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 APPLICATION OF A NUTRITIONAL GROUPING METHOD TO SOIL FUNGI

1955 ◽  
Vol 33 (3) ◽  
pp. 281-288 ◽  
Author(s):  
R. G. Atkinson ◽  
J. B. Robinson
Keyword(s):  
Amino Acids ◽  
Growth Factors ◽  
Yeast Extract ◽  
Soil Fungi ◽  
Basal Medium ◽  
Maximum Growth ◽  
Potassium Nitrate ◽  
Soil Extract ◽  
Mineral Salts ◽  
Soil Extracts

In tests with seven different liquid media in which the common nitrogen source was potassium nitrate and the carbohydrate substrate was glucose, at a concentration of only 0.1%, most of the 1914 soil fungi isolated fell into one of three nutritional groups requiring, respectively, for maximum growth amino acids, amino acids plus growth factors, or yeast extract. Relatively few isolates required growth factors alone or a combination of yeast and soil extracts. Most of the isolates grew poorly in the basal medium containing only mineral salts, and glucose, with or without soil extract. Although fungi requiring yeast extract were much less frequently isolated from soil on, rather than remote from, tubers grown in a soybean green-manured plot, isolates requiring amino acids, or yeast plus soil extracts, were correspondingly increased on immature and mature tubers, respectively. In a second plot, however, not specially treated, no differences were observed in the nutritional spectra of fungi isolated from the two kinds of soil environment.

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 The Role of Amino Acids for the In Vitro Culture of Some Species of Forage Legumes I. Trifolium pratense L

2013 ◽  
Vol 70 (1) ◽  
pp. 87-92
Author(s):  
Gabriela Maria VICAȘ ◽  
Mircea SAVATTI
Keyword(s):  
Amino Acids ◽  
In Vitro Culture ◽  
Culture Medium ◽  
Trifolium Pratense ◽  
Basal Medium ◽  
Red Clover ◽  
Forage Legumes ◽  
Trifolium Pratense L

Establishing the effect of the amino acids as additional additives to the culture medium is and will be in the future one of our concerns of interest for the in vitro culture of some plants. The present study examines the effect of the glicocol added to the LS basal medium over the embryos of the Trifolium pratense L specie cultivated in vitro. There were followed: the percentage of plant regeneration of the red clover, its multiplication capacity and the formation of the root system, and also the evolution of the callus obtained on mediums with 2,4D, BA and amino acid.

Nutritional Factors Affecting Growth and Production of Antimicrobial Substances by Streptococcus lactis subsp. diacetylactis S1-67/C

1983 ◽  
Vol 46 (6) ◽  
pp. 514-517 ◽  
Author(s):  
N. S. REDDY ◽  
B. RANGANATHAN
Keyword(s):  
Amino Acids ◽  
Yeast Extract ◽  
Casein Hydrolysate ◽  
Basal Medium ◽  
Good Growth ◽  
Mineral Salts ◽  
Nutritional Factors ◽  
Maximum Production ◽  
Antimicrobial Substances ◽  
Streptococcus Lactis

The present study pertains to the effect of nutritional factors on the growth and production of antimicrobial substances (AS) by Streptococcus lactis subsp. diacetylactis S1-67/C. Among nine media tested, yeast extract dextrose broth supported good growth and maximum production of AS. Addition of beef extract and yeast extract at 1.0 and 0.6% levels, respectively, increased growth as well as production of AS. Of ten carbohydrates examined, maximum production of AS was achieved with 1% glucose followed by fructose, 4% molasses, lactose, sucrose, galactose, mannitol, maltose and 2% molasses. Xylose inhibited production of AS, although it stimulated growth of the organism. Peptone, tryptone and tryptose (each at the 1.5% level) significantly stimulated production of AS. Other nitrogen sources, including soytone, casein hydrolysate and proteose peptone, retarded production of inhibitory substances. Among the amino acids, L-leucine, DL-methionine and L-glutamic acid were most essential for growth and production of AS, whereas L-lysine, L-proline, DL-serine, DL-asparatic acid, L-arginine-HCl and DL-tryptophan were stimulatory. Other amino acids such as DL-ornithine, L-cysteine-HCl and DL-citrulline slightly stimulated AS production. In the presence of cynocobalmin, niacin, folic acid, calcium pantothenate and riboflavin, S. lactis subsp. diacetylactis S1-67/C produced maximum amounts of inhibitory substances. Omission of individual mineral salts from the basal medium did not affect production of AS by the organism.

In vitro exhaustion of pancreatic beta-cells

1986 ◽  
Vol 250 (5) ◽  
pp. E502-E511 ◽  
Author(s):  
M. Hoenig ◽  
L. C. MacGregor ◽  
F. M. Matschinsky
Keyword(s):  
Amino Acids ◽  
Arachidonic Acid ◽  
Pancreatic Beta Cells ◽  
Basal Medium ◽  
In Vitro Study ◽  
Bicarbonate Buffer ◽  
Isolated Pancreatic Islets ◽  
Perifusion System ◽  
Secretory Capacity

To learn more about possible limited beta-cell secretory capacity and factors essential for insulin release, a perifusion system was applied that allowed the in vitro study of insulin secretion from isolated pancreatic islets for more than 6 h. Islets isolated from rats were stimulated with various glucose concentrations (7.5, 16.7, and 30 mM), alpha-ketoisocaproate (30 mM), and 30 mM glucose plus 1 mM 3-isobutyl-1-methylxanthine for several hours in Krebs-Ringer-bicarbonate buffer (KRB) or RPMI 1640. Islets showed "exhaustion" with all stimulatory conditions used when KRB was the perifusion medium. This was not prevented by addition of amino acids, phosphate, myo-inositol or arachidonic acid. With RPMI 1640 as the basal medium, exhaustion was not seen at 7.5 mM but was readily approached at higher glucose concentrations. It is possible that the exhaustion phenomenon observed here is due to a depletion of a readily releasable insulin pool.

STUDIES ON THE RHIZOSPHERE MICROFLORA OF CITRUS TREES: II. QUALITATIVE DISTRIBUTION OF THE BACTERIAL FLORA

1962 ◽  
Vol 8 (4) ◽  
pp. 479-484 ◽  
Author(s):  
G. Rangaswami ◽  
V. N. Vasantharajan
Keyword(s):  
Amino Acids ◽  
Methylene Blue ◽  
Growth Factors ◽  
Yeast Extract ◽  
Bacterial Flora ◽  
Soil Extract ◽  
Gram Negative ◽  
Rhizosphere Microflora ◽  
Nitrate Reducers ◽  
Significant Difference

Studies were made on the relative incidence of various morphological, physiological, and nutritional groups of bacteria in the rhizosphere regions of growing and non-growing roots of three species of Citrus as compared to those in the soil. Gram-negative non-sporing rods were more abundant in the rhizospheres of both growing and non-growing roots than in the soil, whereas Gram-positive rods, cocci, and sporeformers were more numerous in the soil than in the rhizospheres. Nitrate reducers, gelatin liquefiers, starch hydrolyzers, and methylene blue reducers occurred in greater numbers in the rhizospheres than in soil. Growing roots seemed to stimulate preferentially nitrate reducers and gelatin liquefiers, whereas cellulose decomposers and pectin reducers were in higher proportions in non-growing roots than in the growing roots as well as in soil. There was no significant difference between populations of azotobacter occurring in the rhizospheres and soil, but sulphur-oxidizing bacteria were absent in the rhizospheres of both growing and non-growing roots. Bacteria that require amino acids for growth were more abundant in the rhizosphere of growing than non-growing roots, whereas those requiring growth factors in yeast extract and soil extract were less abundant in the growing roots than in soil. The numbers associated with non-growing roots appeared to be intermediate between the growing roots and soil.

EVIDENCE FOR NEGATIVE FEEDBACK IN THE CONTROL OF ETHANOLAMINE BIOSYNTHESIS IN EXCISED TOMATO ROOTS

1959 ◽  
Vol 37 (5) ◽  
pp. 1071-1083 ◽  
Author(s):  
William G. Boll
Keyword(s):  
Amino Acids ◽  
Yeast Extract ◽  
Negative Feedback ◽  
Culture Media ◽  
Vitamin B ◽  
Tomato Roots ◽  
Carry Over

The isolation of a clone of excised tomato roots (clone R3), and the modifications of White's medium necessary for successful culture of this clone, are described. The medium includes pyridoxin. Either ethanolamine, dimethylethanolamine, glycine, L-serine, L-valine, DL-norleucine, or L-isoleucine (and possibly L-tryptophane) replaced pyridoxin to a greater or lesser extent. L-Alanine, L-lysine, and L-threonine did not replace pyridoxin. The replacement of pyridoxin by ethanolamine is not dependent upon the carry-over of pyridoxin in the inoculum and clone R3 has been subcultured for over a year in a medium containing ethanolamine but no added pyridoxin. Explanations of this fact are given.Nutritional experiments are described in which ethanolamine and amino acids, which will also partly replace pyridoxin, were supplied together in the absence of pyridoxin. The results support the hypothesis that exogenous ethanolamine leads to the loss of a vitamin B6 dependent enzyme necessary for the biosynthesis of ethanolamine. The results are of incidental interest when considering the use of complex additives (e.g. yeast extract) in culture media, and to the explanation of toxicity of natural metabolites.

Somatic Embryogenesis and In vitro Plant Regeneration in Vigna trilobata (L.) Verd. - A Potential Pasture Legume

1970 ◽  
Vol 19 (1) ◽  
pp. 89-99
Author(s):  
K. Choudhary ◽  
M. Singh ◽  
M. S. Rathore ◽  
N. S. Shekhawat
Keyword(s):  
Somatic Embryogenesis ◽  
Growth Regulators ◽  
Somatic Embryos ◽  
Basal Medium ◽  
Long Term Study ◽  
Continuous Application ◽  
First Time ◽  
Pasture Legume

This long term study demonstrates for the first time that it is possible to propagate embryogenic Vigna trilobata and to subsequently initiate the differentiation of embryos into complete plantlets. Initiation of callus was possible on 2,4-D. Somatic embryos differentiated on modified MS basal nutrient medium with 1.0 mg/l  of 2,4-D and 0.5 mg/l  of Kn. Sustained cell division resulted in globular and heart shape stages of somatic embryos. Transfer of embryos on to a fresh modified MS basal medium with 0.5 mg/l of Kn and 0.5 mg/l of GA3 helped them to attain maturation and germination. However, the propagation of cells, as well as the differentiation of embryos, were inhibited by a continuous application of these growth regulators. For this reason, a long period on medium lacking these growth regulators was necessary before the differentiation of embryos occurred again. The consequences for improving the propagation of embryogenic cultures in Vigna species are discussed. Key words: Pasture  legume, Vigna trilobata, Globular, Heart shape, somatic embryogenesis D.O.I. 10.3329/ptcb.v19i1.4990 Plant Tissue Cult. & Biotech. 19(1): 89-99, 2009 (June)

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