"Carbon Group" (36 results)

Violet Red Bile Agar with Lacose (VRBL) 500g, containing Bile and Violet Red dye, is based on MacConkey Agar (Cat. CL-1052). It can be used for the detection and enumeration of lactose-fermenting bacteria and the differentiation of coliforms or Coli aerogenes group from non-lactose fermenting organisms in dairy products, water, and foods. Peptone provides nitrogen, vitamins, minerals, and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group. Lactose is the fermentable carbohydrate providing carbon and energy. Bile salts and crystal violet inhibit Gram-positive bacteria and neutral red is a pH indicator. Sodium chloride supplies essential electrolytes for transport and osmotic balance and bacteriological agar is the solidifying agent.

It is convenient to use the pour plate method. Lactose fermenters form red colonies with red-purple halos. Occasionally the cocci of the intestinal tract can develop as small, punctiform red colonies. The purplish red colonies with a diameter of at least (sometimes surrounded by a reddish zone of precipitated bile) are considered as typical colonies of coliforms and do not require further confirmation. Atypical colonies (e.g. of smaller size), and all colonies derived from milk products that contain sugars other than lactose, may result in colonies with an appearance that looks like the typical coliforms. These colonies should be confirmed in tubes of Brilliant Green Bile Broth (Cat CL-1228).

Letheen Agar Modified is a modification of Letheen Broth Base. This medium is highly nutritious and recommended for use in the microbiological testing of cosmetics. It can also be used to inactivate quaternary ammonium compounds and other preservatives when establishing the number of bacteria present in cosmetics and other materials. Beef extract, casein peptone and meat peptone provide nitrogen, vitamins, minerals, and amino acids essential for growth. Yeast extract is the source of vitamins, particularly of the B-group. Glucose is the fermentable carbohydrate providing carbon and energy. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Lecithin, polisorbate 80 and sodium bisulphite neutralize quaternary ammonium compounds and partially neutralize the preservative system commonly found in cosmetics. Bacteriological Agar is the solidifying agent. The medium can be used for microbiological samples from surfaces that have been treated with disinfectants.

Faecal Coliforms Broth Base (m-FC) is prepared according to the formula proposed by Geldreich, Clark and Bert. The medium is used for the cultivation and enumeration of faecal coliforms microorganisms. It is also suitable for the membrane filter technique at a high temperature. Many standard procedures specify the use of Faecal coliforms Media for testing water and foods. Faecal coliforms are differentiated from other coliforms due to their ability to grow at 44,5±0,5 ºC. Proteose and Tryptose provide nitrogen, vitamins, minerals, and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group essential for bacterial growth. Lactose is the fermentable carbohydrate as a carbon and energy source. Bile salts and aniline blue inhibit growth of Gram-positive bacteria. Sodium chloride maintains the osmotic balance. Aniline blue and rosolic acid, which is provided by the supplement, are the differential indicators. Bacteriological agar is the solidifying agent.

Faecal Coliforms Agar Base (m-FC) is prepared according to the formula proposed by Geldreich, Clark and Bert. It can be used for the cultivation and enumeration of faecal coliforms microorganisms. This medium is suitable for the membrane filter technique at a high temperature. Many standard procedures specify the use of Faecal coliforms Media for testing water and foods. Faecal coliforms are differentiated from other coliforms from environmental sources by their ability to grow at 44.5 ± 0.5 ºC. Proteose and Tryptose provide nitrogen, vitamins, minerals, and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group essential for bacterial growth. Lactose is the fermentable carbohydrate as a carbon and energy source. Bile salts and aniline blue inhibit growth of Gram-positive bacteria. Sodium chloride maintains the osmotic balance. Aniline blue and rosolic acid, which is provided by the supplement, are the differential indicators. Bacteriological agar is the solidifying agent.

EC with MUG Fluorogenic Agar has a similar formula to EC Medium but an additional 4 methylumbelliferyl- ß-D-glucuronide (MUG) that is recommended for the membrane-filter technique for the detection of E. coli. Faecal contamination is a serious issue as it can cause contracting diseases from pathogens. The medium improves detection methods of coliform groups, in particular E. coli and can be used in investigating drinking water, wastewater, and general water quality monitoring to help prevent the spread of disease. 

The medium can be used at 35±2 ºC for detection of coliform organisms or at 44.5 ºC for isolation of E. coli. The Bile salts act as selective agent inhibiting Gram-positive bacteria, bacilli and enterococci but allowing E. coli to develop. The Potassium salts have a high buffering capacity and tryptose provides the nutrients for growth and Lactose is the fermentable carbohydrate as carbon and energy source. Sodium chloride maintains the osmotic balance abnd the bacteriological agar is the solidifying agent. E. coli produces enzyme ß-D-glucuronidase that hydrolyzes MUG to yield a fluorogenic product that is detectable under long-wave (366 nm) UV light.

Biggy Agar is the abbreviation for Bismuth Glucose Glycine Yeast Agar which is used to isolate and differentiate Candida albicans and Candida tropicalis, and to differentiate the species according to the Nickerson method. Nickerson discovered that Candida albicans can be differentiated from other types of Candida spp. on this medium based on colony morphology. Yeast extract is a source of vitamins, particularly of the B-group essential for growth and glycine stimulates growth. Dextrose is the fermentable carbohydrate providing carbon and energy. Candida spp reduce bismuth sulphite to bismuth sulphide forming brown to black colonies. Bismuth ammonium citrate and Sodium sulphite inhibit bacterial growth without affecting the growth of Candida species. The different species of Candida produce different kinds of infections. Candidiasis, the most encountered opportunistic fungal infection, is mostly caused by Candida albicans. Candida tropicalis and Candida glabrata infections occur less often. Candida spp are present in clinical specimens resulting from environmental contamination, colonization, or a disease process.

King FG Agar is used for the enumeration of psychotrophic microorganisms in foods and drinks. Psychotrophic organisms are extremophile organisms that are capable of grow and reproduce in low temperatures ranging from 0 to 20 ºC and are widespread in natural environments and in foods. Psychrotrophic microorganisms are well-known for their degradative activities in foods. Some are pathogenic or toxinogenic for humans, animals, or plants.

Organisms in this group are Pseudomonas, Achromobacter, Alcaligenes, Flavobacterium, and Aeromonas, as well as other species of Enterobacteriaceae from the genera: Escherichia, Proteus, Klebsiella, Enterobacter and Hafnia. These are all Gram-negative bacteria. Peptone provides nitrogen, vitamins, minerals, and amino acids essential for growth. Maltose is the fermentable carbohydrate that gives carbon and energy. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Potassium phosphate and magnesium sulphate provide minerals and ions and act as a buffer. Bacteriological agar is the solidifying agent and crystal violet inhibits Gram-positive bacteria.

Brilliant Green Agar Modified is a selective medium for the isolation of Salmonella, except for S.typhy from water, food, and animal foodstuffs. This medium inhibits the growth of Pseudomonas aeruginosa and partially inhibits the growth of Proteus spp. which may be similar in appearance to Salmonella. Salmonella can be present in small numbers and is often accompanied by considerably larger numbers of other Enterobacteriaceae or bacteria of other families. A pre-enrichment stage is used to permit the detection of low numbers of Salmonella or injured Salmonella.

Beef extract, Casein peptone and Meat peptone provide nitrogen, vitamins, minerals, and amino acids that are essential for growth. Yeast extract is a source of vitamins, particularly of the B-group essential for bacterial growth. Lactose and Sucrose are the fermentable carbohydrate providing carbon and energy. Phenol red is the pH indicator and brilliant green inhibits Gram-positive and most Gram-negative bacteria, except Salmonella. If the medium overheats, brilliant green may lose its properties. Bacteriological agar is the solidifying agent. The ISO normative 6579 recommends the Brilliant Green Agar as a second selective medium.

KF Streptococcal Agar is a selective medium for the isolation and enumeration of faecal enterococci in water, foodstuffs, and other materials. It is used for the plate count of enterococci in water samples and for determining the presence of Enterococcus faecalis in milk and its derivatives, as well as in other foods.

The isolation and enumeration of faecal enterococci is made according to APHA for the examination of water (1998) and foodstuffs (1992). Peptone mixture provides nitrogen, vitamins, minerals, and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group. Maltose and Lactose are the fermentable carbohydrates which are used as carbon and energy sources. Sodium glycerophosphate is a buffering agent and sodium azide is a selective agent that inhibits Gram-negative bacteria. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Bacteriological agar is the solidifying agent.

The addition of TTC 1% Supplement (2,3,5-trypheniltetrazolium-chloride) allows faecal enterococci to develop a red colour as the result of the reduction of tetrazolium to formazan, an insoluble red pigment, by actively growing microbial cells.

Enterococcus Confirmatory Agar is used to confirm the presence of enterococci in water and other sources of sanitary interest. The presence of intestinal enterococci, also known as faecal streptococci, is an indicator for faecal contamination, especially when the contamination occurred a long time ago and the less resistant coliform bacteria, including Escherichia coli, may already be dead at the time of analysis. Casein peptone provides nitrogen, vitamins, minerals, and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group essential for bacterial growth and dextrose is the fermentable carbohydrate providing carbon and energy. Sodium azide inhibits Gram-negative bacteria and Methylene blue is an inhibitor of some Gram-positive bacteria. Methylene blue is also the pH indicator. Bacteriological agar is the solidifying agent.

To the prepared test tubes, to cover half of the slanted surface, aseptically add a volume of either Enterococcus Selective Broth (Cat. CL-1204) or Enterococcus Confirmatory Broth (same formulation as this medium but without the agar). Using growth from KAA Presumptive Broth (Cat. CL-1209), inoculate both the surface and the broth in the Confirmatory Agar/Broth mixture tube.

KF Streptococcal Agar with Bromocresol Purple is a selective medium for the isolation and enumeration of faecal enterococci in water, foodstuffs, and other materials. It can be used for the plate count of enterococci in water samples and for determining the presence of Enterococcus faecalis in milk and its derivatives, as well as in other foods. The isolation and enumeration of faecal enterococci is made according to APHA for the examination of water (1998) and foodstuffs (1992).

Peptone mixture provides nitrogen, vitamins, minerals, and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group. Maltose and Lactose are the fermentable carbohydrates as carbon and energy sources. Sodium glycerophosphate is a buffering agent. Sodium azide is a selective agent that inhibits Gram-negative bacteria. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Bromocresol purple is a pH indicator. Bacteriological agar is the solidifying agent. The addition of TTC 1% Supplement (2,3,5 Trypheniltetrazolium chloride) allows faecal enterococci to develop a red colour as the result of the reduction of tetrazolium to formazan, an insoluble red pigment, by actively growing microbial cells.

Violet Red Bile Agar with Glucose (VRBG) 5kg is a selective medium that contains Bile and Violet Red dye, for the isolation and enumeration of enterobacteria. It is based on MacConkey Medium (Cat. CL-1052) used for the detection and enumeration of bile tolerant Gram-negative Enterobacteriaceae in dairy products and foods. In this medium, the lactose is replaced by glucose as the carbohydrate. VRBG agar is the preferred medium for use in investigations into raw materials, processed foods, and plant hygiene. The Enterobacteriaceae group includes lactose-fermenting coliforms bacteria and non-lactose fermenting species like Salmonella and Shigella. Pancreatic digest of gelatin provides nitrogen, vitamins, minerals, and amino acids essential for growth. Yeast extract is the source of vitamins, particularly of the B-group. Glucose is the fermentable carbohydrate providing carbon and energy. Glucose fermenters form red colonies in the presence of the pH indicator neutral red. Bile salts and crystal violet inhibit Gram-positive bacteria. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Bacteriological agar is the solidifying agent.

The European Pharmacopoeia recommends this medium for: “Microbiological examination of non-sterile products: test for specified microorganisms”. This medium can be used for the testing of bile-tolerant Gram-negative bacteria in products. ISO 21528 proposes VRBG Agar for the detection and enumeration of Enterobacteriaceae. The pour plate method suppresses the growth of Gram-negative non-fermenting bacteria due to its semi-anaerobic conditions. The fermentation of glucose is likewise stimulated and results in the formation of purple-red colonies, clearly visible, surrounded by a zone of the same colour. Note that coliforms will ferment the glucose and produce acid with or without gas. Klebsiella and Citrobacter, which are more heat-resident than coliforms, also grow in this medium and can indicate a production process defect (insufficient heating).