In vitro inhibition of nonsymbiotic nitrogen-fixing bacteria by rhizosphere actinomycetes associated with grasses

1982 ◽  
Vol 28 (6) ◽  
pp. 705-709 ◽  
Author(s):  
D. A. Zuberer ◽  
Mark Roth
Keyword(s):  
Antibiotic Production ◽  
Nitrogen Fixing ◽  
Diazotrophic Bacteria ◽  
Bacterial Strains ◽  
Free Living ◽  
Vitro Assay ◽  
Genus Streptomyces ◽  
Central Texas ◽  
Actinomycete Isolate

Eighty-five isolates of actinomycetes were obtained from the rhizospheres of 10 indigenous grasses of central Texas. Of these, 10 were classified as members of the genus Nocardia; the remainder were members of the genus Streptomyces. To determine whether antibiotic production might be a significant factor in the establishment of associative symbioses between grasses and diazotrophic bacteria, 12 strains of free-living nitrogen-fixing bactria were cross streaked against each actinomycete isolate. This in vitro assay indicated that 78% of the 85 isolates were antagonistic to at least one of the 12 nitrogen-fixing bacterial strains.

scholarly journals Diazotrophic bacteria in the growth of micropropagated ornamental pineapple

2019 ◽  
Vol 13 (2) ◽  
pp. 269-278
Author(s):  
Adriano Bortolotti Silva ◽  
Ligiane Aparecida Florentino ◽  
Dalvana De Sousa Pereira ◽  
Paulo Roberto Correa Landgraf ◽  
Ana Carolina Rodrigues Alves ◽  
...  
Keyword(s):  
Shoot Growth ◽  
Ex Vivo ◽  
Control Treatment ◽  
In Vitro Cultivation ◽  
Ms Medium ◽  
Ex Vitro ◽  
Diazotrophic Bacteria ◽  
Bacterial Strains ◽  
Indole 3 Acetic Acid

Ornamental pineapple is a hardy plant with significant landscaping value. Tissue culture of plants is viable for producing plants with a high phytosanitary quality. However, one of the difficulties with this cultivar is the acclimatization process, which is slow and can cause losses. The objective of the present study was to verify the potential of inoculation with diazotrophic bacteria for in vitro and ex vivo growth of ornamental pineapple. A group of diazotrophic bacterial strains selected at the Universidade José do Rosário Vellano (UNIFENAS) was prioritized in this study, and the treatments included bacterial strains UNIFENAS (100-13, 100-60, 100-68, 100-153, 100-167 and 100-198). These strains were evaluated in terms of their capacity to produce indole 3-acetic acid. Subsequently, plants were cultivated in a medium composed of MS medium salts (1/4), adding 1 mL of the bacterial strain. In the control treatment, the plants were maintained in 2 mL of MS medium. 7 days after inoculation, the plants were transplanted into the MS, where they were maintained for 30 days. After in vitro cultivation, the plants were transferred to pots containing commercial Plantmax® substrate and maintained under these conditions for 60 days. The diazotrophic bacteria were able to synthesize auxins, and their inoculation promoted greater growth in vitro and ex vitro in the plants. In the acclimatization phase, the plants inoculated with UNIFENAS strains (100-60, 100-68 and 100-153) promoted a higher shoot growth, chlorophyll content and nitrate reductase enzyme activity.

Research on Improvement of Nitrogenase Activity of Free-Living Nitrogen-Fixing Bacteria Using DBD Plasma

2013 ◽  
Vol 671-674 ◽  
pp. 2674-2678 ◽  
Author(s):  
Yan Yun Zhu ◽  
Xiao Li Zhu ◽  
Fang She Yang
Keyword(s):  
Rhizosphere Soil ◽  
Barrier Discharge ◽  
Nitrogenase Activity ◽  
Nitrogen Fixing ◽  
Bacterial Strains ◽  
Dbd Plasma ◽  
Nitrogen Fixing Bacteria ◽  
Free Living ◽  
Reduction Assay ◽  
Rrna Sequencing

Nitrogen-fixing bacteria were screened from the rhizosphere soil of plants in Shaanxi in China. 36 free-living nitrogen-fixing bacterial strains were isolated and their nitrogenase activity were determined by acetylene reduction assay (ARA), two strains named FLNB03 and FLNB09 with higher nitrogenase activity were isolated and identified by 16S rRNA sequencing. The datum showed that FLNB03 was similar to Acinetobacter and their similarity reached 99%, FLNB09 was similar to Agrobacterium sp. and their similarity reached 99%. Then both of them were treated using Dielectric Barrier Discharge (DBD) plasma for mutation and their mutants called FLNB03-2 and FLNB09-3 were obtained. The nitrogenase activity of FLNB03-2 was 0.61±0.10 nmol•107cfu-1•h-1, and that of FLNB09-3 was 0.40±0.05 nmol•107cfu-1•h-1, their nitrogenase activity increased by 22.00% and 14.29% than their original bacteria respectively. FLNB03-2 and FLNB09-3 might be used as microbial fertilizer.

scholarly journals Mining Milk for Factors which Increase the Adherence of Bifidobacterium longum subsp. infantis to Intestinal Cells

Foods ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 196 ◽  
Author(s):  
Erinn Quinn ◽  
Helen Slattery ◽  
Aoife Thompson ◽  
Michelle Kilcoyne ◽  
Lokesh Joshi ◽  
...  
Keyword(s):  
Bifidobacterium Longum ◽  
Goat Milk ◽  
Vital Role ◽  
Intestinal Cells ◽  
Bacterial Strains ◽  
Gastrointestinal Microbiota ◽  
Milk Oligosaccharides ◽  
Vitro Assay ◽  
Breastfed Infants

Bifidobacteria play a vital role in human nutrition and health by shaping and maintaining the gut ecosystem. In order to exert a beneficial effect, a sufficient population of bifidobacteria must colonise the host. In this study, we developed a miniaturised high-throughput in vitro assay for assessing the colonising ability of bacterial strains in human cells. We also investigated a variety of components isolated from different milk sources for their ability to increase the adherence of Bifidobacterium longum subsp. infantis ATCC 15697, a common member of the gastrointestinal microbiota of breastfed infants, to HT-29 cells. Both conventional and miniaturised colonisation assays were employed to examine the effect of 13 different milk-derived powders on bacterial adherence, including positive controls which had previously resulted in increased bifidobacterial adherence (human milk oligosaccharides and a combination of 3′- and 6′-sialylactose) to intestinal cells. Immunoglobulin G enriched from bovine whey and goat milk oligosaccharides resulted in increased adhesion (3.3- and 8.3-fold, respectively) of B. infantis to the intestinal cells and the miniaturised and conventional assays were found to yield comparable and reproducible results. This study highlights the potential of certain milk components to favourably modulate adhesion of bifidobacteria to human intestinal cells.

scholarly journals CHEMICAL COMPOSITION, IN VITRO ANTIBACTERIAL, AND ANTIOXIDANT ACTIVITY OF ESSENTIAL OIL FROM LEAVES OF AJUGA PARVIFLORA BENTH

2018 ◽  
Vol 11 (14) ◽  
pp. 57
Author(s):  
Sanjay Kumar ◽  
Mohammad S Javed ◽  
Pawan Kumar ◽  
Rishendra Kumar
Keyword(s):  
Antioxidant Activity ◽  
Essential Oil ◽  
Chemical Constituents ◽  
Radical Scavenging ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Vitro Assay ◽  
Germacrene D ◽  
Antibacterial And Antioxidant Activity

Objectives: The aim of our study was to evaluate the phytogenic chemical compounds and assess their antibacterial and antioxidant activity of essential oil of Ajuga parviflora Benth. growing in the Himalayan region. Methods: In the present study, the phytochemical constituents of essential oil were isolated by steam distillation and screened by gas chromatography (GC) and GC–mass spectrometry (GC-MS) analysis from A. parviflora is rich in oxygenated monoterpenoids and sesquiterpenoids. The essential oil was further evaluated for their antibacterial by well-diffusion method and antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay at various concentrations. Results: The major chemical constituents were α-cadinol (21.36%), α-muurolol (14.2%), cubebol (12.76%), germacrene D-4-ol (9.6%), germacrene D (4.32%), farnesyl acetate (3.58%), longifolol acetate (2.76%), and β-bourbonene (2.35 %) whereas monoterpenoids were minor constituents. The zone of inhibition (ZOI) shown by essential oil against test bacterial strains at concentration of 500 μg/ml to Gram-negative bacteria Pseudomonas aeruginosa (5.6 mm), Escherichia coli (5 mm), Salmonella typhimurium (8.6 mm), and Proteus vulgaris (10.7 mm) and Gram-positive bacteria Bacillus subtilis (8.3 mm). At the same time, ZOI of standard antibiotic ciprofloxacin against test bacterial strains was P. aeruginosa (9.6 mm), E. coli (14.3mm), S. typhimurium (19.3 mm), P. vulgaris (17.8 mm), and B. subtilis (20.6 mm), respectively. The free radical scavenging property of A. parviflora employed by in vitro assay methods like scavenging activity of DPPH was 81% at 500 μg/ml concentrations, respectively. Conclusion: Our study showed that α-cadinol, α-muurolol, and cubebol as the major components in this oil which was absent in previous findings of A. parviflora and essential oil had potent antibacterial and antioxidant activity, respectively.

scholarly journals Isolation, Characterization, and Efficacy of Actinobacteria Associated with Arbuscular Mycorrhizal Spores in Promoting Plant Growth of Chili (Capsicum flutescens L.)

2021 ◽  
Vol 9 (6) ◽  
pp. 1274
Author(s):  
Leardwiriyakool Chaiya ◽  
Jaturong Kumla ◽  
Nakarin Suwannarach ◽  
Tanongkiat Kiatsiriroat ◽  
Saisamorn Lumyong
Keyword(s):  
Plant Growth ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Fruit Production ◽  
In Vitro Assay ◽  
Vitro Assay ◽  
Genus Streptomyces ◽  
Plant Growth Promoting ◽  
Growth Promoting

Nowadays, microorganisms that display plant growth promoting properties are significantly interesting for their potential role in reducing the use of chemical fertilizers. This research study proposed the isolation of the actinobacteria associated with arbuscular mycorrhizal fungi (AMF) spores and the investigation of their plant growth promoting properties in the in vitro assay. Three actinobacterial strains were obtained and identified to the genus Streptomyces (GETU-1 and GIG-1) and Amycolatopsis (GLM-2). The results indicated that all actinobacterial strains produced indole-3-acetic acid (IAA) and were positive in terms of siderophore, endoglucanase, and ammonia productions. In the in vitro assay, all strains were grown in the presence of water activity within a range of 0.897 to 0.998, pH values within a range of 5–11, and in the presence of 2.5% NaCl for the investigation of drought, pH, and salt tolerances, respectively. Additionally, all strains were able to tolerate commercial insecticides (propargite and methomyl) and fungicides (captan) at the recommended dosages for field applications. Only, Amycolatopsis sp. GLM-2 showed tolerance to benomyl at the recommended dose. All the obtained actinobacteria were characterized as plant growth promoting strains by improving the growth of chili plants (Capsicum flutescens L.). Moreover, the co-inoculation treatment of the obtained actinobacteria and AMF (Claroideoglomus etunicatum) spores could significantly increase plant growth, contribute to the chlorophyll index, and enhance fruit production in chili plants. Additionally, the highest value of AMF spore production and the greatest percentage of root colonization were observed in the treatment that had been co-inoculated with Streptomyces sp. GETU-1.

scholarly journals Potassium solubilization in phonolite rock by diazotrophic bacteria

2017 ◽  
Vol 8 (1) ◽  
pp. 17 ◽  
Author(s):  
Ligiane Aparecida Florentino ◽  
Adauton Vilela Rezende ◽  
Cássia Cristina Bachião Miranda ◽  
Aline Carvalho Mesquita ◽  
José Ricardo Mantovani ◽  
...  
Keyword(s):  
Plant Growth ◽  
Ph Value ◽  
Carbon Sources ◽  
Control Treatment ◽  
Nitrogen Fixing ◽  
Diazotrophic Bacteria ◽  
Bacterial Strains ◽  
Nitrogen Fixing Bacteria ◽  
Rock Powder ◽  
Potential Use

Some strains of nitrogen fixing bacteria, besides fixing the N2, can produce phytohormones, control pathogens, act in solubilization of minerals containing phosphorus (P) and potassium (K), contributing to plant growth. However, the solubilization of minerals containing K has been little exploited. Therefore, the aim of this study was to evaluate potassium solubilization (K) of phonolite rock by strains of associative nitrogen fixing bacteria supplied with two different carbon sources. Twelve bacterial strains were cultured for seven days at 25°C in Aleksandrov medium supplemented with phonolite rock powder. The experiment was carried out in a completely randomized factorial design, 13 x 2 (12 bacterial strains and a control without inoculation) and two carbon sources (glucose and sucrose) with four repetitions. After the growth, the supernatant was separated by centrifugation and analyzed for the final pH value and the content of K. All diazotrophic bacteria strains contributed to increase the release of K when compared to the control treatment. The strain UNIFENAS 100-94 solubilized 130 mg L-1 K in the presence of the two carbon sources, indicating the potential use of these diazotrophic bacterial strains for K solubilization from minerals.

scholarly journals Hybrid nanostructurated material for biomedical applications

2011 ◽  
Vol 1 (2) ◽  
pp. 064-071 ◽  
Keyword(s):  
Essential Oil ◽  
Core Shell ◽  
Bacterial Strains ◽  
Vitro Assay ◽  
Hybrid Nanomaterial ◽  
The Core ◽  
Antimicrobial Materials ◽  
Citrus Maxima ◽  
Biofilm Development

The purpose of this study was to assess the antibacterial activity of a novel hybrid organic-inorganic nanostructurated material based on Fe3O4/PEG600/Citrus maxima essential oil. The core/shell material was synthesized by reacting PEG600 with Fe3O4 nanoparticles, under microwave condition. The core/shell was modified by adsorbtion of C. maxima essential oil as an extra-shell. The nanostructurated material was characterized by HR-TEM and FT-IR. The hybrid nanomaterial was screened for their in vitro antimicrobial activity against Gram – positive and Gram–negative bacterial strains. The in vitro assay of the influence of the magnetic biomaterial on bacterial adherence to cellular and acellular substrata and biofilm development demonstrated that novel hybrid nanostructurated materials could be used for the development of novel antimicrobial materials with anti-adherent properties

Bacterial Aggregation in Relation to Peritoneal Dialysis

1990 ◽  
Vol 10 (1) ◽  
pp. 21-24 ◽  
Author(s):  
Gregor Reid ◽  
Susanne Schwarz-Faulkner ◽  
Jacqueline A. McGroarty ◽  
Andrew W. Bruce
Keyword(s):  
Peritoneal Dialysis ◽  
Staphylococcus Epidermidis ◽  
Potential Mechanism ◽  
Bacterial Strains ◽  
Exit Site ◽  
Vitro Assay ◽  
Bacterial Aggregation ◽  
Dialysis Solutions ◽  
Gram Positive Cocci

The ability of gram-positive cocci to aggregate and form biofilms at the exit site and on catheter surfaces in continuous ambulatory peritoneal dialysis (CAPD) has been associated with peritonitis. In the present study, 16 (80%) of 20 dialysate effluents from patients with staphylococcal peritonitis were found to contain aggregates of Staphylococcus epidermidis or S. aureus. Using an in vitro assay system, 20 (83%) of 24 pathogenic bacterial strains were found to aggregate in fresh dialysis solutions within 4 to 24 h at 37°C. Further studies with one strain, S. epidermidis 1938, showed increased aggregation when the bacteria were incubated in dialysate effluents compared to fresh dialysis solutions. Viability experiments showed that aggregated bacteria were less sensitive to the killing effects of fresh dialysis solutions and that dialysate effluents could support bacterial growth. The results suggest that attention be paid to aggregation as a potential mechanism used by bacteria in causation of peritonitis.

scholarly journals PHYSIOLOGICAL CHARACTERIZATION OF DIAZOTROPHIC BACTERIA ISOLATED FROM Brachiaria brizantha RHIZOSPHERE

2019 ◽  
Vol 32 (3) ◽  
pp. 658-666 ◽  
Author(s):  
ANA BEATRIZ CARVALHO TERRA ◽  
FLÁVIA ROMAM DA COSTA SOUZA ◽  
JOSÉ RICARDO MANTOVANI ◽  
ADAUTON VILELA DE REZENDE ◽  
LIGIANE APARECIDA FLORENTINO
Keyword(s):  
Phosphate Solubilization ◽  
Ph Value ◽  
Salt Resistance ◽  
Diazotrophic Bacteria ◽  
Bacterial Strains ◽  
Brachiaria Brizantha ◽  
Metabolic Characteristics ◽  
Ph Values ◽  
Iaa Production

ABSTRACT The objective of this study was to evaluate the ability of diazotrophic bacteria isolated from Brachiaria brizantha rhizosphere to grow at different pH values and salt concentrations, to produce indoleacetic acid (IAA), and to solubilize phosphate. Both acidity and salinity tolerance tests were performed on modified solid FAM medium. Acidity resistance tests were performed at pH values of 4.0, 5.0, 6.0, and 7.0, while, salt resistance was evaluated at concentrations of 0.01, 5.02, 9.99, 14.96, 19.98, 24.95, 29.98, 34.94, 39.97, 44.94, and 49.96 gL-1 NaCl. For the IAA production assay, bacterial strains were cultivated in liquid DYGS medium both in the absence and presence of tryptophan (Trp). In addition, phosphorus solubilization assay was performed in GL liquid medium. All strains grew at every pH value tested, and a high diversity was observed after salt resistance, IAA production, and phosphate solubilization testing. Strains UNIFENAS 100-51, UNIFENAS 100-52, UNIFENAS 100-60, UNIFENAS 100-63, and UNIFENAS 100-65 were those with the best growth at the highest salt concentrations. Furthermore, in the presence of Trp, strains UNIFENAS 100-63 and UNIFENAS 100-69 were the ones with the highest IAA production. Strain UNIFENAS 100-52 showed the best response to the in vitro phosphate solubilization assay. Based on these results, it can be seen that studies related to the physiological and metabolic characteristics of diazotrophic bacterial strains are important to ensure greater success in the field.

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