we are using calcium alginate immobilized microalgae for various purpose. due to the multiplication of cells inside the beads, the microalgal cells leaking out from the beads, this leakage of cells from the beads is the serious issue for us, so if anybody has better idea to prevent the leakage of cells from the immobilized beads. please share with me.
Playing with the concentration and molecular weight/monomer composition of the alginate may help. Especially the monomer composition has a great influence on the mechanics of the gel at the same concentration. Also higher molecular weight usually is beneficial for the gel properties. Furthermore, you can think about a twofold gel embedding with cell-containing microbeads encapsulated again into macrobeads of neat alginate.
Concentration and "viscosity" play an essential role. We use medium viscosity and 2.5% bau you can combine the two parameters as you need.
Thanks @Nikolaus and @Micheli for your suggestions, but I have gone through some paper, where they have suggested the use of some cross linking agents for more stability.
I think in one point ur alginate beads will reach a maximum saturation point and you have to measure the microalgal density near to that point. In my case, I use alginate disc (3 mm diameter) and I didn't have problems with leakage. But if your problem is the stability of the matrix u should consider washing the beads time to time in calcium solution in order to mantain the strength.
@Jose Thank you so much for your suggestions. The leakage problem is coming when beads incubated with the medium, due to the growth of microalgae inside the beads. In the initial stage, there is no leakage of cells but as the growth of microalgae increases, the cells started coming out or sometimes beads will burst. One more thing I want to know that Is there any effect of temperature on the alginate viscosity because I am autoclaving at 121 C before beads preparation.
Hi Ravindra! I also had the same problem when my strains growth too much in the alginate. I think all depends on what is ur saturation point, and this also depends on the size of ur species and how it growths in the alginate (in my case, Chlorella growths in small colonies, with 16-32 individuals aprox, similar to a morula). Regarding the question about autoclaving, the temperature affects negatively the alginate strength and viscosity (it breaks the alginate chains. Some people recommend filter-sterilization. But in my experience I didn't have too much problems autoclaving my alginate solutions!
@Thanks Jose. I am also using Chlorella and Chlamydomonas microalgae How much percentage of alginate and calcium chloride you using for preparation if you are following some protocol please share with me.
That's good! I used Chlorella and Chlamydomonas inmobilized in alginate discs for my undergraduated thesis. The percentage of alginate and calcium chloride was 4% and 2%, respectively.
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