著者

中井 智司 山根 小雪 細見 正明

出版者

Japan Society on Water Environment

雑誌

水環境学会誌 = Journal of Japan Society on Water Environment (ISSN:09168958)

巻号頁・発行日

vol.23, no.11, pp.726-730, 2000-11-10

参考文献数

11

被引用文献数

3 4

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Four polyphenols, gallic acid (GA), ellagic acid (EA), pyrogallic acid (PA), and (+)-catechin (CAT), released from <i>Myriophyllum spicatum</i>, are anti-algal allelochemicals. In this paper, we investigated the inhibitory effects of each of these polyphenols on blue-green algae (<i>Microcystis aeruginosa</i> and <i>Phormidium tenue</i>), green algae (<i>Selenastrum capricornutum</i> and <i>Scenedesmus quadricauda</i>), and diatoms (<i>Nitzschia palea</i> and <i>Achnanthes minutissima</i>). We also determined the collective actions of the 4 polyphenols on the inhibition of algal growth.<br>Among the 6 algae, <i>M. aeruginosa</i> was the only one whose growth was significantly inhibited by each of the 4 polyphenols, while PA, GA, and EA each caused some degree of growth inhibition in <i>P. tenue</i> and the 2 green algae. Because none of the 4 polyphenols showed any inhibitory effect on growth of <i>N. palea</i> and growth of <i>A. minutissima</i> was not inhibited by PA, GA or CAT, diatoms appear to have strong resistance to such polyphenols. The algal assays we used to investigate the collective effects of polyphenols showed that (<i>i</i>) blue-green algae, <i>M. aeruginosa</i> and <i>P. tenue</i> were most sensitive to the synergistic actions of PA, GA and CAT, and (<i>ii</i>) the synergistic actions toward the 2 green algae and the 2 diatoms were concentration-dependent. These results indicate the possible feasibility of selectively controlling growth of blue-green algae through use of these polyphenols and/or the allelopathic effects of <i>M. spicatum</i>. Measurement of the autoxidation rates of the 4 polyphenols suggests that (<i>i</i>) their inhibitory effects on the growth of <i>M. aeruginosa</i> could be caused by products of their autoxidation, such as radicals, and (<i>ii</i>) the synergistic action of PA, GA and CAT might be due to acceleration of their autoxidation resulting in increasing production of such autoxidation products.