Affinity of Diazinon and Humic Substances as a Substrate of Microorganisms in Paddy Soil

논토양미생물의 Diazinon과 부식물질에 대한 기질 친화성

In order to investigate waether soil microorganism prefer diazinon to humic substances as their substate, the growth of soil bacteria and the activities of monooxygenase and ${\alpha}-,{\beta}-esterase$ were measured after treatment of diazinon and humic substances in defined medium at $30{\pm}1^{\circ}C$. Also, the degradation rate of diazinon was determined by addition of humic substances to the medium. The number of soil bacteria was increased from 1 day and 3 days after the treatment with humic substances and diazinon, respectively. And it showed about 1.5 times more with humic substances than diazinon at 10 days. Monooxygenase(MO) activity with the treatment of humic substances was higher than diazinon until 3 days after treatment in the order of HA > FA > humin. Esterase(ES) activity with the treament of humin and HA was higher than dizainon from 5 dyas, but FA was much similar to diazinon. The degradation rate of diazinon showed more persistancy by addition of humic substances ; 51.4% with humin treatment, 58.9% with HA, 62.4% with FA and 71.9% in control at 10 days after treatment. Therefore, as soil microorganisms perfer humic substances to diazinon, the degreadation rate of diazinon might be delayed by addition of humic stbstances in submerged soil.

Diazinon과 부식물질인 humin, HA, FA에 대한 토양미생물의 기질 선호성을 알아보기 위하여 한정비재에 diazinon과 부식물질을 각각 처리하여 항온($30^{\circ}C{\pm}1$)으로 유지하면서 토양미생물의 균수와 MO 활성, ${\alpha}$, -${\beta}$-ES 활성을 측정하였으며, 각각의 부식물질 첨가에 따른 diazinon의 분해속도를 조사하였다. 1. 토양미생물의 균수가 부식물질 처리구에서는 초기 1일부터 급격히 증가한 반면 dizainon 처리구에서는 3일후 부터 증가하였으며, 10일후 부식물질 처리구가 diazinon 처리구보다 약 1.5배 많았다. 2. MO 활성은 부식물질 처리구에서 diazinon처리구보다 3일까지 높았으며, HA > FA > humin의 순이었다. 3. ${\alpha}$-ES와 ${\beta}$-ES 활성은 비슷한 경향이었으며, humin과 HA에서는 diazinon보다 5일이후 높았지만, FA는 diazinon과 거의 비슷한 수준이었다. 4. 부식물질을 첨가함으로써 diazinon의 분해속도는 지연되었으며, 10일후의 분해율은 humin, HA, FA 첨가구에서 각각 51.4%, 58.9%, 62.4%이었고, 무첨가구에서는 71.9%이었다.