Characterization of plant growth-promoting bacteria inhabiting Vriesea gigantea Gaud. and Tillandsia aeranthos (Loiseleur) L.B. Smith (Bromeliaceae)

Microorganisms that live inside and around a plant can supply it with essential substances, such as phytohormones and essential nutrients. The present investigation aimed to isolate and characterize the phyllosphere, the endophytic, and the water tank bacteria associated with Vriesea gigantea and Tillandsia aeranthos. The bacteria were tested for siderophore and indole-3-acetic acid (IAA) production, phosphate solubilization, and presence of the nif H gene. Genetic diversity of the bacterial isolates was evaluated by rep-PCR. Sixty-eight bacterial strains were isolated from 3 different microhabitats of V. gigantea and from 2 microhabitats of T. aeranthos bromeliad plants. Gram-positive, spore-forming bacilli comprised most bacterial isolates. All isolates produced IAA in vitro in presence of very low amounts of tryptophan. More than 70% of the evaluated bacteria presented the ability of siderophore production and phosphate solubilization, and possessed the nif H gene. It was not possible to distinguish well-defined groups of isolates based on the bromeliad species and microhabitat they inhabit using genetic characterization by rep-PCR. Water tanks presented the most abundant diversity compared with phyllosphere and endophytes, probably due to the high nutrient concentration, which promotes an ideal environment for complex microbial communities.

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Screening of Azotobacter isolates for PGP properties and antifungal activity

Zbornik Matice srpske za prirodne nauke ◽

10.2298/zmspn1529065b ◽

2015 ◽

pp. 65-72 ◽

Cited By ~ 3

Author(s):

Dragana Bjelic ◽

Jelena Marinkovic ◽

Branislava Tintor ◽

Sonja Tancic ◽

Aleksandra Nastasic ◽

...

Keyword(s):

Antifungal Activity ◽

Phosphate Solubilization ◽

Phytopathogenic Fungi ◽

Antagonistic Effect ◽

Bacterial Isolates ◽

Plant Growth Promoting ◽

Fusarium Sp ◽

Growth Promoting ◽

Indole 3 Acetic Acid

?mong 50 bacterial isolates obtained from maize rhizospher?, 13 isolates belonged to the genus Azotobacter. Isolates were biochemically characterized and estimated for pH and halo tolerance ability and antibiotic resistance. According to characterization, the six representative isolates were selected and further screened in vitro for plant growth promoting properties: production of indole-3-acetic acid (IAA), siderophores, hydrogen cyanide (HCN), exopolysaccharides, phosphate solubilization and antifungal activity (vs. Helminthosporium sp., Macrophomina sp., Fusarium sp.). Beside HCN production, PGP properties were detected for all isolates except Azt7. All isolates produced IAA in the medium without L-tryptophan and the amount of produced IAA increased with concentration of precursor in medium. The highest amount of IAA was produced by isolates Azt4 (37.69 and 45.86 ?g ml-1) and Azt5 (29.44 and 50.38 ?g ml-1) in the medium with addition of L-tryptophan (2.5 and 5 mM). The isolates showed the highest antifungal activity against Helminthosporium sp. and the smallest antagonistic effect on Macrophomina sp. Radial Growth Inhibition (RGI) obtained by the confrontation of isolates with tested phytopathogenic fungi, ranged from 10 to 48%.

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Bioprospecting of elite plant growth-promoting bacteria for the maize crop

Acta Scientiarum Agronomy ◽

10.4025/actasciagron.v42i1.44364 ◽

2020 ◽

Vol 42 ◽

pp. e44364 ◽

Cited By ~ 1

Author(s):

Angela Cristina Ikeda ◽

Daiani Cristina Savi ◽

Mariangela Hungria ◽

Vanessa Kava ◽

Chirlei Glienke ◽

...

Keyword(s):

Plant Growth ◽

Plant Growth Promoting Bacteria ◽

Bacterial Strains ◽

Maize Crop ◽

Agriculture Sustainability ◽

Plant Growth Promoting ◽

Promote Plant Growth ◽

Growth Promoting ◽

Biological Nitrogen

The use of plant growth-promoting bacteria (PGPB), which aims to replace chemical fertilizers and biological control, is a goal for achieving agriculture sustainability. In this scenario, our goal was to identify and evaluate the potential of bacteria isolated from maize roots to promote plant growth and be used as inoculants. We evaluated 173 bacterial strains isolated from the maize (Zea mays L.) rhizosphere for the properties of their PGPB in vitro. Twelve strains were positive for siderophores, indole acetic acid (IAA) production, biological nitrogen fixation (BNF), and phosphate solubilization. Sequence analysis of 16S rRNA identified these strains as belonging to the genera Cellulosimicrobium, Stenotrophomonas, Enterobacter, and Bacillus. The elite strains were evaluated under greenhouse conditions upon the inoculation of two maize hybrids, ATL100 and KWX628. The ability of the isolates to promote plant growth was dependent on the maize genotype; Enterobacter sp. LGMB208 showed the best ability to promote growth of hybrid ATL100, while Enterobacter sp. strains LGMB125, LGMB225, and LGMB274 and Cellulosimicrobium sp. strain LGMB239 showed the best ability to promote growth of hybrid KWX628. The results highlight the potential of bacterial genera little explored as maize PGPB but indicate the need to investigate their interactions with different plant genotypes.

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IN VITRO FORMATION OF ASSOCIATED BIOFILMS BY TRICHODERMA SPP. AND PLANT GROWTH PROMOTING BACTERIA (PGPB)

ÈKOBIOTEH ◽

10.31163/2618-964x-2020-3-3-324-330 ◽

2020 ◽

Vol 3 (3) ◽

pp. 324-330

Author(s):

N.F. Galimzianova ◽

◽

G.E. Aktuganov ◽

T.F. Boyko ◽

E.A. Gilavnova ◽

...

Keyword(s):

Plant Protection ◽

Phytopathogenic Fungi ◽

Plant Residues ◽

Fungal Mycelium ◽

Plant Growth Promoting Bacteria ◽

Bacterial Strains ◽

Trichoderma Spp ◽

Yield Increase ◽

Plant Growth Promoting

The capability to formation of combined biofilms by the fungi from Trichoderma genus and several PGP-bacteria including Pseudomonas extremaustralis, P. koreensis, P. mandelii and Advenella kashmirensis has been demonstrated. The strains of Trichoderma used in the experiment not only exert antagonism to phytopathogenic fungi, but also accelerate the decomposition of plant residues. It was found that microscopic fungi whose mycelial structure offers advantages in reaching and assimilating of nutrient substrates, during their growth can favor to directional moving of bacteria cells. The explored bacterial strains moved along the fungal mycelium on the surface of the medium, and in areas where the medium was absent, the bacteria moved inside the hyphae, leaving them when the mycelium reached the substrate. The findings evidence the potential of considered microorganisms for developing of a new generation multifunctional biopreparation for agriculture, contributing not only to crop yield increase and plant protection against phytopathogenic fungi, but also maintaining soil fertility.

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Role of Two Plant Growth-Promoting Bacteria in Remediating Cadmium-Contaminated Soil Combined with Miscanthus floridulus (Lab.)

Plants ◽

10.3390/plants10050912 ◽

2021 ◽

Vol 10 (5) ◽

pp. 912

Author(s):

Shuming Liu ◽

Hongmei Liu ◽

Rui Chen ◽

Yong Ma ◽

Bo Yang ◽

...

Keyword(s):

Plant Growth ◽

Contaminated Soils ◽

Translocation Factor ◽

Plant Growth Promoting Bacteria ◽

Bacterial Strains ◽

Pgp Traits ◽

Cd Tolerance ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Cd Translocation

Miscanthus spp. are energy plants and excellent candidates for phytoremediation approaches of metal(loid)s-contaminated soils, especially when combined with plant growth-promoting bacteria. Forty-one bacterial strains were isolated from the rhizosphere soils and roots tissue of five dominant plants (Artemisia argyi Levl., Gladiolus gandavensis Vaniot Houtt, Boehmeria nivea L., Veronica didyma Tenore, and Miscanthus floridulus Lab.) colonizing a cadmium (Cd)-contaminated mining area (Huayuan, Hunan, China). We subsequently tested their plant growth-promoting (PGP) traits (e.g., production of indole-3-acetic acid, siderophore, and 1-aminocyclopropane-1-carboxylate deaminase) and Cd tolerance. Among bacteria, two strains, Klebsiella michiganensis TS8 and Lelliottia jeotgali MR2, presented higher Cd tolerance and showed the best results regarding in vitro growth-promoting traits. In the subsequent pot experiments using soil spiked with 10 mg Cd·kg−1, we investigated the effects of TS8 and MR2 strains on soil Cd phytoremediation when combined with M. floridulus (Lab.). After sixty days of planting M. floridulus (Lab.), we found that TS8 increased plant height by 39.9%, dry weight of leaves by 99.1%, and the total Cd in the rhizosphere soil was reduced by 49.2%. Although MR2 had no significant effects on the efficiency of phytoremediation, it significantly enhanced the Cd translocation from the root to the aboveground tissues (translocation factor > 1). The combination of K. michiganensis TS8 and M. floridulus (Lab.) may be an effective method to remediate Cd-contaminated soils, while the inoculation of L. jeotgali MR2 may be used to enhance the phytoextraction potential of M. floridulus.

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The Effects of Plant Growth-Promoting Bacteria with Biostimulant Features on the Growth of a Local Onion Cultivar and a Commercial Zucchini Variety

Agronomy ◽

10.3390/agronomy11050888 ◽

2021 ◽

Vol 11 (5) ◽

pp. 888

Author(s):

Giorgia Novello ◽

Patrizia Cesaro ◽

Elisa Bona ◽

Nadia Massa ◽

Fabio Gosetti ◽

...

Keyword(s):

Plant Growth ◽

Growth Promotion ◽

Global Market ◽

Plant Growth Promoting Bacteria ◽

Bacterial Strains ◽

Mineral Concentration ◽

Positive Effects ◽

Plant Growth Promoting ◽

Onion Cultivar ◽

Growth Promoting

The reduction of chemical inputs due to fertilizer and pesticide applications is a target shared both by farmers and consumers in order to minimize the side effects for human and environmental health. Among the possible strategies, the use of biostimulants has become increasingly important as demonstrated by the fast growth of their global market and by the increased rate of registration of new products. In this work, we assessed the effects of five bacterial strains (Pseudomonas fluorescens Pf4, P. putida S1Pf1, P. protegens Pf7, P. migulae 8R6, and Pseudomonas sp. 5Vm1K), which were chosen according to their previously reported plant growth promotion traits and their positive effects on fruit/seed nutrient contents, on a local onion cultivar and on zucchini. The possible variations induced by the inoculation with the bacterial strains on the onion nutritional components were also evaluated. Inoculation resulted in significant growth stimulation and improvement of the mineral concentration of the onion bulb, induced particularly by 5Vm1K and S1Pf1, and in different effects on the flowering of the zucchini plants according to the bacterial strain. The present study provides new information regarding the activity of the five plant growth-promoting bacteria (PGPB) strains on onion and zucchini, two plant species rarely considered by the scientific literature despite their economic relevance.

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

Journal of Engineering Environment and Agriculture Research ◽

10.34002/jeear.v1i0.17 ◽

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.

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Multifarious Indigenous Diazotrophic Rhizobacteria of Rice (Oryza sativa L.) Rhizosphere and Their Effect on Plant Growth Promotion

Frontiers in Nutrition ◽

10.3389/fnut.2021.781764 ◽

2022 ◽

Vol 8 ◽

Author(s):

Mohammad Imran Mir ◽

Bee Hameeda ◽

Humera Quadriya ◽

B. Kiran Kumar ◽

Noshin Ilyas ◽

...

Keyword(s):

Plant Growth ◽

Phosphate Solubilization ◽

Nitrogenase Activity ◽

Hydrolytic Enzymes ◽

Seed Vigor ◽

Bacterial Isolates ◽

Diazotrophic Bacteria ◽

Pgp Traits ◽

Rice Plants

A diverse group of rhizobacteria persists in the rhizospheric soil, on the surface of roots, or in association with rice plants. These bacteria colonize plant root systems, enhance plant growth and crop yield. Indigenous rhizobacteria are known to promote soil health, grain production quality and serve as sustainable bioinoculant. The present study was aimed to isolate, identify and characterize indigenous plant growth promoting (PGP) diazotrophic bacteria associated with the rhizosphere of rice fields from different areas of Jammu and Kashmir, India. A total of 15 bacteria were isolated and evaluated for various PGP traits, antagonistic activity against phytopathogens, production of hydrolytic enzymes and biofilm formation under in-vitro conditions. The majority of the isolated bacteria were Gram-negative. Out of 15 bacterial isolates, nine isolates produced IAA (12.24 ± 2.86 to 250.3 ± 1.15 μg/ml), 6 isolates exhibited phosphate solubilization activity (36.69 ± 1.63 to 312.4 ± 1.15 μg/ml), 7 isolates exhibited rock phosphate solubilization while 5 isolates solubilized zinc (10–18 mm), 7 isolates showed siderophore production, 8 isolates exhibited HCN production, 6 isolates exhibited aminocyclopropane-1-carboxylate (ACC) deaminase activity, 13 isolates exhibited cellulase activity, nine isolates exhibited amylase and lipase activity and six isolates exhibited chitinase activity. In addition, 5 isolates showed amplification with the nifH gene and showed a significant amount of nitrogenase activity in a range of 0.127–4.39 μmol C2H4/mg protein/h. Five isolates viz., IHK-1, IHK-3, IHK-13, IHK-15 and IHK-25 exhibited most PGP attributes and successfully limited the mycelial growth of Rhizoctonia solani and Fusarium oxysporum in-vitro. All the five bacterial isolates were identified based on morphological, biochemical and 16S rDNA gene sequencing study, as Stenotrophomonas maltophilia, Enterobacter sp., Bacillus sp., Ochrobactrum haematophilum and Pseudomonas aeruginosa. Rice plants developed from seeds inoculated with these PGP strains individually had considerably higher germination percentage, seed vigor index and total dry biomass when compared to control. These findings strongly imply that the PGP diazotrophic bacteria identified in this work could be employed as plant growth stimulators in rice.

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COLONIZATION of Rubus glaucus BENTH BY AZORHIZOBIUM CAULINODANS ORS571 USIG A FLAVONOIDE NARINGENINA

BISTUA REVISTA DE LA FACULTAD DE CIENCIAS BASICAS ◽

10.24054/01204211.v2.n2.2016.2117 ◽

2016 ◽

Vol 14 (2) ◽

pp. 15

Author(s):

Giovani Orlando Cancino Escalante ◽

S E Cancino ◽

Enrique Quevedo Garcia

Keyword(s):

Bacterial Colonization ◽

Lateral Roots ◽

Plant Growth Promoting Bacteria ◽

Azorhizobium Caulinodans ◽

Intensity Parameters ◽

Plant Growth Promoting ◽

Measuring Frequency ◽

Northwest Region ◽

Azorhizobium Caulinodans Ors571

Root systems of two Andean blackberry materials (thorn and thornless) of Rubus glaucus Benth cultured in vitro in the presence of five treatments (four flavonoids and one control) were inoculated with Azorhizobium caulinodans ORS571 (pXLGD4) (a strain carrying the lacZ reporter gene which facilitated the detection of bacterial colonization). Evaluation of colonization effectiveness for each treatment was done by means of application of experimental design measuring frequency and intensity parameters. Statistical analysis showed differences at comparing flavonoids vs. control and the overall higher effectiveness of the flavonoid naringenin. Observation of colonization was made by light and electron microscope confirming internal colonization of Andean blackberry roots by A. caulinodans. This is the first work demonstrating root colonization of R.glaucus by azorhizobia and therefore settling the basis for future investigations and scientific applications related to interaction with plant growth-promoting bacteria under the effect of flavonoids, along with possible implications of common benefit for non-legume crops in the northwest region of Colombia. Key Words: Azorhizobium caulinodans ORS571, Andean blackberry, flavonoids, LacZ, lateral roots, naringenin.

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Inorganic Phosphate Solubilization by a Novel Isolated Bacterial Strain Enterobacter sp. ITCB-09 and Its Application Potential as Biofertilizer

Agriculture ◽

10.3390/agriculture10090383 ◽

2020 ◽

Vol 10 (9) ◽

pp. 383 ◽

Cited By ~ 3

Author(s):

Gustavo Enrique Mendoza-Arroyo ◽

Manuel Jesús Chan-Bacab ◽

Ruth Noemi Aguila-Ramírez ◽

Benjamín Otto Ortega-Morales ◽

René Efraín Canché Solís ◽

...

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Inorganic Phosphate ◽

Extracellular Polymeric Substances ◽

Phosphate Solubilization ◽

Rrna Gene ◽

Bacterial Strains ◽

Habanero Pepper ◽

Phosphate Solubilizing

The excessive use of fertilizers in agriculture is mainly due to the recognized plant requirements for soluble phosphorus. This problem has limited the implementation of sustainable agriculture. A viable alternative is to use phosphate solubilizing soil microorganisms. This work aimed to isolate inorganic phosphorus-solubilizing bacteria from the soils of agroecosystems, to select and identify, based on sequencing and phylogenetic analysis of the 16S rRNA gene, the bacterium with the highest capacity for in vitro solubilization of inorganic phosphate. Additionally, we aimed to determine its primary phosphate solubilizing mechanisms and to evaluate its effect on Habanero pepper seedlings growth. A total of 21 bacterial strains were isolated by their activity on Pikovskaya agar. Of these, strain ITCB-09 exhibited the highest ability to solubilize inorganic phosphate (865.98 µg/mL) through the production of organic acids. This strain produced extracellular polymeric substances and siderophores that have ecological implications for phosphate solubilization. 16S rRNA gene sequence analysis revealed that strain ITCB-09 belongs to the genus Enterobacter. Enterobacter sp. ITCB-09, especially when immobilized in beads, had a positive effect on Capsicum chinense Jacq. seedling growth, indicating its potential as a biofertilizer.

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Growth response of wheat cultivars to bacterial inoculation in calcareous soil

Plant Soil and Environment ◽

10.17221/75/2010-pse ◽

2010 ◽

Vol 56 (No. 12) ◽

pp. 570-573 ◽

Cited By ~ 14

Author(s):

D. Egamberdieva

Keyword(s):

Plant Growth ◽

Calcareous Soil ◽

Dry Weight ◽

Plant Growth Promoting Bacteria ◽

Wheat Cultivars ◽

Bacterial Strains ◽

Bacterial Inoculation ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Selection Of

In this study the plant growth-promoting bacteria were analysed for their growth-stimulating effects on two wheat cultivars. The investigations were carried out in pot experiments using calcareous soil. The results showed that bacterial strains Pseudomonas spp. NUU1 and P. fluorescens NUU2 were able to colonize the rhizosphere of both wheat cultivars. Their plant growth-stimulating abilities were affected by wheat cultivars. The bacterial strains Pseudomonas sp. NUU1 and P. fluorescens NUU2 significantly stimulated the shoot and root length and dry weight of wheat cv. Turon, whereas cv. Residence was less affected by bacterial inoculation. The results of our study suggest that inoculation of wheat with Pseudomonas strains can improve plant growth in calcareous soil and it depends upon wheat cultivars. Prior to a selection of good bacterial inoculants, it is recommended to select cultivars that benefit from association with these bacteria.

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