Using an FTIR Spectrometer to Analyze How a Bacterial Culture is Affected by Differences between Culture Medium Ingredients (Peptones and Yeast Extracts)

User Benefits

- It evaluates the impact of culture medium ingredients (peptones, yeast extract, etc.) from different manufacturers and of different types on the metabolism and composition of cultured bacteria - It uses principal component analysis (PCA) and cluster analysis to differentiate between normal cultures and irregular cultures that are affected by using different culture medium ingredients. - FTIR can be used for quality control of culture medium ingredients used in the production of microbial-based products and for equivalence testing when making changes to culture medium ingredients.

Introduction

When microorganisms are used to produce materials or manufacture microbial products, the composition of the culture medium and the ingredients used in it have a major impact on the growth and metabolism of the microorganisms being cultured. Lot-to-lot and manufacturer-to-manufacturer variability in culture medium ingredients is a particular concern for naturally sourced ingredients, such as peptones and yeast extract, because variations in these ingredients can have unanticipated effects on the quality and yield of a final product. Therefore, ongoing monitoring of the impact of different culture ingredients on a microbial culture is an essential part of a stable manufacturing process. Fourier transform infrared (FTIR) spectrometry, an analytical technique used to characterize the molecular structure of analyte substances, has garnered attention for its effectiveness in identifying microorganisms. The infrared spectrum of a microorganism recorded by FTIR contains information on its lipids, polysaccharides, proteins, carbohydrates, and other molecular components, and it can be used to monitor microbial cultures performed under a fixed set of conditions (using the same culture medium, temperature, and time). This Application News describes a technique that combines the IRXross FTIR spectrometer with a DRS-8000 diffuse reflectance accessory (custom model) for monitoring cultures of microbial-based products.

September 28, 2026 GMT