A bacterial strain was isolated from soil and identified as lactic acid bacteria, however, after fermentation on MRS medium for 24 hr, the clear supernatant of the fermented media was subjected to HPLC analysis and the results showed the presence of different organic acids but no trace of lactic acid was detected, how could this be explained since lactic acid bacteria must produce lactic acid in the fermentation medium ?
Hello, lactic acid bacteria mens they producing the lactic acid from sugar during fermentation. If no lactic acid in fermentation liquid it can be detection problem of your culture that you cultivated is not lactobacteria.
It could either be a detection problem of the HPLC itself (this can be ruled out if you try another method for lactic acid detection, e.g. colorimetric lactate assay or a NADH-based quick tests), or something went wrong during the fermentation. Is it known what strain was isolated exactly? Which organic acids were you able to detect?
It can be an HPLC detection problem. HPLC operational conditions have a huge effect on the resolution of detected peaks and as Lactic and Acetic acid peaks resolution time is really close to each other, they may have overlapped on each other. You may want to change the type, concentration, or pH of your mobile phase or temperature of the HPLC column to get a better resolution of peaks.
- Badges
- Science topic