In the past study, we reported that Cicuta virosa dominantly grow on the pond of Hitachi mine and the roots accumulated high concentration of Zn. We also reported that Pseudomonas putida isolated from the roots of C. virosa was related to enhance the growth of C. virosa and to increase Zn uptake of the roots by mobilizing in-solubilized Zn in the soil. The object of this study is to clarify Zn absorption mechanism of C. virosa, identifying Zn-solubilizing compound produced by P. putida.

P. putida was cultured in RSM medium for 48 hours under dark and shaking condition at 23°C, and then, the culture was centrifuged. The supernatant was separated by the extraction of ethyl acetate, XAD-4, and Amberlite IRA 400J. In the result of solubilization test, the absorbed fraction of Amberlite IRA 400J showed Zn-solubilizing activity. Currently, this fraction was purified using Mightysil RP-18 GP, and the Zn-solubilizing compound was identified by instrumental analysis. This time, we will report that the addition of the compound toward C. virosa growing on the pond soil was conducted to examine whether Zn absorption of C. virosa is increased or not. Through these results, we will discuss the Zn absorption mechanism of C. virosa related to P. putida.