scholarly journals Genetic and nutritional diversity of Bacillus subtilis isolates demonstrating different aspects related to plant growth promotion

Author(s):  
Bianca de Melo Silveira dos Santos ◽  
Maura Santos dos Reis de Andrade Silva ◽  
Davy William Hidalgo Chávez ◽  
Everlon Cid Rigobelo

Currently, agricultural practices have been undergoing intense transformations, imposing major challenges such as maintaining productivity with lower production costs and environmental impacts. One of the alternatives to meet these requirements is the use of plant growth promoting bacteria, including Bacillus subtilis. However, different isolates may express different aspects and levels of plant growth promotion. The present study aimed to verify the genetic and nutritional diversity of eight B. subtilis isolates, demonstrating different aspects and levels of plant growth promotion. Eight B. subtilis isolates were analyzed as to their nutritional diversity by BiologEcoPlate TM kit, genetic diversity by Box-PCR, and a trial in greenhouse conditions. The experimental design in greenhouse trial was completely randomized with 9 treatments and five replicates, resulting in 45 pots. Treatments were eight Bacillus subtilis strains, and a control treatment using plants without bacterial inoculation. Isolates 290 and 287 are genetically similar, while isolates 248 and 263 also showed similarity. Genetic and substrate consumption (carbon) analyses showed differences and similarities among isolates, allowing the distribution of isolates into different groups. It was observed that the isolate with the highest ability to promote plant growth was the only isolate that consumed glycyl-L- glutamic acid. These results open the way for further investigations in an attempt to clarify what are the conditions and / or characteristics required by isolates for the plant growth promotion to be more effective.

2021 ◽  
Vol 11 (5) ◽  
pp. 2233
Author(s):  
Maria J. Ferreira ◽  
Angela Cunha ◽  
Sandro Figueiredo ◽  
Pedro Faustino ◽  
Carla Patinha ◽  
...  

Root−associated microbial communities play important roles in the process of adaptation of plant hosts to environment stressors, and in this perspective, the microbiome of halophytes represents a valuable model for understanding the contribution of microorganisms to plant tolerance to salt. Although considered as the most promising halophyte candidate to crop cultivation, Salicornia ramosissima is one of the least-studied species in terms of microbiome composition and the effect of sediment properties on the diversity of plant-growth promoting bacteria associated with the roots. In this work, we aimed at isolating and characterizing halotolerant bacteria associated with the rhizosphere and root tissues of S. ramosissima, envisaging their application in saline agriculture. Endophytic and rhizosphere bacteria were isolated from wild and crop cultivated plants, growing in different estuarine conditions. Isolates were identified based on 16S rRNA sequences and screened for plant-growth promotion traits. The subsets of isolates from different sampling sites were very different in terms of composition but consistent in terms of the plant-growth promoting traits represented. Bacillus was the most represented genus and expressed the wider range of extracellular enzymatic activities. Halotolerant strains of Salinicola, Pseudomonas, Oceanobacillus, Halomonas, Providencia, Bacillus, Psychrobacter and Brevibacterium also exhibited several plant-growth promotion traits (e.g., 3-indole acetic acid (IAA), 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, siderophores, phosphate solubilization). Considering the taxonomic diversity and the plant-growth promotion potential of the isolates, the collection represents a valuable resource that can be used to optimize the crop cultivation of Salicornia under different environmental conditions and for the attenuation of salt stress in non-halophytes, considering the global threat of arable soil salinization.


2021 ◽  
Vol 16 (8) ◽  
pp. 75-80
Author(s):  
Pitchaiah Pelapudi ◽  
Sasikala Ch ◽  
Swarnabala Ganti

In the present rapid growing world, need for a sustainable agricultural practice which helps in meeting the adequate food demand is much needed. In this context, plant growth promoting bacteria were brought into the spot light by the researchers. Though the plant growth promoting bacteria have several beneficial applications, due to some of the disadvantages in the field conditions, they lagged behind. In the current research work, native PGPR were isolated from the rhizosphere soil samples of maize with an aim to isolate the nitrogen fixing, phosphate solubilising and potash solubilising bacteria. Out of the several isolates, potent PGPR isolates viz., Paenibacillus durus PCPB067, Bacillus megaterium PCBMG041 and Paenibacillus glucanolyticus PCPG051 were isolated and identified by using the 16 S rRNA gene sequencing studies. Genomic DNA sequences obtained were deposited in the NCBI Genbank and accession numbers were assigned as MW793452, MW793456 and MW843633. In order to check the efficacy of the PGPR isolates, pot trials were conducted by taking maize as the host plant. Several parameters viz. shoot length, shoot weight, root length, root weight and weight of the seeds were tested in which PGP treatment showed good results (shoot length - 187±3.5 cm, shoot weight - 31±4 g, root length - 32±3.6 cm, root weight - 17±2 g, yield- 103.3±6.1 g) when compared to the chemical fertilizer treatment (shoot length - 177±3.5 cm, shoot weight - 25±3.6 g, root length - 24±3.5 cm, root weight - 14.6±1.52 g, yield- 85.6±7.6 g). Based on the results, it can be stated that these native PGPR isolates can be effectively used in the plant growth promotion of maize.


2016 ◽  
Vol 46 (2) ◽  
pp. 149-158 ◽  
Author(s):  
Ariana Alves Rodrigues ◽  
Marcus Vinicius Forzani ◽  
Renan de Souza Soares ◽  
Sergio Tadeu Sibov ◽  
José Daniel Gonçalves Vieira

ABSTRACT Microorganisms play a vital role in maintaining soil fertility and plant health. They can act as biofertilizers and increase the resistance to biotic and abiotic stress. This study aimed at isolating and characterizing plant growth-promoting bacteria associated with sugarcane, as well as assessing their ability to promote plant growth. Endophytic bacteria from leaf, stem, root and rhizosphere were isolated from the RB 867515 commercial sugarcane variety and screened for indole acetic acid (IAA) production, ability to solubilize phosphate, fix nitrogen and produce hydrogen cyanide (HCN), ammonia and the enzymes pectinase, cellulase and chitinase. A total of 136 bacteria were isolated, with 83 of them presenting some plant growth mechanism: 47 % phosphate solubilizers, 26 % nitrogen fixers and 57 % producing IAA, 0.7 % HCN and chitinase, 45 % ammonia, 30 % cellulose and 8 % pectinase. The seven best isolates were tested for their ability to promote plant growth in maize. The isolates tested for plant growth promotion belong to the Enterobacteriaceae family and the Klebsiella, Enterobacter and Pantoea genera. Five isolates promoted plant growth in greenhouse experiments, showing potential as biofertilizers.


2019 ◽  
Vol 85 (19) ◽  
Author(s):  
Evan Mayer ◽  
Patricia Dörr de Quadros ◽  
Roberta Fulthorpe

ABSTRACT A collection of bacterial endophytes isolated from stem tissues of plants growing in soils highly contaminated with petroleum hydrocarbons were screened for plant growth-promoting capabilities. Twenty-seven endophytic isolates significantly improved the growth of Arabidopsis thaliana plants in comparison to that of uninoculated control plants. The five most beneficial isolates, one strain each of Curtobacterium herbarum, Paenibacillus taichungensis, and Rhizobium selenitireducens and two strains of Plantibacter flavus were further examined for growth promotion in Arabidopsis, lettuce, basil, and bok choy plants. Host-specific plant growth promotion was observed when plants were inoculated with the five bacterial strains. P. flavus strain M251 increased the total biomass and total root length of Arabidopsis plants by 4.7 and 5.8 times, respectively, over that of control plants and improved lettuce and basil root growth, while P. flavus strain M259 promoted Arabidopsis shoot and root growth, lettuce and basil root growth, and bok choy shoot growth. A genome comparison between P. flavus strains M251 and M259 showed that both genomes contain up to 70 actinobacterial putative plant-associated genes and genes involved in known plant-beneficial pathways, such as those for auxin and cytokinin biosynthesis and 1-aminocyclopropane-1-carboxylate deaminase production. This study provides evidence of direct plant growth promotion by Plantibacter flavus. IMPORTANCE The discovery of new plant growth-promoting bacteria is necessary for the continued development of biofertilizers, which are environmentally friendly and cost-efficient alternatives to conventional chemical fertilizers. Biofertilizer effects on plant growth can be inconsistent due to the complexity of plant-microbe interactions, as the same bacteria can be beneficial to the growth of some plant species and neutral or detrimental to others. We examined a set of bacterial endophytes isolated from plants growing in a unique petroleum-contaminated environment to discover plant growth-promoting bacteria. We show that strains of Plantibacter flavus exhibit strain-specific plant growth-promoting effects on four different plant species.


2002 ◽  
Vol 48 (3) ◽  
pp. 230-238 ◽  
Author(s):  
Yuming Bai ◽  
Frederic D'Aoust ◽  
Donald L Smith ◽  
Brian T Driscoll

Endophytic bacteria reside within plant tissues and have often been found to promote plant growth. Fourteen strains of putative endophytic bacteria, not including endosymbiotic Bradyrhizobium strains, were isolated from surface-sterilized soybean (Glycine max. (L.) Merr.) root nodules. These isolates were designated as non-Bradyrhizobium endophytic bacteria (NEB). Three isolates (NEB4, NEB5, and NEB17) were found to increase soybean weight when plants were co-inoculated with one of the isolates and Bradyrhizobium japonicum under nitrogen-free conditions, compared with plants inoculated with B. japonicum alone. In the absence of B. japonicum, these isolates neither nodulated soybean, nor did they affect soybean growth. All three isolates were Gram-positive spore-forming rods. While Biolog tests indicated that the three isolates belonged to the genus Bacillus, it was not possible to determine the species. Phylogenetic analysis of 16S rRNA gene hypervariant region sequences demonstrated that both NEB4 and NEB5 are Bacillus subtilis strains, and that NEB17 is a Bacillus thuringiensis strain.Key words: root nodule, endophytic bacteria, plant-growth-promoting bacteria, Bacillus subtilis, Bacillus thuringiensis.


2022 ◽  
Vol 11 (1) ◽  
pp. e29611124799
Author(s):  
Cristiane Rodrigues Silva ◽  
Rafael Monção Miller ◽  
Bárbara Costa Pereira ◽  
Lílian Aveleda ◽  
Victor Augustus Marin

A genomic analysis of the potential application of a Serratia marcescens strain in the plant-growth promotion. We performed whole-genome sequencing of Serratia marcescens isolated from a Minas Frescal Cheese. The genomic repertoire revealed a bacterium of agricultural and biotechnological interest. In the plant-growth promotion traits, we highlight genes encoding proteins possibly responsible for the biosynthesis of phytohormone indole acetic acid, organic compounds that act in iron uptake, and the Phosphate solubilization system. Genes encoding for enzymes like the versatile L-asparaginase stimulates the development of seeds and grains and can benefit the food industry due to a mitigation effect on acrylamide and notably, has medical applications as a chemotherapeutic agent or is applicable by its antimicrobial and anti-inflammatory properties. Moreover, functional diversity of genes encoding for resistance to different metals and metabolism of xenobiotics genes can be found in this strain, reinforcing its biotechnological potential. The versatile enzymes that can be produced by S. marcescens benefit the food, pharmaceutical, textile, agronomic, and cosmetic industries. The relevant genetic systems of S. marcescens described here may be used to promote plant growth and health and improve the environment. To the best of our knowledge, this is the first genome sequence report on S. marcescens isolated from cheese, with potential application as promoting plant growth and providing a baseline for future genomic studies on the development of this species.


Author(s):  
Lynda Kelvin-Asogwa ◽  
Frank C. Ogbo

Aim: To isolate plant growth promoting Bacillus strains from maize roots and to characterize using molecular methods, the strain with greatest potential for plant growth promotion. Place and Duration of Study: Department of Applied Microbiology and Brewing, Nnamdi Azikiwe University, Awka, between February 2019 and March 2020. Methodology: The isolation of plant growth promoting rhizobacteria (PGPR) from maize roots was made using Nitrogen Free Bromothymol Blue (NFB) broth. They were screened for Phosphate solubilizing activities on Pikovskaya (PVK) agar. Quantitative determination and solubilization of different types of Phosphates was carried out using Pikovskaya broth. Optimization of factors affecting phosphate such as NaCl concentration, initial pH of the medium, size of inoculum, was done using pvk broth. Evaluation of other plant growth promoting properties were carried out such as IAA, Ammonia, cellulase and HCN production.  Results: Eleven Nitrogen fixing bacteria were isolated using NFB broth based on colour change of the medium from green to blue.  Test for phosphate solubilization abilities of the organisms revealed that nine of the isolates solubilized phosphate on PVK agar. Organism coded with IS52 gave the least solubilization index of 1.14 while isolate IS19 gave the highest index of 3.4. Isolate IS19 yielded the highest amount of 73.5µg/ml P, while isolate IS30 was the weakest solubilizer in PVK broth, yielding 19.4µg/ml P. The best isolate IS19, produced the plant growth hormone Indole Acetic acid at a concentration of 105.4μg/ml. The organism also gave a positive result for ammonia and cellulase production but did not produce Hydrogen cyanide. It was identified as Bacillus subtilis using the 16S rRNA gene sequencing. Conclusion: Bacillus subtilis fixed Nitrogen qualitatively and solubilized insoluble phosphates in addition to other plant growth promoting properties, thus Bacillus subtilis has potential for plant growth promotion, making it an efficient strain for biofertilizer production


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 888
Author(s):  
Giorgia Novello ◽  
Patrizia Cesaro ◽  
Elisa Bona ◽  
Nadia Massa ◽  
Fabio Gosetti ◽  
...  

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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