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Research Article
Open Access Peer-reviewed

Bacterial Communitie’s Diversity of Rhizosphere’s Soils of Two Legumes, Cajanus cajan and Milletia laurentii, Revealed by Illumina Miseq Sequencing of 16S rRNA Gene

Alvychelle Benith Banga , Augustin Aimé Lebonguy, Angélique Espérance Lembella Boumba, Joseph Goma-Tchimbakala
World Journal of Agricultural Research. 2022, 10(1), 20-29. DOI: 10.12691/wjar-10-1-4
Received May 08, 2022; Revised June 11, 2022; Accepted June 21, 2022

Abstract

Microbial organic fertilizers have been shown to boost plant productivity. These microorganisms of interest are more numerous in the soil around the roots or rhizosphere. Objective of this study was to assess bacterial communities’ diversity of in the rhizosphere of two legumes, Milletia laurentii and Cajanus cajan, growing on the same soil. First of all, the levels Mg, N, Fe, C total, P, NH4+ and particle size were determined by spectrophotometry, Kjeldahl method, Olsen method, Walkey-Black method, Nessler reagent, DEB method and Robinson pipette method, respectively. Next, bacterial diversity was determined by Sequencing Illumina Miseq of 16S rRNA gene. Results showed that contents of carbon, total nitrogen, ammoniacal nitrogen, phosphorus, iron and magnesium were slightly elevated in Milletia rhizosphere compared to Cajanus. According to the USDA's textural triangle, both soils have a sandy loam soil texture. In terms of diversity, all OTUs (1434) were divided into 30 phyla, 50 classes, 158 families and 314 genera for the 2 soils. Proteobacteria (58.62% - 48.71%), Acidobacteria (27.29% - 9.46%), Firmicutes (8.26% - 7.21%) and Bacteroidetes (13.70% - 2.53%) were most dominant phyla in both rhizospheres (Cajanus - Milletia). The most dominant classes were Alphaproteobacteria (51.44% - 38.90%), Acidobacteriia (26.57% - 8.67%), Bacilli (8.19% - 7.18%), Sphingobacteria (9.83% - 2.50%) and Gammaproteobacteria (4.27% - 3.39%). At the family level, Hyphomicrobiaceae (35.05%-24.22%), Bradyrhizobiaceae (17.32%-11.70%) and Bacillaceae (18.98%-6.49%) were most abundant. Finally, Acidobacterium (26.55%-4.58%), Rhodoplanes (21.63%-7.50%), Bradyrhizobium (17.27%-1.96%) and Bacillus (6.43%-6.29%) were the most abundant genera. Thus, bacterial diversity of the rhizosphere of these two legumes encourages their use for the isolation of bacteria with biofertilizing potential.

1. Introduction

The need to increase agricultural production to meet the needs of a growing world population has led to the use of chemical and/or organic fertilizers. Unfortunately, the misuse and uncontrolled use of the latter is the cause of environmental pollution and public health problems 1. Indeed, antimicrobials (antifungal, antibacterial and antiparasitic) are introduced into the soil with the use of manure from animals treated with drugs to prevent diseases and improve their growth. This has the consequence of distributing multidrug-resistant microorganisms in the environment that adapt to new environment contaminated by horizontal gene transfer with other bacteria 2, 3. In addition, manure of animal origin may contain heavy metals such as lead and cadmium but also pathogenic microorganisms 4. 5 highlighted that agricultural and industrial development has led to an increase of Cd concentration in agricultural soils. However, toxicity of this metal leads to inhibition of carbon fixation, decreases the chlorophyll content and consequently photosynthetic activity of plants 6 In addition, the misuse of nitrogen fertilizers is at the origin of eutrophication of water bodies which leads to a decrease in the amount of dissolved oxygen with the risk of death of aquatic organisms 7.

Therefore it’s interesting to opt for low-polluting and environmentally compatible soil amendment methods 1, 8. 9 state that microbial agents offer an attractive and feasible option for developing biological tools to replace or supplement chemicals. This idea has been supported by 10 who state that the exploitation of microorganisms as biofertilizers is considered an alternative to chemical fertilizers. This is because microbial fertilizers increase nutrient availability, solubilize phosphates, fix atmospheric nitrogen, produce phytohormones that improve plant growth, and protect the plant from pathogens 11. In the other hand 12 point out in this sense that there is a need to explore the different mutualistic interactions between plant roots and microbiome of the rhizosphere. According to 9, the exploration of microorganisms that reside in the vicinity of the plant will make it possible to achieve this goal by moving to wards microorganisms in the rhizosphere. Similarly, 13 evaluated the effect of co-inoculation of Rhizobium and mycorrhizae on the agronomic performance of cowpea. Results of study of these authors showed that co-inoculation of crops increased pod yields. It’s clear that beneficial application of the rhizosphere microbiome as a biofertilizer in agricultural practices has become an innovative and environmentally friendly technology to improve soil fertility and plant growth 14, 15.

Thus, knowledge of the diversity of microbial communities colonizing the rhizosphere can be a first step in the screening of microorganisms that have beneficial effects on sustainable plant production. In Congo few studies have focused on microorganisms in the rhizosphere. Only 16 studied the diversity and structure of microbial communities in three soils south of Brazzaville. The results of these authors showed that microbial communities differ from one soil to another. But for the same soil, are the microbial communities of the rhizosphere specific to a given plant ? This study aims to look for microorganisms in the rhizosphere that can be used as biofertilizers. The objective is to assess the diversity and structure of bacterial communities in the rhizosphere of two legumes, Milletia laurentii and Cajanus cajan, growing on the same soil.

2. Material and Methods

2.1. Soil Survey and Sampling Site

The study was conducted in the Scientific City of Brazzaville: (4°16'42, 1439''S, 15°14'24, 6538'' E). According to 17, the climate of Brazzaville called "transitional equatorial" is of the Low-Congolese type. This type of climate prevails over the South-West of the Congo and experiences moderate rainfall whose monthly distribution shows a very marked dry season of four to five months (May-September), framed by two periods of rain of which that of February to May is the most abundant. Relative humidity is always high around 75% 18. Annual rainfall averages are of the order of 1200 to 1500 mm. Average temperatures hover around 25°C. However, there are monthly averages that sometimes reach 27°C in the rainy season and 19°C in the dry season 18.

For soil sampling, an equilateral triangle of 1 m side was drawn from the tree (Cajanus Cajan and Milletia Laurentii). Then the soils were taken from the horizon 0-10 cm, using an auger, at the vertices on each side and in middle of triangle. The four soil samples were mixed to form a composite sample. Each composite sample was separated in two and packaged in sterile glass jars and transported to the laboratory using a cooler. In the laboratory, the soils were kept at 4°C until they were used. Before soil use, the stones and roots were removed. One of the batches of the two samples was used for the analysis of diversity of bacterial communities and the other for physicochemical characterization and cultivable strains’ study.

2.2. Physicochemical Characterization of Soils

Total carbon of soil samples was determined by the Walkey-Black method 19. Total nitrogen was determined using the Kjeldahl method described by 20. Ammoniacal nitrogen was determined using Nessler's reagent 20. Phosphorus was determined by Olsen's method 21. Finally, total iron was determined by the DEB method 22. Magnesium was determined by spectrophotometry. Particle size was determined by Robinson's pipette method 23.

2.3. Study of Bacterial Communities
2.3.1. DNA Extraction

DNA extraction, Illumina-Hiseq sequencing and bioinformatics analyses were carried out at Mr DNA laboratories (USA). Genomic DNA was extracted from 0.5g of dry soil sample using the PowerSoil kit (MOBIO Laboratory, Carlsbad, CA, USA) following the manufacturer's instructions. The concentration of the extracted DNA was estimated using the Nanodrop 2000C spectrophotometer (Thermo Scientific, Wilmington, DE, USA). Finally, DNA extracts from soil samples were stored at 80°C until use.


2.3.2. PCR Amplification and Illumina-Miseq Sequencing

The V4 region of the bacterial 16S rRNA gene was amplified with primers 515F (5'-GTGCCAGCMGCCGCGGTAA-3') and 806R (5'-GGACTACHVGGTWTCTAAT-3'). The PCR reaction was conducted as follows: a denaturation was carried out at 94°C for 3 minutes, 30-35 denaturation cycles at 94°C for 30 s for amplification, hybridization at 53°C for 40s, then elongation at 72°C for 1 minute and a final extension at 72°C for 5 minutes. After amplification, PCR products were visualized by electrophoresis on 2% agarose gel. Then, the two samples were grouped and purified together in equal proportions based on their DNA concentrations. The samples were purified using the ampure XP calibrated ball method. Then, pooled and purified PCR products are used to prepare the Illumina DNA bank. Sequencing was performed at MR DNA (www.mrdnalab.com, Shalowater, TX, USA).

2.4. Bioinformatics Analysis and Statistical Processing

Sequences were assembled and the barcodes eliminated. Then 150 bp sequences and chimeras were removed. The OTUs were defined by grouping the sequences at 3% divergence. The final OTUs were taxonomically classified using the BLAST program against the organized database derived from RDPII and NCBI (www.ncbi.nlm.nih.gov, http://rdp.cme.msu.edu). The analysis of sequence data and calculation of the relative abundances of all taxa were carried out using Excel 2013 software. Then, the rarefaction curves and alpha diversity indices namely Chao1, Shannon, Simpson and equitability J’ were plotted and calculated using the PAST software. Finally, bacterial community’ diversity of two soils was determined by principal component analysis (PCA) to compare relative levels of genus and phylum diversity using Graph Pad software.

3. Results

3.1. Soil Characteristics

Table 1 shows physicochemical properties of two soils. The soil around Cajanus is composed of 75.17% sand, 18.33% silt and 6.5% clay. According to USDA’ textural triangle, this soil was a sandy loam. For soil around Milletia, particle size analysis gave the following percentages: 67.69% for sand, 7.77% for clay and 24.54% for silt. The USDA textural triangle gives the same texture as the previous soil. The contents of carbon, total nitrogen, ammoniacal nitrogen, phosphorus, iron and magnesium were slightly high in the soil sample around Milletia. However, the equality of variances test (F-Test) between the two soils shows that the difference in the values obtained for all parameters is not significant (P > 0.05).

3.2. Composition of the Bacterial Community
3.2.1. Rarefaction Curve

The rarefaction curve obtained with the Cajanus soil sample shows that the maximum diversity (Shannon index) is reached from 1201 OTUs. When the number of OTUs is increased, the Shannon index no longer increases and the curve shows a plateau. Thus the sampling effort is reached. For the Milletia soil sample, maximum diversity was reached with 2010 OTUs. The increase in the sampling effort, i.e. number of sequences, does not lead to an increase in the Shannon index (diversity) illustrated by a plateau.


3.2.2. Alpha Diversity Analysis

The Illumina sequencing resulted in 45.412 and 32.781 raw sequences for Cajanus and Milletia soil, respectively. After bioinformatics treatment the number of sequences decreased by 15.316 and 15.359 respectively for the Cajanus and Milletia soil. These sequences were grouped into 471 OTUs for Cajanus soil and 963 OTUs for Milletia soil. Then OTUs were classified into phylum, class, order, family and genus in the 2 soils. For Sol Cajanus, eight (8) phyla were the most representative with a relative abundance > 1%. These are: Proteobacteria (48.71%), Acidobacteria (27.29%), Firmicutes (8.26%), Chloroflexi (5.83%), Actinobacteria (3.24%), Bacteroidetes (2.53%), Nitrospirae (1.41%) and Gemmatimonadetes (1.12%). While for Sol Milletia, seven (7) phyla were the most representative among which: Proteobacteria (58.62%), Bacteroidetes (13.70%), Acidobacteria (9.46%), Firmicutes (7.21%), Actinobacteria (5.05%), Nitrospirae (2.42%) and Planctomycetes (1.22%) (Figure 2).

The Chao 1 estimator shows that both soils have the specific richness of 9. However, the diversity was slightly higher in Cajanus soil (H'= 1.43; 1-D= 0.67) than in Milletia soil (H'= 1.33; 1-D= 0.60). With regard to equitability in both soils, sequences were unevenly distributed in the phyla. This shows a low equiabability.

The Venn diagram (Figure 3) shows that 20 OTUs are common to both soil samples. However, the number of OTUs specific to Soil Cajanus and Milletia was 1 and 4, respectively.

Principal Component Analysis (PCA) was performed with the 9 most abundant phyla for both soils (Figure 4). The results show that Chloroflexi, Firmicutes and Acidobacteria are abundant in Cajanus soil while Gemmatimonadetes, Nitrospirae, Planctomycetes, Actinobacteria, Bacteroidetes and Proteobacteria abundant in Milletia soil. Taking into account axis 1, Gemmatimonadetes, Planctomycetes, Nitrospirae, Actinobacteria are negatively correlated and Proteobacteria is positively correlated. On the other hand, on axis 2, Chloroflexi, Firmicutes and Acidobacteria are positively correlated while Bacteroidetes is negatively correlated.

At the gender level, the PCA results showed that axes 1 and 2 explain 100% of the total variation (Figure 5). Axis 1 represents 61.52% and axis 2 38.48% of the observed variation. The PCA also shows that the genera Rhodoplanes, Bradyrhizobium, Sphingobacterium, Bacillus and Mesorhizobium are positively correlated with axis 1, but Acidobacterium, Skermanella, Chloroflexus are negatively correlated.


3.2.3. Relative Abundance of Classes

For Cajanus soil, 11 classes were the most representative with a relative abundance > 1%. These are: Alphaproteobacteria (38.90%), Acidobacteriia (26.57%), Bacilli (8.19%), Chloroflexia (5.13%), Gammaproteobacteria (4.27%), Betaproteobacteria (3.94%), Actinobacteria (3.24%), Sphingobacteriia (2.50%), Deltaproteobacteria (1.58%), Nitrospira (1.41%) and Gemmatimonadetes (1.12%). While the classes of Alphaproteobacteria (51.44%), Sphingobacteria (9.83%), Acidobacteriia (8.67%), Bacilli (7.18%), Actinobacteria (5.05%), Gammaproteobacteria (3.39%), Gemmatimonadetes (3.39%), Betaproteobacteria (3.28%), Nitrospira (2.42%) and Planctomycetia (1.17%) were the most representative in Milletia soil (Figure 6).


3.2.4. Relative Abundance of Families

For Cajanus soil, 17 families were the most dominant with an abundance > 1%. These are: Hyphomicrobiaceae (35.05%), Bacillaceae (18.98%), Bradyrhizobiaceae (11.70%), Streptomycetaceae (3.66%), Methylobacteriaceae (3.44%), Hyphomonadaceae (3.00%), Pseudomonadaceae (2.40%), unclassified family Rhizobiales (2.07%), Sphingomonadaceae (1.91%), Mycobacteriaceae (1.75%), Rhizobiaceae (1.58%), Peanibacillaceae (1.58%) and Cystobacteriaceae (1.03%). While for Milletia soil, 14 families were the most representative among which: Hyphomicrobiaceae (24.22%), Bradyrhizobiaceae (17.32%), Bacillaceae (6.49%), Sphingobacteriaceae (5.80%), Chitinophagaceae (4.02%), Flavobacteriaceae (3.70%), Nitrospiraceae (2.42%), Xanthobacteriaceae (2.30), Sinobacteriaceae (2.11%), Sphingomonadaceae (1.97%), Burkholderiaceae (1.72%), Planctomycetaceae (1.17%), Mycobacteriaceae (1.08%) and Rhizobiaceae (1.08%) (Figure 7).


3.2.5. Relative Abundance of Genera

Sixteen genera were the most representative in the Cajanus soil, with a relative abundance > 1%. These genera are: Acidobacterium (26.55%), Skermanella (17.52%), Rhodoplanes (7.50%), Bacillus (6.29%), Chloroflexus (4.74%), Steroidobacter (2.34%), Sphingomonas (2.32%), Bradyrhizobium (1.96%), Dongia (1.80), Sphingobacterim (1.74%), Nitrospira (1.37%), Microvirga (1.30%), Cupriavidus (1.12%), Gemmatimonas (1.12%), Chelatococcus (1.03%) and Streptomyces (1.02%). While, in Milletia soil, the most representative genera (19) were Rhodoplanes (21.63%), Bradyrhizobium (17.27%), Bacillus (6.43%), Sphingobacterium (5.68%), Acidobacterium (4.58%), Mesorhizobium (4.06%), Nitrospira (2.42%), Steroidobacter (2.05%), Hyphomicrobium (1.53%), Pedomicrobium (1.53%), Streptomyces (1.45%), Burkholderia (1.45%), Nitratireductor (1.33%), Niastella (1.33%), Sphingomonas (1.22%), Gemmatimonas (1.22%), Mycobacterium (1.08%) and Holophaga (1.08%) (Figure 8).

4. Discussion

The rhizosphere of legumes can contain bacteria that can stimulate plant growth and protect them from bio-aggressors. The latter can be used as biological fertilizers or biostimulant microorganisms 24, 25. Knowledge of this microflora can thus allow their isolation and selection. The objective of this study was to study the composition and diversity of bacterial communities in the rhizosphere of Milletia laurentii and Cajanus cajan, two legumes growing on the soil of the scientific city of Brazzaville, by Sequencing Illumina-Miseq of the 16S rRNA gene. Initially, particle size and physicochemical analyses were carried out. The results showed that soil samples under Cajanus cajan and Milletia laurentii have a sandy soil texture according to the USDA textural triangle. Although in the study by 16, soil texture was not presented, nevertheless, the clay, silt and sand contents found in our study were very similar to the results of these authors. For the mineral elements C, P, N, NH4+, Mg and Fe, the levels were slightly elevated in the Milletia soil. However, the F-test showed that the difference is not significant. This may be due to the fact that the two plants are not very far apart from each other. In addition, the relatively low content of mineral elements in the two soil samples can be explained by the fact that that Brazzaville capital of the Republic of Congo is located in the tropical zone where the rains are abundant. The latter leach the soils by depleting them of mineral elements. Carbon and nitrogen are two of the most important elements that affect soil productivity and environmental quality 26. According to 27 it is accepted that the higher the C/N ratio of a product, the slower it degrades in the soil and the more stable humus it provides.

Regarding the diversity of bacterial communities, illumina sequencing resulted in 15316 and 15359 sequences respectively for Cajanus and Milletia soils. In both soils, analysis of the rarefaction curve showed that the sample effort was achieved illustrated by a plateau. The sequences obtained were grouped into 471 OTUs for Cajanus soil and 963 OTUs for Milletia soil with a similarity of 97%. Then, OTUs were classified at different taxonomic levels.

Proteobacteria was the most abundant phylum in both soil samples. These results are consistent with previous studies that have shown that Proteobacteria is the phylum the most representative in soils 16, 28, 29. The predominance of this phylum is probably due to their metabolic capacity. Indeed, the bacteria belonging to this phylum intervene in biogeochemical cycles 30. Nevertheless, other phyla have also been identified namely Acidobacteria (27.29%), Firmicutes (8.26%), Chloroflexi (5.83%), Actinobacteria (3.24%), Bacteriodetes (2.53%), Nitrospirae (1.41%) and Gemmatimonadetes (1.12%) for Cajanus soil and Bacteroidetes (13.70%), Acidobacteria (9.46%), Firmicutes (7.21%), Actinobacteria (5.05%), Nitrospirae (2.42%) and Planctomycetes for Milletia soil. The microbial community is therefore different from one soil to another. These phyla intervene in various ways in the soil. Indeed, Firmicutes produce metabolites necessary for the biocontrol and growth of plants. As for Acidobacteria, it was pointed out by 31 that bacteria belonging to this phylum are capable of to use nitrite as a source of nitrogen, to adapt to variations in macroelements and nutrients to soil acidity and the production of exopolysaccharides. Moreover, this diversity can be justified by the fact that many previous studies have shown that structure and diversity soil microbial communities are affected by many factors including plant species, soil types, biological selection and farm management 16, 32, 33, 34. Thus, Milletia and Cajanus being two different legumes, the leaves that fall around the trunk to form humus and the exudates released at the roots may not have the same composition. This probably influences the composition of the bacterial community. The study of the diversity α at the phylum level showed that the two rhizosphere soil samples have a specific richness of 9 (Chao 1 estimator). However, the diversity was slightly higher in Cajanus soil (H' = 1.43; 1-D = 0.67) than in Milletia soil (H' = 1.33; 1-D = 0.60). With regard to equitability in both soils, the sequences were unevenly distributed in the phyla. This shows low equitability. According to 35 and 36, bacterial richness and diversity play a crucial role in soil quality and ecosystem sustainability. These authors claimed that reducing soil richness and bacterial diversity could contribute to altering plant performance and insufficient resistance to diseases and pests in continuous crops. At the class level, Alphaproteobacteria were more dominant in both soils (Milletia and Cajanus). These results are consistent with those found by 37. However, the abundance of this class was higher in the Milletia soil (51.44%) than in the soil of the Cajanus rhizosphere (38.90%). The predominance of this class in the soil Milletia is probably due to the difference in composition of the leaves and exudates released by the latter since these two legumes grow on the same soil and enjoy the same climate of Brazzaville. 38 claim that Alphaproteobacteria is widespread in soil but is also dominant in nodules, stems and leaves. A field investigation by these authors had indicated that the aerial parts of the plants (leaves) harbor bacterial communities complex and highly variable and that only a small number of bacterial taxa belonging mainly to Alphaproteobacteria is plant-specific. Other classes have also been identified, these are: Acidobacteriia (26.57%), Bacilli (8.19%), Chloroflexia (5.13%), Gammaproteobacteria (4.27%), Betaproteobacteria (3.94%), Actinobacteria (3.24%), Sphingobacteriia (2.50%), Deltaproteobacteria (1.58%), Nitrospira (1.41%) and Gemmatimonadetes (1.12%) for Cajanus soil, and Sphingobacteria (9.83%), Acidobacteriia (8.67%), Bacilli (7.18%), Actinobacteria (5.05%), Gammaproteobacteria (3.39%), Gemmatimonadetes (3.39%), Betaproteobacteria (3.28%), Nitrospira (2.42%) and Planctomycetia (1.17%) for Milletia soil. These classes have also been identified in previous studies 16, 30.

The Hyphomicrobiaceae family was the most dominant in both soil samples with a relative abundance of 35.05% and 24.22% respectively for the Cajanus and Milletia rhizospheres. These results are different from those found by 16. In the study of these authors, it is the family bacillaceae that was dominant in the soil of the Scientific City of Brazzaville, with a relative abundance of 25.37%. While Hyphomicrobiaceae accounted for only 6.40%. These differences may be related to the sampling point that is not the same and the sampling period. Indeed, the collection of ORSTOM soil, in the study of 16, was carried out at the geographical coordinate point 4°16'42.1439" S and 15°14'24.6538" E. While in our study the soil was taken around the point of latitude -4.27825 and longitude 15.24118. Although the points are located in the same site, the environment, in terms of vegetation, is not the same. However, Hyphomicrobiaceae were dominant in SNR soil in the study by 16. An other authors 39 founded in their study more Hyphomicrobiaceae in the raw soil than in the rhizosphere. Other families have been identified such as: Bacillaceae (18.98%), Bradyrhizobiaceae (11.70%), Streptomycetaceae (3.66%), Methylobacteriaceae (3.44%), Hyphomonadaceae (3.00%), Pseudomonadaceae (2.40%), unclassified family Rhizobiales (2.07%), Sphingomonadaceae (1.91%), Mycobacteriaceae (1.75%), Rhizobiaceae (1.58%), Peanibacillaceae (1.58%) and Cystobacteriaceae (1.03%). While for Milletia soil, the most representative families were Bradyrhizobiaceae (17.32%), Bacillaceae (6.49%), Sphingobacteriaceae (5.80%), Chitinophagaceae (4.02%), Flavobacteriaceae (3.70%), Nitrospiraceae (2.42%), Xanthobacteriaceae (2.30), Sinobacteriaceae (2.11%), Sphingomonadaceae (1.97%), Burkholderiaceaes (1.72%), Planctomycetaceae (1.17%), Mycobacteriaceae (1.08%) and Rhizobiaceae (1.08%). These families have also been identified in previous studies. For example, 40 identified, among others, in the rhizosphere of Paeonia jishanensis Sphingomonadaceae, Bradyrhizobiaceae, Chitinophagaceae, Planctomycetaceae, Pseudomonadaceae and Flavobacteriaceae. 38 showed that at the lower taxonomic ranks within Alphaproteobacteria, sequences belonging to members of Methylobacteriaceae and Sphingomonadaceae are more abundant in stems than in soil and nodules. In addition, Methylobacteriaceae and Sphingomonadaceae have been found as endophytes in a number of plants 38. Bacteria in these families can benefit from plant life through their ability to use methanol (as a carbon source) released by the metabolism of the pectin that makes up the plant cell wall 38.

The Venn diagram made from the dominant genera showed that the two soil samples of the rhizosphere of Milletia and Cajanus have 20 common genera confirming the proximity of sampling points. Nevertheless, four genera have been specific to the Milletia rhizosphere and one genus specific to the Cajanus rhizosphere. This difference can be justified by the composition of the leaves and exudates secreted at the roots. In terms of genera, Acidobacterium was the most dominant genus in the Cajanus rhizosphere with a relative abundance of (26.55%) while in the Milletia rhizosphere, the genus Rhodoplanes was the most dominant with a relative abundance of 21.63%. These results are different from those found by 16 at ground level in the scientific city of Brazzaville (e.g. ORSTOM). Indeed, these authors found Bacillus as the dominant genus with a relative abundance of 25.27%. However, Acidobacterium (8.49%) and Rhodoplanes (15.48%) were more abundant in the rhizosphere of MFILOU and SNR respectively. According to 41, different plant species secrete different types of root exudates, this can change the structure of microbial communities at the rhizosphere. The following genera have also been identified with abundances > 1%. These are: Skermanella (17.52%), Rhodoplanes (7.50%), Bacillus (6.29%), Chloroflexus (4.74%), Steroidobacter (2.34%), Sphingomonas (2.32%), Bradyrhizobium (1.96%), Dongia (1.80), Sphingobacterim (1.74%), Nitrospira (1.37%), Microvirga (1.30%), Cupriavidus (1.12%), Gemmatimonas (1.12%), Chelatococcus (1.03%) and Streptomyces (1.02%). While, in the Milletia soil, the most representative were Bradyrhizobium (17.27%), Bacillus (6.43%), Sphingobacterium (5.68%), Acidobacterium (4.58%), Mesorhizobium (4.06%), Nitrospira (2.42%), Steroidobacter (2.05%), Hyphomicrobium (1.53%), Pedomicrobium (1.53%), Streptomyces (1.45%), Burkholderia (1.45%), Nitratireductor (1.33%), Niastella (1.33%), Sphingomonas (1.22%), Gemmatimonas (1.22%), Mycobacterium (1.08%) and Holophaga (1.08%). These genera have been identified in previous studies 16, 30, 40, 42, 43. Bacteria belonging to its different taxonomic genera play an important role in plant growth. Indeed, bacteria of the genus Bradyrhizobium enrich the medium with nitrogen which can also promote the transfer of nitrogen in the medium to non-legume plants, through root-root contact, mycorrhizal networks, root exudates and following the decomposition of nitrogen-enriched residues 42. With regard to the genus Bacillus, 44 have shown that they form a group of bacteria with very diverse enzymatic activities (proteolytic, amylolytic, pectinolytic, cellulolytic, lipasic) and produce metabolites such as bacteriocins and other antimicrobial molecules. Also, they possess the ability to withstand harsh environmental conditions due to their stability and natural rigidity. 42 point out that Bacillus secrete several metabolites not only to improve plant growth but also to inhibit the microbial growth of pathogens in the soil by degrading cell walls. As for bacteria belonging to the genus Mesorhizobium, 45 point out that they are symbiotic bacteria of legumes, nitrogen fixers, belonging to the group of rhizobacteria. The latter promote plant growth by solubilizing phosphate which leads to an increase in crop productivity. 46 showed that Rhizobium/Bradyrhizobium co-inoculation increases root weight and shoots, plant vigor, nitrogen fixation and grain yield of various legumes. Thus, Rhizobium, Gram-negative bacteria living in the soil, promote plant growth by fixing atmospheric nitrogen, in symbiotic association with legumes and also improve soil fertility 47. With regard to Sphingobacterium, 48 also indicated that they are producers of siderophores that provide iron to plants that is present in the soil as insoluble ferric oxide by making it unavailable to plant pathogens. As for 49, bacteria of the genus Streptomyces, also identified in our study, produce abundant metabolites that play various roles in agriculture such as plant growth and resistance to plant pathogens. It was indicated in the study conducted by 50 that Streptomyces can produce metabolites including cellulase and natamycin under the conditions of sound-based solid-state fermentation. These bacteria belong to the group of rhizobacteria that promote plant growth. It has been reported by 44, that these bacteria can alleviate abiotic stress in plants and can help resist cold stress by inducing the production of antioxidants and the secretion of phytohormones in plants. Thus, several of the identified genera may have an interest in agriculture and/or biotechnology.

5. Conclusion

The diversity and structure of bacterial communities in the rhizosphere of two legumes Cajanus cajan and Milletia laurentii growing on the same soil were determined using the Illumina Miseq technique targeting the 16S rRNA gene. The results showed that the Cajanus rhizosphere is slightly more diverse than the Milletia rhizosphere. Nevertheless, the rhizosphere of these two soils contains phyla that contain bacteria such as Bradyrhizobium, Bacillus, Sphingobacterium, Mesorhizobium, Rhizobium, Streptomyces capable of producing phytohormones, antimicrobial molecules to eliminate plant pathogens, mineralize organic matter and even fix atmospheric nitrogen. Thus, these soils can be used as a source for the isolation of microbial biofertilizers.

Acknowledgments

This research was funded by the authors. The Institute for Research in Exact and Natural Sciences provided technical support.

Conflict of Interest

The authors do not declare any conflict of interest in this work.

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[4]  Li S., Zou D., Li L., Wu L., Liu F., Zeng X., Wang H., Zhu Y. and Xiao Z. 2020. Evolution of heavy metals during thermal treatment of manure: A critical review and out looks. Chemosphere.
In article      View Article  PubMed
 
[5]  Borquez C., Frias-Espericueta M.G. and Voltolina D. 2016. Removal of cadmium and lead by adapted strains of Pseudomonas aeruginosa and Enterobacter cloacae. Rev. Int. Contam. Ambient. 32, 407-412.
In article      View Article
 
[6]  Gallego S.M., Pena L.B., Barcia R.A., Azpilicueta C.E., Iannone M.F., Rosales E.P., Benavides M.P. 2012. Unravelling cadmium toxicity and tolerance in plants: insight into regulatory mechanisms. Environ. Exp. Bot 83, 33-46.
In article      View Article
 
[7]  Okafor N. 2011. Pollution of aquatic systems: Pollution through eutrophication, fecal materials, and oil spills. Environmental Microbiology of aquatic and waste systems, 151-187.
In article      View Article
 
[8]  Zhang M.M., Fan S.H., Guan F.Y. and Yin Z.X. 2020. Soil bacterial community structure of mixed bamboo and broad-leaved, Scientific reports, nature research, vol. 1(210). 6522.
In article      View Article  PubMed
 
[9]  Prashar P., Kapoor N., Sachdeva S. 2013. Rhizosphere: its structure, bacterial diversity and signifiance. Rev Environ Sci Biotechnol.
In article      View Article
 
[10]  Mahanty T., Bhattacharjee S., Goswami M., Bhattacharyya P., Das B., Ghosh A and Tribedy P. 2016. Biofertilizers: a potentiel approach for sustainable agriculture development. Environ. Sci. Poll. Res. 23, 1-21.
In article      
 
[11]  Mazid M. and Khan T.A. 2015. Future of biofertilizers in Indian agriculture: an overview. International Journal of Agricultural and Food Research 3(3): 10-23.
In article      View Article
 
[12]  Babolola O.O. and Igiehon O.N. 2017. Biofertilizers and sustainable agriculture: exploring arbuscular mycorrhizal fungi. Appl. Microbiol. Biotechnol 101: 4871-4881.
In article      View Article  PubMed
 
[13]  Aboubacar K., Ousmane Z.M., Amadou H.I., Issaka S., Zoubeirou A.M. 2013. Effect of rhizobial and mycorrhizal co-inoculation on the agronomic performance of cowpea [Vigna unguiculata (L.) Walp. ] in Niger. Journal of Applied Biosciences 72, 5846-5854.
In article      View Article
 
[14]  Murgese P., Santamaria P., Leoni B. and Crecchio C. 2020. Ameliorative effects of PGPB on yield physiological parameters, and nutrient transporters gene expression in Barattiere (Cucumus melo L.). J. Soil. Sci. Plant. Nutr. 20,784-793.
In article      View Article
 
[15]  Fasusi O.A., Cruz C., Babolola O.O. 2021. Agricultural sustainability: Microbial biofertilizers in rhizosphere management. Agriculture 11-163.
In article      View Article
 
[16]  Mabiala S.T., Goma-Tchimbakala J., Goma-Tchimbakala E.J.C.D., Lebonguy A.A and Banga A.B. 2020. Diversity of the Bacterial Community of Three Soils Revealed by Illumina-Miseq Sequencing of 16S rRNA Gene in the South of Brazzaville, Congo. American Journal of Microbiological Research, vol. 8: 141-149.
In article      View Article
 
[17]  Samba-Kimbata M.J. 1978. Le climat du Bas-Congo. Thèse 3ème cycle Géographie, Université de Dijon, Faculté des Sciences Humaines, Centre de recherche de climatologie, 280p.
In article      
 
[18]  Vennetier P. 1977. Climat In Atlas de la République Populaire du Congo. Les Editions Jeune Afrique, Paris (France), 10-15.
In article      
 
[19]  Nelson D.W. and Sommers L.E. 1982. Total carbon, organic carbon and organic matter, in Methods of soil analysis, Part 2 American Society of Agronomy, Madison, 1982, pp. 539-579.
In article      View Article  PubMed
 
[20]  Bremmer J.M. and Mulvaney C.S. 1982. Nitrogen-Total carbon, chez Methods of soil analysis, Chemical and Microbiological properties, American Society of Agronomy, Soil Science Society of Americana, Madison, 1982, 595-624.
In article      View Article
 
[21]  Murphey J. and Riley P.P. 1962. A modified single solution method for the determination of phosphate in natural water. Anal. Chimim. Acta, vol. 27, pp.31-36.
In article      View Article
 
[22]  Segalen P.P. 1971. La détermination du fer libre dans les sols à sesquioxydes, Cah. ORSTOM, sér. Pédol. Vol. 9(11), pp. 3-27.
In article      
 
[23]  Dabin B. 1967. Application des dosages automatiques à l’analyse des sols; 3ème partie, Cahiers ORSTOM, série Pédologie, vol (3), pp. 257-263.
In article      
 
[24]  Weil A. and Duval J. 2009. Les amendements organiques, fumiers et composts. Dans Guide de gestion globale de la ferme maraichère biologique et diversifiée; Module 7: Amendement et fertilisation. Equiterre; 1-19.
In article      
 
[25]  Alabouvette C. and Cordier C. 2018. Fertilité biologique des sols: des microorganismes utiles à la croissance des plantes. Innovations Agronomiques 69, 61-70.
In article      
 
[26]  Hamarashid N.H., Othman M.A. and Hussain M.A.H. 2010. Effects of soil texture on chemical compositions, microbial populations and carbon mineralization in soil, Egypt. J. Expp. Biol. (Bot), vol. 6(11), pp. 59-64.
In article      
 
[27]  Robin D. 1997. Interest of biochemical characterization for the evaluation of the proportion of stable organic matter after decomposition in soil and the classification of organomeral products. Agronomy, EDP Sciences 17(3), pp. 157-171.
In article      View Article
 
[28]  Lauber C.L., Hamady M., Knight R. and Fierer N. 2009. Pyrosequencing-based assessment of soil pH as a predictor of soil bacterial community structure at the continental scale. Appl Environ Microbiol, vol. 75, pp. 5111-5120.
In article      View Article  PubMed
 
[29]  Janssen P.H. 2006. Identifying the dominant Soil Bacterial Taxa in Librairies of 16S rRNA Genes. Applied and Environmental Microbiology, 72, 1719-1728.
In article      View Article  PubMed
 
[30]  Putrie R.F.W., Aryantha I.P. and Antonius I.S. 2020. Diversity of endophytic and rhizosphere bacteria from pineaple (Ananas comosus) plant in semi arid ecosystem. Biodiversitas Vol 21, Number 7, pp: 3084-3093.
In article      View Article
 
[31]  Ek-Ramos M.J., Gomez-Flores R., Orozco-Flores A.A., Rodriguez-Padilla C., Gonzalez-Ochoa G. and Tamez-Guerra P. 2009. Bioactive products from plant-endophytic Gram-Positive bacteria. Front Microbiol 10: 463
In article      View Article  PubMed
 
[32]  Klein E., Katan J. and Gamliel A. 2016. Soil suppressiveness by organic amendement to Fusarium disease in cucumber: Effect on pathogen and host. Phytoparasitica, vol. 44, pp. 239-249.
In article      View Article
 
[33]  Qiu M., Zhang R., Xue C., Zhang S., Li S., Zhang N. and Shen Q. 2012. Application of bio-organic fertilizers can control Fusarium wilt of cucumber plants by regulating microbial community of rhizosphere soil, Biol. Fertil. Soils, vol. 48, pp. 807-816.
In article      View Article
 
[34]  Sun B., Dong Z.X., Zhang X.X., Li Y., Cao H. and Cui Z.L. 2011. Rice to Vegetables: Short-Versus Long-term Impact of Land-Use Change on the Indigenous Soil Microbial Community, Microb. Ecol. Vol. 1(262), pp. 474-485.
In article      View Article  PubMed
 
[35]  Alami M.M., Xue J., Ma Y., Zhu D., Gong Z., Shu S. and Wang X. 2020. Structure, Diversity, and Composition of Bacterial Communities in Rhizospheric Soil of Coptis chinensis Franch under Continuously Cropped Fields, Diversity, vol, 1(212), 57.
In article      View Article
 
[36]  Kennedy A.C. and Smith K.L. 1995. Soil microbial diversity and the sustainability of agriculture soil, Plant Soil, vol. 170, pp. 75-86.
In article      View Article
 
[37]  Antoun S.A. 2016. Bacterial Diversity in hyperarid Atacama Desert Soils. Journal of Geophysical Research: Biogeo sciences, 112, G04S17.
In article      
 
[38]  Francesco P., Frascella A., Santopolo L., Bazzicalupo M., Biondi E.G., Scotti C. and Mengoni A. 2012. Exploring the plant-associated bacterial communities in Medicago sativa L. BCM Microbiology 12: 78.
In article      View Article  PubMed
 
[39]  Uroz S., Marc B., Claude M., Pascal F.K. and Francis M. 2010. Pyrosequencing reveals a contrasted bacterial diversity between oak rhizosphere and surrounding soil. Environmental Microbiology Reports 2(2), 281-288.
In article      View Article  PubMed
 
[40]  Wang Q., Jiang X., Guan D., Wei D., Zhao B., Ma M., Chen S., Li L., Cao F. and Li L. 2017. Long-term fertilization changes bacterial communities in the maize rhizosphere of Chinese Mollisols. Applied Soil Ecology.
In article      View Article
 
[41]  Xuan X., Liu L., He X., Wang K., Xie Q., O’Donnell A.G. and Chen C. 2015. The Bradyrhizobium-legume symbiosis is dominant in shrubby ecosystem of the karst region Southwest China. European Journal of Soil Biology 68 (2015) 1-8.
In article      View Article
 
[42]  Barelli F., Santos F.L., 2021. Plant microbiome structure and benefits for sustainable agriculture. Current Plant Biology 26, 100198, 2021.
In article      View Article
 
[43]  Yin P., Shi P., Zhang Y., Hu Z., Ma K., Wang H. and Chai T. 2017. The Response of Soil Bacterial communities to Mining Subsidence in the West China Aeolian Sand Area. Applied Soil Ecology 121, 1-10.
In article      View Article
 
[44]  Zubair M., Hamif A., Farzand A., Sheikh M.M.T., Khan R.A., Suleman M., Ayaz M. and Gao X. 2019. Genetic Screening and Expression Analysis of Psychrophilic Bacillus spp. Reveal Their Potentiel to Alleviate Cold Stress and Modulate Phytohormones in Wheat. Microorganisms 2019, 7, 337.
In article      View Article  PubMed
 
[45]  Verma J.P., Yadav J., Tiwari N.K. 2012. Enhancement of nodulation and yield of chickpea by co-inoculation of indigenous Mesorhizobium spp. and plant growth promoting rhizobacteria on nodulation Plant growth-promoting rhizobacteria in eastern Uttar Pradesh. Commun. Soil Sci. Plant Anal. 43, 605-621.
In article      View Article
 
[46]  Valverde A., Burgos A., Friscella T., Rivas R., Velaz-quez E., Rodriguez-Barrueco C., Cervantes E., Chamber M. and Igual J.M. 2006. Deferential effects of coinoculations with Pseudomonas jessenii PS06 (a phosphate-solubilizing bacteria) and Mesorhizobium ciceri C-2/2 strains on the growth and seed yield of chickpea under greenhouse and field conditions. Plant Soil 287, 43-50.
In article      View Article
 
[47]  Marques A.P.G.C, Pires C., Moreira H., Rangel A.O.S.S., Castro P.M.L. 2010. Assessment of the plant growth promotion abilities of six bacterial isolates using zeamays as indicator plants. Soil Biol. Biochem. 42, 1229-1235.
In article      View Article
 
[48]  Tian F., Ding Y., Zhu H., Yao L. and Du B. 2009. Genetic Diversity of Siderophore producing bacteria of Tobacco rhizosphere. Brazilian Journal of Microbiology (2009): 40: 276-284.
In article      View Article  PubMed
 
[49]  Hu D., Li S., Li Y., Peng J., Wei X., Ma J., Zhang C., Jia N., Wang E. and Wang Z. 2020. Streptomyces sp. Strain TOR3209: a rhizosphere bacterium promoting growth of tomato by affecting the rhizosphere microbial communities.
In article      View Article  PubMed
 
[50]  Zheng Z.H., Qiao Y.J., Li Z.Z., Wang X., Zhu B. and Hu Y.G. 2019. Effect of legume-cereal mixtures on the diversity of bacterial communities in the rhizosphere, Plant Soil Environ 58. (4): 174-180.
In article      View Article
 

Published with license by Science and Education Publishing, Copyright © 2022 Alvychelle Benith Banga, Augustin Aimé Lebonguy, Angélique Espérance Lembella Boumba and Joseph Goma-Tchimbakala

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Cite this article:

Normal Style
Alvychelle Benith Banga, Augustin Aimé Lebonguy, Angélique Espérance Lembella Boumba, Joseph Goma-Tchimbakala. Bacterial Communitie’s Diversity of Rhizosphere’s Soils of Two Legumes, Cajanus cajan and Milletia laurentii, Revealed by Illumina Miseq Sequencing of 16S rRNA Gene. World Journal of Agricultural Research. Vol. 10, No. 1, 2022, pp 20-29. http://pubs.sciepub.com/wjar/10/1/4
MLA Style
Banga, Alvychelle Benith, et al. "Bacterial Communitie’s Diversity of Rhizosphere’s Soils of Two Legumes, Cajanus cajan and Milletia laurentii, Revealed by Illumina Miseq Sequencing of 16S rRNA Gene." World Journal of Agricultural Research 10.1 (2022): 20-29.
APA Style
Banga, A. B. , Lebonguy, A. A. , Boumba, A. E. L. , & Goma-Tchimbakala, J. (2022). Bacterial Communitie’s Diversity of Rhizosphere’s Soils of Two Legumes, Cajanus cajan and Milletia laurentii, Revealed by Illumina Miseq Sequencing of 16S rRNA Gene. World Journal of Agricultural Research, 10(1), 20-29.
Chicago Style
Banga, Alvychelle Benith, Augustin Aimé Lebonguy, Angélique Espérance Lembella Boumba, and Joseph Goma-Tchimbakala. "Bacterial Communitie’s Diversity of Rhizosphere’s Soils of Two Legumes, Cajanus cajan and Milletia laurentii, Revealed by Illumina Miseq Sequencing of 16S rRNA Gene." World Journal of Agricultural Research 10, no. 1 (2022): 20-29.
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[1]  Kumar S., Satyavir S.D., Kumar R.S., 2022. Biofertilizers: An ecofriendly technology for nutrient recycling and environmental sustainability. Current Research in Microbial Sciences 3(2022) 1000094.
In article      View Article  PubMed
 
[2]  Buta M., Korzeniewska E., Harnisz M., Hebeny J., Zielinski W., Rolbiecki D., Bajkacz S., Felis E., Kokoszka K., 2021. Microbial and chemical polluants one the manure-crops pathway in the perspective of “One health” holistic approach. Science of the total Environment 785 (2021) 147411.
In article      View Article  PubMed
 
[3]  Felden B., Cattoira V., 2018. Bacterial adaptation to antibiotics through regulatory RNAs. Antimicrob. Agents Chemother. 62, 1-11.
In article      View Article  PubMed
 
[4]  Li S., Zou D., Li L., Wu L., Liu F., Zeng X., Wang H., Zhu Y. and Xiao Z. 2020. Evolution of heavy metals during thermal treatment of manure: A critical review and out looks. Chemosphere.
In article      View Article  PubMed
 
[5]  Borquez C., Frias-Espericueta M.G. and Voltolina D. 2016. Removal of cadmium and lead by adapted strains of Pseudomonas aeruginosa and Enterobacter cloacae. Rev. Int. Contam. Ambient. 32, 407-412.
In article      View Article
 
[6]  Gallego S.M., Pena L.B., Barcia R.A., Azpilicueta C.E., Iannone M.F., Rosales E.P., Benavides M.P. 2012. Unravelling cadmium toxicity and tolerance in plants: insight into regulatory mechanisms. Environ. Exp. Bot 83, 33-46.
In article      View Article
 
[7]  Okafor N. 2011. Pollution of aquatic systems: Pollution through eutrophication, fecal materials, and oil spills. Environmental Microbiology of aquatic and waste systems, 151-187.
In article      View Article
 
[8]  Zhang M.M., Fan S.H., Guan F.Y. and Yin Z.X. 2020. Soil bacterial community structure of mixed bamboo and broad-leaved, Scientific reports, nature research, vol. 1(210). 6522.
In article      View Article  PubMed
 
[9]  Prashar P., Kapoor N., Sachdeva S. 2013. Rhizosphere: its structure, bacterial diversity and signifiance. Rev Environ Sci Biotechnol.
In article      View Article
 
[10]  Mahanty T., Bhattacharjee S., Goswami M., Bhattacharyya P., Das B., Ghosh A and Tribedy P. 2016. Biofertilizers: a potentiel approach for sustainable agriculture development. Environ. Sci. Poll. Res. 23, 1-21.
In article      
 
[11]  Mazid M. and Khan T.A. 2015. Future of biofertilizers in Indian agriculture: an overview. International Journal of Agricultural and Food Research 3(3): 10-23.
In article      View Article
 
[12]  Babolola O.O. and Igiehon O.N. 2017. Biofertilizers and sustainable agriculture: exploring arbuscular mycorrhizal fungi. Appl. Microbiol. Biotechnol 101: 4871-4881.
In article      View Article  PubMed
 
[13]  Aboubacar K., Ousmane Z.M., Amadou H.I., Issaka S., Zoubeirou A.M. 2013. Effect of rhizobial and mycorrhizal co-inoculation on the agronomic performance of cowpea [Vigna unguiculata (L.) Walp. ] in Niger. Journal of Applied Biosciences 72, 5846-5854.
In article      View Article
 
[14]  Murgese P., Santamaria P., Leoni B. and Crecchio C. 2020. Ameliorative effects of PGPB on yield physiological parameters, and nutrient transporters gene expression in Barattiere (Cucumus melo L.). J. Soil. Sci. Plant. Nutr. 20,784-793.
In article      View Article
 
[15]  Fasusi O.A., Cruz C., Babolola O.O. 2021. Agricultural sustainability: Microbial biofertilizers in rhizosphere management. Agriculture 11-163.
In article      View Article
 
[16]  Mabiala S.T., Goma-Tchimbakala J., Goma-Tchimbakala E.J.C.D., Lebonguy A.A and Banga A.B. 2020. Diversity of the Bacterial Community of Three Soils Revealed by Illumina-Miseq Sequencing of 16S rRNA Gene in the South of Brazzaville, Congo. American Journal of Microbiological Research, vol. 8: 141-149.
In article      View Article
 
[17]  Samba-Kimbata M.J. 1978. Le climat du Bas-Congo. Thèse 3ème cycle Géographie, Université de Dijon, Faculté des Sciences Humaines, Centre de recherche de climatologie, 280p.
In article      
 
[18]  Vennetier P. 1977. Climat In Atlas de la République Populaire du Congo. Les Editions Jeune Afrique, Paris (France), 10-15.
In article      
 
[19]  Nelson D.W. and Sommers L.E. 1982. Total carbon, organic carbon and organic matter, in Methods of soil analysis, Part 2 American Society of Agronomy, Madison, 1982, pp. 539-579.
In article      View Article  PubMed
 
[20]  Bremmer J.M. and Mulvaney C.S. 1982. Nitrogen-Total carbon, chez Methods of soil analysis, Chemical and Microbiological properties, American Society of Agronomy, Soil Science Society of Americana, Madison, 1982, 595-624.
In article      View Article
 
[21]  Murphey J. and Riley P.P. 1962. A modified single solution method for the determination of phosphate in natural water. Anal. Chimim. Acta, vol. 27, pp.31-36.
In article      View Article
 
[22]  Segalen P.P. 1971. La détermination du fer libre dans les sols à sesquioxydes, Cah. ORSTOM, sér. Pédol. Vol. 9(11), pp. 3-27.
In article      
 
[23]  Dabin B. 1967. Application des dosages automatiques à l’analyse des sols; 3ème partie, Cahiers ORSTOM, série Pédologie, vol (3), pp. 257-263.
In article      
 
[24]  Weil A. and Duval J. 2009. Les amendements organiques, fumiers et composts. Dans Guide de gestion globale de la ferme maraichère biologique et diversifiée; Module 7: Amendement et fertilisation. Equiterre; 1-19.
In article      
 
[25]  Alabouvette C. and Cordier C. 2018. Fertilité biologique des sols: des microorganismes utiles à la croissance des plantes. Innovations Agronomiques 69, 61-70.
In article      
 
[26]  Hamarashid N.H., Othman M.A. and Hussain M.A.H. 2010. Effects of soil texture on chemical compositions, microbial populations and carbon mineralization in soil, Egypt. J. Expp. Biol. (Bot), vol. 6(11), pp. 59-64.
In article      
 
[27]  Robin D. 1997. Interest of biochemical characterization for the evaluation of the proportion of stable organic matter after decomposition in soil and the classification of organomeral products. Agronomy, EDP Sciences 17(3), pp. 157-171.
In article      View Article
 
[28]  Lauber C.L., Hamady M., Knight R. and Fierer N. 2009. Pyrosequencing-based assessment of soil pH as a predictor of soil bacterial community structure at the continental scale. Appl Environ Microbiol, vol. 75, pp. 5111-5120.
In article      View Article  PubMed
 
[29]  Janssen P.H. 2006. Identifying the dominant Soil Bacterial Taxa in Librairies of 16S rRNA Genes. Applied and Environmental Microbiology, 72, 1719-1728.
In article      View Article  PubMed
 
[30]  Putrie R.F.W., Aryantha I.P. and Antonius I.S. 2020. Diversity of endophytic and rhizosphere bacteria from pineaple (Ananas comosus) plant in semi arid ecosystem. Biodiversitas Vol 21, Number 7, pp: 3084-3093.
In article      View Article
 
[31]  Ek-Ramos M.J., Gomez-Flores R., Orozco-Flores A.A., Rodriguez-Padilla C., Gonzalez-Ochoa G. and Tamez-Guerra P. 2009. Bioactive products from plant-endophytic Gram-Positive bacteria. Front Microbiol 10: 463
In article      View Article  PubMed
 
[32]  Klein E., Katan J. and Gamliel A. 2016. Soil suppressiveness by organic amendement to Fusarium disease in cucumber: Effect on pathogen and host. Phytoparasitica, vol. 44, pp. 239-249.
In article      View Article
 
[33]  Qiu M., Zhang R., Xue C., Zhang S., Li S., Zhang N. and Shen Q. 2012. Application of bio-organic fertilizers can control Fusarium wilt of cucumber plants by regulating microbial community of rhizosphere soil, Biol. Fertil. Soils, vol. 48, pp. 807-816.
In article      View Article
 
[34]  Sun B., Dong Z.X., Zhang X.X., Li Y., Cao H. and Cui Z.L. 2011. Rice to Vegetables: Short-Versus Long-term Impact of Land-Use Change on the Indigenous Soil Microbial Community, Microb. Ecol. Vol. 1(262), pp. 474-485.
In article      View Article  PubMed
 
[35]  Alami M.M., Xue J., Ma Y., Zhu D., Gong Z., Shu S. and Wang X. 2020. Structure, Diversity, and Composition of Bacterial Communities in Rhizospheric Soil of Coptis chinensis Franch under Continuously Cropped Fields, Diversity, vol, 1(212), 57.
In article      View Article
 
[36]  Kennedy A.C. and Smith K.L. 1995. Soil microbial diversity and the sustainability of agriculture soil, Plant Soil, vol. 170, pp. 75-86.
In article      View Article
 
[37]  Antoun S.A. 2016. Bacterial Diversity in hyperarid Atacama Desert Soils. Journal of Geophysical Research: Biogeo sciences, 112, G04S17.
In article      
 
[38]  Francesco P., Frascella A., Santopolo L., Bazzicalupo M., Biondi E.G., Scotti C. and Mengoni A. 2012. Exploring the plant-associated bacterial communities in Medicago sativa L. BCM Microbiology 12: 78.
In article      View Article  PubMed
 
[39]  Uroz S., Marc B., Claude M., Pascal F.K. and Francis M. 2010. Pyrosequencing reveals a contrasted bacterial diversity between oak rhizosphere and surrounding soil. Environmental Microbiology Reports 2(2), 281-288.
In article      View Article  PubMed
 
[40]  Wang Q., Jiang X., Guan D., Wei D., Zhao B., Ma M., Chen S., Li L., Cao F. and Li L. 2017. Long-term fertilization changes bacterial communities in the maize rhizosphere of Chinese Mollisols. Applied Soil Ecology.
In article      View Article
 
[41]  Xuan X., Liu L., He X., Wang K., Xie Q., O’Donnell A.G. and Chen C. 2015. The Bradyrhizobium-legume symbiosis is dominant in shrubby ecosystem of the karst region Southwest China. European Journal of Soil Biology 68 (2015) 1-8.
In article      View Article
 
[42]  Barelli F., Santos F.L., 2021. Plant microbiome structure and benefits for sustainable agriculture. Current Plant Biology 26, 100198, 2021.
In article      View Article
 
[43]  Yin P., Shi P., Zhang Y., Hu Z., Ma K., Wang H. and Chai T. 2017. The Response of Soil Bacterial communities to Mining Subsidence in the West China Aeolian Sand Area. Applied Soil Ecology 121, 1-10.
In article      View Article
 
[44]  Zubair M., Hamif A., Farzand A., Sheikh M.M.T., Khan R.A., Suleman M., Ayaz M. and Gao X. 2019. Genetic Screening and Expression Analysis of Psychrophilic Bacillus spp. Reveal Their Potentiel to Alleviate Cold Stress and Modulate Phytohormones in Wheat. Microorganisms 2019, 7, 337.
In article      View Article  PubMed
 
[45]  Verma J.P., Yadav J., Tiwari N.K. 2012. Enhancement of nodulation and yield of chickpea by co-inoculation of indigenous Mesorhizobium spp. and plant growth promoting rhizobacteria on nodulation Plant growth-promoting rhizobacteria in eastern Uttar Pradesh. Commun. Soil Sci. Plant Anal. 43, 605-621.
In article      View Article
 
[46]  Valverde A., Burgos A., Friscella T., Rivas R., Velaz-quez E., Rodriguez-Barrueco C., Cervantes E., Chamber M. and Igual J.M. 2006. Deferential effects of coinoculations with Pseudomonas jessenii PS06 (a phosphate-solubilizing bacteria) and Mesorhizobium ciceri C-2/2 strains on the growth and seed yield of chickpea under greenhouse and field conditions. Plant Soil 287, 43-50.
In article      View Article
 
[47]  Marques A.P.G.C, Pires C., Moreira H., Rangel A.O.S.S., Castro P.M.L. 2010. Assessment of the plant growth promotion abilities of six bacterial isolates using zeamays as indicator plants. Soil Biol. Biochem. 42, 1229-1235.
In article      View Article
 
[48]  Tian F., Ding Y., Zhu H., Yao L. and Du B. 2009. Genetic Diversity of Siderophore producing bacteria of Tobacco rhizosphere. Brazilian Journal of Microbiology (2009): 40: 276-284.
In article      View Article  PubMed
 
[49]  Hu D., Li S., Li Y., Peng J., Wei X., Ma J., Zhang C., Jia N., Wang E. and Wang Z. 2020. Streptomyces sp. Strain TOR3209: a rhizosphere bacterium promoting growth of tomato by affecting the rhizosphere microbial communities.
In article      View Article  PubMed
 
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