scholarly journals Rice-Associated Rhizobacteria as a Source of Secondary Metabolites against Burkholderia glumae

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2567
Author(s):  
Giann Carlos Peñaloza Atuesta ◽  
Walter Murillo Arango ◽  
Jordi Eras ◽  
Diego Fernándo Oliveros ◽  
Jonh Jairo Méndez Arteaga
Keyword(s):  
Growth Promotion ◽  
Phylogenetic Analyses ◽  
Inorganic Phosphorus ◽  
Antagonistic Activity ◽  
Diffusion Method ◽  
Rrna Gene ◽  
Growth Promoters ◽  
Burkholderia Glumae ◽  
Main Compound

Various diseases, including bacterial panicle blight (BPB) and sheath rot, threaten rice production. It has been established that Burkholderia glumae (B. glumae) is the causative agent of the above mentioned pathologies. In the present study, antagonistic activity, growth promotion, and the metabolite profiles of two rhizobacteria, isolated in different paddy fields, were assessed against B. glumae. Strains were identified based on 16S rRNA gene sequences, and the phylogenetic analyses showed that both strains belong to the genus Enterobacter, with high similarity to the strain Enterobacter tabaci NR146667.2 (99%). The antagonistic activity was assessed with the disc diffusion method. Active fractions were isolated through a liquid/liquid extraction with ethyl acetate (EtOAc) from the fermentation media, and their antibacterial activities were evaluated following the Clinical and Laboratory Standards Institute (CLSI) guidelines. The Pikovskaya modified medium was used to test the ability of in vitro inorganic phosphorus solubilization, and BSB1 proved to be the best inorganic phosphorus solubilizer, with a solubilization index (SI) of 4.5 ± 0.2. The glass-column fractionation of the EtOAc extracted from BCB11 produced an active fraction (25.9 mg) that inhibited the growth of five B. glumae strains by 85–95%. Further, metabolomic analysis, based on GC–MS, showed 3-phenylpropanoic acid (3-PPA) to be the main compound both in this fraction (46.7%), and in the BSB1 extract (28.6%). This compound showed antibacterial activity against all five strains of B. glumae with a minimum inhibitory concentration (MIC) of 1000 mg/L towards all of them. The results showed that rice rhizosphere microorganisms are a source of compounds that inhibit B. glumae growth and are promising plant growth promoters (PGP).

Effect of the endophytic plant growth promoting Enterobacter ludwigii EB4B on tomato growth

2020 ◽  
Vol 13 (2) ◽  
pp. 54-65 ◽  
Author(s):  
M.E.A. Bendaha ◽  
H.A. Belaouni
Keyword(s):  
Root Length ◽  
Biocontrol Agent ◽  
Growth Promotion ◽  
Dry Weight ◽  
Antagonistic Activity ◽  
Rrna Gene ◽  
Plant Growth Promoting ◽  
Enterobacter Ludwigii ◽  
Tomato Growth

SummaryThis study aims to develop a biocontrol agent against Fusarium oxysporum f.sp. radicis-lycopersici (FORL) in tomato. For this, a set of 23 bacterial endophytic isolates has been screened for their ability to inhibit in vitro the growth of FORL using the dual plate assay. Three isolates with the most sound antagonistic activity to FORL have been qualitatively screened for siderophore production, phosphates solubilization and indolic acetic acid (IAA) synthesis as growth promotion traits. Antagonistic values of the three candidates against FORL were respectively: 51.51 % (EB4B), 51.18 % (EB22K) and 41.40 % (EB2A). Based on 16S rRNA gene sequence analysis, the isolates EB4B and EB22K were closely related to Enterobacter ludwigii EN-119, while the strain EB2A has been assigned to Leclercia adecarboxylata NBRC 102595. The promotion of tomato growth has been assessed in vitro using the strains EB2A, EB4B and EB22K in presence of the phytopathogen FORL. The treatments with the selected isolates increased significantly the root length and dry weight. Best results were observed in isolate EB4B in terms of growth promotion in the absence of FORL, improving 326.60 % of the root length and 142.70 % of plant dry weight if compared with untreated controls. In the presence of FORL, the strain EB4B improved both root length (180.81 %) and plant dry weight (202.15 %). These results encourage further characterization of the observed beneficial effect of Enterobacter sp. EB4B for a possible use as biofertilizer and biocontrol agent against FORL.

scholarly journals Characterisation of Plant Growth-Promoting Endophytic Bacteria from Sugarcane and Their Antagonistic Activity against Fusarium moniliforme

2021 ◽  
Vol 32 (3) ◽  
pp. 97-118
Author(s):  
Nittaya Pitiwittayakul ◽  
Duanpen Wongsorn ◽  
Somboon Tanasupawat
Keyword(s):  
Plant Growth ◽  
Endophytic Bacteria ◽  
Fusarium Moniliforme ◽  
Growth Promotion ◽  
Antagonistic Activity ◽  
Rrna Gene ◽  
Burkholderia Gladioli ◽  
Plant Growth Promoting ◽  
Chemical Usage

The use of endophytic bacteria in agriculture provides an effective way of improving crop yield and significantly reducing chemical usage, such as fungicides. This research was conducted to explore endophytic bacteria with plant growth promotion (PGP) and antifungal activities against Fusarium moniliforme AIT01. In this study, we obtained 52 isolates of endophytic bacteria associated with the roots and stems of sugarcane from Nakhon Ratchasima province, Thailand. In vitro antagonistic activity test showed that 14 out of 52 isolates had antagonistic activity against the fungal pathogen F. moniliforme AIT01. These antagonistic endophytic bacteria were identified as belonging to six different species as follows: Nguyenibacter vanlangensis, Acidomonas methanolica, Asaia bogorensis, Tanticharoenia aidae, Burkholderia gladioli and Bacillus altitudinis based on phenotypic characteristics, along with phylogenetic analysis of their 16S rRNA gene sequences. Seven isolates effectively inhibited F. moniliforme AIT01 mycelial growth by up to 40%. The volatile compounds of six isolates reduced the growth of F. moniliforme AIT01 by over 23%. Moreover, riceberry rice seedlings previously treated with B. gladioli CP28 were found to strongly reduce infection with phytopathogen by 80% in comparison to the non-treated control. Furthermore, the isolates also showed relevant PGP features, including ammonia production, zinc and phosphate solubilisation, auxin and siderophore biosynthesis. These results demonstrated that the tested endophytic bacteria could be successfully utilised as a source of PGP and biocontrol agent to manage diseases caused by F. moniliforme.

scholarly journals Endophytic Bacterial Isolates From Halophytes Demonstrate Phytopathogen Biocontrol and Plant Growth Promotion Under High Salinity

2021 ◽  
Vol 12 ◽  
Author(s):  
Christos A. Christakis ◽  
Georgia Daskalogiannis ◽  
Anastasia Chatzaki ◽  
Emmanouil A. Markakis ◽  
Glykeria Mermigka ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
High Salinity ◽  
Growth Promotion ◽  
Antagonistic Activity ◽  
Rrna Gene ◽  
In Planta ◽  
Promoting Effect ◽  
Cakile Maritima

Halophytic endophytes potentially contribute to the host’s adaptation to adverse environments, improving its tolerance against various biotic and abiotic stresses. Here, we identified the culturable endophytic bacteria of three crop wild relative (CWR) halophytes: Cakile maritima, Matthiola tricuspidata, and Crithmum maritimum. In the present study, the potential of these isolates to improve crop adaptations to various stresses was investigated, using both in vitro and in-planta approaches. Endophytic isolates were identified by their 16S rRNA gene sequence and evaluated for their ability to: grow in vitro in high levels of NaCl; inhibit the growth of the economically important phytopathogens Verticillium dahliae, Ralstonia solanacearum, and Clavibacter michiganensis and the human pathogen Aspergillus fumigatus; provide salt tolerance in-planta; and provide growth promoting effect in-planta. Genomes of selected isolates were sequenced. In total, 115 endophytic isolates were identified. At least 16 isolates demonstrated growth under increased salinity, plant growth promotion and phytopathogen antagonistic activity. Three showed in-planta suppression of Verticillium growth. Furthermore, representatives of three novel species were identified: two Pseudomonas species and one Arthrobacter. This study provides proof-of-concept that the endophytes from CWR halophytes can be used as “bio-inoculants,” for the enhancement of growth and stress tolerance in crops, including the high-salinity stress.

An investigation of antibacterial activity of New Zealand seaweed-associated marine bacteria

2021 ◽  
Author(s):  
Mehrnoush Tangestani ◽  
Paul Broady ◽  
Arvind Varsani
Keyword(s):  
New Zealand ◽  
Biomedical Application ◽  
Bacterial Species ◽  
Antibacterial Properties ◽  
Antagonistic Activity ◽  
Marine Macroalgae ◽  
Diffusion Method ◽  
Rrna Gene ◽  
Associated Bacteria ◽  
Phylogenetic Identification

Aim: To explore seaweed-associated bacteria as prospective producers of bioactive material with antibacterial properties. Materials & methods: 143 bacterial species were isolated from the surface of 15 New Zealand marine macroalgae. Bacterial extracts obtained using dimethyl sulfoxide and ethyl acetate were screened for antagonistic activities against three antimicrobial susceptibility indicators: Kocuria rhizophila, Staphylococcus epidermidis and Escherichia coli, using well-diffusion method. For selected species, minimum inhibitory concentration was determined, followed by a phylogenetic identification based on 16S rRNA gene sequences. Results: Among all bacteria screened, seven that belonged to the genera Vibrio, Pseudoalteromonas, Psychromonas and Cobetia, showed antagonistic activity against all three indicators. Conclusion: Seaweed-associated bacteria produce bioactive compounds with antimicrobial potential and possible biomedical application in aquatic habitats.

scholarly journals Studies on Antibacterial Activity and Diversity of Cultivable Actinobacteria Isolated from Mangrove Soil in Futian and Maoweihai of China

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Feina Li ◽  
Shaowei Liu ◽  
Qinpei Lu ◽  
Hongyun Zheng ◽  
Ilya A. Osterman ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Fluorescent Protein ◽  
Protein Biosynthesis ◽  
Antibacterial Activities ◽  
Antagonistic Activity ◽  
Diffusion Method ◽  
Rrna Gene ◽  
Reporter System ◽  
Mangrove Soil

Mangrove is a rich and underexploited ecosystem with great microbial diversity for discovery of novel and chemically diverse antimicrobial compounds. The goal of the study was to explore the pharmaceutical actinobacterial resources from mangrove soil and gain insight into the diversity and novelty of cultivable actinobacteria. Consequently, 10 mangrove soil samples were collected from Futian and Maoweihai of China, and the culture-dependent method was employed to obtain actinobacteria. A total of 539 cultivable actinobacteria were isolated and distributed in 39 genera affiliated to 18 families of 8 orders by comparison analysis of partial 16S rRNA gene sequences. The dominant genus was Streptomyces (16.0 %), followed by Microbacterium (14.5 %), Agromyces (14.3 %), and Rhodococcus (11.9 %). Other 35 rare actinobacterial genera accounted for minor proportions. Notably, 11 strains showed relatively low 16S rRNA gene sequence similarities (< 98.65 %) with validly described species. Based on genotypic analyses and phenotypic characteristics, 115 out of the 539 actinobacterial strains were chosen as representative strains to test their antibacterial activities against “ESKAPE” bacteria by agar well diffusion method and antibacterial mechanism by the double fluorescent protein reporter system. Fifty-four strains in 23 genera, including 2 potential new species, displayed antagonistic activity in antibacterial assay. Meanwhile, 5 strains in 3 genera exhibited inhibitory activity on protein biosynthesis due to ribosome stalling. These results demonstrate that cultivable actinobacteria from mangrove soil are potentially rich sources for discovery of new antibacterial metabolites and new actinobacterial taxa.

scholarly journals Plant Growth Promotion Potential Is Equally Represented in Diverse Grapevine Root-Associated Bacterial Communities from Different Biopedoclimatic Environments

2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Ramona Marasco ◽  
Eleonora Rolli ◽  
Marco Fusi ◽  
Ameur Cherif ◽  
Ayman Abou-Hadid ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Plant Growth ◽  
Bacterial Communities ◽  
Growth Promotion ◽  
Rrna Gene ◽  
Similar Distribution ◽  
Bacterial Assemblage ◽  
Pgp Traits ◽  
Associated Bacteria

Plant-associated bacteria provide important services to host plants. Environmental factors such as cultivar type and pedoclimatic conditions contribute to shape their diversity. However, whether these environmental factors may influence the plant growth promoting (PGP) potential of the root-associated bacteria is not widely understood. To address this issue, the diversity and PGP potential of the bacterial assemblage associated with the grapevine root system of different cultivars in three Mediterranean environments along a macrotransect identifying an aridity gradient were assessed by culture-dependent and independent approaches. According to 16S rRNA gene PCR-DGGE, the structure of endosphere and rhizosphere bacterial communities was highly diverse (P=0.03) and was associated with a cultivar/latitudinal/climatic effect. Despite being diverse, the bacterial communities associated with Egyptian grapevines shared a higher similarity with the Tunisian grapevines than those cultivated in North Italy. A similar distribution, according to the cultivar/latitude/aridity gradients, was observed for the cultivable bacteria. Many isolates (23%) presentedin vitromultiple stress resistance capabilities and PGP activities, the most frequent being auxin synthesis (82%), insoluble phosphate solubilisation (61%), and ammonia production (70%). The comparable numbers and types of potential PGP traits among the three different environmental settings indicate a strong functional homeostasis of beneficial bacteria associated with grape root.

scholarly journals The In Vitro and In Planta Interspecies Interactions Among Rice-Pathogenic Burkholderia Species

Plant Disease ◽  
2021 ◽  
Vol 105 (1) ◽  
pp. 134-143
Author(s):  
Namgyu Kim ◽  
Mohamed Mannaa ◽  
Juyun Kim ◽  
Ji-Eun Ra ◽  
Sang-Min Kim ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Fluorescent Protein ◽  
Antagonistic Activity ◽  
In Vitro Assays ◽  
Interspecies Interactions ◽  
In Planta ◽  
Burkholderia Glumae ◽  
Burkholderia Species ◽  
Green Fluorescent

Burkholderia glumae, B. plantarii, and B. gladioli are responsible for serious diseases in rice crops and co-occurrence among them has been reported. In this study, in vitro assays revealed antagonistic activity among these organisms, with B. gladioli demonstrating strong inhibition of B. glumae and B. plantarii. Strains of B. glumae and B. plantarii that express green fluorescent protein were constructed and used for cocultivation assays with B. gladioli, which confirmed the strong inhibitory activity of B. gladioli. Cell-free supernatants from each species were tested against cultures of counterpart species to evaluate the potential to inhibit bacterial growth. To investigate the inhibitory activity of B. gladioli on B. glumae and B. plantarii in rice, rice plant assays were performed and quantitative PCR (qPCR) assays were developed for in planta bacterial quantification. The results indicated that coinoculation with B. gladioli leads to significantly reduced disease severity and colonization of rice tissues compared with single inoculation with B. glumae or B. plantarii. This study demonstrates the interactions among three rice-pathogenic Burkholderia species and strong antagonistic activity of B. gladioli in vitro and in planta. The qPCR assays developed here could be applied for accurate quantification of these organisms from in planta samples in future studies.

scholarly journals Alteration of the Ileal Microbiota of Weanling Piglets by the Growth-Promoting Antibiotic Chlortetracycline

2009 ◽  
Vol 75 (17) ◽  
pp. 5489-5495 ◽  
Author(s):  
Elizabeth Rettedal ◽  
S�bastien Vilain ◽  
Stacy Lindblom ◽  
Kelly Lehnert ◽  
Clay Scofield ◽  
...  
Keyword(s):  
Growth Promotion ◽  
Pcr Amplification ◽  
Growing Pigs ◽  
Rrna Gene ◽  
Significant Shift ◽  
Growth Promoters ◽  
Antibiotic Resistant ◽  
Operational Taxonomic Units ◽  
Bacterial Microbiota ◽  
Antibiotic Growth Promoters

ABSTRACT Antibiotics such as chlortetracycline (CTC) have been used to promote growth of pigs for decades, but concerns over increased antibiotic-resistant infections in humans have prompted the development of alternative strategies. Developing alternatives to antibiotic growth promoters (AGPs) could be informed by information on the mechanisms of growth promotion, notably, how AGPs affect the microbial populations of the gastrointestinal tract. Pigs from three sows were aseptically delivered by cesarean section. Six piglets were distributed to each of two foster mothers until weaning, when piglets were fed a diet with or without 50 mg/kg CTC for 2 weeks. The ileal bacterial microbiota was characterized by using a cultivation-independent approach based on DNA extraction, PCR amplification, cloning, and sequencing of the 16S rRNA gene pool. The ileal and mucosal communities of these growing pigs were dominated by Lactobacillus bacteria, various members of the family Clostridiaceae, and members of the poorly known genus Turicibacter. Overall, CTC treatment resulted in three shifts: a decrease in L actobacillus johnsonii, an increase in L. amylovorus, and a decrease in Turicibacter phylotypes. The composition of the microbiota varied considerably between individual pigs, as revealed by shared operational taxonomic units (OTUs) and similarity (SONS) analysis (θYC values). While the observed variation between untreated pigs obscured the possible effect of CTC, ∫-LIBSHUFF and SONS analyses of pooled libraries indicated a significant shift due to CTC in both the lumen and the mucosa, with some OTUs unique to either treated or control ileum. DOTUR analysis revealed little overlap between control and treated communities at the 3% difference level, indicating unique ileal communities in the presence of CTC.

scholarly journals Antibiotic susceptibility and phylogenetic analyses for the origins and serotypes of Listeriamonocytogenes strains isolated from ice cream and cream cakes

2020 ◽  
Vol 44 (5) ◽  
pp. 1100-1109
Author(s):  
Orkun BABACAN
Keyword(s):  
16S Rrna ◽  
Antibiotic Susceptibility ◽  
Phylogenetic Analyses ◽  
Ice Cream ◽  
Penicillin G ◽  
Diffusion Method ◽  
Rrna Gene ◽  
Gene Sequences ◽  
Serotype 1 ◽  
Hlya Gene

Listeria monocytogenes is a zoonotic bacterium which also infects humans. The aim of this study was to isolate this organism from cream cakes and ice cream and obtain 16S rRNA and hlyA gene sequences from isolates in order to perform phylogenetic analyses. Serotypes and antibiotic susceptibility were also determined. The cream cake and ice cream samples were examined for L. monocytogenes according to ISO 11290-1 and using the mini Vidas LMO 2 kit procedure. Antibiotic susceptibilities were investigated using the disc diffusion method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Clinical and Laboratory Standards Institute (CLSI) standards. The Sanger DNA sequencing method for phylogenetic analysis was used for L. monocytogenes isolates. A total of 16 (n =128, 12.50%) L. monocytogenes strains, 9 (12.16%) from cream cake samples and 7 (12.96%) from ice cream samples, were isolated. This was the first investigation involving sequencing of L. monocytogenes isolated from cream cakes and ice creams in Turkey. All isolates were susceptible to sulfamethoxazole/trimethoprim, tetracycline, streptomycin, gentamicin, meropenem, and erythromycin. The numbers of isolates resistant to sulbactam/ampicillin, penicillin G, chloramphenicol, and ampicillin were 16, 2, 1, and 1, respectively. Moreover, 3 isolates showed intermediate resistance to amikacin and 2 to ciprofloxacin. The hlyA gene sequences of 11 of the L. monocytogenesisolates isolated from milk were closely related to the hlyA gene sequences of the GenBank reference strains. The comparison of the 16s rRNA gene sequences of the L. monocytogenes strains with the GenBank reference serotypes identified 1 isolate as serotype 1/2c, 1 as serotype 1/2a, and 1 as serotype 4. Nucleic acid sequencing is useful for identification of L. monocytogenes. The 16S rRNAand hlyA sequences can be used to determine the origin and relationship between L. monocytogenesisolates, as well as the serotype.

scholarly journals Plant Growth-Promoting Activity of Pseudomonas aeruginosa FG106 and Its Ability to Act as a Biocontrol Agent against Potato, Tomato and Taro Pathogens

Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 140
Author(s):  
Farideh Ghadamgahi ◽  
Saeed Tarighi ◽  
Parissa Taheri ◽  
Ganapathi Varma Saripella ◽  
Alice Anzalone ◽  
...  
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Genome Mining ◽  
16S Rrna Gene Sequencing ◽  
Control Agent ◽  
Rrna Gene ◽  
Clavibacter Michiganensis Subsp ◽  
Ability To Act

P. aeruginosa strain FG106 was isolated from the rhizosphere of tomato plants and identified through morphological analysis, 16S rRNA gene sequencing, and whole-genome sequencing. In vitro and in vivo experiments demonstrated that this strain could control several pathogens on tomato, potato, taro, and strawberry. Volatile and non-volatile metabolites produced by the strain are known to adversely affect the tested pathogens. FG106 showed clear antagonism against Alternaria alternata, Botrytis cinerea, Clavibacter michiganensis subsp. michiganensis, Phytophthora colocasiae, P. infestans, Rhizoctonia solani, and Xanthomonas euvesicatoria pv. perforans. FG106 produced proteases and lipases while also inducing high phosphate solubilization, producing siderophores, ammonia, indole acetic acid (IAA), and hydrogen cyanide (HCN) and forming biofilms that promote plant growth and facilitate biocontrol. Genome mining approaches showed that this strain harbors genes related to biocontrol and growth promotion. These results suggest that this bacterial strain provides good protection against pathogens of several agriculturally important plants via direct and indirect modes of action and could thus be a valuable bio-control agent.

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