scholarly journals Isolation and some properties of extracellular amylases from Fusarium martii var. minus f.2

2014 ◽  
Vol 16 (2) ◽  
pp. 237-245 ◽  
Author(s):  
Joanna Boguszewska
Keyword(s):  
Enzymatic Activity ◽  
Active Center ◽  
Liquid Culture ◽  
Culture Medium ◽  
Sh Groups ◽  
Liquid Culture Medium

α-amylase and glucoamylase were isolated from the liquid culture medium of <i>Fusarium martii</i>. At 10<sup>-3</sup> M concentrations PCMB inhibited the activity of both enzymes, which indicated that they require SH groups for enzymatic activity, α-amylase was also inhibited by DFP at 10<sup>-3</sup> M. One may thus assume that serine is present in the active center of the examined amylase.

Isolation of previously uncultured rumen bacteria by dilution to extinction using a new liquid culture medium

2011 ◽  
Vol 84 (1) ◽  
pp. 52-60 ◽  
Author(s):  
Nikki Kenters ◽  
Gemma Henderson ◽  
Jeyamalar Jeyanathan ◽  
Sandra Kittelmann ◽  
Peter H. Janssen
Keyword(s):  
Liquid Culture ◽  
Culture Medium ◽  
Rumen Bacteria ◽  
Liquid Culture Medium

scholarly journals FORMATION OF TRYPSIN FROM TRYPSINOGEN BY AN ENZYME PRODUCED BY A MOLD OF THE GENUS PENICILLIUM

1938 ◽  
Vol 21 (5) ◽  
pp. 601-620 ◽  
Author(s):  
M. Kunitz
Keyword(s):  
Temperature Coefficient ◽  
Acid Medium ◽  
Experimental Error ◽  
Protein Concentration ◽  
Liquid Culture ◽  
Culture Medium ◽  
Specific Activity ◽  
Crystalline Form ◽  
Liquid Culture Medium ◽  
Autocatalytic Activation

1. A powerful kinase which changes trypsinogen to trypsin was found to be present in the synthetic liquid culture medium of a mold of the genus Penicillium. 2. The concentration of kinase in the medium is increased gradually during the growth of the mold organism and continues to increase for some time even after the mold has ceased growing. 3. Mold kinase transforms trypsinogen to trypsin only in an acid medium. It differs thus from enterokinase and trypsin which activate trypsinogen best in a slightly alkaline medium. 4. The action of the mold kinase in the process of transformation of trypsinogen is that of a typical enzyme. The process follows the course of a catalytic unimolecular reaction, the rate of formation of a definite amount of trypsin being proportional to the concentration of kinase added. The ultimate amount of trypsin formed, however, is independent of the concentration of kinase used. 5. The formation of trypsin from trypsinogen by mold kinase is not accompanied by any measurable loss of protein. 6. The temperature coefficient of formation of trypsin from trypsinogen by mold kinase varies from Q5–15 = 1.70 to Q25–30 = 1.25 with a corresponding variation in the value of µ from 8100 to 4250. 7. Trypsin formed from trypsinogen by means of mold kinase is identical in crystalline form with the crystalline trypsin obtained by spontaneous autocatalytic activation of trypsinogen at pH 8.0. The two products have within the experimental error the same solubility and specific activity. A solution saturated with the crystals of either one of the trypsin preparations does not show any increase in protein concentration or activity when crystals of the other trypsin preparation are added. 8. The Penicillium mold kinase has a slight activating effect on chymo-trypsinogen the rate being only 1–2 per cent of that of trypsinogen. The activation, as in the case of trypsinogen, takes place only in an acid medium. 9. Mold kinase is rapidly destroyed when brought to pH 6.5 or higher, and also when heated to 70°C. In the temperature range of 50–60°C. the inactivation of kinase follows a unimolecular course with a temperature coefficient of Q10 = 12.1 and µ = 53,500. The molecular weight of mold kinase, as determined by diffusion, is 40,000.

Detection Method for Histamine-Producing, Dairy-Related Bacteria using Diamine Oxidase and Leucocrystal Violet

1989 ◽  
Vol 52 (2) ◽  
pp. 105-108 ◽  
Author(s):  
SUSAN S. SUMNER ◽  
STEVE L. TAYLOR
Keyword(s):  
Hydrogen Peroxide ◽  
Liquid Culture ◽  
Diamine Oxidase ◽  
Culture Medium ◽  
Detection Method ◽  
Enzyme System ◽  
Color Formation ◽  
Liquid Culture Medium ◽  
Leucocrystal Violet ◽  
Purple Color

A detection method for histamine-producing, dairy-related bacteria was developed that involves a two-step sequential enzyme system. First, isolated bacteria are incubated in MRS broth or trypticase soy broth fortified with histidine. The histamine formed during this incubation period is reacted with diamine oxidase, which catalyzes the oxidation of histamine to form imidazole acetaldehyde, ammonia, and hydrogen peroxide. The hydrogen peroxide is then detected by the formation of crystal violet from the leuco base in the presence of horseradish peroxidase. Liquid culture medium containing bacteria that produce greater than 1200 nmole histamine per ml will develop a positive purple color. Cultures containing bacteria that produce little or no histamine will not develop a purple color. Other amines often found in cheese, such as tyramine, cadaverine, or putrescine, will not interfere with the color formation.

A PROCEDURE FOR RAPID RECOVERY OF AFLATOXINS FROM CHEESE AND OTHER FOODS1

1971 ◽  
Vol 34 (3) ◽  
pp. 119-123 ◽  
Author(s):  
C. N. Shih ◽  
E. H. Marth
Keyword(s):  
Liquid Culture ◽  
Culture Medium ◽  
Peanut Butter ◽  
Corn Meal ◽  
Water Fraction ◽  
Food Residue ◽  
Liquid Culture Medium ◽  
Chloroform Layer ◽  
Sequential Addition ◽  
Chloroform Methanol

A rapid and efficient method has been developed to recover aflatoxin from cheese and other foods. The procedure involves: (a) blending the sample with a mixture of chloroform, methanol, and water (solvents are used in such proportions that a miscible (monophasic) system is formed, (b) adding more chloroform and water so the mixture becomes biphasic, (c) filtering to remove the food residue, (d) separating the lower chloroform layer which contains virtually all of the aflatoxin, and (e) purification, if necessary, of the material in step (d) after it has been concentrated. Purification is achieved by sequential addition of methanol, water, and hexane; recovery of tho methanol-water fraction; and extraction of aflatoxins from it with chloroform. Purification can be eliminated if the substrate contains little or no lipid or pigment which, if present, interfere with thin-layer chromaographic analysis. Extraction can be done in approximately 35 min and purification in approximately 20 min. When aflatoxins were added to various substrates, the method recovered 92–98% B1 and 96–100% G1 from rice; 95–96% B1 and 90–95% G1 from peanut butter; 93–94% B1 and 92–98% G1 from Cheddar cheese; 100% B1 and G1 from corn meal; 91–100% B1, 91–100% B2, 90–96% G1, and 92–100% G2 from brick cheese; and 97–100% B1, 95–100% B2, 92–100% G1, and 98–100% G2 from a liquid culture medium.

Rapid analysis of GBSS1 and Vinv genes expressed in potato tubers using microtubers produced in liquid culture medium

2020 ◽  
Vol 39 (11) ◽  
pp. 1415-1424
Author(s):  
Yuhya Wakasa ◽  
Atsushi Kasai ◽  
Muneo Yamazaki ◽  
Yutaka Tabei ◽  
Mutsuo Tsuyama ◽  
...  
Keyword(s):  
Liquid Culture ◽  
Culture Medium ◽  
Rapid Analysis ◽  
Potato Tubers ◽  
Liquid Culture Medium

scholarly journals EnteroaggregativeEscherichia coliassociated with an outbreak of diarrhoea in a neonatal nursery ward

1996 ◽  
Vol 117 (1) ◽  
pp. 11-16 ◽  
Author(s):  
M. Čobeljić ◽  
B. Miljković-Selimović ◽  
D. Paunović-Todosijević ◽  
Z. Veličković ◽  
Z. Lepšanović ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Liquid Culture ◽  
Culture Medium ◽  
Multiple Antibiotic Resistance ◽  
E Coli ◽  
Source Of Infection ◽  
Liquid Culture Medium ◽  
Aggregative Adherence ◽  
Mode Of Transmission ◽  
Age Range

SummaryOver a 9-day period in February 1995, 16 newborn babies (age range 2–11 days) and 3 infants (24, 47 and 180 days of age) in a neonatal nursery ward developed diarrhoea accompanied by pyrexia and weight loss. Known enteropathogens were not detected in their stools butEscherichia colidisplaying aggregative adherence to HEp-2 cells (enteroaggregativeE. coli) were found in 12 (63%) ill infants and in none of 5 well neonates (P= 0·02). The illness lasted 3–9 days (mean 5·2) in 16 babies, whereas in 3 neonates it showed a protracted course of 18–20 days. The source of infection and the mode of transmission remained unclear. The outbreak isolates manifested properties common in this new group of diarrhoeagenicE. coli: mannose-resistant haemagglutination, haemolysis on blood agar, and clump formation in liquid culture medium. They belonged to the O4E. coliserogroup and expressed multiple antibiotic resistance.

scholarly journals Biotransformation of Tryptophan by Liquid Medium Culture of Psilocybe coprophila (Basidiomycetes)

2006 ◽  
Vol 61 (11-12) ◽  
pp. 806-808
Author(s):  
Julio Alarcón ◽  
Leyla Foncea ◽  
Sergio Águila ◽  
Joel B. Alderete
Keyword(s):  
Liquid Medium ◽  
Chemical Reactions ◽  
Liquid Culture ◽  
Culture Medium ◽  
Liquid Culture Medium ◽  
Wide Range ◽  
Modern Tool ◽  
Medium Culture

Abstract Chemical reactions performed by fungi have been used as a modern tool in chemistry. In this work, we show the tryptophan biotransformation with Psilocybe coprophila on liquid culture medium. The results prove once more the versatility of fungi in performing a wide range of industrially attractive chemical reactions.

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