ESTIMATION OF ALGAL BIOMASS

Sent: 27 September 2000

From: Maria Vicenta Valdivia mvaldivi@fundch.cl

To: AQUA-L@killick.ifmt.nf.ca

Question:

Does anyone know how I could make a gross estimation of the
biomass concentration (g/ml) of Isochrysis sp. (tahiti) from the
culture concentration in cells/ml?

Maria Vicenta Valdivia

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COMMENTS 1:

Isochrysis is reported to have a weight of 17.3 picograms (10^-12g) per cell.
This will vary with strain and culture conditions.

Nancy Hadley

E-mail: hadleyn@xiphias.mrd.dnr.state.sc.us

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COMMENTS 2 :

Unfortunately, those two parameters do not correlate well.  We've tried
multiple times to correlate cell count to biomass, but the cells will vary in size and density too drastically to accurately predict the biomass from cell count.  However, light transmission does generally correlate very well to biomass concentration.  Thus, for our continuous cultures, we use a small homemade "light shoot" with a 20W halogen bulb on one side and a photocell on the other with clear acrylic separating the culture liquid.  It's not the greatest setup, but we can correlate linearly (millivolts vs. total suspended solids) to an r2 of better than 0.95, and it only costs about $20-25.  Of course you'll need some device to read the millivolts from the photocell, but this could be done crudely for not much money.

Mike Chris

E-mail: mchris@unix1.sncc.lsu.edu

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