diversity and structure. Soil temperature and soil moisture also significantly influenced fungal community structure, while available phosphorus had the greatest effect on fungal diversity. In each season, bacterial genera Acidothermus, Roseiarcus, and Bradyrhizobium, along with fungal genera Saitozyma, Mortierella, Trichoderma, etc., were dominant in bacterial and fungal communities, respectively. Bacterial community functions in four seasons were dominated by chemoheterotrophy, cellulolysis, and nitrogen fixation. Saprotrophic fungi occupied a high proportion in soil samples of all seasons. In addition, correlation analysis revealed that the bamboo shoot productivity was positively correlated with multiple microbial taxa involved in carbon and nitrogen cycles. It is proposed that highly abundant microbes involved in carbohydrate degradation and nitrogen fixation in the rhizosphere soil may contribute to the attribute of producing bamboo shoots all year round in C. pingbianense. This study is among the few cases revealing the connection between bamboo shooting characteristics and soil microorganisms, and provides new physiological and ecological insights into the forest management of woody bamboos.
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Affiliation(s)
| | | | - Hanqi Yang
- Institute of Highland Forest Science, Chinese Academy of Forestry, Kunming, Yunnan, China
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Wang JL, Liu KL, Zhao XQ, Gao GF, Wu YH, Shen RF. Microbial keystone taxa drive crop productivity through shifting aboveground-belowground mineral element flows. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 811:152342. [PMID: 34919922 DOI: 10.1016/j.scitotenv.2021.152342] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/05/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
Unbalanced fertilization of nutritional elements is a potential threat to environmental quality and agricultural productivity in acid soil. Harnessing keystone taxa in soil microbiome represents a promising strategy to enhance crop productivity as well as reducing the adverse environmental effects of fertilizers, with the goal of agricultural sustainability. However, there is a lack of information on which and how soil microbial keystone taxa contribute to sustainable crop productivity in acid soil. Here, we examined soil microbial communities (including bacteria, fungi, and archaea) and soil nutrients, and the mineral nutrition and yield of maize subjected to different inorganic and organic fertilization treatments over 35 years in acid soil. The application of organic fertilizer alone or in combination with inorganic fertilizers sustained high maize yield when compared with the other fertilization treatments. Microbial abundances and community structures rather than their alpha diversities explained the main variation in maize yield among different treatments. Sixteen soil keystone taxa (a fungal operational taxonomic unit and 15 bacterial operational taxonomic units) were identified from the microbial co-occurrence network. Among them, five keystone taxa (in Hypocreales, Bryobacter, Solirubrobacterales, Thermomicrobiales, and Roseiflexaceae) contributed to high maize yield through increasing phosphorus flow and inhibiting toxic aluminum and manganese flow from soils to plants. However, the remaining eleven keystone taxa (in Conexibacter, Acidothermus, Ktedonobacteraceae, Deltaproteobacteria, Actinobacteria, Elsterales, Ktedonobacterales, and WPS-2) exerted the opposite effects. As a result, maize productivity varied among different fertilization treatments because of the altered maize mineral element flows by microbial keystone taxa. We conclude that microbial keystone taxa drive crop productivity through shifting aboveground-belowground mineral element flows in acid soil. This study highlights the importance of microbial keystone taxa for sustainable crop productivity in acid soil and provides deep insights into the relationships between soil microbial keystone taxa, crop mineral nutrition, and productivity.
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Affiliation(s)
- Jia Lin Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Kai Lou Liu
- National Engineering and Technology Research Center for Red Soil Improvement, Jiangxi Institute of Red Soil, Nanchang 331717, China.
| | - Xue Qiang Zhao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Gui-Feng Gao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Yong Hong Wu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Ren Fang Shen
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Heterotrophic Bacteria Play an Important Role in Endemism of Cephalostachyum pingbianense (Hsueh & Y.M. Yang ex Yi et al.) D.Z. Li & H.Q. Yang, 2007, a Full-Year Shooting Woody Bamboo. FORESTS 2022. [DOI: 10.3390/f13010121] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The previous studies show soil microbes play a key role in the material and nutrient cycles in the forest ecosystem, but little is known about how soil microbes respond to plant distribution, especially in the soil bacterial community in woody bamboo forests. Cephalostachyum pingbianense (Hsueh & Y.M. Yang ex Yi et al.) D.Z. Li & H.Q. Yang, 2007 is known as the only bamboo species producing shoots all year round in natural conditions. Endemic to the Dawei mountain in Yunnan of China, this species is a good case to study how soil bacteria respond to plant endemic distribution. In this work, we assayed the soil chemical properties, enzyme activity, changes in the bacterial community along the distribution range of the C. pingbianense forest. The results showed that soil nutrients at the range edge were nitrogen-rich but phosphorus-deficient, and soil pH value and soil urease activity were significantly lower than that of the central range. No significant difference was detected in soil bacterial diversity, community composition, and function between the central and marginal range of C. pingbianense forest. Notably, the relative abundance of heterotrophy bacteria, such as Variibacter and Acidothermus, in the soil of the C. pingbianense forest was significantly higher than that of the outside range, which may lead to a higher soil organic carbon mineralization rate. These results imply that abundant heterotrophy bacteria were linked to the endemism and full-year shooting in C. pingbianense. Our study is amongst the first cases demonstrating the important role of heterotrophy bacteria in the distribution formation of endemic woody bamboos in special soil habitats, and provides insight into germplasm conservation and forest management in woody bamboos.
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Wang B, Yan J, Li G, Cao Q, Chen H, Zhang J. The addition of bean curd dreg improved the quality of mixed cow manure and corn stalk composting: enhancing the maturity and improving the micro-ecological environment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:27095-27108. [PMID: 33501580 DOI: 10.1007/s11356-021-12572-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 01/15/2021] [Indexed: 06/12/2023]
Abstract
Bean curd dreg (BCD) is a by-product of bean products, which can be used as a great ingredient for composting, but it combined with cow manure and corn stalk composting was rarely reported. In this study, the effect of BCD on the maturity and the micro-ecological environment was investigated under a lab-scale composting experiment and found that BCD was conducive to improve the maturity of compost during the BCD application. The excitation-emission matrix (EEM) showed that the final humus content in BCD treatments was richer than that in CK treatment. High-throughput sequencing results showed that BCD-applied better ameliorated the bacteria community structure with higher Actinomycetes abundance and lower denitrifying bacteria abundance in the late stage of composting. PICRUSt results showed that BCD-added decreased the abundance of microbial metabolic genes in the high temperature period (> 70 °C), but the metabolic abundance increased rapidly as the temperature cooled down. Compared with CK, the metabolic abundance decreased significantly on day 24, which was consistent with the conclusion of composting maturity. Redundancy analysis (RDA) results indicated that there were significant discrepancies in the microbial community structure of samples at different composting periods and the change of the dominant population in the BCD-treated compost samples were more outstanding than that in the CK treatment. Hence, BCD is a very good composting modifier that compensates for the disadvantages of composting and enhances the fertility of the compost product.
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Affiliation(s)
- Bing Wang
- College of Chemical Engineering, Northeast Electric Power University, NO.169 Changchun Road, Chuanying District, Jilin City, 132012, Jilin Province, China.
| | - Jianquan Yan
- College of Chemical Engineering, Northeast Electric Power University, NO.169 Changchun Road, Chuanying District, Jilin City, 132012, Jilin Province, China
| | - Guomin Li
- College of Chemical Engineering, Northeast Electric Power University, NO.169 Changchun Road, Chuanying District, Jilin City, 132012, Jilin Province, China
| | - Qingtong Cao
- College of Chemical Engineering, Northeast Electric Power University, NO.169 Changchun Road, Chuanying District, Jilin City, 132012, Jilin Province, China
| | - Houhe Chen
- School of Electrical Engineering, Northeast Electric Power University, Jilin, 132012, China
| | - Jian Zhang
- College of Chemical Engineering, Northeast Electric Power University, NO.169 Changchun Road, Chuanying District, Jilin City, 132012, Jilin Province, China
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A Degeneration Gradient of Poplar Trees Contributes to the Taxonomic, Functional, and Resistome Diversity of Bacterial Communities in Rhizosphere Soils. Int J Mol Sci 2021; 22:ijms22073438. [PMID: 33810508 PMCID: PMC8036350 DOI: 10.3390/ijms22073438] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/22/2021] [Accepted: 03/23/2021] [Indexed: 12/27/2022] Open
Abstract
Bacterial communities associated with roots influence the health and nutrition of the host plant. However, the microbiome discrepancy are not well understood under different healthy conditions. Here, we tested the hypothesis that rhizosphere soil microbial diversity and function varies along a degeneration gradient of poplar, with a focus on plant growth promoting bacteria (PGPB) and antibiotic resistance genes. Comprehensive metagenomic analysis including taxonomic investigation, functional detection, and ARG (antibiotics resistance genes) annotation revealed that available potassium (AK) was correlated with microbial diversity and function. We proposed several microbes, Bradyrhizobium, Sphingomonas, Mesorhizobium, Nocardioides, Variovorax, Gemmatimonadetes, Rhizobacter, Pedosphaera, Candidatus Solibacter, Acidobacterium, and Phenylobacterium, as candidates to reflect the soil fertility and the plant health. The highest abundance of multidrug resistance genes and the four mainly microbial resistance mechanisms (antibiotic efflux, antibiotic target protection, antibiotic target alteration, and antibiotic target replacement) in healthy poplar rhizosphere, corroborated the relationship between soil fertility and microbial activity. This result suggested that healthy rhizosphere soil harbored microbes with a higher capacity and had more complex microbial interaction network to promote plant growing and reduce intracellular levels of antibiotics. Our findings suggested a correlation between the plant degeneration gradient and bacterial communities, and provided insight into the role of high-turnover microbial communities as well as potential PGPB as real-time indicators of forestry soil quality, and demonstrated the inner interaction contributed by the bacterial communities.
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Competitive Exclusion and Metabolic Dependency among Microorganisms Structure the Cellulose Economy of an Agricultural Soil. mBio 2021; 12:mBio.03099-20. [PMID: 33402535 PMCID: PMC8545098 DOI: 10.1128/mbio.03099-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microorganisms that degrade cellulose utilize extracellular reactions that yield free by-products which can promote interactions with noncellulolytic organisms. We hypothesized that these interactions determine the ecological and physiological traits governing the fate of cellulosic carbon (C) in soil. We performed comparative genomics with genome bins from a shotgun metagenomic-stable isotope probing experiment to characterize the attributes of cellulolytic and noncellulolytic taxa accessing 13C from cellulose. We hypothesized that cellulolytic taxa would exhibit competitive traits that limit access, while noncellulolytic taxa would display greater metabolic dependency, such as signatures of adaptive gene loss. We tested our hypotheses by evaluating genomic traits indicative of competitive exclusion or metabolic dependency, such as antibiotic production, growth rate, surface attachment, biomass degrading potential, and auxotrophy. The most 13C-enriched taxa were cellulolytic Cellvibrio (Gammaproteobacteria) and Chaetomium (Ascomycota), which exhibited a strategy of self-sufficiency (prototrophy), rapid growth, and competitive exclusion via antibiotic production. Auxotrophy was more prevalent in cellulolytic Actinobacteria than in cellulolytic Proteobacteria, demonstrating differences in dependency among cellulose degraders. Noncellulolytic taxa that accessed 13C from cellulose (Planctomycetales, Verrucomicrobia, and Vampirovibrionales) were also more dependent, as indicated by patterns of auxotrophy and 13C labeling (i.e., partial labeling or labeling at later stages). Major 13C-labeled cellulolytic microbes (e.g., Sorangium, Actinomycetales, Rhizobiales, and Caulobacteraceae) possessed adaptations for surface colonization (e.g., gliding motility, hyphae, attachment structures) signifying the importance of surface ecology in decomposing particulate organic matter. Our results demonstrated that access to cellulosic C was accompanied by ecological trade-offs characterized by differing degrees of metabolic dependency and competitive exclusion.
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Wang Y, Zhu J, Fang J, Shen L, Ma S, Zhao Z, Yu W, Jiang W. Diversity, Composition and Functional Inference of Gut Microbiota in Indian Cabbage white Pieris canidia (Lepidoptera: Pieridae). Life (Basel) 2020; 10:E254. [PMID: 33113860 PMCID: PMC7692319 DOI: 10.3390/life10110254] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 10/23/2020] [Indexed: 11/17/2022] Open
Abstract
We characterized the gut microbial composition and relative abundance of gut bacteria in the larvae and adults of Pieris canidia by 16S rRNA gene sequencing. The gut microbiota structure was similar across the life stages and sexes. The comparative functional analysis on P. canidia bacterial communities with PICRUSt showed the enrichment of several pathways including those for energy metabolism, immune system, digestive system, xenobiotics biodegradation, transport, cell growth and death. The parameters often used as a proxy of insect fitness (development time, pupation rate, emergence rate, adult survival rate and weight of 5th instars larvae) showed a significant difference between treatment group and untreated group and point to potential fitness advantages with the gut microbiomes in P. canidia. These data provide an overall view of the bacterial community across the life stages and sexes in P. canidia.
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Affiliation(s)
- Ying Wang
- Laboratory of Environmental Entomology, College of Life Sciences, Shanghai Normal University, 100 Guilin Rd., Shanghai 200234, China; (Y.W.); (J.F.); (L.S.); (S.M.); (Z.Z.); (W.Y.)
| | - Jianqing Zhu
- Shanghai Zoological Park, 2381 Hongqiao Rd., Shanghai 200335, China;
| | - Jie Fang
- Laboratory of Environmental Entomology, College of Life Sciences, Shanghai Normal University, 100 Guilin Rd., Shanghai 200234, China; (Y.W.); (J.F.); (L.S.); (S.M.); (Z.Z.); (W.Y.)
| | - Li Shen
- Laboratory of Environmental Entomology, College of Life Sciences, Shanghai Normal University, 100 Guilin Rd., Shanghai 200234, China; (Y.W.); (J.F.); (L.S.); (S.M.); (Z.Z.); (W.Y.)
| | - Shuojia Ma
- Laboratory of Environmental Entomology, College of Life Sciences, Shanghai Normal University, 100 Guilin Rd., Shanghai 200234, China; (Y.W.); (J.F.); (L.S.); (S.M.); (Z.Z.); (W.Y.)
| | - Zimiao Zhao
- Laboratory of Environmental Entomology, College of Life Sciences, Shanghai Normal University, 100 Guilin Rd., Shanghai 200234, China; (Y.W.); (J.F.); (L.S.); (S.M.); (Z.Z.); (W.Y.)
| | - Weidong Yu
- Laboratory of Environmental Entomology, College of Life Sciences, Shanghai Normal University, 100 Guilin Rd., Shanghai 200234, China; (Y.W.); (J.F.); (L.S.); (S.M.); (Z.Z.); (W.Y.)
| | - Weibin Jiang
- Laboratory of Environmental Entomology, College of Life Sciences, Shanghai Normal University, 100 Guilin Rd., Shanghai 200234, China; (Y.W.); (J.F.); (L.S.); (S.M.); (Z.Z.); (W.Y.)
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15
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Silva Rabelo CAB, Okino CH, Sakamoto IK, Varesche MBA. Isolation of Paraclostridium CR4 from sugarcane bagasse and its evaluation in the bioconversion of lignocellulosic feedstock into hydrogen by monitoring cellulase gene expression. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 715:136868. [PMID: 32014768 DOI: 10.1016/j.scitotenv.2020.136868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 05/15/2023]
Abstract
Bioconversion of sugarcane bagasse (SCB) into hydrogen (H2) and organic acids was evaluated using a biomolecular approach to monitor the quantity and expression of the cellulase (Cel) gene. Batch reactors at 37 °C were operated with Paraclostridium sp. (10% v/v) and different substrates (5 g/L): glucose, cellulose and SCB in natura and pre-heat treated and hydrothermally. H2 production from glucose was 162.4 mL via acetic acid (2.9 g/L) and 78.4 mL from cellulose via butyric acid (2.9 g/L). H2 production was higher in hydrothermally pretreated SCB reactors (92.0 mL), heat treated (62.5 mL), when compared to in natura SCB (51.4 mL). Butyric acid (5.8, 4.9 and 4.0 g/L) was the main acid observed in hydrothermally, thermally pretreated, and in natura SCB, respectively. In the reactors with cellulose and reactors with hydrothermally pretreated SCB, the Cel gene copy number 3 and 2 log were higher, respectively, during the stage of maximum H2 production rate, when compared to the initial stage. Differences in Cel gene expression were observed according to the concentration of soluble sugars in the reaction medium. That is, there was no gene expression at the initial phase of the experiment using SCB with 2.6 g/L of sugars and increase of 2.2 log in gene expression during the phases with soluble sugars of <1.4 g/L.
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Affiliation(s)
- Camila Abreu B Silva Rabelo
- Laboratory of Biological Processes, Department of Hydraulics and Sanitation, Engineering School of São Carlos, University of São Paulo (EESC - USP) Campus II, São Carlos, SP CEP 13563-120, Brazil.
| | - Cintia Hiromi Okino
- Embrapa Pecuária Sudeste, Rod Washington Luiz, Km 234, Fazenda Canchim, PO Box 339, São Carlos, SP, Brazil
| | - Isabel Kimiko Sakamoto
- Laboratory of Biological Processes, Department of Hydraulics and Sanitation, Engineering School of São Carlos, University of São Paulo (EESC - USP) Campus II, São Carlos, SP CEP 13563-120, Brazil
| | - Maria Bernadete Amâncio Varesche
- Laboratory of Biological Processes, Department of Hydraulics and Sanitation, Engineering School of São Carlos, University of São Paulo (EESC - USP) Campus II, São Carlos, SP CEP 13563-120, Brazil
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16
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Shi W, Li M, Wei G, Tian R, Li C, Wang B, Lin R, Shi C, Chi X, Zhou B, Gao Z. The occurrence of potato common scab correlates with the community composition and function of the geocaulosphere soil microbiome. MICROBIOME 2019; 7:14. [PMID: 30709420 PMCID: PMC6359780 DOI: 10.1186/s40168-019-0629-2] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 01/17/2019] [Indexed: 05/17/2023]
Abstract
BACKGROUND Soil microorganisms can mediate the occurrence of plant diseases. Potato common scab (CS) is a refractory disease caused by pathogenic Streptomyces that occurs worldwide, but little is known about the interactions between CS and the soil microbiome. In this study, four soil-root system compartments (geocaulosphere soil (GS), rhizosphere soil (RS), root-zone soil (ZS), and furrow soil (FS)) were analyzed for potato plants with naturally high (H) and low (L) scab severity levels. We aimed to determine the composition and putative function of the soil microbiome associated with potato CS. RESULTS The copy numbers of the scab phytotoxin biosynthetic gene txtAB and the bacterial 16S rRNA gene as well as the diversity and composition of each of the four soil-root system compartments were examined; GS was the only compartment that exhibited significant differences between the H and L groups. Compared to the H group, the L group exhibited a lower txtAB gene copy number, lower bacterial 16S copy number, higher diversity, higher co-occurrence network complexity, and higher community function similarity within the GS microbiome. The community composition and function of the GS samples were further revealed by shotgun metagenomic sequencing. Variovorax, Stenotrophomonas, and Agrobacterium were the most abundant genera that were significantly and positively correlated with the scab severity level, estimated absolute abundance (EAA) of pathogenic Streptomyces, and txtAB gene copy number. In contrast, Geobacillus, Curtobacterium, and unclassified Geodermatophilaceae were significantly negatively correlated with these three parameters. Compared to the function profiles in the L group, several genes involved in "ABC transporters," the "bacterial secretion system," "quorum sensing (QS)," "nitrogen metabolism," and some metabolism by cytochrome P450 were enriched in the H group. In contrast, some antibiotic biosynthesis pathways were enriched in the L group. Based on the differences in community composition and function, a simple model was proposed to explain the putative relationships between the soil microbiome and CS occurrence. CONCLUSIONS The GS microbiome was closely associated with CS severity in the soil-root system, and the occurrence of CS was accompanied by changes in community composition and function. The differential functions provide new clues to elucidate the mechanism underlying the interaction between CS occurrence and the soil microbiome, and varying community compositions provide novel insights into CS occurrence.
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Affiliation(s)
- Wencong Shi
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, 271018, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Mingcong Li
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, 271018, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Guangshan Wei
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, SOA, Xiamen, 361005, China
- South China Sea Resource Exploitation and Protection Collaborative Innovation Center (SCS-REPIC), Sun Yat-Sen University, Guangzhou, 510275, China
| | - Renmao Tian
- Department of Botany and Microbiology, Institute for Environmental Genomics, University of Oklahoma, Norman, USA
| | - Cuiping Li
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, 271018, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Bing Wang
- College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
- National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Tai'an, 271018, China
| | - Rongshan Lin
- College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
- National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Tai'an, 271018, China
| | - Chunyu Shi
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, 271018, China
- College of Agronomy, Shandong Agricultural University, Tai'an, 271018, China
| | - Xiuli Chi
- Plant Protection Station, Jiaozhou Agricultural Bureau, Qingdao, 266300, China
| | - Bo Zhou
- College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China.
- National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Tai'an, 271018, China.
| | - Zheng Gao
- State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, 271018, China.
- College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China.
- Department of Botany and Microbiology, Institute for Environmental Genomics, University of Oklahoma, Norman, USA.
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17
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Yin Y, Gu J, Wang X, Song W, Zhang K, Zhang X, Lu C, Liu J. Effects of chromium(III) on enzyme activities and bacterial communities during swine manure composting. BIORESOURCE TECHNOLOGY 2017; 243:693-699. [PMID: 28709075 DOI: 10.1016/j.biortech.2017.06.169] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/26/2017] [Accepted: 06/29/2017] [Indexed: 05/25/2023]
Abstract
The present study investigated the effects of different concentrations of chromium (i.e., 200 and 700mgkg-1 Cr corresponding to Cr200 and Cr700, respectively) on the microorganisms in swine manure compost. The results demonstrated that a high concentration of Cr(III) could inhibit the activity of key microbial enzymes (i.e., dehydrogenase, cellulase, and urease) in the early composting stages, with maximal inhibition rates of 54.9%, 32.8%, and 46.7% for cellulase, urease, and dehydrogenase, respectively. Furthermore, the bacterial abundances were determined by quantitative PCR and their compositions were evaluated by denaturing gradient gel electrophoresis. Cr200 and Cr700 had significant inhibitory effects on the abundances of bacteria. The DGGE results showed that Cr200 and Cr700 changed the bacterial community structure and diversity, where Cr(III) might enhance the abundance of pathogenic bacteria (e.g., Saccharomonospora) and decrease the abundances of bacteria that degrade cellulose and lignin (e.g., Paenibacillus) during composting.
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Affiliation(s)
- Yanan Yin
- College of Resources and Environmental Sciences, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Jie Gu
- College of Resources and Environmental Sciences, Northwest A & F University, Yangling, Shaanxi 712100, China; Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi 712100, China.
| | - Xiaojuan Wang
- College of Resources and Environmental Sciences, Northwest A & F University, Yangling, Shaanxi 712100, China; Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Wen Song
- College of Science, Northwest A&F University, Yangling 712100, China
| | - Kaiyu Zhang
- College of Resources and Environmental Sciences, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Xin Zhang
- College of Science, Northwest A&F University, Yangling 712100, China
| | - Chunya Lu
- College of Resources and Environmental Sciences, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Jiayao Liu
- College of Resources and Environmental Sciences, Northwest A & F University, Yangling, Shaanxi 712100, China
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Djemiel C, Grec S, Hawkins S. Characterization of Bacterial and Fungal Community Dynamics by High-Throughput Sequencing (HTS) Metabarcoding during Flax Dew-Retting. Front Microbiol 2017; 8:2052. [PMID: 29104570 PMCID: PMC5655573 DOI: 10.3389/fmicb.2017.02052] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 10/06/2017] [Indexed: 11/13/2022] Open
Abstract
Flax dew-retting is a key step in the industrial extraction of fibers from flax stems and is dependent upon the production of a battery of hydrolytic enzymes produced by micro-organisms during this process. To explore the diversity and dynamics of bacterial and fungal communities involved in this process we applied a high-throughput sequencing (HTS) DNA metabarcoding approach (16S rRNA/ITS region, Illumina Miseq) on plant and soil samples obtained over a period of 7 weeks in July and August 2014. Twenty-three bacterial and six fungal phyla were identified in soil samples and 11 bacterial and four fungal phyla in plant samples. Dominant phyla were Proteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes (bacteria) and Ascomycota, Basidiomycota, and Zygomycota (fungi) all of which have been previously associated with flax dew-retting except for Bacteroidetes and Basidiomycota that were identified for the first time. Rare phyla also identified for the first time in this process included Acidobacteria, CKC4, Chlorobi, Fibrobacteres, Gemmatimonadetes, Nitrospirae and TM6 (bacteria), and Chytridiomycota (fungi). No differences in microbial communities and colonization dynamics were observed between early and standard flax harvests. In contrast, the common agricultural practice of swath turning affects both bacterial and fungal community membership and structure in straw samples and may contribute to a more uniform retting. Prediction of community function using PICRUSt indicated the presence of a large collection of potential bacterial enzymes capable of hydrolyzing backbones and side-chains of cell wall polysaccharides. Assignment of functional guild (functional group) using FUNGuild software highlighted a change from parasitic to saprophytic trophic modes in fungi during retting. This work provides the first exhaustive description of the microbial communities involved in flax dew-retting and will provide a valuable benchmark in future studies aiming to evaluate the effects of other parameters (e.g., year-to year and site variability etc.) on this complex process.
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Affiliation(s)
- Christophe Djemiel
- Univ. Lille, Centre National de la Recherche Scientifique, UMR 8576 - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Sébastien Grec
- Univ. Lille, Centre National de la Recherche Scientifique, UMR 8576 - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Simon Hawkins
- Univ. Lille, Centre National de la Recherche Scientifique, UMR 8576 - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
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Montella S, Ventorino V, Lombard V, Henrissat B, Pepe O, Faraco V. Discovery of genes coding for carbohydrate-active enzyme by metagenomic analysis of lignocellulosic biomasses. Sci Rep 2017; 7:42623. [PMID: 28198423 PMCID: PMC5309792 DOI: 10.1038/srep42623] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 01/13/2017] [Indexed: 12/03/2022] Open
Abstract
In this study, a high-throughput sequencing approach was applied to discover novel biocatalysts for lignocellulose hydrolysis from three dedicated energy crops, Arundo donax, Eucalyptus camaldulensis and Populus nigra, after natural biodegradation. The microbiomes of the three lignocellulosic biomasses were dominated by bacterial species (approximately 90%) with the highest representation by the Streptomyces genus both in the total microbial community composition and in the microbial diversity related to GH families of predicted ORFs. Moreover, the functional clustering of the predicted ORFs showed a prevalence of poorly characterized genes, suggesting these lignocellulosic biomasses are potential sources of as yet unknown genes. 1.2%, 0.6% and 3.4% of the total ORFs detected in A. donax, E. camaldulensis and P. nigra, respectively, were putative Carbohydrate-Active Enzymes (CAZymes). Interestingly, the glycoside hydrolases abundance in P. nigra (1.8%) was higher than that detected in the other biomasses investigated in this study. Moreover, a high percentage of (hemi)cellulases with different activities and accessory enzymes (mannanases, polygalacturonases and feruloyl esterases) was detected, confirming that the three analyzed samples were a reservoir of diversified biocatalysts required for an effective lignocellulose saccharification.
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Affiliation(s)
- Salvatore Montella
- Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, via Cintia, 4 80126 Naples, Italy
| | - Valeria Ventorino
- Department of Agricultural Sciences, University of Naples "Federico II", Portici (Napoli), Italy
| | - Vincent Lombard
- CNRS UMR 7257, Aix-Marseille University, 13288 Marseille, France.,INRA, USC 1408 AFMB, 13288 Marseille, France
| | - Bernard Henrissat
- CNRS UMR 7257, Aix-Marseille University, 13288 Marseille, France.,INRA, USC 1408 AFMB, 13288 Marseille, France.,Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Olimpia Pepe
- Department of Agricultural Sciences, University of Naples "Federico II", Portici (Napoli), Italy
| | - Vincenza Faraco
- Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, via Cintia, 4 80126 Naples, Italy
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Ben Guerrero E, Soria M, Salvador R, Ceja-Navarro JA, Campos E, Brodie EL, Talia P. Effect of Different Lignocellulosic Diets on Bacterial Microbiota and Hydrolytic Enzyme Activities in the Gut of the Cotton Boll Weevil ( Anthonomus grandis). Front Microbiol 2016; 7:2093. [PMID: 28082962 PMCID: PMC5186755 DOI: 10.3389/fmicb.2016.02093] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 12/09/2016] [Indexed: 11/13/2022] Open
Abstract
Cotton boll weevils, Anthonomus grandis, are omnivorous coleopteran that can feed on diets with different compositions, including recalcitrant lignocellulosic materials. We characterized the changes in the prokaryotic community structure and the hydrolytic activities of A. grandis larvae fed on different lignocellulosic diets. A. grandis larvae were fed on three different artificial diets: cottonseed meal (CM), Napier grass (NG) and corn stover (CS). Total DNA was extracted from the gut samples for amplification and sequencing of the V3-V4 hypervariable region of the 16S rRNA gene. Proteobacteria and Firmicutes dominated the gut microbiota followed by Actinobacteria, Spirochaetes and a small number of unclassified phyla in CM and NG microbiomes. In the CS feeding group, members of Spirochaetes were the most prevalent, followed by Proteobacteria and Firmicutes. Bray-Curtis distances showed that the samples from the CS community were clearly separated from those samples of the CM and NG diets. Gut extracts from all three diets exhibited endoglucanase, xylanase, β-glucosidase and pectinase activities. These activities were significantly affected by pH and temperature across different diets. We observed that the larvae reared on a CM showed significantly higher activities than larvae reared on NG and CS. We demonstrated that the intestinal bacterial community structure varies depending on diet composition. Diets with more variable and complex compositions, such as CS, showed higher bacterial diversity and richness than the two other diets. In spite of the detected changes in composition and diversity, we identified a core microbiome shared between the three different lignocellulosic diets. These results suggest that feeding with diets of different lignocellulosic composition could be a viable strategy to discover variants of hemicellulose and cellulose breakdown systems.
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Affiliation(s)
- Emiliano Ben Guerrero
- Instituto de Biotecnología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Centro Nacional de Investigaciones Agropecuarias - Instituto Nacional de Tecnología Agropecuaria Castelar Hurlingham, Argentina
| | - Marcelo Soria
- Instituto de Investigaciones en Biociencias Agrícolas y Ambientales-Consejo Nacional de Investigaciones Científicas y Técnicas, Cátedra de Microbiología Agrícola, Facultad de Agronomía, Universidad de Buenos Aires Buenos Aires, Argentina
| | - Ricardo Salvador
- Instituto de Microbiología y Zoología Agrícola, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Centro Nacional de Investigaciones Agropecuarias - Instituto Nacional de Tecnología Agropecuaria Castelar Hurlingham, Argentina
| | - Javier A Ceja-Navarro
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory Berkeley, CA, USA
| | - Eleonora Campos
- Instituto de Biotecnología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Centro Nacional de Investigaciones Agropecuarias - Instituto Nacional de Tecnología Agropecuaria CastelarHurlingham, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)Buenos Aires, Argentina
| | - Eoin L Brodie
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory Berkeley, CA, USA
| | - Paola Talia
- Instituto de Biotecnología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Centro Nacional de Investigaciones Agropecuarias - Instituto Nacional de Tecnología Agropecuaria CastelarHurlingham, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)Buenos Aires, Argentina
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Wang W, Wang H, Feng Y, Wang L, Xiao X, Xi Y, Luo X, Sun R, Ye X, Huang Y, Zhang Z, Cui Z. Consistent responses of the microbial community structure to organic farming along the middle and lower reaches of the Yangtze River. Sci Rep 2016; 6:35046. [PMID: 27725750 PMCID: PMC5057158 DOI: 10.1038/srep35046] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 09/15/2016] [Indexed: 12/17/2022] Open
Abstract
Soil microorganisms play a crucial role in the biogeochemical cycling of nutrient elements and maintaining soil health. We aimed to investigate the response of bacteria communities to organic farming over different crops (rice, tea and vegetable) along the middle and lower reaches of the Yangtze River of China. Compared with conventional farming, organic farming significantly increased soil nutrients, soil enzyme activities, and bacterial richness and diversity. A Venn diagram and principal component analysis revealed that the soils with 3 different crops under organic farming have more number and percent of shared OTUs (operational taxonomic units), and shared a highly similar microbial community structure. Under organic farming, several predominant guilds and major bacterial lineages (Rhizobiales, Thiotrichaceae, Micromonosporaceae, Desulfurellaceae and Myxococcales) contributing to nutrient (C, N, S and P) cycling were enriched, whereas the relative abundances of acid and alkali resistant microorganisms (Acidobacteriaceae and Sporolactobacillaceae) were increased under conventional farming practices. Our results indicated that, for all three crops, organic farming have a more stable microflora and the uniformity of the bacterial community structure. Organic agriculture significantly increased the abundance of some nutrition-related bacteria, while reducing some of the abundance of acid and alkali resistant bacteria.
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Affiliation(s)
- Wenhui Wang
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Hui Wang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Youzhi Feng
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Lei Wang
- Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Nanjing 210042, China
| | - Xingji Xiao
- Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Nanjing 210042, China
| | - Yunguan Xi
- Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Nanjing 210042, China
| | - Xue Luo
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Ruibo Sun
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Xianfeng Ye
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yan Huang
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhengguang Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhongli Cui
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
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Characterization of three plant biomass-degrading microbial consortia by metagenomics- and metasecretomics-based approaches. Appl Microbiol Biotechnol 2016; 100:10463-10477. [PMID: 27418359 PMCID: PMC5119850 DOI: 10.1007/s00253-016-7713-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 06/16/2016] [Accepted: 06/27/2016] [Indexed: 02/01/2023]
Abstract
The selection of microbes by enrichment on plant biomass has been proposed as an efficient way to develop new strategies for lignocellulose saccharification. Here, we report an in-depth analysis of soil-derived microbial consortia that were trained to degrade once-used wheat straw (WS1-M), switchgrass (SG-M) and corn stover (CS-M) under aerobic and mesophilic conditions. Molecular fingerprintings, bacterial 16S ribosomal RNA (rRNA) gene amplicon sequencing and metagenomic analyses showed that the three microbial consortia were taxonomically distinct. Based on the taxonomic affiliation of protein-encoding sequences, members of the Bacteroidetes (e.g. Chryseobacterium, Weeksella, Flavobacterium and Sphingobacterium) were preferentially selected on WS1-M, whereas SG-M and CS-M favoured members of the Proteobacteria (e.g. Caulobacter, Brevundimonas, Stenotrophomonas and Xanthomonas). The highest degradation rates of lignin (~59 %) were observed with SG-M, whereas CS-M showed a high consumption of cellulose and hemicellulose. Analyses of the carbohydrate-active enzymes in the three microbial consortia showed the dominance of glycosyl hydrolases (e.g. of families GH3, GH43, GH13, GH10, GH29, GH28, GH16, GH4 and GH92). In addition, proteins of families AA6, AA10 and AA2 were detected. Analysis of secreted protein fractions (metasecretome) for each selected microbial consortium mainly showed the presence of enzymes able to degrade arabinan, arabinoxylan, xylan, β-glucan, galactomannan and rhamnogalacturonan. Notably, these metasecretomes contain enzymes that enable us to produce oligosaccharides directly from wheat straw, sugarcane bagasse and willow. Thus, the underlying microbial consortia constitute valuable resources for the production of enzyme cocktails for the efficient saccharification of plant biomass.
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Cellulose and hemicellulose decomposition by forest soil bacteria proceeds by the action of structurally variable enzymatic systems. Sci Rep 2016; 6:25279. [PMID: 27125755 PMCID: PMC4850484 DOI: 10.1038/srep25279] [Citation(s) in RCA: 192] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 04/14/2016] [Indexed: 12/22/2022] Open
Abstract
Evidence shows that bacteria contribute actively to the decomposition of cellulose and hemicellulose in forest soil; however, their role in this process is still unclear. Here we performed the screening and identification of bacteria showing potential cellulolytic activity from litter and organic soil of a temperate oak forest. The genomes of three cellulolytic isolates previously described as abundant in this ecosystem were sequenced and their proteomes were characterized during the growth on plant biomass and on microcrystalline cellulose. Pedobacter and Mucilaginibacter showed complex enzymatic systems containing highly diverse carbohydrate-active enzymes for the degradation of cellulose and hemicellulose, which were functionally redundant for endoglucanases, β-glucosidases, endoxylanases, β-xylosidases, mannosidases and carbohydrate-binding modules. Luteibacter did not express any glycosyl hydrolases traditionally recognized as cellulases. Instead, cellulose decomposition was likely performed by an expressed GH23 family protein containing a cellulose-binding domain. Interestingly, the presence of plant lignocellulose as well as crystalline cellulose both trigger the production of a wide set of hydrolytic proteins including cellulases, hemicellulases and other glycosyl hydrolases. Our findings highlight the extensive and unexplored structural diversity of enzymatic systems in cellulolytic soil bacteria and indicate the roles of multiple abundant bacterial taxa in the decomposition of cellulose and other plant polysaccharides.
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24
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Nguyen TM, Kim J. Description of Variovorax humicola sp. nov., isolated from a forest topsoil. Int J Syst Evol Microbiol 2016; 66:2520-2527. [PMID: 27082126 DOI: 10.1099/ijsem.0.001082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Employing a modified cultivation method, we studied two bacterial strains, UC10 and UC38T, found on the Kyonggi University campus, Suwon in Gyeonggi-Do province, South Korea. These strains were non-spore-forming, Gram-stain-negative, motile and rod-shaped. Growth occurred in the presence of 0-2 % (w/v) NaCl, at pH 4-9 and a temperature range of 4-35 °C. On an R2A agar plate incubated for 5 days at 28 °C, irregular, raised and pale-yellowish colonies were observed. Comparative analysis of nearly full-length 16S rRNA gene sequences indicated that these strains were closely related to Variovorax guangxiensis GXGD002T, with 98.6 % similarity. Strains UC10 and UC38T were 98.0 % similar to V.ariovorax soli GH9-3T; 97.8 % to V.ariovorax dokdonensis DS-43T; 97.3-97.7 % to V.ariovorax ginsengisoli Gsoil 3165T; 97.7-98.0 % to V.ariovorax paradoxus IAM 12373T; 97.4-97.6 % to V.ariovorax defluvii 2C1-bT; and 97.3-97.4 % to V.ariovorax boronicumulans BAM-48T. The predominant ubiquinone was Q-8. The primary polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids were C16 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C17 : 0 cyclo. DNA-DNA hybridization assays indicated 89.2-91.4 % genomic DNA similarity between strains UC10 and UC38T. Moreover, genomic DNA similarity between these novel strains and reference strains of the genus Variovoraxwas less than the 70 %. Based on these results, strain UC38T was designated a representative of a novel species of the genus Variovorax, with the proposed name Variovorax humicola sp. nov. The type strain is UC38T (=KACC 18501T=NBRC 111520T).
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Affiliation(s)
- Tuan Manh Nguyen
- Department of Life Science, College of Natural Sciences, Kyonggi University, Gyeonggi-Do 443-760, South Korea.,Thai Nguyen University of Agriculture and Forestry, Quyet Thang commune, Thai Nguyen City, Vietnam
| | - Jaisoo Kim
- Department of Life Science, College of Natural Sciences, Kyonggi University, Gyeonggi-Do 443-760, South Korea
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25
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Leung HTC, Maas KR, Wilhelm RC, Mohn WW. Long-term effects of timber harvesting on hemicellulolytic microbial populations in coniferous forest soils. THE ISME JOURNAL 2016; 10:363-75. [PMID: 26274049 PMCID: PMC4737928 DOI: 10.1038/ismej.2015.118] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 06/03/2015] [Accepted: 06/04/2015] [Indexed: 11/09/2022]
Abstract
Forest ecosystems need to be sustainably managed, as they are major reservoirs of biodiversity, provide important economic resources and modulate global climate. We have a poor knowledge of populations responsible for key biomass degradation processes in forest soils and the effects of forest harvesting on these populations. Here, we investigated the effects of three timber-harvesting methods, varying in the degree of organic matter removal, on putatively hemicellulolytic bacterial and fungal populations 10 or more years after harvesting and replanting. We used stable-isotope probing to identify populations that incorporated (13)C from labeled hemicellulose, analyzing (13)C-enriched phospholipid fatty acids, bacterial 16 S rRNA genes and fungal ITS regions. In soil microcosms, we identified 104 bacterial and 52 fungal hemicellulolytic operational taxonomic units (OTUs). Several of these OTUs are affiliated with taxa not previously reported to degrade hemicellulose, including the bacterial genera Methylibium, Pelomonas and Rhodoferax, and the fungal genera Cladosporium, Pseudeurotiaceae, Capronia, Xenopolyscytalum and Venturia. The effect of harvesting on hemicellulolytic populations was evaluated based on in situ bacterial and fungal OTUs. Harvesting treatments had significant but modest long-term effects on relative abundances of hemicellulolytic populations, which differed in strength between two ecozones and between soil layers. For soils incubated in microcosms, prior harvesting treatments did not affect the rate of incorporation of hemicellulose carbon into microbial biomass. In six ecozones across North America, distributions of the bacterial hemicellulolytic OTUs were similar, whereas distributions of fungal ones differed. Our work demonstrates that diverse taxa in soil are hemicellulolytic, many of which are differentially affected by the impact of harvesting on environmental conditions. However, the hemicellulolytic capacity of soil communities appears resilient.
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Affiliation(s)
- Hilary T C Leung
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kendra R Maas
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Roland C Wilhelm
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - William W Mohn
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
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26
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Ventorino V, Parillo R, Testa A, Viscardi S, Espresso F, Pepe O. Chestnut green waste composting for sustainable forest management: Microbiota dynamics and impact on plant disease control. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2016; 166:168-77. [PMID: 26496847 DOI: 10.1016/j.jenvman.2015.10.018] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 09/25/2015] [Accepted: 10/11/2015] [Indexed: 05/03/2023]
Abstract
Making compost from chestnut lignocellulosic waste is a possible sustainable management strategy for forests that employs a high-quality renewable organic resource. Characterization of the microbiota involved in composting is essential to better understand the entire process as well as the properties of the final product. Therefore, this study investigated the microbial communities involved in the composting of chestnut residues obtained from tree cleaning and pruning. The culture-independent approach taken highlighted the fact that the microbiota varied only slightly during the process, with the exception of those of the starting substrate and mature compost. The statistical analysis indicated that most of the bacterial and fungal species in the chestnut compost persisted during composting. The dominant microbial population detected during the process belonged to genera known to degrade recalcitrant lignocellulosic materials. Specifically, we identified fungal genera, such as Penicillium, Fusarium, Cladosporium, Aspergillus and Mucor, and prokaryotic species affiliated with Bacilli, Actinobacteria, Flavobacteria and γ-Proteobacteria. The suppressive properties of compost supplements for the biocontrol of Sclerotinia minor and Rhizoctonia solani were also investigated. Compared to pure substrate, the addition of compost to the peat-based growth substrates resulted in a significant reduction of disease in tomato plants of up to 70 % or 51 % in the presence of Sclerotinia minor or Rhizoctonia solani, respectively. The obtained results were related to the presence of putative bio-control agents and plant growth-promoting rhizobacteria belonging to the genera Azotobacter, Pseudomonas, Stenotrophomonas, Bacillus, Flavobacterium, Streptomyces and Actinomyces in the chestnut compost. The composting of chestnut waste may represent a sustainable agricultural practice for disposing of lignocellulosic waste by transforming it into green waste compost that can be used to improve the fitness of agricultural plants.
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Affiliation(s)
- Valeria Ventorino
- Department of Agriculture, Division of Microbiology, University of Naples Federico II, Via Università, 100, 80055, Portici, NA, Italy
| | - Rita Parillo
- Department of Agriculture, Division of Biology and Protection of Agricultural and Forest Systems, University of Naples Federico II, Via Università, 100, 80055, Portici, NA, Italy
| | - Antonino Testa
- Department of Agriculture, Division of Biology and Protection of Agricultural and Forest Systems, University of Naples Federico II, Via Università, 100, 80055, Portici, NA, Italy
| | - Sharon Viscardi
- Department of Agriculture, Division of Microbiology, University of Naples Federico II, Via Università, 100, 80055, Portici, NA, Italy
| | - Francesco Espresso
- Department of Agriculture, Division of Microbiology, University of Naples Federico II, Via Università, 100, 80055, Portici, NA, Italy
| | - Olimpia Pepe
- Department of Agriculture, Division of Microbiology, University of Naples Federico II, Via Università, 100, 80055, Portici, NA, Italy.
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27
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Dias M, Melo M, Schwan R, Silva C. A new alternative use for coffee pulp from semi-dry process to β-glucosidase production by Bacillus subtilis. Lett Appl Microbiol 2015; 61:588-95. [DOI: 10.1111/lam.12498] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 09/10/2015] [Accepted: 09/14/2015] [Indexed: 11/29/2022]
Affiliation(s)
- M. Dias
- Department of Biology; Federal University of Lavras; Lavras MG Brazil
| | - M.M. Melo
- Department of Biology; Federal University of Lavras; Lavras MG Brazil
| | - R.F. Schwan
- Department of Biology; Federal University of Lavras; Lavras MG Brazil
| | - C.F. Silva
- Department of Biology; Federal University of Lavras; Lavras MG Brazil
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28
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Prospection and Evaluation of (Hemi) Cellulolytic Enzymes Using Untreated and Pretreated Biomasses in Two Argentinean Native Termites. PLoS One 2015; 10:e0136573. [PMID: 26313257 PMCID: PMC4552170 DOI: 10.1371/journal.pone.0136573] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 08/04/2015] [Indexed: 01/30/2023] Open
Abstract
Saccharum officinarum bagasse (common name: sugarcane bagasse) and Pennisetum purpureum (also known as Napier grass) are among the most promising feedstocks for bioethanol production in Argentina and Brazil. In this study, both biomasses were assessed before and after acid pretreatment and following hydrolysis with Nasutitermes aquilinus and Cortaritermes fulviceps termite gut digestome. The chemical composition analysis of the biomasses after diluted acid pretreatment showed that the hemicellulose fraction was partially removed. The (hemi) cellulolytic activities were evaluated in bacterial culture supernatants of termite gut homogenates grown in treated and untreated biomasses. In all cases, we detected significantly higher endoglucanase and xylanase activities using pretreated biomasses compared to untreated biomasses, carboxymethylcellulose and xylan. Several protein bands with (hemi) cellulolytic activity were detected in zymograms and two-dimensional gel electrophoresis. Some proteins of these bands or spots were identified as xylanolytic peptides by mass spectrometry. Finally, the diversity of cultured cellulolytic bacterial endosymbionts associated to both Argentinean native termite species was analyzed. This study describes, for the first time, bacterial endosymbionts and endogenous (hemi) cellulases of two Argentinean native termites as well as their potential application in degradation of lignocellulosic biomass for bioethanol production.
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Wang X, Sharp CE, Jones GM, Grasby SE, Brady AL, Dunfield PF. Stable-Isotope Probing Identifies Uncultured Planctomycetes as Primary Degraders of a Complex Heteropolysaccharide in Soil. Appl Environ Microbiol 2015; 81:4607-15. [PMID: 25934620 PMCID: PMC4551180 DOI: 10.1128/aem.00055-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 04/23/2015] [Indexed: 11/20/2022] Open
Abstract
The exopolysaccharides (EPSs) produced by some bacteria are potential growth substrates for other bacteria in soil. We used stable-isotope probing (SIP) to identify aerobic soil bacteria that assimilated the cellulose produced by Gluconacetobacter xylinus or the EPS produced by Beijerinckia indica. The latter is a heteropolysaccharide comprised primarily of l-guluronic acid, d-glucose, and d-glycero-d-mannoheptose. (13)C-labeled EPS and (13)C-labeled cellulose were purified from bacterial cultures grown on [(13)C]glucose. Two soils were incubated with these substrates, and bacteria actively assimilating them were identified via pyrosequencing of 16S rRNA genes recovered from (13)C-labeled DNA. Cellulose C was assimilated primarily by soil bacteria closely related (93 to 100% 16S rRNA gene sequence identities) to known cellulose-degrading bacteria. However, B. indica EPS was assimilated primarily by bacteria with low identities (80 to 95%) to known species, particularly by different members of the phylum Planctomycetes. In one incubation, members of the Planctomycetes made up >60% of all reads in the labeled DNA and were only distantly related (<85% identity) to any described species. Although it is impossible with SIP to completely distinguish primary polysaccharide hydrolyzers from bacteria growing on produced oligo- or monosaccharides, the predominance of Planctomycetes suggested that they were primary degraders of EPS. Other bacteria assimilating B. indica EPS included members of the Verrucomicrobia, candidate division OD1, and the Armatimonadetes. The results indicate that some uncultured bacteria in soils may be adapted to using complex heteropolysaccharides for growth and suggest that the use of these substrates may provide a means for culturing new species.
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Affiliation(s)
- Xiaoqing Wang
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Christine E Sharp
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Gareth M Jones
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | | | - Allyson L Brady
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Peter F Dunfield
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
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30
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Butera G, Ferraro C, Alonzo G, Colazza S, Quatrini P. The gut microbiota of the wood-feeding termite Reticulitermes lucifugus (Isoptera; Rhinotermitidae). ANN MICROBIOL 2015. [DOI: 10.1007/s13213-015-1101-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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31
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Genome Assemblies of Three Soil-Associated Devosia species: D. insulae, D. limi, and D. soli. GENOME ANNOUNCEMENTS 2015; 3:3/3/e00514-15. [PMID: 25999556 PMCID: PMC4440970 DOI: 10.1128/genomea.00514-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Agricultural soils constitute highly diverse ecosystems with very rich bacterial populations. Recent studies employing next-generation sequencing techniques have begun to explore the dynamics of bacterial species of such soils and utilized metagenomics approaches to understand how the diversity in soil microorganisms is affected or modified by agricultural practices. Understanding any microorganism's environmental adaptability in the genomic era starts by fully appreciating their encoding genome. Here, we report the draft genome sequences of three Devosia species based on three type strains that originated from soil samples: D. insulae strain DS-56, D. limi strain DSM17137, and D. soli strain GH2-10.
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32
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Benskin CMH, Rhodes G, Pickup RW, Mainwaring MC, Wilson K, Hartley IR. Life history correlates of fecal bacterial species richness in a wild population of the blue tit Cyanistes caeruleus. Ecol Evol 2015; 5:821-35. [PMID: 25750710 PMCID: PMC4338966 DOI: 10.1002/ece3.1384] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 12/04/2014] [Indexed: 11/24/2022] Open
Abstract
Very little is known about the normal gastrointestinal flora of wild birds, or how it might affect or reflect the host's life-history traits. The aim of this study was to survey the species richness of bacteria in the feces of a wild population of blue tits Cyanistes caeruleus and to explore the relationships between bacterial species richness and various life-history traits, such as age, sex, and reproductive success. Using PCR-TGGE, 55 operational taxonomic units (OTUs) were identified in blue tit feces. DNA sequencing revealed that the 16S rRNA gene was amplified from a diverse range of bacteria, including those that shared closest homology with Bacillus licheniformis, Campylobacter lari, Pseudomonas spp., and Salmonella spp. For adults, there was a significant negative relationship between bacterial species richness and the likelihood of being detected alive the following breeding season; bacterial richness was consistent across years but declined through the breeding season; and breeding pairs had significantly more similar bacterial richness than expected by chance alone. Reduced adult survival was correlated with the presence of an OTU most closely resembling C. lari; enhanced adult survival was associated with an OTU most similar to Arthrobacter spp. For nestlings, there was no significant change in bacterial species richness between the first and second week after hatching, and nestlings sharing the same nest had significantly more similar bacterial richness. Collectively, these results provide compelling evidence that bacterial species richness was associated with several aspects of the life history of their hosts.
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Affiliation(s)
| | - Glenn Rhodes
- Centre for Ecology and Hydrology, Lancaster Environment Centre Library Avenue, Bailrigg, Lancaster, LA1 4AP, UK
| | - Roger W Pickup
- Division of Biomedical and Life Sciences, School of Health and Medicine, Lancaster University Lancaster, LA1 4YQ, UK
| | - Mark C Mainwaring
- Lancaster Environment Centre, Lancaster University Lancaster, LA1 4YQ, UK
| | - Kenneth Wilson
- Lancaster Environment Centre, Lancaster University Lancaster, LA1 4YQ, UK
| | - Ian R Hartley
- Lancaster Environment Centre, Lancaster University Lancaster, LA1 4YQ, UK
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Isolation and characterization of Achromobacter sp. CX2 from symbiotic Cytophagales, a non-cellulolytic bacterium showing synergism with cellulolytic microbes by producing β-glucosidase. ANN MICROBIOL 2014. [DOI: 10.1007/s13213-014-1009-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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34
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Dias M, da Cruz Pedrozo Miguel MG, Duarte WF, Silva CF, Schwan RF. Epiphytic bacteria biodiversity in Brazilian Cerrado fruit and their cellulolytic activity potential. ANN MICROBIOL 2014. [DOI: 10.1007/s13213-014-0927-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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35
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Campos E, Negro Alvarez MJ, Sabarís di Lorenzo G, Gonzalez S, Rorig M, Talia P, Grasso DH, Sáez F, Manzanares Secades P, Ballesteros Perdices M, Cataldi AA. Purification and characterization of a GH43 β-xylosidase from Enterobacter sp. identified and cloned from forest soil bacteria. Microbiol Res 2014; 169:213-20. [DOI: 10.1016/j.micres.2013.06.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 06/10/2013] [Accepted: 06/11/2013] [Indexed: 10/26/2022]
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Jiménez DJ, Dini-Andreote F, van Elsas JD. Metataxonomic profiling and prediction of functional behaviour of wheat straw degrading microbial consortia. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:92. [PMID: 24955113 PMCID: PMC4064818 DOI: 10.1186/1754-6834-7-92] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 05/23/2014] [Indexed: 05/09/2023]
Abstract
BACKGROUND Mixed microbial cultures, in which bacteria and fungi interact, have been proposed as an efficient way to deconstruct plant waste. The characterization of specific microbial consortia could be the starting point for novel biotechnological applications related to the efficient conversion of lignocellulose to cello-oligosaccharides, plastics and/or biofuels. Here, the diversity, composition and predicted functional profiles of novel bacterial-fungal consortia are reported, on the basis of replicated aerobic wheat straw enrichment cultures. RESULTS In order to set up biodegradative microcosms, microbial communities were retrieved from a forest soil and introduced into a mineral salt medium containing 1% of (un)treated wheat straw. Following each incubation step, sequential transfers were carried out using 1 to 1,000 dilutions. The microbial source next to three sequential batch cultures (transfers 1, 3 and 10) were analyzed by bacterial 16S rRNA gene and fungal ITS1 pyrosequencing. Faith's phylogenetic diversity values became progressively smaller from the inoculum to the sequential batch cultures. Moreover, increases in the relative abundances of Enterobacteriales, Pseudomonadales, Flavobacteriales and Sphingobacteriales were noted along the enrichment process. Operational taxonomic units affiliated with Acinetobacter johnsonii, Pseudomonas putida and Sphingobacterium faecium were abundant and the underlying strains were successfully isolated. Interestingly, Klebsiella variicola (OTU1062) was found to dominate in both consortia, whereas K. variicola-affiliated strains retrieved from untreated wheat straw consortia showed endoglucanase/xylanase activities. Among the fungal players with high biotechnological relevance, we recovered members of the genera Penicillium, Acremonium, Coniochaeta and Trichosporon. Remarkably, the presence of peroxidases, alpha-L-fucosidases, beta-xylosidases, beta-mannases and beta-glucosidases, involved in lignocellulose degradation, was indicated by predictive bacterial metagenome reconstruction. Reassuringly, tests for specific (hemi)cellulolytic enzymatic activities, performed on the consortial secretomes, confirmed the presence of such gene functions. CONCLUSION In an in-depth characterization of two wheat straw degrading microbial consortia, we revealed the enrichment and selection of specific bacterial and fungal taxa that were presumably involved in (hemi) cellulose degradation. Interestingly, the microbial community composition was strongly influenced by the wheat straw pretreatment. Finally, the functional bacterial-metagenome prediction and the evaluation of enzymatic activities (at the consortial secretomes) revealed the presence and enrichment of proteins involved in the deconstruction of plant biomass.
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Affiliation(s)
- Diego Javier Jiménez
- Department of Microbial Ecology, Center for Ecological and Evolutionary Studies (CEES), University of Groningen (RUG), Nijenborgh 7, 9747AG Groningen, The Netherlands
| | - Francisco Dini-Andreote
- Department of Microbial Ecology, Center for Ecological and Evolutionary Studies (CEES), University of Groningen (RUG), Nijenborgh 7, 9747AG Groningen, The Netherlands
| | - Jan Dirk van Elsas
- Department of Microbial Ecology, Center for Ecological and Evolutionary Studies (CEES), University of Groningen (RUG), Nijenborgh 7, 9747AG Groningen, The Netherlands
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Hložková K, Suman J, Strnad H, Ruml T, Paces V, Kotrba P. Characterization of pbt genes conferring increased Pb2+ and Cd2+ tolerance upon Achromobacter xylosoxidans A8. Res Microbiol 2013; 164:1009-18. [PMID: 24125695 DOI: 10.1016/j.resmic.2013.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 09/03/2013] [Indexed: 10/26/2022]
Abstract
The cluster of pbtTFYRABC genes is carried by plasmid pA81. Its elimination from Achromobacter xylosoxidans A8 resulted in increased sensitivity towards Pb(2+) and Cd(2+). Predicted pbtTRABC products share strong similarities with Pb(2+) uptake transporter PbrT, transcriptional regulator PbrR, metal efflux P1-ATPases PbrA and CadA, undecaprenyl pyrophosphatase PbrB and its signal peptidase PbrC from Cupriavidus metallidurans CH34. Expression of pbtABC or pbtA in a metal-sensitive Escherichia coli GG48 rendered the strain Pb(2+)-, Cd(2+)- and Zn(2+)-tolerant and caused decreased accumulation of the metal ions. Accumulation of Pb(2+), but not of Cd(2+) or Zn(2+), was promoted in E. coli expressing pbtT. Additional genes of the pbt cluster are pbtF and pbtY, which encode the cation diffusion facilitator (CDF)-like transporter and a putative fatty acid hydroxylase of unknown function, respectively. Expression of pbtF did not confer increased metal tolerance upon E. coli GG48, although the protein showed measurable Pb(2+)-efflux activity. Unlike the pbtT promoter, promoters of pbtABC, pbtF and pbtY contain features characteristic of promoters controlled by metal-responsive transcriptional regulators of the MerR family. Upregulation of pbtABC, pbtF and pbtY upon Pb(2+), Cd(2+) and Zn(2+) exposure was confirmed in wild-type Achromobacter xylosoxidans A8. Gel shift assays proved binding of purified PbtR to the respective promoters.
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Affiliation(s)
- Kateřina Hložková
- Department of Biochemistry and Microbiology, Institute of Chemical Technology, Prague, Technická 3, CZ-166 28 Prague, Czech Republic.
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Community composition and cellulase activity of cellulolytic bacteria from forest soils planted with broad-leaved deciduous and evergreen trees. Appl Microbiol Biotechnol 2013; 98:1449-58. [PMID: 23893311 DOI: 10.1007/s00253-013-5130-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 07/06/2013] [Accepted: 07/13/2013] [Indexed: 01/26/2023]
Abstract
Cellulolytic bacteria in forest soil provide carbon sources to improve the soil fertility and sustain the nutrient balance of the forest ecological system through the decomposition of cellulosic remains. These bacteria can also be utilized for the biological conversion of biomass into renewable biofuels. In this study, the community compositions and activities of cellulolytic bacteria in the soils of forests planted with broad-leaved deciduous (Chang Qing Garden, CQG) and broad-leaved evergreen (Forest Park, FP) trees in Wuhan, China were resolved through restriction fragment length polymorphism (RFLP) and sequencing analysis of the 16S rRNA gene. All of the isolates exhibited 35 RFLP fingerprint patterns and were clustered into six groups at a similarity level of 50 %. The phylogeny analysis based on the 16S rRNA gene sequence revealed that these RFLP groups could be clustered into three phylogenetic groups and further divided into six subgroups at a higher resolution. Group I consists of isolates from Bacillus cereus, Bacillus subtilis complex (I-A) and from Paenibacillus amylolyticus-related complex (I-B) and exhibited the highest cellulase activity among all of the cellulolytic bacteria isolates. Cluster II consists of isolates belonging to Microbacterium testaceum (II-A), Chryseobacterium indoltheticum (II-B), and Flavobacterium pectinovorum and the related complex (II-C). Cluster III consists of isolates belonging to Pseudomonas putida-related species. The community shift with respect to the plant species and the soil properties was evidenced by the phylogenetic composition of the communities. Groups I-A and I-B, which account for 36.0 % of the cellulolytic communities in the CQG site, are the dominant groups (88.4 %) in the FP site. Alternatively, the ratio of the bacteria belonging to group III (P. putida-related isolates) shifted from 28.0 % in CQG to 4.0 % in FP. The soil nutrient analysis revealed that the CQG site planted with deciduous broad-leaved trees has a richer organic nutrient (total organic carbon and total nitrogen) than the FP site planted with evergreen broad-leaved trees. Against this background, the population density and the diversity of cellulolytic bacteria in the CQG site are clearly higher than those in the FP site, and the latter was dominated with high-cellulase-activity Bacillus- and Paenibacillus-related bacteria. The canonical correspondence analysis further indicated that the distribution of these groups is correlated with the FP site, whereas groups II and III are correlated with the organic nutrient-rich CQG site.
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Romano N, Gioffré A, Sede SM, Campos E, Cataldi A, Talia P. Characterization of Cellulolytic Activities of Environmental Bacterial Consortia from an Argentinian Native Forest. Curr Microbiol 2013; 67:138-47. [DOI: 10.1007/s00284-013-0345-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 02/21/2013] [Indexed: 11/29/2022]
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Abstract
This review outlines information about the Gram-negative, aerobic bacterium Variovorax paradoxus. The genomes of these species have G+C contents of 66.5-69.4 mol%, and the cells form yellow colonies. Some strains of V. paradoxus are facultative lithoautotrophic, others are chemoorganotrophic. Many of them are associated with important catabolic processes including the degradation of toxic and/or complex chemical compounds. The degradation pathways or other skills related to the following compounds, respectively, are described in this review: sulfolane, 3-sulfolene, 2-mercaptosuccinic acid, 3,3'-thiodipropionic acid, aromatic sulfonates, alkanesulfonates, amino acids and other sulfur sources, polychlorinated biphenyls, dimethyl terephthalate, linuron, 2,4-dinitrotoluene, homovanillate, veratraldehyde, 2,4-dichlorophenoxyacetic acid, anthracene, poly(3-hydroxybutyrate), chitin, cellulose, humic acids, metal-EDTA complexes, yttrium, rare earth elements, As(III), trichloroethylene, capsaicin, 3-nitrotyrosine, acyl-homoserine lactones, 1-aminocyclopropane-1-carboxylate, methyl tert-butyl ether, geosmin, and 2-methylisoborneol. Strains of V. paradoxus are also engaged in mutually beneficial interactions with other plant and bacterial species in various ecosystems. This species comprises probably promising strains for bioremediation and other biotechnical applications. Lately, the complete genomes of strains S110 and EPS have been sequenced for further investigations.
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Isolation and identification of cellulolytic bacteria from the gut of Holotrichia parallela larvae (Coleoptera: Scarabaeidae). Int J Mol Sci 2012; 13:2563-2577. [PMID: 22489111 PMCID: PMC3317674 DOI: 10.3390/ijms13032563] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 02/17/2012] [Accepted: 02/20/2012] [Indexed: 11/21/2022] Open
Abstract
In this study, 207 strains of aerobic and facultatively anaerobic cellulolytic bacteria were isolated from the gut of Holotrichia parallela larvae. These bacterial isolates were assigned to 21 genotypes by amplified ribosomal DNA restriction analysis (ARDRA). A partial 16S rDNA sequence analysis and standard biochemical and physiological tests were used for the assignment of the 21 representative isolates. Our results show that the cellulolytic bacterial community is dominated by the Proteobacteria (70.05%), followed by the Actinobacteria (24.15%), the Firmicutes (4.35%), and the Bacteroidetes (1.45%). At the genus level, Gram-negative bacteria including Pseudomonas, Ochrobactrum, Rhizobium, Cellulosimicrobium, and Microbacterium were the predominant groups, but members of Bacillus, Dyadobacter, Siphonobacter, Paracoccus, Kaistia, Devosia, Labrys, Ensifer, Variovorax, Shinella, Citrobacter, and Stenotrophomonas were also found. Furthermore, our results suggest that a significant amount of bacterial diversity exists among the cellulolytic bacteria, and that Siphonobacter aquaeclarae, Cellulosimicrobium funkei, Paracoccus sulfuroxidans, Ochrobactrum cytisi, Ochrobactrum haematophilum, Kaistia adipata, Devosia riboflavina, Labrys neptuniae, Ensifer adhaerens, Shinella zoogloeoides, Citrobacter freundii, and Pseudomonas nitroreducens are reported to be cellulolytic for the first time in this study. Our results indicate that the scarab gut is an attractive source for the study of novel cellulolytic microorganisms and enzymes useful for cellulose degradation.
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