scholarly journals Diversity and plant growth-promoting potential of (un)culturable bacteria in the Hedera helix phylloplane

2020 ◽  
Author(s):  
Vincent Stevens ◽  
Sofie Thijs ◽  
Jaco Vangronsveld
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Alpha Diversity ◽  
Growth Media ◽  
Culturable Bacteria ◽  
Bacterial Strains ◽  
Hedera Helix ◽  
Culture Independent ◽  
Plant Growth Promoting

Abstract BackgroundA diverse community of microbes naturally exists on the phylloplane, the surface of leaves. It is one of the most prevalent microbial habitats on earth and bacteria are the most abundant members, living in a community that is highly dynamic. While culture-independent approaches greatly increased our knowledge microbial communities such as the phylloplane, one of the challenges for microbiologists today remains to develop strategies to “culture the uncultured”.ResultsWe isolated bacteria from the phylloplane of Hedera helix (common ivy), a widespread evergreen, using the growth media LB, LB01, YMA, YFlour and YEx. We further included a comparison with the uncultured phylloplane, which contained the highest intra-sample (alpha) diversity. Inter-sample (beta) diversity shifts from LB and LB01 containing the highest amount of resources to YMA and YFlour which are more selective, and YEx which is more limited but also more varied in resources. The H. helix phylloplane is dominated by Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes in a distribution also found in other phyllosphere studies which further strengthens the finding that the phyllosphere community composition on higher taxonomic level is similar across various host plant species. All growth media more or less equally favored Actinobacteria and Gammaproteobacteria, whereas Bacteroidetes could only be found on LB01, YEx and YMA. LB and LB01 greatly favored Firmicutes and YFlour was most selective for Betaproteobacteria. At genus level, LB favored the growth of Bacillus and Stenotrophomonas, while YFlour was most selective for Burkholderia and Curtobacterium. The in vitro plant growth promotion (PGP) profile that we obtained by testing 200 isolates constitutes an important first step to find candidates with advantageous traits within microbe-assisted approaches. Our isolation effort also resulted in a significant collection of bacterial strains underrepresented in public databases, mostly from the phylum Actinobacteria.ConclusionsThis study contributes as a case study of bacterial culturability including an evaluation of five different growth media, a comparison with the uncultured H. helix phylloplane community and its relation with functional characteristics such as PGP potential which help us to understand the ecological and functional role of microbial members living in the phylloplane.

scholarly journals Diversity and plant growth-promoting potential of (un)culturable bacteria in the Hedera helix phylloplane

2020 ◽  
Author(s):  
Vincent Stevens ◽  
Sofie Thijs ◽  
Jaco Vangronsveld
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Alpha Diversity ◽  
Growth Media ◽  
Culturable Bacteria ◽  
Bacterial Strains ◽  
Hedera Helix ◽  
Culture Independent ◽  
Plant Growth Promoting

Abstract BackgroundA diverse community of microbes naturally exists on the phylloplane, the surface of leaves. It is one of the most prevalent microbial habitats on earth and bacteria are the most abundant members, living in a community that is highly dynamic. While culture-independent approaches greatly increased our knowledge of microbial communities such as the phylloplane, one of the challenges for microbiologists today remains to develop strategies to culture the vast diversity of microorganisms.ResultsWe isolated bacteria from the phylloplane of Hedera helix (common ivy), a widespread evergreen that constitutes an excellent model for studying the phylloplane in the field, using the growth media LB, LB01, YMA, YFlour and YEx. We also included a comparison with the uncultured phylloplane, which contained the highest intra-sample (alpha) diversity. Inter-sample (beta) diversity shifts from LB and LB01 containing the highest amount of resources to YMA and YFlour which are more selective, and YEx which is more limited but also more varied in resources. We show the H. helix phylloplane is dominated by Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes. Further, all growth media more or less equally favored Actinobacteria and Gammaproteobacteria, whereas Bacteroidetes could only be found on LB01, YEx and YMA. LB and LB01 greatly favored Firmicutes and YFlour was most selective for Betaproteobacteria. At genus level, LB favored the growth of Bacillus and Stenotrophomonas, while YFlour was most selective for Burkholderia and Curtobacterium. The in vitro plant growth promotion (PGP) profile that we obtained by testing 200 isolates constitutes an important first step to find candidates with advantageous traits within microbe-assisted approaches. Our isolation effort also resulted in a significant collection of bacterial strains underrepresented in public databases, mostly from the phylum Actinobacteria.ConclusionsThis study contributes as a case study of bacterial culturability including an evaluation of five different growth media, a comparison with the uncultured H. helix phylloplane community and its relation with functional characteristics such as PGP potential which help us to understand the putative ecological and functional role of microbial members living in the phylloplane.

scholarly journals Diversity and plant growth-promoting potential of (un)culturable bacteria in the Hedera helix phylloplane

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Vincent Stevens ◽  
Sofie Thijs ◽  
Jaco Vangronsveld
Keyword(s):  
Plant Growth ◽  
Yeast Extract ◽  
High Throughput Sequencing ◽  
Growth Promotion ◽  
Luria Bertani ◽  
Growth Media ◽  
Culturable Bacteria ◽  
Hedera Helix ◽  
Plant Growth Promoting

Abstract Background A diverse community of microbes naturally exists on the phylloplane, the surface of leaves. It is one of the most prevalent microbial habitats on earth and bacteria are the most abundant members, living in communities that are highly dynamic. Today, one of the key challenges for microbiologists is to develop strategies to culture the vast diversity of microorganisms that have been detected in metagenomic surveys. Results We isolated bacteria from the phylloplane of Hedera helix (common ivy), a widespread evergreen, using five growth media: Luria–Bertani (LB), LB01, yeast extract–mannitol (YMA), yeast extract–flour (YFlour), and YEx. We also included a comparison with the uncultured phylloplane, which we showed to be dominated by Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes. Inter-sample (beta) diversity shifted from LB and LB01 containing the highest amount of resources to YEx, YMA, and YFlour which are more selective. All growth media equally favoured Actinobacteria and Gammaproteobacteria, whereas Bacteroidetes could only be found on LB01, YEx, and YMA. LB and LB01 favoured Firmicutes and YFlour was most selective for Betaproteobacteria. At the genus level, LB favoured the growth of Bacillus and Stenotrophomonas, while YFlour was most selective for Burkholderia and Curtobacterium. The in vitro plant growth promotion (PGP) profile of 200 isolates obtained in this study indicates that previously uncultured bacteria from the phylloplane may have potential applications in phytoremediation and other plant-based biotechnologies. Conclusions This study gives first insights into the total bacterial community of the H. helix phylloplane, including an evaluation of its culturability using five different growth media. We further provide a collection of 200 bacterial isolates underrepresented in current databases, including the characterization of PGP profiles. Here we highlight the potential of simple strategies to obtain higher microbial diversity from environmental samples and the use of high-throughput sequencing to guide isolate selection from a variety of growth media.

scholarly journals Diversity and Plant Growth-Promoting Potential of (un)culturable Bacteria in the Hedera Helix Phylloplane

2020 ◽  
Author(s):  
Vincent Stevens ◽  
Sofie Thijs ◽  
Jaco Vangronsveld
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Growth Media ◽  
Culturable Bacteria ◽  
Bacterial Strains ◽  
Hedera Helix ◽  
Plant Growth Promoting ◽  
Diverse Community ◽  
And Function

Abstract BackgroundAn abundant and diverse community of microorganisms naturally exists on the phylloplane, the surface of leaves. It is one of the most prevalent microbial habitats on earth and bacteria are by far the most abundant members, living in a community that is highly dynamic. To increase our knowledge about the diversity and function of microbial communities living in the phylloplane, culture-dependent and -independent approaches help us a great deal.ResultsHere we isolated bacteria from the phylloplane of Hedera helix (common ivy), a widespread evergreen, using five different growth media. We further included a comparison with the uncultured phylloplane, which we show to contain the highest intra-sample diversity. Inter-sample bacterial diversity shifts from growth media most rich in nutrients to those which are more selective. The four major phyla Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes comprised the vast majority of phyla in the uncultured H. helix phylloplane, which furthermore were fully represented within growth medium samples. The plant growth promotion (PGP) profile we obtained by testing 200 isolates can help to select candidates with advantageous traits within various microbe-assisted approaches. Our isolation effort also resulted in a significant collection of bacterial strains underrepresented in public databases, mostly from the phylum Actinobacteria. ConclusionsThis study contributes as a case study of bacterial culturability and its relation with functional characteristics such as PGP potential which also is an important step towards understanding the ecological and functional role of microbial members living in the H. helix phylloplane.

scholarly journals Rice Bacterial Endophytes; 16S-Based Taxonomic Profiling, Isolation and Simplified Endophytic Community from Two Venezuelan Cultivars

2017 ◽  
Author(s):  
Felix Moronta-Barrios ◽  
Fabrizia Gionechetti ◽  
Alberto Pallavicini ◽  
Edgloris Marys ◽  
Vittorio Venturi
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
In Planta ◽  
Bacterial Strains ◽  
Taxonomic Profiling ◽  
Culture Independent ◽  
Plant Growth Promoting ◽  
Set Up ◽  
Endophytic Community

Rice is currently the most important food crop in the world and we are only just beginning to study the bacterial associated microbiome. It is of importance to perform screenings of the core rice microbiota and also to develop new plant-microbe models and simplified communities for increasing our understanding about the formation and function of its microbiome. In order to begin to address this aspect, we have performed the isolation of bacterial strains from the endorhizosphere of two rice cultivars from Venezuela. The validation of plant-growth promoting bacterial activities in vitro has led us to select and characterize 15 isolates for in planta studies such as germination test, endophytism ability and plant growth promotion. Consequently, a set of 10 isolates was selected for the set-up of an endophytic consortium as a simplified model of the natural rice bacterial endomicrobiota. Upon inoculation, the colonization and abundance of each strain within the rice roots was tracked by a culture-independent technique in gnotobiotic conditions in a 30 days period. Four strains belonging to Pseudomonas, Agrobacterium and Delftia genera have shown a promising capacity for colonizing and coexistence in root tissues. On the other hand, a bacterial community taxonomic profiling of the rhizosphere and the endorhizosphere of both cultivars were obtained and are discussed. This study is part of a growing body of research on core crops microbiome and simplified microbiomes, which strengthens the formation process of the endophytic community leading to a better understanding of the rice microbiome.

scholarly journals Isolation and Studies on Bacterial Endophytes from Two Venezuelan Rice Cultivars

2017 ◽  
Author(s):  
Felix Moronta-Barrios ◽  
Fabrizia Gionechetti ◽  
Alberto Pallavicini ◽  
Edgloris Marys ◽  
Vittorio Venturi
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Rice Cultivars ◽  
In Planta ◽  
Taxonomic Profiling ◽  
Culture Independent ◽  
Plant Growth Promoting ◽  
Set Up ◽  
And Function

Rice is currently the most important food crop in the world and we are only just beginning to study the bacterial associated microbiome. It is of importance to perform screenings of the core rice microbiota and also to develop new plant-microbe models and simplified communities for increasing our understanding about the formation and function of its microbiome. In order to begin to address this aspect, we have performed the isolation of hundreds bacterial isolates obtained from endorhizosphere of two rice cultivars from Venezuela. The validation of plant-growth promoting bacterial activities in vitro has led us to select and characterize 15 isolates for in planta studies such as germination test, endophytism ability and plant growth promotion. Consequently, a set of 10 isolates was selected for the set-up of an endophytic consortium as a simplified model of the natural rice bacterial endomicrobiota. Upon inoculation, the colonization and abundance of each strain within the rice roots was tracked by a culture-independent technique in gnotobiotic conditions in a 30 days period. Four strains belonging to Pseudomonas, Agrobacterium and Delftia genera have shown a promising capacity for colonizing and coexistence in root tissues. On the other hand, a bacterial community taxonomic profiling of the rhizosphere and the endorhizosphere of both cultivars were obtained and are discussed. This study is part of a growing body of research on core crops microbiome and simplified microbiomes, which strengthens the formation process of the endophytic community leading to a better understanding of the rice microbiome.

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

Agronomy ◽  
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.

scholarly journals Plant growth promotion properties of bacterial strains isolated from the rhizosphere of the Jerusalem artichoke (Helianthus tuberosusL.) adapted to saline–alkaline soils and their effect on wheat growth

2017 ◽  
Vol 63 (3) ◽  
pp. 228-237 ◽  
Author(s):  
Xiaolin Liu ◽  
Xiangyue Li ◽  
Yan Li ◽  
Runzhi Li ◽  
Zhihong Xie
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Yellow River ◽  
Growth Promotion ◽  
Jerusalem Artichoke ◽  
Yellow River Delta ◽  
Bacterial Strains ◽  
Wheat Growth ◽  
The Yellow River Delta ◽  
Plant Growth Promoting

The Jerusalem artichoke (JA; Helianthus tuberosus), known to be tolerant to saline–alkaline soil conditions, has been cultivated for many years in the Yellow River delta, Shandong Province coastal zone, in China. The aim of our study was to isolate nitrogen-fixing bacteria colonizing the rhizosphere of JA and to characterize other plant growth promotion properties. The ultimate goal was to identify isolates that could be used as inoculants benefiting an economic crop, in particular for improving wheat growth production in the Yellow River delta. Bacterial strains were isolated from the rhizosphere soil of JA on the basis of growth on nitrogen-free Ashby medium. Identification and phylogenetic analysis was performed after nucleotide sequencing of 16S rRNA gene. Plant-growth-promoting traits, such as nitrogen fixation activity, phosphate solubilization activity, indole-3-acetic acid production, were determined using conventional methods. Eleven strains were isolated and 6 of them were further examined for their level of salt tolerance and their effect on plant growth promotion. Inoculation of Enterobacter sp. strain N10 on JA and wheat led to significant increases in both root and shoot dry mass and shoot height. Enterobacter sp. strain N10 appeared to be the best plant-growth-promoting rhizobacteria to increase wheat productivity in future field applications.

scholarly journals Isolation, Biochemical and Genomic Characterization of Glyphosate Tolerant Bacteria to Perform Microbe-Assisted Phytoremediation

2021 ◽  
Vol 11 ◽  
Author(s):  
Francisco Massot ◽  
Panagiotis Gkorezis ◽  
Jonathan Van Hamme ◽  
Damian Marino ◽  
Bojana Spirovic Trifunovic ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Large Scale ◽  
Agricultural Soils ◽  
Growth Promotion ◽  
Sole Source ◽  
Bacterial Strains ◽  
Positive Effects ◽  
Assisted Phytoremediation

The large-scale use of the herbicide glyphosate leads to growing ecotoxicological and human health concerns. Microbe-assisted phytoremediation arises as a good option to remove, contain, or degrade glyphosate from soils and waterbodies, and thus avoid further spreading to non-target areas. To achieve this, availability of plant-colonizing, glyphosate-tolerant and -degrading strains is required and at the same time, it must be linked to plant-microorganism interaction studies focusing on a substantive ability to colonize the roots and degrade or transform the herbicide. In this work, we isolated bacteria from a chronically glyphosate-exposed site in Argentina, evaluated their glyphosate tolerance using the minimum inhibitory concentration assay, their in vitro degradation potential, their plant growth-promotion traits, and performed whole genome sequencing to gain insight into the application of a phytoremediation strategy to remediate glyphosate contaminated agronomic soils. Twenty-four soil and root-associated bacterial strains were isolated. Sixteen could grow using glyphosate as the sole source of phosphorous. As shown in MIC assay, some strains tolerated up to 10000 mg kg–1 of glyphosate. Most of them also demonstrated a diverse spectrum of in vitro plant growth-promotion traits, confirmed in their genome sequences. Two representative isolates were studied for their root colonization. An isolate of Ochrobactrum haematophilum exhibited different colonization patterns in the rhizoplane compared to an isolate of Rhizobium sp. Both strains were able to metabolize almost 50% of the original glyphosate concentration of 50 mg l–1 in 9 days. In a microcosms experiment with Lotus corniculatus L, O. haematophilum performed better than Rhizobium, with 97% of glyphosate transformed after 20 days. The results suggest that L. corniculatus in combination with to O. haematophilum can be adopted for phytoremediation of glyphosate on agricultural soils. An effective strategy is presented of linking the experimental data from the isolation of tolerant bacteria with performing plant-bacteria interaction tests to demonstrate positive effects on the removal of glyphosate from soils.

scholarly journals Plant growth promotion of barley (Hordeum vulgare L.) by potassium solubilizing bacteria with multifarious plant growth promoting attributes

2021 ◽  
Vol 8 (sp1) ◽  
pp. 17-24
Author(s):  
Tanvir Kaur ◽  
Rubee Devi ◽  
Divjot Kour ◽  
Ashok Yadav ◽  
Ajar Nath Yadav
Keyword(s):  
Plant Growth ◽  
Environmental Sustainability ◽  
Growth Promotion ◽  
Growth Parameters ◽  
Sugar Content ◽  
Plant Growth Promoting Bacteria ◽  
Bacterial Strains ◽  
Hordeum Vulgare L ◽  
Plant Growth Promoting ◽  
Growth Promoting

Potassium (K) is the foremost macronutrients for growth of plant, soil health and fertility. The huge application of NPK chemical fertilizers negatively impacts the economy and is a threat to environmental sustainability. The rapid depletion of K mineral in soil is due to the application of agrochemicals agricultural fields for the production of crops in India. In present investigation, K-solubilizing microbes (KSM) were isolated and enumerated from cereal crops growing in Sirmour Himachal Pradesh. A total 125 bacteria were isolated and screened for K- solubilization on Aleksandrov agar plates and found that 31 bacterial strains exhibited K-solubilization. These 31 K-solubilizing strains of bacteria were additionally screened for other plant growth promoting (PGP) potential including solubilization of minerals, production of siderophores, ammonia, hydrogen cyanide and indole acetic acids. The performance of an efficient K-solubilizer was evaluated for plant growth promoting ability in pot assay under in vitro conditions. The strain EU-LWNA-25 positively influenced shoot length, fresh weight, carotenoids and total sugar content than the full dose, half dose and control. The strain enhancing physiological and growth parameters was identified by BLASTn analysis as Pseudomonas gessardii EU-LWNA-25. K-solubilizing plant growth promoting bacteria could be suitable bioinoculants for Rabi seasonal crops and overcomes the challenges of sustainable agriculture in K-deficient soil.

scholarly journals Seed-Biopriming of Durum Wheat with Diazotrophic Plant Browth Promoting Bacteria (PGPB) Enhanced Tolerance to Fusarium Head Blight (FHB) and Salinity Stress

2019 ◽  
Author(s):  
Adel Hadj Brahim ◽  
Mouna Jlidi ◽  
Lobna Daoud ◽  
Manel Ben-Ali ◽  
Asmahen Akremi ◽  
...  
Keyword(s):  
Plant Growth ◽  
Durum Wheat ◽  
Abiotic Stresses ◽  
Growth Promotion ◽  
Head Blight ◽  
Biotic And Abiotic Stresses ◽  
Plant Growth Promoting ◽  
Seed Biopriming

Abstract Background The use of bioinoculants based on plant growth-promoting bacteria (PGPB) to promote plant growth under biotic and abiotic stresses is in full expansion. To our knowledge much work has not been, thus far, done on seed-biopriming of durum wheat for tolerance to biotic and abiotic stresses. In the present work, we report detailed account of the effectiveness a potent bacterial strain with proven plant growth-promoting ability and antimicrobial activity. The isolate was selected following screening of several bacterial strains isolated from halophytes that grow in a coastal saline soil in Tunisia for their role in enhancing durum wheat tolerance to both salinity stress and head blight disease.Results Accordingly, Bacillus strains MA9, MA14, MA17 and MA19 were found to have PGPB characteristics as they produced indole-3-acetic acid, siderophores and lytic enzymes, fixed free atmospheric nitrogen, and solubilized inorganic phosphate, in vitro . The in vivo study that involved in planta inoculation assays under control (25 mM NaCl) and stress (125 mM NaCl) conditions indicated that all PGPB strains significantly ( P < 0.05) increased the total plant length, dry weight, root area, seed weight, nitrogen, protein and total mineral content. On the other hand, strain MA17 reduced Fusarium Head Blight (FHB) disease incidence in wheat explants by 64.5%, showing that the strain has antifungal activity as was also displayed by in vitro inhibition study.Conclusions Both in vitro and in vivo studies showed that MA9, MA14 MA9, MA14, MA17 and MA19 strains were able to play the PGPB role. Yet, biopriming with Bacillus strain MA17 offered the highest bioprotection against FHB, plant growth promotion, and salinity tolerance. Hence, the MA17 strain should further be evaluated under field condition and formulated for commercial production. Besides, the strain could further be evaluated for its potential role in bioprotection and growth promotion of other crop plants. We believe, the strain has potential to significantly contribute to wheat production in the arid and semi-arid region, especially the salt affected Middle Eastern Region, besides its potential role in improving wheat production under biotic and abiotic stresses in other parts of the world.

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