Culture Media Non-Agars

Peptone water is a broth medium that is primarily used as an enrichment for bacterial growth. It is composed of animal tissue peptate digestate and sodium chloride. Peptone water is used to dilute and enrich the resuscitation and growth and many microorganisms, ranging anywhere from food to water samples. It is very useful for difficult protocols, strains, and growth conditions. It can also be used in the process of carbohydrate fermentation. It is used for the non-selective pre-enrichment of food microorganisms such as Salmonella and Cronobacter species. It is intended to be used in the diagnosis of disease and other conditions that affect humans. The pre-enrichment nature is designed to help damaged salmonellae recover before introducing them into the medium. The nutrient medium does not have inhibitors and is well buffered during the incubation period.

Buffered peptone water is a liquid that increases the recovery likelihood of Salmonella spp in food samples. Its main purpose is to detect and enumerate Enterobacteriaceae within food samples, used as a diluent. It is usually made of enzymatic digest of casein, sodium chloride, disodium hydrogen phosphate, and potassium dihydrogen phosphate. The enzymatic digestion of casein results in amino acids, nitrogen, carbon, and minerals. On the other hand, sodium chloride maintains the osmotic balance, and the phosphates act as buffering agents.

Buffered peptone water is a material that is rich with nutrients and resuscitates injured bacteria. The phosphate buffer system prevents bacterial damage, while peptone acts as a source of carbon, nitrogen, vitamins and minerals. On the other hand, sodium chloride maintains the osmotic pressure/balance. Buffered peptone water is used to test food and water samples. The product is used for non selective enrichment of bacteria and also employed as a diluent for general use. Buffered peptone water is a non-selective pre-enrichment medium that resuscitates cells that have been injured during the process of food preservation. It is often used as a nonselective pre-enrichment for Salmonella species in the food testing industry. The way to avoid Salmonella contamination is by carrying out different tests to prevent the spread. Buffered peptone water allows the organisms to recover and grow prior to the detection of contamination. The stress of the cells is reduced since selective agents are not present. It also contains phosphate salts that provide buffering capacity to main enrichment. The buffered peptone water provides a carbon and nitrogen source, as well as sodium chloride that maintains the osmotic balance.

Buffered Peptone Water (BPW) is used for the non-selective pre-enrichment of Salmonella spp. from food and is not intended for use in the diagnosis of disease or other conditions in humans. Edel and Kamelmacher found that food preservation techniques involving heat, desiccation, preservatives, high osmotic pressure, or pH changes cause sublethal injury to Salmonella spp. Preenrichment in a non-selective medium allows for repair of cell damage and facilitates the recovery of Salmonella. Lactose Broth is frequently used for this purpose, but it may be detrimental to recovering Salmonellae. Buffered Peptone Water maintains a high pH over the pre-enrichment period and allows in repair of injured cells that may be sensitive to low pH. This is particularly important for vegetable specimens which have a low buffering capacity. Buffered Peptone Water is used in standard methods.

TAAG Life Sciences offers Buffered Peptone Water with 500g per bottle, used for the pre-enrichment of Salmonella spp. The pre-enrichment of the Culture Media is performed by using buffered peptone water to increase target concentration and improve sensitivity. Peptone provides carbon and nitrogen sources to meet the needs of bacterial growth, while sodium chloride maintains osmotic equilibrium. Additionally, potassium dihydrogen phosphate and disodium hydrogen phosphate act as buffers. The use instructions are to suspend 20g in 1L of distilled water, bringing it to the boil water to dissolve completely. In order to sterilize, one must do the autoclaving at 121°C for 15 minutes. Then it must be poured into sterile petri plates, drying the surface of the gel before inoculation. The storage conditions indicate that the container must be kept tightly closed, stored in a cool, dry place, away from bright light, for a period of 3 years. The formulation per liter is 10g of tryptone, 5g of sodium chloride, 3.5g of disodium hydrogen phosphate, 1.5g of potassium dihydrogen phosphate.