Isolation and identification of N2-fixing Pseudomonas associated with wetland rice

1983 ◽  
Vol 29 (8) ◽  
pp. 867-873 ◽  
Author(s):  
W. L. Barraquio ◽  
J. K. Ladha ◽  
I. Watanabe

Semisolid yeast extract medium amended with glucose and tryptic soy agar were used to isolate aerobically N2-fixing (C2H2-reducing) heterotrophic bacteria from the root of wetland rice. The isolates were identified as Pseudomonas by gel immunodiffusion and fluorescent antibody techniques in combination with their morphological, cultural, and biochemical characteristics. The N2-fixing H2-utilizing Pseudomonas described in this paper is a new species.

1977 ◽  
Vol 23 (11) ◽  
pp. 1568-1572 ◽  
Author(s):  
S. W. Tanenbaum ◽  
M. Flashner

A new species of Arthrobacter is described for which the name A. sialophilus is proposed. The organism was obtained by elective culture from soil using Collocalia mucoid, and can readily be induced in replacement minimal media with appropriate substrates, to form the enzyme neuraminidase. It undergoes sphere–rod–sphere morphogenesis, is gram-variable, non-motile, aerobic, catalase-positive, oxidase-negative, fails to release acid or gas from saccharides, has a GC content of 56.0 mol % and can grow at temperatures up to 45 °C. The peptidoglycan composition of its spherical form contains neither diaminopimelic acid nor arabinose as components, but does manifest the presence of glycine. Its generation time at 30 °C on tryptone – yeast extract medium is 1.6 h. Accessory growth factors do not appear to be required. The organism, though colorless in the dark, provides a bright yellow water-insoluble pigment after exposure to light. The foregoing combination of properties distinguishes this isolate from other well-described Arthrobacter spp.


INDIAN DRUGS ◽  
2013 ◽  
Vol 50 (11) ◽  
pp. 25-28
Author(s):  
K Narayanan ◽  
◽  
N.D. Chopade ◽  
V.M Subrahmanyam ◽  
J. Venkata Rao

Microbial chitinases are commercially exploited for their biocontrol properties and generation of useful products from chitinous waste. Availability of highly active chitinolytic enzymes is a major problem. The present study was carried out to improve chitinase production by Aspergillus terreus using a chemical mutagen, ethidium bromide. The organism was cultivated on lactose- yeast extract medium. The production medium consisting of chitin- yeast extract medium was seeded at 10% level. The wild strains were exposed to ethidium bromide in the concentration range 1.5- 6.0 µg/mL. Generally, all the mutated strains showed an improved chitinase yield compared to the control. Highest yield was observed with the strain exposed to 6 µg/mL of ethidium bromide. The yield was 25.03 % higher compared to the wild strain. The mutated strain was slimy in nature. Protein content of the mutated strain decreased by 11%. Ethidium bromide at a concentration of 1.5 µg/mL was considered optional, at which the strain was stable with increase of 21.80 % in enzyme activity and 4.41% increase in protein content. Increased enzyme yield with decreased non-specific protein could be useful in producing cost effective enzyme.


2001 ◽  
Vol 64 (5) ◽  
pp. 721-724 ◽  
Author(s):  
J. DEL CAMPO ◽  
F. CARLIN ◽  
C. NGUYEN-THE

Four Enterobacteriaceae (Enterobacter agglomerans and Rhanella aquatilis) and six pseudomonads (Pseudomonas fluorescens, Pseudomonas chlororaphis, Pseudomonas putida) isolated from minimally processed green endive were coinoculated at 10°C with Listeria monocytogenes in a minimal medium. Pseudomonads did not modify the growth of L. monocytogenes, whereas Enterobacteriaceae reduced its maximal population by 2 to 3 log CFU/ml. The same effect was observed in a diluted yeast extract medium supplemented with amino acids and glucose, in which L. monocytogenes grown alone reached 109 to 1010 CFU/ml. In the same diluted yeast extract medium, not supplemented with glucose and amino acids, the maximal population of L. monocytogenes in the presence of both Enterobacteriaceae and pseudomonads was only slightly reduced (less than 0.5 log CFU/ml). Culture filtrates of the Enterobacteriaceae had no inhibitory activity on L. monocytogenes. The effect of the Enterobacteriaceae on L. monocytogenes growth was presumably due to a competition for glucose and/or amino acids.


1978 ◽  
Vol 41 (8) ◽  
pp. 626-630 ◽  
Author(s):  
S. M. HARMON ◽  
D. A. KAUTTER

Several media recommended for confirming isolates of Clostridium perfringens from selective plating media were evaluated. Media for testing motility, reduction of nitrate to nitrite, fermentation of lactose, and liquefaction of gelatin were found to be the most useful. A modified motility-nitrate medium, developed during the study, and lactose-gelatin medium were the most satisfactory for doing these tests. Fermentation of salicin and raffinose in peptone-yeast extract medium was also useful for differentiating atypically reacting strains of C. perfringens from a variety of culturally similar clostridia.


1964 ◽  
Vol 10 (6) ◽  
pp. 837-842 ◽  
Author(s):  
H. S. Shieh

A marine bacterium, isolated by an enrichment technique, is able to utilize choline as the sole carbon and nitrogen source in a medium containing various salts. The morphological and biochemical characteristics of the organism indicate that it is a new species. Substrate feeding coupled with culture filtrate analyses indicate that choline is metabolized as follows: choline → betaine → dimethylglycine + formaldehyde → sarcosine + formaldehyde → serine → pyruvate + ammonia without transmethylation being involved. This pathway has not previously been reported for other bacteria or for animal tissues.


1980 ◽  
Vol 26 (10) ◽  
pp. 1209-1213 ◽  
Author(s):  
S. M. Martin ◽  
B. R. Glick ◽  
W. G. Martin

An examination of conditions for the growth of Desulfovibrio desulfuricans, with the aim of optimizing hydrogenase production, is reported. An ammonium sulfate – lactate – yeast extract medium gave 5 to 10 times as much hydrogenase activity as a peptone – yeast extract medium. It made little if any difference whether the gas used for sparging was nitrogen, hydrogen, or a mixture thereof but increasing the rate of sparging and agitation did result in a slight decrease in activity. Control of pH during culture development was of little benefit to hydrogenase production. At least two hydrogenases were present in D. desulfuricans: one periplasmic, the other membrane bound.Desulfovibrio desulfuricans produced more hydrogenase than did either D. gigas and D. vulgaris.


Author(s):  
M. Jason MacDonald ◽  
Godwin B. D'Cunha

2006 NSIS Honourable Mention, Undergraduate Student ResearchPrize Winning PaperThe enrichment of a Rhodotorula glufinis strain and the determination of itsphenylalanine ammonia lyase (E.C.4.3.1.5 - PAL) activity and attempts to measure peroxidase (E.C.1.11.1. 7) activity included conventional mycological procedures along with chemical and microscopic examination. Sabouraud dextrose medium was found to be the most suitable for cell growth, but cells grown on yeast-extract medium exhibited optimal enzyme activity. Growth and PAL activity were measured in yeast cells grown in yeast-extract broth medium for 24-27 h. The appearance of a reddish pink color associated with the yeast cells coincided with the appearance of appreciable PAL activity. The maximum PAL activity and biomass of yeast obtained in the yeast extract medium ranged from 33 to 35 unitslmg dry cells and 7.5 to 8.0 g dry cells/l, respectively. In addition to phenylalanine, Rhodatowla PAL also used phenylalanine methyl-ester as a substrate. No peroxidase activity was found in these R. glutinis cells.L'enrichissement de la souche de Rhodatarula glutinis et la detenmination de l'activite de la phenylalanine ammoniac-lyase (E.C.4.3.1.5 - PAL) chez cette souche, de meme que les tentatives de mesure de I'activite de la peroxydase (E.C.1 .11.1 .7), ont compris I'utilisation de procedures mycologiques traditionnelles ainsi que des examens microscopiques et chimiques. Nous avons constate que la gelose Sabouraud au dextrose est Ie meilleur milieu pour assurer la croissance cellulaire, mais que l'activite enzymatique est optimale dans les cellules cultivees sur un milieu a base d'extrait de levure. Nousavons mesure la croissance de cellulesde levure culliveesdans un bouillon a base d'extrait de levure pendant 24 a 27 heures et nous avons mesure I'activite de la PAL dans ces memes cellules. L'apparition d'une couleur rose rougeatre associee aux cellules de levure a coIncide avec Ie debut d'une periode d'activite notable de laPAL. L'activite maxima Ie de la PAL obtenue dans Ie milieu a base d'exlrait de levure a varie de 33 a 35 unites par mg de cellules seches, tandis que la biomasse de levure maximale obtenue dans Ie meme milieu a varie de 7,5 a 8,0 9 de cellules seches par litre. En plus de la phenylalanine, la PAlde Rhodotorula a utilise I'ester methylique de la phenylalanine comme substrat. Aucune activite de la peroxydase n'a ete observee dans ces cellules de R. glutinis.•


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