Estimation of Staphylococcus aureus growth rates from CO 2 with absorption spectroscopy

It is very important to monitor and evaluate the growth of Staphylococcus aureus (S. aureus) under various conditions. However, so far there is no technology that can monitor S. aureus in real time. This work proves that the wavelength modulated absorption spectroscopy (WMAS) based on tunable diode lasers can quickly measure the concentration of carbon dioxide produced by microorganisms. We use a variety of fitting models to get the growth curves of S. aureus and calculated the relationship between the growth rate and time through the obtained growth curve. Using the proposed technology, we have studied the growth status of S. aureus at different temperatures (five points in the range of 26–43°C), and the results show that the maximum growth rate have a strong temperature dependence. Therefore, it is proved that WMAS monitoring S. aureus is a user-friendly, non-invasive, fast, and high signal-to-noise ratio technology, which can be used for rapid and accurate bacterial growth assessment in the industry.