THE INFLUENCE OF SOIL AND ROOT EXTRACTS ON THE ASSOCIATIVE GROWTH OF SELECTED SOIL BACTERIA

1963 ◽  
Vol 9 (2) ◽  
pp. 187-197 ◽  
Author(s):  
E. C. S. Chan ◽  
H. Katznelson ◽  
J. W. Rouatt
Keyword(s):  
Mixed Culture ◽  
Soil Bacteria ◽  
Agar Medium ◽  
Soil Extract ◽  
Antagonistic Effect ◽  
Pseudomonas Sp ◽  
Population Changes ◽  
Agrobacterium Radiobacter ◽  
Root Extracts ◽  
Wheat Population

These studies are concerned with the growth interrelationships of mixed cultures of five soil organisms in soil extract and root extracts of 2-, 4-, and 8-week-old oats, soybeans, and wheat. Population changes of Agrobacterium radiobacter, Arthrobacter citreus, Azotobacter chroococcum, Bacillus cereus, and a Pseudomonas sp. in pure and mixed culture were followed by plating on selective media. B. cereus and A. chroococcum grew poorly alone or in mixed culture in the extracts. In soil extract, A. citreus predominated over, or was nearly equal in number to, the Gram-negative forms (Pseudomonas and Agrobacterium). In root extracts, Pseudomonas sp. always predominated over A. citreus in mixed culture. A. radiobacter was inhibited in mature root extracts (8-week-old plants) although in pure culture it recovered after a period. An antagonistic effect of Pseudomonas sp. on A. chroococcum plated on nitrogen-free agar medium was found to be related to the kind of agar used.

GROWTH INTERACTIONS OF ARTHROBACTER GLOBIFORMIS AND PSEUDOMONAS SP. IN RELATION TO THE RHIZOSPHERE EFFECT

1961 ◽  
Vol 7 (5) ◽  
pp. 759-767 ◽  
Author(s):  
E. C. S. Chan ◽  
H. Katznelson
Keyword(s):  
Soil Extract ◽  
Soil Microflora ◽  
Biologically Active ◽  
Arthrobacter Globiformis ◽  
Pseudomonas Sp ◽  
Mineral Salts ◽  
Root Extracts ◽  
Cultural Conditions ◽  
Alkaline Conditions ◽  
Casamino Acids

Studies on the influence of plant roots on the soil microflora have shown that the number of Gram-negative rods in the rhizosphere is relatively higher than the number of Gram-positive rods, coccoid rods, and sporeforming types. This ecological phenomenon was duplicated and studied in a model system using a Pseudomonas sp. as representative of the rhizosphere and Arthrobacter globiformis as representative of the soil flora. Growth of A. globiformis was strongly suppressed in the presence of the pseudomonad in root extracts of mature plants and in a medium containing casamino acids, yeast extract, glucose, and mineral salts (CAYG medium); suppression was less marked in soil extract. The pseudomonad was unaffected in the association. A. globiformis was inhibited in the first 48-hour incubation in CAYG medium by acid elaborated by the pseudomonad; the pH dropped to 5.3 in 16 hours but rose steadily to alkaline conditions after 48 hours, resulting in a delayed increase in the number of A. globiformis to approximately that of a pure culture, in 5 days. Under cultural conditions favoring pigment production by the pseudomonad, growth of A. globiformis was completely inhibited throughout this period. Another toxic principle was also produced by the pseudomonad. This substance was biologically active in mixed culture against the Arthrobacter but was present in low concentration.

scholarly journals Microcolony Cultivation on a Soil Substrate Membrane System Selects for Previously Uncultured Soil Bacteria

2005 ◽  
Vol 71 (12) ◽  
pp. 8714-8720 ◽  
Author(s):  
Belinda C. Ferrari ◽  
Svend J. Binnerup ◽  
Michael Gillings
Keyword(s):  
Soil Bacteria ◽  
Bacterial Species ◽  
Membrane System ◽  
Soil Extract ◽  
Growth Strategy ◽  
Soil Slurry ◽  
Polycarbonate Membrane ◽  
Microbiological Methods ◽  
Candidate Division ◽  
Excessive Nutrients

ABSTRACT Traditional microbiological methods of cultivation recover less than 1% of the total bacterial species, and the culturable portion of bacteria is not representative of the total phylogenetic diversity. Classical cultivation strategies are now known to supply excessive nutrients to a system and therefore select for fast-growing bacteria that are capable of colony or biofilm formation. New approaches to the cultivation of bacteria which rely on growth in dilute nutrient media or simulated environments are beginning to address this problem of selection. Here we describe a novel microcultivation method for soil bacteria that mimics natural conditions. Our soil slurry membrane system combines a polycarbonate membrane as a growth support and soil extract as the substrate. The result is abundant growth of uncharacterized bacteria as microcolonies. By combining microcultivation with fluorescent in situ hybridization, previously “unculturable” organisms belonging to cultivated and noncultivated divisions, including candidate division TM7, can be identified by fluorescence microscopy. Successful growth of soil bacteria as microcolonies confirmed that the missing culturable majority may have a growth strategy that is not observed when traditional cultivation indicators are used.

DECOMPOSITION OF CHLORO-SUBSTITUTED ALIPHATIC ACIDS BY SOIL BACTERIA

1957 ◽  
Vol 3 (2) ◽  
pp. 151-164 ◽  
Author(s):  
H. L. Jensen
Keyword(s):  
Amino Acids ◽  
Yeast Extract ◽  
Soil Bacteria ◽  
Basal Medium ◽  
Soil Extract ◽  
Taxonomic Position ◽  
Vitamin B ◽  
Selective Media ◽  
Aliphatic Acids

Three groups of bacteria capable of decomposing chloro-substituted aliphatic acids were isolated from soil by means of selective media. A group of Pseudomonas-like bacteria (A) decomposed monochloroacetate (and monobromoacetate) readily in media with yeast extract, peptone, or amino acids. They also decomposed α-monochloropropionate with moderate vigor, but had little effect on dichloro-acetate and -propionate, and none on trichloroacetate. A non-sporeforming bacterium of uncertain taxonomic position (B) was able to decompose trichloroacetate in media containing soil extract or vitamin B12, and also in basal medium when associated with vitamin B12-producing strains of Streptomyces. Dichloroacetate was only slightly attacked, and monochloroacetate and α-dichloropropionate not at all. A group of bacteria (C) apparently belonging to Agrobacterium decomposed α-dichloropropionate and dichloroacetate, but was less active towards α-monochloropropionate, and did not attack mono- and tri-chloroacetate. The organisms of groups B and C grew only feebly in ordinary media. The decomposition of monochloroacetate, trichloroacetate, and α-dichloropropionate in soil was accelerated by addition of cell suspensions of groups A, B, and C, respectively. The organisms seemed to be more active in the soil than in vitro.

The growth inhibition of Azotobacter chroococcum by Pseudomonas sp.

1970 ◽  
Vol 16 (1) ◽  
pp. 9-16 ◽  
Author(s):  
E. C. S. Chan ◽  
Pramila Basavanand ◽  
Tiiu Liivak
Keyword(s):  
Agar Medium ◽  
High Sensitivity ◽  
Azotobacter Chroococcum ◽  
Point Of View ◽  
Pseudomonas Sp ◽  
Microbial Interaction ◽  
Metabolic Intermediates ◽  
Microbial Association ◽  
End Products ◽  
Diffusible Factor

When Azotobacter chroococcum and Pseudomonas sp. were grown together on nitrogen-deficient azotobacter agar medium, the growth of the azotobacter was inhibited. Studies were undertaken to explain this microbial interaction. No demonstrable active diffusible factor was found in cell-free filtrates (neutralized) and extracts. Experiments with indicator agar plates and HEPES-buffered liquid medium suggested that the interaction was attributable to the transformation by the pseudomonad of metabolic intermediates of azotobacter to inhibitory acidic end products. The high sensitivity of A. chroococcum to acidity resulted in the inhibition phenomenon. This microbial association is discussed briefly from the point of view of the ecology of the two species.

Native soil bacteria isolates in Mexico exhibit a promising antagonistic effect againstFusarium oxysporumf. sp.radicis-lycopersici

2013 ◽  
pp. n/a-n/a ◽  
Author(s):  
Jesús Damián Cordero-Ramírez ◽  
Raquel López-Rivera ◽  
Alejandro Miguel Figueroa-Lopez ◽  
María Elena Mancera-López ◽  
Juan Carlos Martínez-Álvarez ◽  
...  
Keyword(s):  
Soil Bacteria ◽  
Antagonistic Effect ◽  
Native Soil

QUALITATIVE STUDIES OF SOIL MICROORGANISMS: XI. FURTHER OBSERVATIONS ON THE NUTRITIONAL CLASSIFICATION OF BACTERIA

1953 ◽  
Vol 31 (4) ◽  
pp. 438-447 ◽  
Author(s):  
I. L. Stevenson ◽  
J. W. Rouatt
Keyword(s):  
Soil Bacteria ◽  
Inorganic Nitrogen ◽  
Basal Medium ◽  
Slight Modification ◽  
Original System ◽  
Potassium Nitrate ◽  
Soil Extract ◽  
Original Method ◽  
Casamino Acids

A review of the method developed in this laboratory in 1943 for the nutritional classification of soil bacteria has suggested slight amendments in certain differential media: (1) the substitution of vitamin-free casamino acids for a combination of amino acids, and (2) the addition of vitamin B12 to the growth factor media. In a comparative study with a newly proposed scheme of classification, the more selective plating medium advocated was found to be less suitable for the isolation of soil bacteria than the nonselective soil extract agar in the original method. Furthermore, the replacement of potassium nitrate with diammonium phosphate as source of inorganic nitrogen in the basal medium failed to cause any significant change in the nutritional grouping. Results from the nutritional classification of some 600 isolates by the two methods showed that the new procedure represents only a slight modification of the original system.

scholarly journals Green Synthesis Concept of Nanoparticles From Environmental Bacteria and Their Effects on Pathogenic Bacteria

2020 ◽  
pp. 1289-1297
Author(s):  
Ghada Mohammed Saleh
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Soil Bacteria ◽  
Pathogenic Bacteria ◽  
Pseudomonas Sp ◽  
Good Source ◽  
Force Microscopy ◽  
Atomic Force ◽  
Environmental Bacteria ◽  
Inhibition Zones

Soil bacteria play an interesting role in the reduction of Ag+ ions and the formation of silver nanoparticles (AgNPs), which may be a good source for nanoparticles and play a major role in nanotechnology applications. The concept of this project was to study the effects of these environmentally produced nanoparticles on the growth of some pathogenic bacteria. The environmental bacteria were isolated from soil, purified on broth cultures, and centrifuged, while the supernatant was extracted to detect its ability to convert silver nitrate to nanoparticles. The AgNPs was detected by Atomic Force Microscopy (AFM), while Granularity Cumulating Distribution (GCD) was employed to estimate the AgNPs sizes. The results showed the synthesis of AgNPs with sizes of 63.50nm and 45.81nm from the extracts of environmental Pseudomonas sp. and Enterobacter, respectively. The synthesized AgNPs from the extracts of all environmental bacteria showed antibacterial activity against some pathogenic bacteria (Gram positive and Negative) with variable inhibition zones. In conclusion, environmental bacteria can be a cheap source of nanoparticles.

N-Methyl-D-Aspartate (NMDA) Receptor Antagonistic Effect and Ginsenoside Content of Panax ginseng C. A. Meyer Cultivar Root Extracts

2020 ◽  
Vol 28 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Seung Eun Lee ◽  
Jang Uk Kim ◽  
Hyeon Soo Jeong ◽  
Je Hun Choi ◽  
Yun Jeong Ji ◽  
...  
Keyword(s):  
Nmda Receptor ◽  
Panax Ginseng ◽  
Antagonistic Effect ◽  
Root Extracts ◽  
Ginsenoside Content
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