FAQ

Aerobic plate count, coliforms and E. coli, Salmonella, Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, Vibrio, Clostridium perfringens, yeasts and moulds and Cronobacter: the media named in each FDA Bacteriological Analytical Manual chapter, matched to Taiwan-made dehydrated media for US laboratories qualifying a second source.

Aerobic plate count, coliforms, E. coli, Enterobacteriaceae, Salmonella, Staphylococcus aureus, Listeria monocytogenes, lactic acid bacteria, yeasts and moulds, Bacillus cereus, Vibrio parahaemolyticus, Clostridium perfringens and Cronobacter: the media named in each Taiwan FDA (TFDA) announced method, matched to Taiwan-made products.

Casamino acids are casein hydrolysed completely with hydrochloric acid, consisting almost entirely of free amino acids. How they differ from tryptone and enzymatic casein peptone in hydrolysis, tryptophan, salt and use.

The three standard LB (Luria-Bertani) formulations with grams per litre, how much agar for LB Agar, step-by-step preparation and sterilisation, when to add antibiotics, and the usual causes of failure.

Soy peptone is a plant nitrogen source made by enzymatic hydrolysis of soybean protein, also known as Soytone or papaic digest of soybean meal. Its composition, non-GMO and animal-origin-free claims, filtered versus non-filtered grades, and its use in TSB, lactic acid bacteria and industrial fermentation.

Tryptose is an enzymatic digest of mixed casein and meat protein used in media for fastidious organisms such as Brucella and Listeria. Tryptone is a pancreatic digest of casein alone, used in LB and TSB. Raw material, hydrolysis, specification and the formulations that call for each.

Peptone is a mixture of peptides and amino acids made by hydrolysing protein, and the main nitrogen source in culture media. How it is made, the main types, tryptone versus peptone, and how to pick one for your organism.

Yeast peptone is a plant-based nitrogen source made by enzymatic hydrolysis of yeast protein, high in peptides and free of animal components. How it is made, typical specifications, how to pair it with yeast extract, its use in lactic acid bacteria, probiotic, Bacillus and cell culture work, and what to check when buying.

Most often the agar was not fully dissolved, an acidic formulation hydrolysed it, or it was remelted. The usual agar concentration is about 1.5% and it sets at roughly 35 to 40 °C.

Ask three things: what the organism needs (amino acids, vitamins, growth factors), what the process needs (fast growth or secondary metabolites) and what the product needs (plant-based, Halal, cost). Most processes combine two nitrogen sources.

First check the measuring conditions: 25 °C, before sterilisation, with a calibrated electrode. Most dehydrated media need no adjustment; when they do, use 1 N NaOH or HCl in small steps.

The difference is in raw material origin and process traceability: no porcine or non-Halal-slaughtered animal materials, compliant enzymes and processing aids, and audits by a certification body. The formulation and performance are unchanged.

Weigh, dissolve, check pH, dispense, autoclave at 121 °C for 15 minutes. The common mistakes at each step, and why agar media must be fully dissolved by heating before sterilisation.

Slight darkening is the normal Maillard reaction; obvious caramelisation, precipitate or turbidity usually means sugars and amino acids were overheated, phosphate precipitated with magnesium or calcium, or the water was unsuitable.

Unopened powders keep until the labelled expiry at 2 to 30 °C in a dry, dark place; after opening, moisture is the main enemy. Caking, darkening and poor solubility all signal deterioration.

A TDS is the product specification, an SDS the safety data, and a COA the test results of one specific batch. Members can download the TDS and SDS from the product page; a COA is retrieved with the product Ref. and batch number.

Total nitrogen reflects protein content; amino nitrogen the share already hydrolysed to small molecules. A higher AN/TN means shorter peptides that cells use directly, but higher is not always better.

All three formulations share the same ingredients and differ by a single number, but that number decides whether your experiment succeeds.

Different microorganisms need different nutrients, so peptones are made from animal, plant and yeast sources with enzymatic or acid hydrolysis. How the source and process change growth, yield and compliance, and how to choose.

When performing microbial cultivation, industrial fermentation, probiotic development, or cell culture, many professionals rely on yeast-derived nitrogen s…

A common issue encountered during fermentation and microbial cultivation is the sudden discoloration of the culture medium. A previously light-yellow broth…

Many assume that as long as MRS Broth supports the growth of your bacterial strain, it’s good enough. However, if you are manufacturing foods, fermented pr…