scholarly journals Cultivable mushroom growth-promoting bacteria and their impact on Agaricus blazei productivity

2013 ◽  
Vol 48 (6) ◽  
pp. 636-644 ◽  
Author(s):  
Li-Sen Young ◽  
Jiunn-Nan Chu ◽  
Asif Hameed ◽  
Chiu-Chung Young
Keyword(s):  
Nitrogen Fixation ◽  
Protein Complex ◽  
Phosphate Solubilization ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Agaricus Blazei ◽  
Bacterial Isolates ◽  
Mycelium Growth ◽  
Growth Promoting ◽  
Solubilization Ability

The objective of this work was to identify growth-promoting bacteria isolated from Agaricus blazei and to evaluate their effect on mushroom mycelial growth and productivity. A total of 56 A. blazei-associated bacterial isolates were obtained from casing soil and identified by 16S rRNA gene sequencing. Bacteria were evaluated as to phosphate-solubilization ability, nitrogen-fixation capability, and secretion of cellulase. Superior isolates were tested for their to effect on A. blazei productivity, micelial growth, and on the contents of the polysaccharide-protein complex and of N, P, K, Ca, and Mg. Bacterial isolates were identified as actinobacteria (60%), firmicutes (20%), and proteobacteria (20%). Among them, ten isolates had phosphate-solubilization ability, eight showed nitrogen-fixation capability, and 12 isolates promoted A. blazei mycelium growth. Bacterial inoculation reduces time till harvest in up to 26 days, increases fresh mushroom yield up to 215%, and increases total polysaccharide-protein complex content twofold when compared to the non-inoculated control. The actinobacteria group is the predominant A. blazei-associated phylum.

scholarly journals Isolation and characterization of plant growth-promoting endophytic bacteria of wild legumes growing on sandy soils of Binh Thuan province, Vietnam

2021 ◽  
Vol 10 (3) ◽  
pp. 246-254
Author(s):  
Dang Thi Ngoc Thanh ◽  
Pham Thi Thu Ly ◽  
Pham Thi Nga ◽  
Pham Van Ngot
Keyword(s):  
Nitrogen Fixation ◽  
Plant Growth ◽  
Endophytic Bacteria ◽  
Phosphate Solubilization ◽  
Sandy Soils ◽  
Legume Species ◽  
Bacterial Isolates ◽  
Isolation And Characterization ◽  
Plant Growth Promoting ◽  
Growth Promoting

The roots of two legume species (Tephrosia purpurea and Tephrosia villosa) that grew wild on dry sandy soils of Binh Thuan province were sources for isolating plant growth-promoting endophytic bacteria. Semi-solid LGI medium was used for the isolation of nitrogen-fixing bacteria from root extracts. All bacterial isolates isolates were evaluated for their ability to solubilize calcium orthophosphate on solid NBRIP medium and their ability to produce IAA in Burk's liquid medium supplemented with 100 mg/L tryptophan. The possibilities of nitrogen fixation, phosphate solubilization and IAA synthesis were all quantitative examined by colorimetric method. Twenty-two bacterial isolates of T. purpurea and 18 isolates of T. villosa were capable of nitrogen fixation in the range of 1.94 to 2.81 mg/L NH4+, whereas only 18 isolates of T. purpurea and 16 isolates of T. villosa showed phosphate solubilization in the range of 12.30 – 48.90 mg/L P2O5, and IAA production in the range of 0.38 – 12.72 mg/L. Sixteen outstanding bacterial isolates of the two legume species were identified by MALDI-TOF technique. The results showed that 13 isolates had high similarity with five bacterial genera including Klebsiella, Cronobacter, Enterobacter, Burkholderia, and Bacillus with score values in the range of 2.070 – 2.411.

scholarly journals Salix purpurea and Eleocharis obtusa Rhizospheres Harbor a Diverse Rhizospheric Bacterial Community Characterized by Hydrocarbons Degradation Potentials and Plant Growth-Promoting Properties

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1987
Author(s):  
Fahad Alotaibi ◽  
Soon-Jae Lee ◽  
Marc St-Arnaud ◽  
Mohamed Hijri
Keyword(s):  
Carbon Source ◽  
Plant Growth ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Petrochemical Plant ◽  
Bacterial Isolates ◽  
Pgp Traits ◽  
Degrading Bacteria ◽  
Plant Growth Promoting ◽  
Growth Promoting

Phytoremediation, a method of phytomanagement using the plant holobiont to clean up polluted soils, is particularly effective for degrading organic pollutants. However, the respective contributions of host plants and their associated microbiota within the holobiont to the efficiency of phytoremediation is poorly understood. The identification of plant-associated bacteria capable of efficiently utilizing these compounds as a carbon source while stimulating plant-growth is a keystone for phytomanagement engineering. In this study, we sampled the rhizosphere and the surrounding bulk soil of Salixpurpurea and Eleocharis obusta from the site of a former petrochemical plant in Varennes, QC, Canada. Our objectives were to: (i) isolate and identify indigenous bacteria inhabiting these biotopes; (ii) assess the ability of isolated bacteria to utilize alkanes and polycyclic aromatic hydrocarbons (PAHS) as the sole carbon source, and (iii) determine the plant growth-promoting (PGP) potential of the isolates using five key traits. A total of 438 morphologically different bacterial isolates were obtained, purified, preserved and identified through PCR and 16S rRNA gene sequencing. Identified isolates represent 62 genera. Approximately, 32% of bacterial isolates were able to utilize all five different hydrocarbons compounds. Additionally, 5% of tested isolates belonging to genera Pseudomonas, Acinetobacter, Serratia, Klebsiella, Microbacterium, Bacillus and Stenotrophomonas possessed all five of the tested PGP functional traits. This culture collection of diverse, petroleum-hydrocarbon degrading bacteria, with multiple PGP traits, represents a valuable resource for future use in environmental bio- and phyto-technology applications.

scholarly journals Genomic characterization and computational phenotyping of nitrogen-fixing bacteria isolated from Colombian sugarcane fields

2019 ◽  
Author(s):  
Luz K. Medina-Cordoba ◽  
Aroon T. Chande ◽  
Lavanya Rishishwar ◽  
Leonard W. Mayer ◽  
Lina C. Valderrama-Aguirre ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Nitrogen Fixation ◽  
Plant Growth ◽  
Phosphate Solubilization ◽  
Bacterial Isolates ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
A Genome ◽  
Plant Growth Promoting ◽  
Growth Promoting

ABSTRACTPrevious studies have shown that the sugarcane microbiome harbors diverse plant growth promoting (PGP) microorganisms, including nitrogen-fixing bacteria, and the objective of this study was to design a genome-enabled approach to prioritize sugarcane associated nitrogen-fixing bacteria according to their potential as biofertilizers. Using a systematic high throughput approach, 22 pure cultures of nitrogen-fixing bacteria were isolated and tested for diazotrophic potential by PCR amplification of nitrogenase (nifH) genes, common molecular markers for nitrogen fixation capacity. Genome sequencing confirmed the presence of intact nitrogenase nifH genes and operons in the genomes of 18 of the isolates. Isolate genomes also encoded operons for phosphate solubilization, siderophore production operons, and other PGP phenotypes. Klebsiella pneumoniae strains comprised 14 of the 22 nitrogen-fixing isolates, and four others were members of closely related genera to Klebsiella. A computational phenotyping approach was developed to rapidly screen for strains that have high potential for nitrogen fixation and other PGP phenotypes while showing low risk for virulence and antibiotic resistance. The majority of sugarcane isolates were below a genotypic and phenotypic threshold, showing uniformly low predicted virulence and antibiotic resistance compared to clinical isolates. Six prioritized strains were experimentally evaluated for PGP phenotypes: nitrogen fixation, phosphate solubilization, and the production of siderophores, gibberellic acid and indole acetic acid. Results from the biochemical assays were consistent with the computational phenotype predictions for these isolates. Our results indicate that computational phenotyping is a promising tool for the assessment of benefits and risks associated with bacteria commonly detected in agricultural ecosystems.IMPORTANCEA genome-enabled approach was developed for the prioritization of native bacterial isolates with the potential to serve as biofertilizers for sugarcane fields in Colombia’s Cauca Valley. The approach is based on computational phenotyping, which entails predictions related to traits of interest based on bioinformatic analysis of whole genome sequences. Bioinformatic predictions of the presence of plant growth promoting traits were validated with experimental assays and more extensive genome comparisons, thereby demonstrating the utility of computational phenotyping for assessing the benefits and risks posed by bacterial isolates that can be used as biofertilizers. The quantitative approach to computational phenotyping developed here for the discovery of biofertilizers has the potential for use with a broad range of applications in environmental and industrial microbiology, food safety, water quality, and antibiotic resistance studies.

scholarly journals Genomic characterization and computational phenotyping of nitrogen-fixing bacteria isolated from Colombian sugarcane fields

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luz K. Medina-Cordoba ◽  
Aroon T. Chande ◽  
Lavanya Rishishwar ◽  
Leonard W. Mayer ◽  
Lina C. Valderrama-Aguirre ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Nitrogen Fixation ◽  
Plant Growth ◽  
Phosphate Solubilization ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
Promising Tool ◽  
A Genome ◽  
Plant Growth Promoting ◽  
Growth Promoting

AbstractPrevious studies have shown the sugarcane microbiome harbors diverse plant growth promoting microorganisms, including nitrogen-fixing bacteria (diazotrophs), which can serve as biofertilizers. The genomes of 22 diazotrophs from Colombian sugarcane fields were sequenced to investigate potential biofertilizers. A genome-enabled computational phenotyping approach was developed to prioritize sugarcane associated diazotrophs according to their potential as biofertilizers. This method selects isolates that have potential for nitrogen fixation and other plant growth promoting (PGP) phenotypes while showing low risk for virulence and antibiotic resistance. Intact nitrogenase (nif) genes and operons were found in 18 of the isolates. Isolates also encode phosphate solubilization and siderophore production operons, and other PGP genes. The majority of sugarcane isolates showed uniformly low predicted virulence and antibiotic resistance compared to clinical isolates. Six strains with the highest overall genotype scores were experimentally evaluated for nitrogen fixation, phosphate solubilization, and the production of siderophores, gibberellic acid, and indole acetic acid. Results from the biochemical assays were consistent and validated computational phenotype predictions. A genotypic and phenotypic threshold was observed that separated strains by their potential for PGP versus predicted pathogenicity. Our results indicate that computational phenotyping is a promising tool for the assessment of bacteria detected in agricultural ecosystems.

Assessing the Plant Growth-promoting Traits and Host Specificity of Endophytic Bacteria of Pulse Crops

2021 ◽  
Author(s):  
R. Thamizh Vendan ◽  
D. Balachandar
Keyword(s):  
Plant Growth ◽  
Endophytic Bacteria ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Growth And Yield ◽  
Rrna Gene ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Rrna Gene Sequencing ◽  
Plant Growth Promoting Traits

Background: Symbiotic associations between legumes and Rhizobia are ancient and fundamental. However, the plant growth-promoting endophytes other than Rhizobia are not yet fully explored for pulses productivity. The present study was aimed to isolate efficient endophytic bacteria from pulses, assess their diversity, screen their plant growth-promoting activities and to test their potential as bio inoculants for pulses.Methods: We have isolated several endophytic bacteria from pulse crops more specifically from blackgram (Vigna mungo) and greengram (Vigna radiata). After careful screening, 15 promising endophytic isolates were selected for this study. The identification of endophytic bacterial isolates was performed by 16S rRNA gene sequencing. The isolates were tested for their potential for the plant growth-promoting traits such as nitrogen fixation, phosphate solubilization, indole-3-acetic acid production, siderophore secretion and antifungal activity. Pot culture experiments were conducted with the screened potential endophytic cultures.Result: The 16S rRNA gene sequencing revealed that species of Enterobacter, Bacillus, Pantoea, Pseudomonas, Acromobacter, Ocrobacterium were found as endophytes in blackgram and greengram. The in vitro screening identified Bacillus pumilus (BG-E6), Pseudomonas fluorescens (BG-E5) and Bacillus licheniformis (BG-E3) from blackgram and Pseudomonas chlororaphis (GG-E2) and Bacillus thuringiensis (GG-E7) from greengram as potential plant growth-promoting endophytes. These strains showed antagonism against plant pathogenic fungi. Upon inoculation of these endophytic PGPR strains, the blackgram and greengram growth and yield got increased. Among the strains, BG-E6 recorded 14.7% increased yield in blackgram and GG-E2 accounted for a 19.5% yield increase in greengram compared to respective uninoculated control. The experimental results showed that there was a host specificity found among the endophytic bacterial cultures with pulses. The cross inoculation of endophytic strains did not perform well to enhance the growth and yield of their alternate hosts. 

scholarly journals Screening for Potential Plant Growth-Promoting Rhizobacteria (PGPR) Associated with Five Musa spp. Cultivars in SOCCSKSARGEN, Philippines

2018 ◽  
Vol 1 ◽  
pp. 5
Author(s):  
Giuseppe Haydn Lacorte ◽  
Remedios S. Flamiano ◽  
Malona V. Alinsug ◽  
Paolo M. Tagaloguin
Keyword(s):  
Microbial Population ◽  
Phosphate Solubilization ◽  
Plant Growth Promoting Rhizobacteria ◽  
Bacterial Isolates ◽  
Iaa Production ◽  
Phosphate Solubilizers ◽  
Rhizospheric Bacteria ◽  
Nitrogen Fixers ◽  
Plant Growth Promoting ◽  
Growth Promoting

Rhizospheric bacteria (PGPR) associated with 5 banana cultivars planted in SOCCSKSARGEN were studied. Microbial population in newly established and old plantation was compared. Bacteria were purified and their beneficial characteristics were determined. This study was able to collect one hundred twenty (120) bacterial isolates, 20 (17%) of which were nitrogen-fixers, nineteen (19/20) were phosphate solubilizers and seventeen (17/20) were IAA producers. From this study, five bacterial isolates coded PE05, RS10, PE11, PE13, and PE18 were found positive for nitrogen fixation, phosphate solubilization and IAA production which may be further evaluated for their potential application in the formulation of biofertilizers for banana cultivation. Read full article here.

scholarly journals Characterization of Arsenic-Resistant Endophytic Bacteria From Alfalfa and Chickpea Plants

2021 ◽  
Vol 12 ◽  
Author(s):  
Hazhir Tashan ◽  
Behrouz Harighi ◽  
Jalal Rostamzadeh ◽  
Abdolbaset Azizi
Keyword(s):  
Nitrogen Fixation ◽  
Plant Growth ◽  
Endophytic Bacteria ◽  
Phosphate Solubilization ◽  
Lipase Production ◽  
Growth Potential ◽  
Sodium Arsenate ◽  
Plant Growth Promoting ◽  
Growth Promoting

The present investigation was carried out to isolate arsenic (As)-resistant endophytic bacteria from the roots of alfalfa and chickpea plants grown in arsenic-contamination soil, characterize their As tolerance ability, plant growth-promoting characteristics, and their role to induce As resistance by the plant. A total of four root endophytic bacteria were isolated from plants grown in As-contaminated soil (160–260-mg As kg−1 of soil). These isolates were studied for plant growth-promoting (PGP) characteristics through siderophore, phosphate solubilization, nitrogen fixation, protease, and lipase production, and the presence of the arsenate reductase (arsC) gene. Based on 16S rDNA sequence analysis, these isolates belong to the genera Acinetobacter, Pseudomonas, and Rahnella. All isolates were found As tolerant, of which one isolate, Pseudomonas sp. QNC1, showed the highest tolerance up to 350-mM concentration in the LB medium. All isolates exhibited phosphate solubilization activity. Siderophore production activity was shown by only Pseudomonas sp. QNC1, while nitrogen fixation activity was shown by only Rahnella sp. QNC2 isolate. Acinetobacter sp. QNA1, QNA2, and Rahnella sp. QNC2 exhibited lipase production, while only Pseudomonas sp. QNC1 was able to produce protease. The presence of the arsC gene was detected in all isolates. The effect of endophytic bacteria on biomass production of alfalfa and chickpea in five levels of arsenic concentrations (0-, 10-, 50-, 75-, and 100-mg kg−1 soil) was evaluated. The fresh and dry weights of roots of alfalfa and chickpea plants were decreased as the arsenic concentration of the soil was increased. Results indicate that the fresh and dry root weights of alfalfa and chickpea plants were significantly higher in endophytic bacteria-treated plants compared with non-treated plants. Inoculation of chickpea plants with Pseudomonas sp. QNC1 and Rahnella sp. QNC2 induced lower NPR3 gene expression in chickpea roots grown in soil with the final concentration of 100-mg kg−1 sodium arsenate compared with the non-endophyte-treated control. The same results were obtained in Acinetobacter sp. QNA2-treated alfalfa plants grown in the soil plus 50-mg kg−1 sodium arsenate. These results demonstrated that arsenic-resistant endophytic bacteria are potential candidates to enhance plant-growth promotion in As contamination soils. Characterization of bacterial endophytes with plant growth potential can help us apply them to improve plant yield under stress conditions.

scholarly journals Assessment and Characterization of Xylanolytic Bacteria Isolated from the Gut of Microtermes Obesi for Biomass Pretreatment

2021 ◽  
Author(s):  
Iram Batool ◽  
Falak Sher Khan ◽  
Muhammad Awais ◽  
Dawood Ahmed ◽  
Sami Ullah Khan ◽  
...  
Keyword(s):  
Corn Stover ◽  
Rice Straw ◽  
16S Rrna Gene Sequencing ◽  
Major Constituent ◽  
Rrna Gene ◽  
Bacterial Isolates ◽  
Cotton Stalk ◽  
Termite Gut ◽  
Chemical Pretreatments ◽  
Rrna Gene Sequencing

Abstract The aim of current research was to examine the potential for the production of hemicelluloses degrading enzymes from bacteria harbor in termite gut. The research was also focused on the conversion of lignocellulosic biomass (Corn stover, rice straw and cotton stalk) into fermentable sugars by using enzymes from the bacterial isolates. The bacterial isolates from termite gut were screened for their ability to degrade xylan that is the major constituent of hemicelluloses. Two bacterial isolates were chosen and identified by 16S rRNA gene sequencing. Both isolates TGB9 and TGB10 belong to Bacillus geneus. The isolates have shown higher xylan degrading activity at 50 oC and optimum pH was 6.0. Xylanases from isolate TGB9 and TGB10 were utilized for sccharification of agricultural substrates (stover, rice straw and cotton stalk). As a result higher contents of reducing sugars were observed from corn stover. Xylanases from isolate TGB9 produced higher yields of reducing sugar than isolate TGB10. A comparative study was also performed among chemical pretreatment and xylanases from bacterial isolates. For this purpose agricultural substrates were also treated with H2SO4 and NaOH. Xylanases produced by TGB9 and TGB10 released higher content of sugar from agricultural substrates than chemical pretreatments. So it is concluded that termite gut have bacteria that can hydrolyze hemicelluloses more efficiently than chemicals.

scholarly journals Comparative molecular studies of halophilic bacteria from saline water and soil in the Saudi environment

2020 ◽  
Vol 36 (3) ◽  
Author(s):  
Mohamed Ahmed ◽  
Md. Mohibul Alam Khan ◽  
Saleh M. S. Al-Garni ◽  
Roop Singh Bora ◽  
Saleh A. Kabli
Keyword(s):  
Red Sea ◽  
Saline Water ◽  
Halophilic Bacteria ◽  
16S Rrna Gene Sequencing ◽  
Industrial Applications ◽  
Rrna Gene ◽  
Bacterial Isolates ◽  
High Concentration ◽  
Biochemical Tests ◽  
Water And Soil Samples

Halophilic bacteria are a microorganism that grows optimally in the presence of the very high concentration of sodium chloride. Halophiles are vital sources of various enzymes including hydrolases, which are very stable and catalytically highly efficient at high salt concentration and other extreme conditions such as high temperature, pH and presence of organic solvents.  Several hydrolases such as amylases, proteases, and lipases have been obtained from halophilic bacteria and are commonly used for various industrial applications. We initiated a screening project to isolate and characterize the halophilic bacteria from the Red Sea, which is one of the saltiest bodies of water in the world. Water and soil samples, collected from the Red Sea coast, Jeddah, Saudi Arabia, were screened for isolation of halophilic bacteria. Ten bacterial isolates were obtained, which were characterized by biochemical tests and 16S rRNA gene sequencing. Hydrolase producing bacteria among the isolates were screened by plate assay on starch and gelatin agar plates for amylase and protease, respectively.  Two bacterial isolates i.e Bacillus haynesii and Enterobacter cloacae subsp. were found to possess significant amylase and protease activity. Further characterization of both the strains is in progress.

scholarly journals Isolation and Characterization of Streptomycetes with Plant Growth Promoting Potential from Mangrove Ecosystem

2015 ◽  
Vol 64 (4) ◽  
pp. 339-349 ◽  
Author(s):  
Pooja Shrivastava ◽  
Rajesh Kumar ◽  
Mahesh Yandigeri ◽  
Nityanand Malviya ◽  
Dilip Arora
Keyword(s):  
Plant Growth ◽  
Sodium Dodecyl ◽  
16S Rrna Gene Sequencing ◽  
Mangrove Ecosystem ◽  
Rrna Gene ◽  
Population Count ◽  
Isolation And Characterization ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Enrichment Techniques

A total of 66 actinomycetes isolates were isolated from mangroves of Andhra Pradesh, India, using various enrichment techniques and pre-treatments. The samples were collected from Coringa mangrove ecosystem and pre-treated by enrichment with CaCO3, sodium dodecyl sulphate and phenol, plated on the media supplemented with cycloheximide (50 mg/ml), nystatin (25 mg/ml) and nalidixic acid (50 mg/ml). The population count of actinomycetes fluctuated from 1.9×105 to 8.0×105/g soil. Out of the isolated 66 actinomycetes, 8 isolates possessing plant growth promoting potential were further studied and characterized by physiological and biochemical traits and identified by 16S rRNA gene sequencing as different species of Streptomycetes genera.

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