Factors affecting the production of hydrogenase by Desulfovibrio desulfuricans

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):  
Edwin S. Boatman

The effect of acridine derivatives on bacterial growth has been shown to be dependent upon the concentration used, pH, temperature, and the position of the amino substituents on the acridine molecule. These factors, in turn, affect the amount of acridine bound to cell constituents. Many bacterial species, when grown in media containing acridities, become filamentous, or pleomorphic, or growth may be entirely prevented. The fine-structure of two species of bacteria treated with acriflavine was investigated. Both were Gram-positive bacilli, one was a Corynebacterium, and the other an aerobic spore-bearing Bacillus.Organisms were incubated at 21°c in the presence of concentrations of acriflavine ranging from 0.25 ug/ml to 12 ug/ml in phosphate buffered peptone water yeast extract medium at pH 7.5. Viable counts were carried out and the amount of acriflavine bound, either reversibly or irreversibly, was estimated at 450 mu, using a DB spectrophotometer. Cultures were observed by light microscopy and, after four days growth, were processed for electron microscopy by fixation in veronal-acetate pH 6.1 buffered 0.8% Os O4 for one hour and embedding in Epon 812 resin.


1969 ◽  
Vol 67 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Lynn Harding ◽  
R. E. O. Williams

SUMMARYA tryptone-yeast extract medium enriched with glucose and serum incubated anaerobically at 41° C. was found to give a good yield ofStaphylococcus aureusfrom air samples while suppressing the growth of 70–80% of the other airborne bacteria.Our thanks are due to Miss S. M. Taber and Miss Patricia Wall, the Sisters in the wards where the air samples were collected, for their help. The investigation was financed from the Ministry of Health grant to St Mary's Hospital for the support of clinical research.


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.


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.


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.•


Sign in / Sign up

Export Citation Format

Share Document