Ikawa, M., J.J. Sasner, J. F. Haney
Abstract:
The activity of degradation products of linoleic and linolenic acids in inhibiting the growth of the green alga Chlorella pyrenoidosa was determined using the paper disk- agar plate method.
Hydroperoxides derived from these acids showed some, but less, inhibitory activity. Aldehyde biodegradation products and other related aldehydes and alcohols also showed inhibitory activity, which peaked in the C9-C12 range. Unsaturated compounds were more inhibitory than their saturated counterparts.
Monounsaturated fatty acids of 16 or less carbon atoms were also inhibitory. Oleic acid appears to be unique in that it does not inhibit Chlorella growth.
There is a correlation between inhibition of Chlorella growth by alcohols and aldehydes and the reported properties of alcohols of lowering the gel to liquid-crystal phase transition temperature of biological membranes.
It is concluded that the inhibitory effects of polyunsaturated fatty acids (PUFAs) is due to the acids themselves and not their degradation products and that the effects may be due to effects on membranes.
The evidence for the possible ecological role of PUFAs as toxic agents for various algae and animals is discussed.
(Department of Zoology, University of New Hampshire, Durham, New Hampshire 03824, U.S.A.)
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