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Deng F, Wang H, Xie H, Bao X, He H, Zhang X, Liang C. Low-disturbance farming regenerates healthy deep soil toward sustainable agriculture - Evidence from long-term no-tillage with stover mulching in Mollisols. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 825:153929. [PMID: 35183631 DOI: 10.1016/j.scitotenv.2022.153929] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 02/12/2022] [Accepted: 02/12/2022] [Indexed: 06/14/2023]
Abstract
Currently, global agricultural development is in a critical period, as it contends with a growing population, degraded farmland, and serious environmental issues. Although low-disturbance practices are recommended to improve soil health, it is unclear whether such practices benefit critical deep soil functioning. Here, we compared the soil bacterial communities and physicochemical parameters across 3-m deep soil profiles in a Mollisol of Northeast China at the end of the dormant season after 10 years of farming under conventional tillage without stover mulching (CT), no-tillage without stover mulching (NTNS), and no-tillage with stover mulching (NTSM). We found that low-disturbance practices (NTNS and NTSM), compared with CT, evidently promoted soil bacterial species richness and diversity and enriched potential metabolic diversity. When compared to the bacterial communities in CT, the vertical dissimilarity of bacterial communities in NTNS decreased, while that in NTSM increased, indicating that no-tillage alone homogenized the composition of the bacterial community through soil depth profiles, but straw mulching enhanced the uniqueness of community composition at each layer. In comparison to CT, no-tillage with stover mulching significantly increased the soil water content and root-associated organic carbon (SEOC), and decreased soil pH. Mineral nitrogen declined with depth to 60 cm and then increased to its maximum at 250-300 cm under CT and at 120-150 cm under NTNS and NTSM. More mineral nitrogen at 0-150 cm under low-disturbance practices would provide more available nitrogen for crops in the coming growing season, while the accumulated nitrogen at 150-300 cm under CT may leach into the groundwater. Taken together, our results show that low-disturbance practices can regenerate whole-soil bacterial diversity and potential function, and promote water retention and nitrogen holding capacity within the root zone, thus reducing the dose of nitrogen fertilizer and mitigating nitrogen contamination to deep groundwater, ultimately contributing to agricultural sustainability in Mollisol regions.
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Affiliation(s)
- Fangbo Deng
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; University of Chinese Academy of Sciences, Beijing 100049, China; Key Lab of Conservation Tillage & Ecological Agriculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, Liaoning Province, China
| | - Hongjun Wang
- Duke University Wetland Center, Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Hongtu Xie
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Key Lab of Conservation Tillage & Ecological Agriculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, Liaoning Province, China
| | - Xuelian Bao
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Key Lab of Conservation Tillage & Ecological Agriculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, Liaoning Province, China
| | - Hongbo He
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Key Lab of Conservation Tillage & Ecological Agriculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, Liaoning Province, China
| | - Xudong Zhang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Key Lab of Conservation Tillage & Ecological Agriculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, Liaoning Province, China
| | - Chao Liang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Key Lab of Conservation Tillage & Ecological Agriculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, Liaoning Province, China.
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Network Analysis of Plasmidomes: The Azospirillum brasilense Sp245 Case. INTERNATIONAL JOURNAL OF EVOLUTIONARY BIOLOGY 2014; 2014:951035. [PMID: 25610702 PMCID: PMC4295147 DOI: 10.1155/2014/951035] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 11/10/2014] [Accepted: 11/11/2014] [Indexed: 11/17/2022]
Abstract
Azospirillum brasilense is a nitrogen-fixing bacterium living in association with plant roots. The genome of the strain Sp245, isolated in Brazil from wheat roots, consists of one chromosome and six plasmids. In this work, the A. brasilense Sp245 plasmids were analyzed in order to shed some light on the evolutionary pathways they followed over time. To this purpose, a similarity network approach was applied in order to identify the evolutionary relationships among all the A. brasilense plasmids encoded proteins; in this context a computational pipeline specifically devoted to the analysis and the visualization of the network-like evolutionary relationships among different plasmids molecules was developed. This information was supplemented with a detailed (in silico) functional characterization of both the connected (i.e., sharing homology with other sequences in the dataset) and the unconnected (i.e., not sharing homology) components of the network. Furthermore, the most likely source organism for each of the genes encoded by A. brasilense plasmids was checked, allowing the identification of possible trends of gene loss/gain in this microorganism. Data obtained provided a detailed description of the evolutionary landscape of the plasmids of A. brasilense Sp245, suggesting some of the molecular mechanisms responsible for the present-day structure of these molecules.
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Joe MM, Saravanan VS, Islam MR, Sa T. Development of alginate-based aggregate inoculants of Methylobacterium sp. and Azospirillum brasilense tested under in vitro conditions to promote plant growth. J Appl Microbiol 2013; 116:408-23. [PMID: 24188110 DOI: 10.1111/jam.12384] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 10/04/2013] [Accepted: 10/30/2013] [Indexed: 11/28/2022]
Abstract
AIM To develop co-aggregated bacterial inoculant comprising of Methylobacterium oryzae CBMB20/Methylobacterium suomiense CBMB120 strains with Azospirillum brasilense (CW903) strain and testing their efficiency as inoculants for plant growth promotion (PGP). METHODS AND RESULTS Biofilm formation and co-aggregation efficiency was studied between A. brasilense CW903 and methylobacterial strains M. oryzae CBMB20 and M. suomiense CBMB120. Survival and release of these co-aggregated bacterial strains entrapped in alginate beads were assessed. PGP attributes of the co-aggregated bacterial inoculant were tested in tomato plants under water-stressed conditions. Results suggest that the biofilm formation efficiency of the CBMB20 and CBMB120 strains increased by 15 and 34%, respectively, when co-cultivated with CW903. Co-aggregation with CW903 enhanced the survivability of CBMB20 strain in alginate beads. Water stress index score showed least stress index in plants inoculated with CW903 and CBMB20 strains maintained as a co-aggregated inoculant. CONCLUSIONS This study reports the development of co-aggregated cell inoculants containing M. oryzae CBMB20 and A. brasilense CW903 strains conferred better shelf life and stress abatement in inoculated tomato plants. SIGNIFICANCE AND IMPACT OF THE STUDY These findings could be extended to other PGP bacterial species to develop multigeneric bioinoculants with multiple benefits for various crops.
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Affiliation(s)
- M M Joe
- Department of Agricultural Chemistry, Chungbuk National University, Cheongju, Korea.,Department of Microbiology, School of Life Sciences, Vels University, Chennai, India
| | - V S Saravanan
- Department of Microbiology, Indira Gandhi College of Arts and Science, Kathirkamam, Pondicherry, India
| | - M R Islam
- Department of Biological Sciences, Inha University, Incheon, Korea
| | - T Sa
- Department of Agricultural Chemistry, Chungbuk National University, Cheongju, Korea
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Lynd LR, Weimer PJ, van Zyl WH, Pretorius IS. Microbial cellulose utilization: fundamentals and biotechnology. Microbiol Mol Biol Rev 2002. [PMID: 12209002 DOI: 10.1128/mmbr.66.3.506] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/24/2023] Open
Abstract
Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial cellulose utilization, kinetics of microbial cellulose utilization, and contrasting features compared to soluble substrate kinetics. A biological perspective on processing cellulosic biomass is presented, including features of pretreated substrates and alternative process configurations. Organism development is considered for "consolidated bioprocessing" (CBP), in which the production of cellulolytic enzymes, hydrolysis of biomass, and fermentation of resulting sugars to desired products occur in one step. Two organism development strategies for CBP are examined: (i) improve product yield and tolerance in microorganisms able to utilize cellulose, or (ii) express a heterologous system for cellulose hydrolysis and utilization in microorganisms that exhibit high product yield and tolerance. A concluding discussion identifies unresolved issues pertaining to microbial cellulose utilization, suggests approaches by which such issues might be resolved, and contrasts a microbially oriented cellulose hydrolysis paradigm to the more conventional enzymatically oriented paradigm in both fundamental and applied contexts.
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Affiliation(s)
- Lee R Lynd
- Chemical and Biochemical Engineering, Thayer School of Engineering and Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755, USA.
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Lynd LR, Weimer PJ, van Zyl WH, Pretorius IS. Microbial cellulose utilization: fundamentals and biotechnology. Microbiol Mol Biol Rev 2002; 66:506-77, table of contents. [PMID: 12209002 PMCID: PMC120791 DOI: 10.1128/mmbr.66.3.506-577.2002] [Citation(s) in RCA: 2319] [Impact Index Per Article: 105.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial cellulose utilization, kinetics of microbial cellulose utilization, and contrasting features compared to soluble substrate kinetics. A biological perspective on processing cellulosic biomass is presented, including features of pretreated substrates and alternative process configurations. Organism development is considered for "consolidated bioprocessing" (CBP), in which the production of cellulolytic enzymes, hydrolysis of biomass, and fermentation of resulting sugars to desired products occur in one step. Two organism development strategies for CBP are examined: (i) improve product yield and tolerance in microorganisms able to utilize cellulose, or (ii) express a heterologous system for cellulose hydrolysis and utilization in microorganisms that exhibit high product yield and tolerance. A concluding discussion identifies unresolved issues pertaining to microbial cellulose utilization, suggests approaches by which such issues might be resolved, and contrasts a microbially oriented cellulose hydrolysis paradigm to the more conventional enzymatically oriented paradigm in both fundamental and applied contexts.
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Affiliation(s)
- Lee R Lynd
- Chemical and Biochemical Engineering, Thayer School of Engineering and Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755, USA.
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Chiarini L, Tabacchioni S, Bevivino A. Interactions between rhizosphere microorganisms under iron limitation. Arch Microbiol 1993. [DOI: 10.1007/bf00258147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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