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Pan L, Xu Q, Wei Q, Kong Y, Zhu L, Tian W, Yan Y, Wang H, Chi C, Zhang J, Zhu C. Isolation of the inorganic phosphorus-solubilizing bacteria Lysinibacillus sphaericus and assessing its role in promoting rice growth. Int Microbiol 2024:10.1007/s10123-024-00538-2. [PMID: 38805155 DOI: 10.1007/s10123-024-00538-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 05/09/2024] [Accepted: 05/17/2024] [Indexed: 05/29/2024]
Abstract
Soluble phosphorus scarcity severely limits plant growth and crop yield. In this study, a strain of inorganic phosphorus-solubilizing bacteria, Lysinibacillus sphaericus, was isolated from rice rhizosphere soil. The available phosphorus content in liquid inorganic phosphorus identification medium and in L. sphaericus-inoculated soil increased from 204.28 mg/L to 1124.68 mg/L and from 4.75 mg/kg to 7.04 mg/kg, respectively. The pH decreased significantly from 6.87 to 6.14. Incubation with L. sphaericus significantly increased malic and succinic acid content in the liquid inorganic phosphorus identification medium and increased acid phosphatase and alkaline phosphatase activity in the soil. Inoculation with L. sphaericus significantly increased rice growth, chlorophyll a/b content, and photosynthesis by increasing the soluble phosphorus content in the rice rhizosphere soil under phosphorus-deficient conditions. Further analysis revealed that L. sphaericus improved soil phosphorus release by decreasing soil pH and promoting acid phosphatase and alkaline phosphatase activity. This study supports the production of microbial fertilizers to improve rice yield in phosphorus-deficient conditions.
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Affiliation(s)
- Lin Pan
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China
| | - Qingshan Xu
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China
| | - Qianqian Wei
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China
| | - Yali Kong
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China
| | - Lianfeng Zhu
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China
| | - Wenhao Tian
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China
| | - Yulian Yan
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China
| | - Hangfeng Wang
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China
| | - Chunxin Chi
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China
| | - Junhua Zhang
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China.
| | - Chunquan Zhu
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 310006, China.
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Zhou B, Cheng S, Peng S, Li W, Li C, Wang Q, Wang Y, Guo J. Response of bacterial community structure to different phosphorus additions in a tobacco-growing soil. FRONTIERS IN PLANT SCIENCE 2024; 15:1344733. [PMID: 38516665 PMCID: PMC10954889 DOI: 10.3389/fpls.2024.1344733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Accepted: 02/13/2024] [Indexed: 03/23/2024]
Abstract
Introduction Phosphorus (P), which plays a vital role in plant growth, is continually added to soil to maximize biomass production, leading to excessive P accumulation and water eutrophication. Results In this study, a pot experiment using a subtropical tobacco-growing soil fertilized with four P levels-no P, low P, medium P, and high P-was conducted and rhizosphere and bulk soils were analyzed. Results P addition significantly increased tobacco biomass production (except under low P input) and total soil P and available P content (P<0.05), whereas total nitrogen content decreased in the rhizosphere soils, although this was only significant with medium P application. P fertilization also significantly altered the bacterial communities of rhizosphere soils (P<0.05), but those of bulk soils were unchanged (P>0.05). Moreover, a significant difference was found between rhizosphere soils with low (LR) and high (HR) P inputs (P<0.05). Additionally, compared with rhizosphere soils with no P (CKR), Shannon diversity showed a declining trend, which was significant with LR and HR (P<0.05), whereas an increasing tendency was observed for Chao1 diversity except in LR (P>0.05). Functional prediction revealed that P application significantly decreased the total P and N metabolism of microorganisms in rhizosphere soils (P<0.05). Discussion Collectively, our results indicate that maintaining sustainable agricultural ecosystems under surplus P conditions requires more attention to be directed toward motivating the potential of soil functional microbes in P cycling, rather than just through continual P input.
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Affiliation(s)
- Beibei Zhou
- School of Environment and Ecology, Jiangsu Open University, Nanjing, China
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Shiqian Cheng
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
- School of Agriculture, Ningxia University, Yinchuan, China
| | - Shuang Peng
- School of Environment and Ecology, Jiangsu Open University, Nanjing, China
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Wenqing Li
- Fujian Tobacco Research Institute, Fuzhou, China
| | - Chunying Li
- Fujian Tobacco Research Institute, Fuzhou, China
| | - Qianqian Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Yiming Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Jinping Guo
- Fujian Tobacco Research Institute, Fuzhou, China
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Li ZW, Wang YH, Liu C, Wu YM, Lan GX, Xue YB, Wu QS, Zhou N. Effects of Organophosphate-Degrading Bacteria on the Plant Biomass, Active Medicinal Components, and Soil Phosphorus Levels of Paris polyphylla var. yunnanensis. PLANTS (BASEL, SWITZERLAND) 2023; 12:631. [PMID: 36771715 PMCID: PMC9921132 DOI: 10.3390/plants12030631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 01/26/2023] [Accepted: 01/29/2023] [Indexed: 06/18/2023]
Abstract
Paris polyphylla var. yunnanensis, a medicinal plant that originated in Yunnan (China), has been over-harvested in the wild population, resulting in its artificial cultivation. Given the negative environmental impacts of the excessive use of phosphorus (P) fertilization, the application of organophosphate-degrading bacteria (OPDB) is a sustainable approach for improving the P use efficiency in Paris polyphylla var. yunnanensis production. The present work aimed to analyze the effects of three organic phosphate-solubilizing bacteria of Bacillus on the yield and quality of P. polyphylla var. yunnanensis and the P concentrations in the soil. All the inoculation treatments distinctly increased the rhizome biomass, steroidal, and total saponin concentrations of the rhizomes and the Olsen-P and organic P in the soil. The highest growth rate of rhizomes biomass, steroidal saponins, available phosphorus, and total phosphorus content was seen in the S7 group, which was inoculated with all three OPDB strains, showing increases of 134.58%, 132.56%, 51.64%, and 17.19%, respectively. The highest total saponin content was found in the group inoculated with B. mycoides and B. wiedmannii, which increased by 33.68%. Moreover, the highest organic P content was seen in the group inoculated with B. wiedmannii and B. proteolyticus, which increased by 96.20%. In addition, the rhizome biomass was significantly positively correlated with the saponin concentration, together with the positive correlation between the Olsen-P and organic P and total P. It is concluded that inoculation with organophosphate-degrading bacteria improved the biomass and medicinal ingredients of the rhizome in P. polyphylla var. yunnanensis, coupled with increased soil P fertility, with a mixture of the three bacteria performing best.
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Affiliation(s)
- Zhuo-Wei Li
- Chongqing Engineering Laboratory of Green Planting and Deep Processing of Famous-Region Drug in the Three Gorges Reservoir Region, College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing 404120, China
- College of Environmental and Chemical Engineering, Chongqing Three Gorges University, Chongqing 404120, China
| | - Yue-Heng Wang
- Chongqing Engineering Laboratory of Green Planting and Deep Processing of Famous-Region Drug in the Three Gorges Reservoir Region, College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing 404120, China
| | - Chang Liu
- College of Environmental and Chemical Engineering, Chongqing Three Gorges University, Chongqing 404120, China
| | - Ying-Mei Wu
- Chongqing Engineering Laboratory of Green Planting and Deep Processing of Famous-Region Drug in the Three Gorges Reservoir Region, College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing 404120, China
| | - Guo-Xin Lan
- College of Environmental and Chemical Engineering, Chongqing Three Gorges University, Chongqing 404120, China
| | - Yan-Bin Xue
- Chongqing Engineering Laboratory of Green Planting and Deep Processing of Famous-Region Drug in the Three Gorges Reservoir Region, College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing 404120, China
| | - Qiang-Sheng Wu
- College of Horticulture and Gardening, Yangtze University, Jingzhou 434023, China
| | - Nong Zhou
- Chongqing Engineering Laboratory of Green Planting and Deep Processing of Famous-Region Drug in the Three Gorges Reservoir Region, College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing 404120, China
- College of Pharmacy, Engineering Center of State Ministry of Education for Standardization of Chinese Medicine Processing, Nanjing University of Chinese Medicine, Nanjing 210023, China
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de Moura GGD, de Barros AV, Machado F, da Silva Dambroz CM, Glienke C, Petters-Vandresen DAL, Alves E, Schwan RF, Pasqual M, Dória J. The Friend Within: Endophytic Bacteria as a Tool for Sustainability in Strawberry Crops. Microorganisms 2022; 10:microorganisms10122341. [PMID: 36557594 PMCID: PMC9780916 DOI: 10.3390/microorganisms10122341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/05/2022] [Accepted: 10/21/2022] [Indexed: 11/29/2022] Open
Abstract
Strawberry (Fragaria x ananassa, Duch.) is an important crop worldwide. However, since it is a highly demanding crop in terms of the chemical conditions of the substrate, a large part of strawberry production implies the application of large amounts of fertilizers in the production fields. This practice can cause environmental problems, in addition to increases in the fruit's production costs. In this context, applying plant growth-promoting bacteria in production fields can be an essential strategy, especially thanks to their ability to stimulate plant growth via different mechanisms. Therefore, this study aimed to test in vitro and in vivo the potential of bacteria isolated from strawberry leaves and roots to directly promote plant growth. The isolates were tested in vitro for their ability to produce auxins, solubilize phosphate and fix nitrogen. Isolates selected in vitro were tested on strawberry plants to promote plant growth and increase the accumulation of nitrogen and phosphorus in the leaves. The tested isolates showed an effect on plant growth according to biometric parameters. Among the tested isolates, more expressive results for the studied variables were observed with the inoculation of the isolate MET12M2, belonging to the species Brevibacillus fluminis. In general, bacterial inoculation induced strain-dependent effects on strawberry growth. In vitro and in vivo assays showed the potential use of the B. fluminis MET12M2 isolate as a growth promoter for strawberries.
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Affiliation(s)
| | | | - Franklin Machado
- Phytopathology Department, Federal University of Viçosa, Viçosa 36570-900, Brazil
| | | | - Chirlei Glienke
- Genetic Department, Federal University of Paraná, Curitiba 81531-980, Brazil
| | | | - Eduardo Alves
- Phytopathology Department, Federal University of Lavras, Lavras 37200-900, Brazil
| | | | - Moacir Pasqual
- Agriculture Department, Federal University of Lavras, Lavras 37200-900, Brazil
| | - Joyce Dória
- Agriculture Department, Federal University of Lavras, Lavras 37200-900, Brazil
- Correspondence:
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He D, Wan W. Distribution of Culturable Phosphate-Solubilizing Bacteria in Soil Aggregates and Their Potential for Phosphorus Acquisition. Microbiol Spectr 2022; 10:e0029022. [PMID: 35536021 PMCID: PMC9241762 DOI: 10.1128/spectrum.00290-22] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 04/21/2022] [Indexed: 11/22/2022] Open
Abstract
Deciphering distribution patterns of phosphate-solubilizing bacteria (PSB) and phosphorus-cycling-related genes in soils is important to evaluate phosphorus (P) transformation. However, the linkage between PSB number and P-cycling-related gene abundance in soils, especially soil aggregates, remains largely unknown. Here, we estimated the numbers of PSB and abundances of P-cycling-related genes (i.e., gcd and bpp) in soil aggregates under different fertilization regimes as well as P-solubilizing performance and plant-growth-promoting ability of PSB. We found that tricalcium phosphate-solubilizing bacteria, phytate-degrading bacteria, and gcd and bpp abundances were more abundant in silt plus clay (silt+clay; <53 μm) than in macroaggregate (250 to 2000 μm) and microaggregate (53 to 250 μm). Fertilization treatment and aggregate fractionation showed distinct effects on PSB number and P-cycling-related gene abundance. We found significantly negative correlation between gcd gene abundance and tricalcium phosphate-solubilizing bacterial number (Col-CaP) and dramatically positive correlation between bpp gene abundance and phytate-degrading bacterial number (Col-Phy). P fractions were responsible for PSB number and P-cycling-related gene abundance. The isolated Pseudomonas sp. strain PSB-2 and Arthrobacter sp. strain PSB-5 exhibited good performances for solubilizing tricalcium phosphate. The inoculation of Pseudomonas sp. PSB-2 could significantly enhance plant fresh weight, plant dry weight, and plant height. Our results emphasized distinct distribution characteristics of PSB and P-cycling-related genes in soil aggregates and deciphered a close linkage between PSB number and P-cycling-related gene abundance. Our findings might guide the isolation of PSB from agricultural soils and provide a candidate plant-growth-promoting bacterium for agro-ecosystems. IMPORTANCE Phosphate-solubilizing bacteria are responsible for inorganic P solubilization and organic P mineralization. Elucidating the linkage between phosphate-solubilizing bacterial number and P-cycling-related gene abundance is important to isolate plant-growth-promoting bacteria for agro-ecosystems. Our findings reveal differentiating strategies of phosphate-solubilizing bacteria in soil aggregates, and the deciphered P fractions show strong effects on distribution patterns of phosphate-solubilizing bacteria and P-cycling-related genes. Additionally, we isolated phosphate-solubilizing bacteria with good plant-growth-promoting ability. This study enriches our knowledge of P cycling in soil aggregates and might guide the production and management of farmland.
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Affiliation(s)
- Donglan He
- College of Life Science, South-Central University for Nationalities, Wuhan, People’s Republic of China
| | - Wenjie Wan
- Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, People’s Republic of China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, People’s Republic of China
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6
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Li Q. Perspectives on Converting Keratin-Containing Wastes Into Biofertilizers for Sustainable Agriculture. Front Microbiol 2022; 13:918262. [PMID: 35794912 PMCID: PMC9251476 DOI: 10.3389/fmicb.2022.918262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 05/23/2022] [Indexed: 12/04/2022] Open
Abstract
Keratin-containing wastes become pollution to the environment if they are not treated properly. On the other hand, these wastes can be converted into value-added products applicable to many fields. Organic fertilizers and biofertilizers are important for sustainable agriculture by providing nutrients to enhance the growth speed of the plant and production. Keratin-containing wastes, therefore, will be an important resource to produce organic fertilizers. Many microorganisms exhibit capabilities to degrade keratins making them attractive to convert keratin-containing wastes into valuable products. In this review, the progress in microbial degradation of keratins is summarized. In addition, perspectives in converting keratin into bio- and organic fertilizers for agriculture are described. With proper treatment, feather wastes which are rich in keratin can be converted into high-value fertilizers to serve as nutrients for plants, reduce environmental pressure and improve the quality of the soil for sustainable agriculture.
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7
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Zeng Q, Ding X, Wang J, Han X, Iqbal HMN, Bilal M. Insight into soil nitrogen and phosphorus availability and agricultural sustainability by plant growth-promoting rhizobacteria. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:45089-45106. [PMID: 35474421 DOI: 10.1007/s11356-022-20399-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 04/19/2022] [Indexed: 02/08/2023]
Abstract
Nitrogen and phosphorus are critical for the vegetation ecosystem and two of the most insufficient nutrients in the soil. In agriculture practice, many chemical fertilizers are being applied to soil to improve soil nutrients and yield. This farming procedure poses considerable environmental risks which affect agricultural sustainability. As robust soil microorganisms, plant growth-promoting rhizobacteria (PGPR) have emerged as an environmentally friendly way of maintaining and improving the soil's available nitrogen and phosphorus. As a special PGPR, rhizospheric diazotrophs can fix nitrogen in the rhizosphere and promote plant growth. However, the mechanisms and influences of rhizospheric nitrogen fixation (NF) are not well researched as symbiotic NF lacks summarizing. Phosphate-solubilizing bacteria (PSB) are important members of PGPR. They can dissolve both insoluble mineral and organic phosphate in soil and enhance the phosphorus uptake of plants. The application of PSB can significantly increase plant biomass and yield. Co-inoculating PSB with other PGPR shows better performance in plant growth promotion, and the mechanisms are more complicated. Here, we provide a comprehensive review of rhizospheric NF and phosphate solubilization by PGPR. Deeper genetic insights would provide a better understanding of the NF mechanisms of PGPR, and co-inoculation with rhizospheric diazotrophs and PSB strains would be a strategy in enhancing the sustainability of soil nutrients.
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Affiliation(s)
- Qingwei Zeng
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, 223003, China.
| | - Xiaolei Ding
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, 210037, China
| | - Jiangchuan Wang
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, 223003, China
| | - Xuejiao Han
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, 223003, China
| | - Hafiz M N Iqbal
- Tecnologico de Monterrey, School of Engineering and Sciences, 64849, Monterrey, Mexico
| | - Muhammad Bilal
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, 223003, China
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New Polyfunctional Biorationals Use to Achieve Competitive Yield of Organic Potatoes in the North-West Russian Ecosystem. PLANTS 2022; 11:plants11070962. [PMID: 35406942 PMCID: PMC9003074 DOI: 10.3390/plants11070962] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/25/2022] [Accepted: 03/28/2022] [Indexed: 12/22/2022]
Abstract
To increase the organic potato yield, it is necessary to provide the crop with sufficient nutrients and effective means of biocontrol the diseases. The research goal was to characterize the biorationals’ efficacy to achieve competitive organic potatoes’ yield under various weather conditions. A 4-year trial was carried out in the Leningrad region using Udacha variety potatoes. The tests used liquid forms of new polyfunctional biologicals Kartofin based on highly active Bacillus subtilis I-5-12/23 and organic fertilizer BIAGUM obtained from poultry manure by aerobic fermentation in a closed biofermenter. Significant stimulation in plant growth and development to the flowering phase regardless of the hydrothermal conditions of the growing season was noted. The stimulating effect was determined by the combined use of biorationals pro rata to BIAGUM dose. Kartofin biologicals and BIAGUM almost doubled the potato tubers’ yield compared to the control, regardless of the growing season conditions. At the flowering phase, the biological efficacy in potato fungal diseases incidence and development was near 90% under optimal and 50–75% under drought hydrothermal conditions. At the end of vegetation, the efficiency in fungal diseases incidence and development made up 45–65% under optimal and 45–70% under dry conditions. BIAGUM effectiveness in reducing disease development reached 45–50% regardless of growing season conditions.
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Kumar S, Diksha, Sindhu SS, Kumar R. Biofertilizers: An ecofriendly technology for nutrient recycling and environmental sustainability. CURRENT RESEARCH IN MICROBIAL SCIENCES 2022; 3:100094. [PMID: 35024641 PMCID: PMC8724949 DOI: 10.1016/j.crmicr.2021.100094] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 12/09/2021] [Accepted: 12/09/2021] [Indexed: 01/02/2023] Open
Abstract
Agriculture plays an important role in a country's economy. In modern intensive agricultural practices, chemical fertilizers and pesticides are applied on large scale to increase crop production in order to meet the nutritional requirements of the ever-increasing world population. However, rapid urbanization with shrinking agricultural lands, dramatic change in climatic conditions and extensive use of agrochemicals in agricultural practices has been found to cause environmental disturbances and public health hazards affecting food security and sustainability in agriculture. Besides this, agriculture soils are continuously losing their quality and physical properties as well as their chemical (imbalance of nutrients) and biological health due to indiscriminate use of agrochemicals. Plant-associated microbes with their plant growth- promoting traits have enormous potential to solve these challenges and play a crucial role in enhancing plant biomass and crop yield under greenhouse and field conditions. The beneficial mechanisms of plant growth improvement include enhanced availability of nutrients (i.e., N, P, K, Zn and S), phytohormone modulation, biocontrol of phytopathogens and amelioration of biotic and abiotic stresses. This plant-microbe interplay is indispensable for sustainable agriculture and these microbes may perform essential role as an ecological engineer to reduce the use of chemical fertilizers. Various steps involved for production of solid-based or liquid biofertilizer formulation include inoculum preparation, addition of cell protectants such as glycerol, lactose, starch, a good carrier material, proper packaging and best delivery methods. In addition, recent developments of formulation include entrapment/microencapsulation, nano-immobilization of microbial bioinoculants and biofilm-based biofertilizers. Thus, inoculation with beneficial microbes has emerged as an innovative eco-friendly technology to feed global population with available resources. This review critically examines the current state-of-art on use of microbial strains as biofertilizers in different crop systems for sustainable agriculture and in maintaining soil fertility and enhancing crop productivity. It is believed that acquisition of advanced knowledge of plant-PGPR interactions, bioengineering of microbial communities to improve the performance of biofertilizers under field conditions, will help in devising strategies for sustainable, environment-friendly and climate smart agricultural technologies to deliver short and long terms solutions for improving crop productivity to feed the world in a more sustainable manner.
Modern intensive agricultural practices face numerous challenges that pose major threats to global food security. In order to address the nutritional requirements of the ever-increasing world population, chemical fertilizers and pesticides are applied on large scale to increase crop production. However, the injudicious use of agrochemicals has resulted in environmental pollution leading to public health hazards. Moreover, agriculture soils are continuously losing their quality and physical properties as well as their chemical (imbalance of nutrients) and biological health. Plant-associated microbes with their plant growth- promoting traits have enormous potential to solve these challenges and play a crucial role in enhancing plant biomass and crop yield. The beneficial mechanisms of plant growth improvement include enhanced nutrient availability, phytohormone modulation, biocontrol of phytopathogens and amelioration of biotic and abiotic stresses. Solid-based or liquid bioinoculant formulation comprises inoculum preparation, addition of cell protectants such as glycerol, lactose, starch, a good carrier material, proper packaging and best delivery methods. Recent developments of formulation include entrapment/microencapsulation, nano-immobilization of microbial bioinoculants and biofilm-based biofertilizers. This review critically examines the current state-of-art on use of microbial strains as biofertilizers and the important roles performed by these beneficial microbes in maintaining soil fertility and enhancing crop productivity.
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Key Words
- ABA, Abscisic acid
- ACC, 1-aminocyclopropane-1-carboxylic acid
- AM, Arbuscular mycorrhiza
- APX, Ascorbate peroxidase
- BGA, Blue green algae
- BNF, Biological nitrogen fixation
- Beneficial microorganisms
- Biofertilizers
- CAT, Catalase
- Crop production
- DAPG, 2, 4-diacetyl phloroglucinol
- DRB, Deleterious rhizospheric bacteria
- GA, Gibberellic acid
- GPX, Glutathione/thioredoxin peroxidase
- HCN, Hydrogen cyanide
- IAA, Indole acetic acid
- IAR, Intrinsic antibiotic resistance
- ISR, Induced systemic resistance
- KMB, Potassium mobilizing bacteria
- KSMs, Potassium-solubilizing microbes
- MAMPs, Microbes associated molecular patterns
- PAMPs, Pathogen associated molecular patterns
- PCA, Phenazine-1-carboxylic acid
- PGP, Plant growth-promoting
- PGPR, Plant growth-promoting rhizobacteria
- POD, Peroxidase
- PSB, Phosphate-solubilizing bacteria
- Rhizosphere
- SAR, Systemic acquired resistance
- SOB, Sulphur oxidizing bacteria
- Soil fertility
- Sustainable agriculture
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Affiliation(s)
- Satish Kumar
- Department of Microbiology, CCS Haryana Agricultural University, Hisar 125004, India
| | - Diksha
- Department of Microbiology, CCS Haryana Agricultural University, Hisar 125004, India
| | - Satyavir S Sindhu
- Department of Microbiology, CCS Haryana Agricultural University, Hisar 125004, India
| | - Rakesh Kumar
- Department of Microbiology, CCS Haryana Agricultural University, Hisar 125004, India
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From Lab to Farm: Elucidating the Beneficial Roles of Photosynthetic Bacteria in Sustainable Agriculture. Microorganisms 2021; 9:microorganisms9122453. [PMID: 34946055 PMCID: PMC8707939 DOI: 10.3390/microorganisms9122453] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/16/2021] [Accepted: 11/24/2021] [Indexed: 11/16/2022] Open
Abstract
Photosynthetic bacteria (PSB) possess versatile metabolic abilities and are widely applied in environmental bioremediation, bioenergy production and agriculture. In this review, we summarize examples of purple non-sulfur bacteria (PNSB) through biofertilization, biostimulation and biocontrol mechanisms to promote plant growth. They include improvement of nutrient acquisition, production of phytohormones, induction of immune system responses, interaction with resident microbial community. It has also been reported that PNSB can produce an endogenous 5-aminolevulinic acid (5-ALA) to alleviate abiotic stress in plants. Under biotic stress, these bacteria can trigger induced systemic resistance (ISR) of plants against pathogens. The nutrient elements in soil are significantly increased by PNSB inoculation, thus improving fertility. We share experiences of researching and developing an elite PNSB inoculant (Rhodopseudomonas palustris PS3), including strategies for screening and verifying beneficial bacteria as well as the establishment of optimal fermentation and formulation processes for commercialization. The effectiveness of PS3 inoculants for various crops under field conditions, including conventional and organic farming, is presented. We also discuss the underlying plant growth-promoting mechanisms of this bacterium from both microbial and plant viewpoints. This review improves our understanding of the application of PNSB in sustainable crop production and could inspire the development of diverse inoculants to overcome the changes in agricultural environments created by climate change.
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