Sample Images of Baker’s Yeast Saccharomyces cerevisiae
Images of baker’s yeast Saccharomyces cerevisiae acquired with the Countstar BioFerm. Samples were taken from different manufacturing processes, partly stained with Methylene Blue (lower left) and Methylene Violet (lower right)
Saccharomyces cerevisiae at different stages of a 2-step fermentation process
Upper left: Section of a Countstar BioFerm image showing a starter culture, stained by Methylene Blue (MB). The sample contains a high cell density and cells are highly viable (measured mortality <5%). Lower left: Unstained sample from a freshly inoculated bioreactor; buds are clearly visible. Lower right: Sample was taken at the final stage of the main fermentation process, stained 1:1 by MB (measured mortality: 25%). The red arrows mark dead cells, which incorporated the viability dye MB, leading to a dark colour of the entire cell volumen.
Comparability of measurement data
The graphics above demonstrate the comparability of Countstar BioFerm to manual counting, and the significant lower variations in measurement results, if compared to manual hemocytometer counts
Comparison of manual and automatic diameter distribution analysis
The graphics above demonstrate the higher precison of Countstar BioFerm diameter measurements to a manual survey in a hemocytometer. As in the manual counts a 100 times lower number of cells is analysed, the diameter distribution pattern varies significantly more than in the Countstar BioFerm, where nearly 3,000 yeast cells were analysed.
Reproducibility of cell counting and mortality rate
25 aliquots of diluted Saccharomyces cerevisiae samples, containing a nominal concentration of 6.6×106 cells /mL were analyzed in parallel by a Countstar BioFerm and in a hemocytometer manually.
Both graphics show a much higher variation in single cell counts, carried out manually in a hemocytometer. In contrast, the Countstar BioFerm varies only minimally from the nominal value in concentration (left) and mortality (right).
Saccharomyces cerevisiae at different stages of a 2-step fermentation process
Saccharomyces cerevisiae, stained by Methylene Violet and subsequently analyzed with a Countstar BioFerm system
Left: Section of an acquired Countstar Bioferm image Right: Same section, cells labeled by the Countstar BioFerm image recognition algorithms. Viable cells are surrounded by green circles, stained (dead) cells marked by yellow circles (additionally indicated for this brochure with yellow arrows). Aggregated cells are surrounded by pink circles. A high number of two cells aggregates are visible – a clear indicator of the budding activity of this culture, Yellow arrows, inserted manually, mark the dead cells.
The aggregate histogram of an exponentially growing yeast fermentation documents the high level of budding activity, displaying mainly 2 cell aggregates,
