BD FACSMicroCount
Applications
Microbial fermentation is an important component of industrial microbiology used to manufacture drugs, enzymes, and vaccines, as well as human and animal food additives. Accurate and timely testing of the total biomass, total number of viable microorganisms, or total dead cell count can help prevent batch loss and more accurately determine the best time to harvest to optimize yield.
Monitoring Microbial Fermentation and Enumerating Stock Cultures
The BD FACSMicroCount™ system can produce reliable, quantitative results in 4 to 5 minutes, accurately enumerating a broad range of microorganisms, including fastidious organisms, Mycoplasmas, gram-positive and gram-negative bacteria, yeasts, molds, spores, spirochetes, and anaerobes. This delivers significant time savings over traditional testing methods that can take over 10 days.
By enabling rapid testing, the BD FACSMicroCount empowers manufacturers to realize “real-time” monitoring across all phases of the fermentation process. Constant monitoring allows for optimization at each phase:
- In upstream testing the system can detect media contamination and determine starter culture titer. Early detection of raw material contamination can minimize the impact of a downstream contamination event.
- During fermentation monitoring total biomass, viable, and dead cell counts can be enumerated. This total count (including dead cell counts) is unique to the BD FACSMicroCount system and offers valuable information to help determine the best time to harvest the biomass.
- Downstream testing can determine cell concentrations in both in-process and in-final product samples such as inactivated bulks and concentrates.
BD FACSMicroCount scatter plot showing counts of Streptococcus equi.
Each dot on the plot represents an S. equi cell counted by the BD FACSMicroCount. The result was 3.92 x 109 counts/mL on the BD FACSMicroCount with a corresponding plate count result of 3.40 x 109 cfu/mL.
Correlation of BD FACSMicroCount counts versus plate counts for Streptococcus equi.
Here the BD FACSMicroCount results directly correlate with results from traditional methods (eg, plate count, color changing unit, hemacytometer). Time to result was less than 5 minutes per sample.The BD FACSMicroCount reagent kits are available for enumeration of biomass, viable organisms, and dead cells. The system is fully automated and performs reagent additions, mixing, and sample injections automatically. The system holds a maximum of 42 samples, but also allows for continuous operation utilizing a batch process.
By eliminating manual counting steps that can lead to variable results, the BD FACSMicroCount system provides greater consistency than traditional test methods. Studies that compared counts/mL from the BD FACSMicroCount analysis and cfu/mL by traditional methodology showed excellent correlation and agreement.
| Microorganism | Number of samples | R2 |
|---|---|---|
| Bacillus atrophaeus | 25 | 0.986 |
| Candida albicans | 30 | 0.976 |
| Escherichia coli | 34 | 0.993 |
| Mycoplasma bovis | 23 | 0.974 |
Correlation of BD FACSMicroCount Viable Counts vs. Plate Counts of B. atrophaeus 9372, C. albicans 10231, E. coli 25922, and M. bovis 25025.
This figure shows the correlation of results from the BD FACSMicroCount with the traditional plate method throughout the dynamic range of 10 to 10 cfu/mL.
Fermentation and Probiotic Manufacturing
BD FACSMicroCount counts versus plate counts for Bacillus subtilis (R2= 0.9931), Enterococcus faecium (R2= 0.9944), Lactobacillus casei (R2= 0.9997), and Saccharomyces cerevisiae (R2= 0.9966).
