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Hnini M, Aurag J. Prevalence, diversity and applications potential of nodules endophytic bacteria: a systematic review. Front Microbiol 2024; 15:1386742. [PMID: 38812696 PMCID: PMC11133547 DOI: 10.3389/fmicb.2024.1386742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 04/29/2024] [Indexed: 05/31/2024] Open
Abstract
Legumes are renowned for their distinctive biological characteristic of forming symbiotic associations with soil bacteria, mostly belonging to the Rhizobiaceae familiy, leading to the establishment of symbiotic root nodules. Within these nodules, rhizobia play a pivotal role in converting atmospheric nitrogen into a plant-assimilable form. However, it has been discerned that root nodules of legumes are not exclusively inhabited by rhizobia; non-rhizobial endophytic bacteria also reside within them, yet their functions remain incompletely elucidated. This comprehensive review synthesizes available data, revealing that Bacillus and Pseudomonas are the most prevalent genera of nodule endophytic bacteria, succeeded by Paenibacillus, Enterobacter, Pantoea, Agrobacterium, and Microbacterium. To date, the bibliographic data available show that Glycine max followed by Vigna radiata, Phaseolus vulgaris and Lens culinaris are the main hosts for nodule endophytic bacteria. Clustering analysis consistently supports the prevalence of Bacillus and Pseudomonas as the most abundant nodule endophytic bacteria, alongside Paenibacillus, Agrobacterium, and Enterobacter. Although non-rhizobial populations within nodules do not induce nodule formation, their presence is associated with various plant growth-promoting properties (PGPs). These properties are known to mediate important mechanisms such as phytostimulation, biofertilization, biocontrol, and stress tolerance, emphasizing the multifaceted roles of nodule endophytes. Importantly, interactions between non-rhizobia and rhizobia within nodules may exert influence on their leguminous host plants. This is particularly shown by co-inoculation of legumes with both types of bacteria, in which synergistic effects on plant growth, yield, and nodulation are often measured. Moreover these effects are pronounced under both stress and non-stress conditions, surpassing the impact of single inoculations with rhizobia alone.
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Affiliation(s)
| | - Jamal Aurag
- Microbiology and Molecular Biology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Rabat, Morocco
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Li Y, Wang J, Sun T, Yu X, Yang Z, Zhao Y, Tang X, Xiao H. Community structure of endophytic bacteria of Sargassum thubergii in the intertidal zone of Qingdao in China. AMB Express 2024; 14:35. [PMID: 38615116 PMCID: PMC11016019 DOI: 10.1186/s13568-024-01688-2] [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: 10/25/2023] [Accepted: 03/12/2024] [Indexed: 04/15/2024] Open
Abstract
Endophytic bacteria are one of the symbiotic microbial groups closely related to host algae. However, less research on the endophytic bacteria of marine algae. In this study, the endophytic bacterial community of Sargassum thunbergii was investigated using the culture method and high-throughput sequencing. Thirty-nine endophytic bacterial strains, belonging to two phyla, five genera and sixteen species, were isolated, and Firmicutes, Bacillus and Metabacillus indicus were the dominant taxa at the phylum, genus and species level, respectively. High-throughput sequencing revealed 39 phyla and 574 genera of endophytic bacteria, and the dominant phylum was Proteobacteria, while the dominant genus was Ralstonia. The results also indicated that the endophytic bacteria of S. thunbergii included various groups with nitrogen fixation, salt tolerance, pollutant degradation, and antibacterial properties but also contained some pathogenic bacteria. Additionally, the endophytic bacterial community shared a large number of groups with the epiphytic bacteria and bacteria in the surrounding seawater, but the three groups of samples could be clustered separately. In conclusion, there are a variety of functional endophytic bacteria living in S. thunbergii, and the internal condition of algae is a selective factor for the formation of endophytic bacterial communities. This study enriched the database of endophytic bacteria in marine macroalgae, paving the way for further understanding of the interrelationships between endophytic bacteria, macroalgae, and the environment.
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Affiliation(s)
- Yang Li
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Jing Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Tao Sun
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Xinlong Yu
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Zhibo Yang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Yayun Zhao
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Xuexi Tang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
- Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao, 266000, China.
| | - Hui Xiao
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
- Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao, 266000, China.
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Emitaro WO, Kawaka F, Musyimi DM, Adienge A. Diversity of endophytic bacteria isolated from leguminous agroforestry trees in western Kenya. AMB Express 2024; 14:18. [PMID: 38329624 PMCID: PMC10853127 DOI: 10.1186/s13568-024-01676-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 01/31/2024] [Indexed: 02/09/2024] Open
Abstract
Plants have diverse and vast niches colonized by endophytic microorganisms that promote the wellbeing of host plant. These microbes inhabit internal plant tissues with no signs of ill health. Bacterial endophytes from many plants have been isolated and characterized due to their beneficial roles however their diversity in leguminous plants still remain unexploited. Diversity of bacterial endophytes isolated from Sesbania sesban, Leucaena diversifolia and Calliandra calothyrsus was assessed using morphological and molecular characteristics. A total of 27 pure isolates were recovered from C. Calothyrsus, L. diversifolia and S. sesban constituting 44.4%, 33.3% and 22.2% from the leaves, stems and roots respectively. The isolates differentiated into Gram positive and negative with rods and spherical shapes. Analysis of 16S rRNA gene sequences revealed 8 closely related bacterial genera that consisted of Bacillus (33.3%), Staphylococcus (22.2%), Alcaligens (11.1%), Pantoea (11.1%), Xanthomonas,and Sphingomonas (7.4%) each. Others included Acinetobacter, and Pseudomonas at 3.7% each. Bacterial endophytes of genus bacillus were isolated from all the three plants. These results indicate the presence of high diversity of endophytic bacteria associated with the different parts of L. diversifolia, S. sesban and C. salothyrsus growing in western Kenya.
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Affiliation(s)
- William Omuketi Emitaro
- Department of Biological Sciences, Jaramogi Oginga Odinga University of Science and Technology, 210, Bondo, 40601, Kenya.
| | - Fanuel Kawaka
- Department of Biological Sciences, Jaramogi Oginga Odinga University of Science and Technology, 210, Bondo, 40601, Kenya
| | | | - Asenath Adienge
- Department of Biotechnology, Kenya Forestry Research Institute, 20412-00200, Nairobi, Kenya
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Potential role of rhizobia to enhance chickpea-growth and yield in low fertility-soils of Tunisia. Antonie van Leeuwenhoek 2022; 115:921-932. [PMID: 35639296 DOI: 10.1007/s10482-022-01745-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 05/04/2022] [Indexed: 10/18/2022]
Abstract
Plant growth-promoting rhizobacteria are bacteria that improve plant growth and reduce plant pathogen damages. In this study, 100 nodule bacteria were isolated from chickpea, screened for their plant growth-promoting (PGP) traits and then characterised by PCR-RFLP of 16 S rDNA. Results showed that most of the slow-growing isolates fixed nitrogen but those exhibiting fast-growth did not. Fourteen isolates solubilized inorganic phosphorus, 16 strains produced siderophores, and 17 strains produced indole acetic acid. Co-culture experiments identified three strains having an inhibitory effect against Fusarium oxysporum, the primary pathogenic fungus for chickpea in Tunisia. Rhizobia with PGP traits were assigned to Mesorhizobium ciceri, Mesorhizobium mediterraneum, Sinorhizobium meliloti and Agrobacterium tumefaciens. We noted that PGP activities were differentially distributed between M. ciceri and M. mediterraneum. The region of Mateur in northern Tunisia, with clay-silty soil, was the origin of 53% of PGP isolates. Interestingly, we found that S. meliloti and A. tumefaciens strains did not behave as parasitic nodule-bacteria but as PGP rhizobacteria useful for chickpea nutrition and health. In fact, S. meliloti strains could solubilize phosphorus, produce siderophore and auxin. The A. tumefaciens strains could perform the previous PGP traits and inhibit pathogen growth also. Finally, one candidate strain of M. ciceri (LL10)-selected for its highest symbiotic nitrogen fixation and phosphorus solubilization-was used for field experiment. The LL10 inoculation increased grain yield more than three-fold. These finding showed the potential role of rhizobia to be used as biofertilizers and biopesticides, representing low-cost and environment-friendly inputs for sustainable agriculture.
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Nakei MD, Venkataramana PB, Ndakidemi PA. Soybean-Nodulating Rhizobia: Ecology, Characterization, Diversity, and Growth Promoting Functions. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2022. [DOI: 10.3389/fsufs.2022.824444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The worldwide increase in population continues to threaten the sustainability of agricultural systems since agricultural output must be optimized to meet the global rise in food demand. Sub-Saharan Africa (SSA) is among the regions with a fast-growing population but decreasing crop productivity. Pests and diseases, as well as inadequate nitrogen (N) levels in soils, are some of the biggest restrictions to agricultural production in SSA. N is one of the most important plant-limiting elements in agricultural soils, and its deficit is usually remedied by using nitrogenous fertilizers. However, indiscriminate use of these artificial N fertilizers has been linked to environmental pollution calling for alternative N fertilization mechanisms. Soybean (Glycine max) is one of the most important legumes in the world. Several species of rhizobia from the four genera, Bardyrhizobium, Rhizobium, Mesorhizobium, and Ensifer (formerly Sinorhizobium), are observed to effectively fix N with soybean as well as perform various plant-growth promoting (PGP) functions. The efficiency of the symbiosis differs with the type of rhizobia species, soybean cultivar, and biotic factors. Therefore, a complete understanding of the ecology of indigenous soybean-nodulating rhizobia concerning their genetic diversity and the environmental factors associated with their localization and dominance in the soil is important. This review aimed to understand the potential of indigenous soybean-nodulating rhizobia through a synthesis of the literature regarding their characterization using different approaches, genetic diversity, symbiotic effectiveness, as well as their functions in biological N fixation (BNF) and biocontrol of soybean soil-borne pathogens.
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Mir MI, Kumar BK, Gopalakrishnan S, Vadlamudi S, Hameeda B. Characterization of rhizobia isolated from leguminous plants and their impact on the growth of ICCV 2 variety of chickpea ( Cicer arietinum L.). Heliyon 2021; 7:e08321. [PMID: 34820538 PMCID: PMC8601996 DOI: 10.1016/j.heliyon.2021.e08321] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/14/2021] [Accepted: 11/01/2021] [Indexed: 12/20/2022] Open
Abstract
Six rhizobia-like-bacterial strains in total, secluded from the root and stem nodules of various leguminous plants were characterized for growth promoting ability on ICCV 2 variety of chickpea. Bacterial strains showed production of IAA, NH3, siderophore, HCN, ACC deaminase, hydrolytic enzyme production such as chitinase, amylase, protease, lipase, β-1, 3-glucanase and solubilization of nutrients such as phosphate, zinc and potassium. However the performance of PGP traits characterized in-vitro varied among the six bacterial strains. The sequences of 16S rRNA gene of bacterial strains IHSR, IHRG, IHAA, IHGN-3, IHCP-1 and IHCP-2 showed maximum identity with Rhizobium sp., Rhizobium tropici, Rhizobium multihospitium, Mesorhizobium sp., Burkholderia cepacia and Rhizobium pusense. In plate culture conditions the bacterial strains changed the colour of media (NFB) from green to blue and showed amplification of nifH gene by PCR, and also enhanced nodule formation in chickpea under greenhouse conditions, which explains their nitrogen fixing ability. Scanning electron microscopy studies of chickpea roots showed colonization by all the six bacterial strains in solo and by consortium (IHRG + IHGN-3). Under greenhouse conditions, chickpea plants inoculated with different strains showed improvement in plant height, number of branches, total chlorophyll, nodule number, nodule weight, shoot weight, root weight, root volume and root surface area at 30 and 45 days after sowing (DAS) over the uninoculated control plants. It was also observed at the crop maturity stage all the bacterial strains inoculated separately enhanced pod number, seed number and total NPK compared to uninoculated control plants. This study suggests that bacteria associated with root and stem nodules can be a promising resource to enhance nodulation, PGP and crop yields in chickpea.
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Affiliation(s)
- Mohammad Imran Mir
- Department of Botany, UCS, Osmania University, Hyderabad, 500007, Telangana, India
| | - B Kiran Kumar
- Department of Botany, UCS, Osmania University, Hyderabad, 500007, Telangana, India
| | - Subramaniam Gopalakrishnan
- International Crops Research Institute for the Semi-Arid Tropics, Patancheru, Hyderabad, 502319, Telangana, India
| | - Srinivas Vadlamudi
- International Crops Research Institute for the Semi-Arid Tropics, Patancheru, Hyderabad, 502319, Telangana, India
| | - Bee Hameeda
- Department of Microbiology, UCS, Osmania University, Hyderabad, 500007, Telangana, India
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Liu J, Qi WY, Chen H, Song C, Li Q, Wang SG. Selenium Nanoparticles as an Innovative Selenium Fertilizer Exert Less Disturbance to Soil Microorganisms. Front Microbiol 2021; 12:746046. [PMID: 34589080 PMCID: PMC8473918 DOI: 10.3389/fmicb.2021.746046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 08/20/2021] [Indexed: 11/13/2022] Open
Abstract
Selenium (Se) is an essential trace element in the human body. Se-enriched agricultural products, obtained by applying Se fertilizer, are important sources of Se supplement. However, Se fertilizer may cause a series of environmental problems. This study investigated the transformation of exogenous selenium nanoparticles (SeNPs) and selenite (SeO3 2-) in soil and explored their effects on soil microbial community and typical microorganisms. SeNPs exhibited a slow-release effect in soil, which promoted the growth of soil microorganisms and enriched soil probiotics. SeO3 2- was converted to a stable and low toxic state in soil, increasing persistent free radicals and decreasing microbial abundance and diversity. The influences of SeNPs and SeO3 2- on two typical soil microorganisms (Bacillus sp. and Escherichia coli) were also evaluated, and SeNPs were more difficult to enter into microorganisms directly, with lower toxicity and higher safety. These results indicated that SeNPs were a more environment-friendly Se additive for agriculture applications. This work provides useful information for better understanding the environmental fate and behavior of Se fertilizer in the soil.
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Affiliation(s)
- Jun Liu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, China
| | - Wen-Yu Qi
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, China
| | - Hui Chen
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, China
| | - Chao Song
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, China
| | - Qiang Li
- College of Agriculture and Forestry Science, Linyi University, Linyi, China.,State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Shu-Guang Wang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, China
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Benjelloun I, Thami Alami I, El Khadir M, Douira A, Udupa SM. Co-Inoculation of Mesorhizobium ciceri with Either Bacillus sp. or Enterobacter aerogenes on Chickpea Improves Growth and Productivity in Phosphate-Deficient Soils in Dry Areas of a Mediterranean Region. PLANTS (BASEL, SWITZERLAND) 2021; 10:571. [PMID: 33802918 PMCID: PMC8002673 DOI: 10.3390/plants10030571] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 11/17/2022]
Abstract
Biological nitrogen fixation requires a large amount of phosphorus (P). However, most of the soils are P-deficient and the extensive use of P- chemical fertilizers constitute a serious threat to the environment. In this context, two field experiments were carried out to investigate the effect of co-inoculation of Mesorhizobium ciceri with phosphate solubilizing bacteria (PSB), Bacillus sp., and Enterobacter aerogenes, on chickpea as an alternative to chemical nitrogen (N) and phosphorous fertilizers in P-deficient soils in dry areas of Morocco. The results revealed that combined inoculation of chickpea with rhizobia and PSB showed a significant enhancement of chickpea nodulation, biomass production, yields and N, P, and protein content in grains as compared to single inoculation or single application of N or P. A significantly higher increase was obtained by inoculating chickpea with Mesorhizobium sp. MA72 combined with E. aerogenes P1S6. This combination allowed an enhancement of more than 270% in nodulation, 192% in shoot dry weight and 242% in grain yield. The effect of this combination was equivalent to the effect of combined application of N and P fertilizers. Formulation of biofertilizers based on tasted strains could be used for chickpea co-inoculation in P-deficient soils for an eco-friendly sustainable production of chickpea.
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Affiliation(s)
- Imane Benjelloun
- Department of Microbiology, National Institute of Agronomical Research (INRA), 10 000 Rabat, Morocco; (I.B.); (I.T.A.); (M.E.K.)
- Department of Biology, Faculty of Sciences, Ibn Tofail University, 14 020 Kénitra, Morocco;
- ICARDA-INRA Cooperative Research Project, International Center for Agricultural Research in the Dry Areas (ICARDA), 10 000 Rabat, Morocco
| | - Imane Thami Alami
- Department of Microbiology, National Institute of Agronomical Research (INRA), 10 000 Rabat, Morocco; (I.B.); (I.T.A.); (M.E.K.)
| | - Mohamed El Khadir
- Department of Microbiology, National Institute of Agronomical Research (INRA), 10 000 Rabat, Morocco; (I.B.); (I.T.A.); (M.E.K.)
| | - Allal Douira
- Department of Biology, Faculty of Sciences, Ibn Tofail University, 14 020 Kénitra, Morocco;
| | - Sripada M. Udupa
- ICARDA-INRA Cooperative Research Project, International Center for Agricultural Research in the Dry Areas (ICARDA), 10 000 Rabat, Morocco
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Chen WF, Wang ET, Ji ZJ, Zhang JJ. Recent development and new insight of diversification and symbiosis specificity of legume rhizobia: mechanism and application. J Appl Microbiol 2021; 131:553-563. [PMID: 33300250 DOI: 10.1111/jam.14960] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/26/2020] [Accepted: 12/04/2020] [Indexed: 12/15/2022]
Abstract
Currently, symbiotic rhizobia (sl., rhizobium) refer to the soil bacteria in α- and β-Proteobacteria that can induce root and/or stem nodules on some legumes and a few of nonlegumes. In the nodules, rhizobia convert the inert dinitrogen gas (N2 ) into ammonia (NH3 ) and supply them as nitrogen nutrient to the host plant. In general, this symbiotic association presents specificity between rhizobial and leguminous species, and most of the rhizobia use lipochitooligosaccharides, so called Nod factor (NF), for cooperating with their host plant to initiate the formation of nodule primordium and to inhibit the plant immunity. Besides NF, effectors secreted by type III secretion system (T3SS), exopolysaccharides and many microbe-associated molecular patterns in the rhizobia also play important roles in nodulation and immunity response between rhizobia and legumes. However, the promiscuous hosts like Glycine max and Sophora flavescens can nodulate with various rhizobial species harbouring diverse symbiosis genes in different soils, meaning that the nodulation specificity/efficiency might be mainly determined by the host plants and regulated by the soil conditions in a certain cases. Based on previous studies on rhizobial application, we propose a '1+n-N' model to promote the function of symbiotic nitrogen fixation (SNF) in agricultural practice, where '1' refers to appreciate rhizobium; '+n' means the addition of multiple trace elements and PGPR bacteria; and '-N' implies the reduction of chemical nitrogen fertilizer. Finally, open questions in the SNF field are raised to future think deeply and researches.
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Affiliation(s)
- W F Chen
- State Key Laboratory of Agrobiotechnology, Beijing, P. R. China.,College of Biological Sciences and Rhizobium Research Center, China Agricultural University, Beijing, P. R. China
| | - E T Wang
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, México City, D.F, México
| | - Z J Ji
- College of Life Science and Food Engineering, Horqin Plant Stress Biology Research Institute, Inner Mongolia University for the Nationalities, Tongliao, Inner Mongolia, P. R. China
| | - J J Zhang
- College of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou, Henan Province, P. R. China.,Henan Key Laboratory of Cold Chain Food Quality and Safety Control, Henan Province, P. R. China.,Collaborative Innovation Center for Food Production and Safety of Henan Province, Zhengzhou, Henan Province, P. R. China
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Haouas A, El Modafar C, Douira A, Ibnsouda-Koraichi S, Filali-Maltouf A, Moukhli A, Amir S. Alcaligenes aquatilis GTE53: Phosphate solubilising and bioremediation bacterium isolated from new biotope "phosphate sludge enriched-compost". Saudi J Biol Sci 2021; 28:371-379. [PMID: 33424319 PMCID: PMC7785438 DOI: 10.1016/j.sjbs.2020.10.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/04/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022] Open
Abstract
The isolation and identification of beneficial bacteria from the active phase of composting is considered to be a key bio-quality parameter for the assessment of the process. The aim of this work was the selection and identification of beneficial bacteria from a co-composting experiment of vegetable waste (VW), olive oil mill waste (O2MW), and phosphate sludge (PS). Phosphate-solubilizing strains were isolated from the thermophilic phase using Pikovskaya (PVK) solid medium supplemented with tricalcium phosphate Ca3(PO4) (TCP) as the sole source of phosphorus (P). Therefore, the selected isolate Alcaligenes aquatilis GTE53 was tested to tolerate abiotic stresses (different levels of temperature, variable pH, high salinity and water stress). The isolate was also assessed for indole acetic acid (IAA) and siderophores synthesis, nitrogen fixation, phenol degradation and pathogens inactivation. The quality of the co-composting process was also investigated by monitoring the physico-chemical parameters. The obtained results showed that A. aquatilis GTE53 displayed a higher solubilization index of 2.4 and was efficiently dissolved, up to 162.8 and 247.4 mg·mL-1 of inorganic phosphate from PS and phosphate rock (PR), respectively. A. aquatilis GTE53 exhibited siderophores and IAA release, along with atmospheric nitrogen fixation. In addition to that, A. aquatilis GTE53 showed a high resistance to heat and tolerance to acidic and alkaline pH, high salinity and water stress. Moreover, A. aquatilis GTE53 could degrade 99.2% of phenol from a high-concentrated medium (1100 mg·L-1 of phenol) and can inactivate the most abundant pathogens in industrial wastes: Escherichia coli, Streptococcus sp., Salmonella sp., and Fusarium oxysporum albedinis. Analysis of temperature, pH, electrical conductivity, carbon/nitrogen (C/N) ratio, indicated successful co-composting. An efficient transformation of P to the available form and a great abatement of polyphenols, were also recorded during the process. The findings of this study will help to advance the understanding of A. aquatilis GTE53 functions and will facilitate its application to promote beneficial microbial organisms during composting, thus obtaining a high-quality product.
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Affiliation(s)
- Ayoub Haouas
- Laboratoire Polyvalent en Recherche et Développement, Faculté Polydisciplinaire, Université Sultan Moulay Slimane, Beni Mellal, Morocco
| | - Cherkaoui El Modafar
- Laboratoire d'Agrobiotechnologie et Bioingénierie, Faculté des Sciences et Techniques, Université Cadi Ayyad, Marrakech, Morocco
| | - Allal Douira
- Laboratoire de Botanique Biotechnologie et de Protection des Plantes, Faculté des Sciences, Université Ibn Tofail, Kenitra, Morocco
| | - Saâd Ibnsouda-Koraichi
- Laboratoire de Biotechnologie Microbienne et Molécules Bioactives, Faculté des Sciences et Techniques, Université Sidi Mohamed Ben Abdellah, Fès, Morocco
| | - Abdelkarim Filali-Maltouf
- Laboratoire de Microbiologie et Biologie Moléculaire, Faculté des Sciences, Université Mohammed V, Rabat, Morocco
| | - Abdelmajid Moukhli
- Unité de Recherche d'Amélioration génétique des plantes, Institut national de la Recherche Agronomique, Marrakech, Morocco
| | - Soumia Amir
- Laboratoire Polyvalent en Recherche et Développement, Faculté Polydisciplinaire, Université Sultan Moulay Slimane, Beni Mellal, Morocco
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Tapia-García EY, Hernández-Trejo V, Guevara-Luna J, Rojas-Rojas FU, Arroyo-Herrera I, Meza-Radilla G, Vásquez-Murrieta MS, Estrada-de los Santos P. Plant growth-promoting bacteria isolated from wild legume nodules and nodules of Phaseolus vulgaris L. trap plants in central and southern Mexico. Microbiol Res 2020; 239:126522. [DOI: 10.1016/j.micres.2020.126522] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 05/24/2020] [Accepted: 05/30/2020] [Indexed: 02/07/2023]
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12
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Exogenous phosphorus-solubilizing bacteria changed the rhizosphere microbial community indirectly. 3 Biotech 2020; 10:164. [PMID: 32206498 DOI: 10.1007/s13205-020-2099-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 01/24/2020] [Indexed: 12/12/2022] Open
Abstract
Phosphate-solubilizing bacteria (PSB) have been widely used as biological fertilizer. However, its impact on the local microbial community has less been known. In this study, a mixture of PSB was inoculated into the tomato growth alone or combined with manure fertilizer. The growth parameter results showed that the combination use of PSB and compost could significantly increase the tomato growth and yield. The use of PSB could significantly increase pH, available phosphorus and several kinds of trace elements both in the rhizosphere and non-rhizosphere soil. The quantitative PCR and high-throughput sequencing results showed that the inoculated PSB did not become the dominant strains in the rhizosphere. However, the soil bacterial community structure was changed. The relative abundance of several indigenous bacteria, such as Pseudomonas, decreased, while the population of several bacteria, including Bacillus, Anaerolineaceae, Cytophagaceae, and Gemmationadaceae, increased. The redundancy analysis result showed that the soil properties had a great influence on the indigenous microbial community. In conclusion, the inoculated PSB could not colonize in the soil with a single inoculation. The PSB secreted small molecular organic acids to dissolve inorganic phosphorus and changed the soil properties, which changed the rhizosphere microbial community indirectly.
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