The growth of algae in alginate gel beads is currently being studied at OSU and in various institutions throughout the world. The purpose of this study is to determine which type of modified alginate bead is most suitable for entrapment of growing algae cells. Work over the past week has primarily been focused on the study and monitoring of algal growth in alginate beads containing varying levels of poly(ethylene glycol) “PEG”. The purpose for studying the growth of the Algae entrapped in the alginate bead is to determine which weight percent of PEG will be most conducive to a high level of algae growth. These studies may eventually lead to a suitable method of separating valuable pharmaceuticals from algae using alginate beads.

A 1 wt. % sodium alginate solution was made. Four sodium alginate solutions were made. Three of which contained PEG at 5 wt. %, 10 wt. %, and 20 wt. %. Spherical beads were produced as sodium alginate was dropped through a syringe through use of a mechanical depressor into a 0.1 M calcium chloride solution. After the alginate beads cured, they were washed with water and then placed in 100 ml of medium. The medium provided essential nutrients for algal growth.

A calibration curve was produced by way of corresponding spectrophotometer readings with cell counts done with a hemacytometer. A linear calibration curve was obtained, such that Concentration ≈ ( 2E+7) x (Abs). The individual bead volume was calculated so that a known volume of beads could be dissolved in a 1:1 volume ratio of citric acid. Absorbance was then measured with the spectrophotometer. The results were adjusted to the dilution and calculated for algae concentration. The algae was mesured with a linear calibration curve, such that Concentration ≈ ( 1E+7) x (Abs). Algal growth curves were generated.

Daily growth measurements were plotted to show cell concentration with respect to time. The results show that over the course of 95 hours the cell concentration in the alginate beads increased 2.5 to 3 times in all bead types. The cell concentrations in the medium were also plotted to determine cell leakage from the alginate beads. Minute quantity of leakage was found.

Results were inconclusive after 95 hours, as to which bead type allows the greatest cell concentration. Cell leakage was minimized from all bead types. Algae growth will be allowed to continue within beads for a longer period of time so that more data can be collected.

PEG 5%-4x-10x-PC Tuesday

PEG 10%-4x-10x-PC Tuesday

PEG 20%-4x-10x-PC Tuesday

Alginate-4x-10x-PC Tuesday

PEG 5%-4x-10x-PC-Friday

PEG 10%-4x-10x-PC Friday

PEG 20%-4x-10x-PC Friday

Alginate-4x-10x-PC Friday