　　In our project, we used a photo-bioreactor for microbial cell growth measurement. The photo-bioreactor is originally used to determine gene expression during cell growth, but we used it to measure the growth curve during continuous cultivation in BG-11 of two microalgae in our project.

The followings are the advantages of using this measurement method:

Due to the opened command lines and cheapness of building Arduino devices, the photo-bioreactor we used is cheaper than general photoreactors or spectrophotometers for researchers to measure absorbance.
Compared to recording a single record every time by spectrophotometer, the photo-bioreactor can eliminate batch-to-batch variation after measuring several time points continuously, which significantly improves the accuracy of measurement.
Once calibrated, the photo-bioreactor can automatically cultivate microalgae, measuring concentration in a long period of time, and restores data back to computer automatically. It can eliminate the long-term manual measurements and saves more time for researchers.

(See more detail: Nitrogen Starvation - Experiments - Automatic Measurement)

Team:NYMU-Taipei/Measurement

Measurement