土壤中에 있는 Phenol 分解 細菌의 分離ㆍ同定 및 그 活性

Abstract

Phenol is a toxic and persistent pollutant, and a metabolic intermediate of most aromatic compounds. Phenol is discharged at high concentration from processes of various industries. In order for phenol-wastewater to be treated, phenol-degrading bacteria were isolated from soil and identified by their morphological and biochemical characteristics. Their phenol-degra-dabilities at various temperatures were compared, superior strain was selected and its phenol-degrading activity was tested at various concentrations of phenol. The results are as follows: 1. Six phenol-degrading bacteria were isolated from four of eighteen soil samples and all of them were identified as genus Pseudomonas by morphological and biochemical characteristics. 2. Optimum temperature of each strain was as follows: Strain Ⅰ; 30℃, Strain Ⅱ; 30℃, Strain Ⅲ; 30℃, Strain Ⅳ; 25℃, Strain Ⅴ; 37℃, Strain Ⅵ; 25℃. Of them, Strain Ⅲ had superior degradability at wide temperature range, 20-37℃, especially, at 30℃, Strain Ⅲ could degrade 99% of initial phenol 500㎖/ℓ after 36 hours. 3. Phenol=degrading activity of superior strain, Strain Ⅲ, was tested at various concentrations of phenol. Time for 99% degradation was as follows: 10㎖/ℓ ; 3 hours, 50㎖/ℓ; 6 hours, 100㎖/ℓ; 12 hours, 200㎖/ℓ;24 hours, 500㎖/ℓ; 36 hours. But in the case of 1,000㎖/ℓ, only 20% was degraded after 36 hours and 99% was degraded after 66 hours. In the case of 2,000㎖/ℓ, only 19% was degraded after 66 hours and 98% was degraded after 108 hours. Therefore, Strain Ⅲ was highly active strain capable of degrading phenol 2,000㎖/ℓ as a sole carbon source, although it took a long time to do.;Phenol은 有毒性이고 分解되기 어려운 環境汚梁物質이며 大部分 芳香族化合物의 中間代謝産物이다. 또한 各種 産業工程에서 高濃度로 排出되기 때문에 그 毒性으로 因해 處理時 問題를 일으키므로, phenol 廢水處理를 爲하여, phenol을 sole carbon source로 利用하는 菌株를 土壤으로부터 分離하여, 그 形態學的·生化學的 特性에 依해 同定하였으며, 各 分離菌株의 溫度別 phenol分解能을 比較하여, 優秀菌株에 對하여 phenol濃度別 分解試驗을 實施하여 다음과 같은 結果를 얻었다. 1. 18個 地域의 土壤試料中 4個 地域의 土壞으로부터 6株의 phenol分解細菌이 分離되었으며 모두 Pseudomonas 屬이었다. 2. 初期phenol濃度를 500 ㎎/ℓ로 하여 溫度別별 分解試驗을 한 結果, StrainⅠ, Ⅱ, Ⅲ는 30℃에서, StrainⅣ와 Ⅵ은 25℃에서,Strain Ⅴ는 37℃에서 各各 最高分解率을 나타내었다. 그 中 分解能이 가장 優秀한 菌株는 Strain Ⅲ로, 20~37℃에서 높은 分解率을 나타내었으며, 특히 30℃에서는 36時間後 99%가 分解되었다. 3. 優秀菌株에 對하여 phenol濃度別 分解試驗을 한 結果, 10㎎/ℓ, 50㎎/ℓ, 100㎎/ℓ, 200㎎/ℓ, 500㎎/ℓ의 境遇는 各各 3時間, 6時間, 12時間, 24時間, 36時間에 99%가 分解되었고, 1,000㎎/ℓ의 境遇는 36時間後 20%만이 分解되었고 66時間에 되어서야 99%가 分解되었다. 2.000㎎/ℓ의 境遇, 66時間까지의 分解率은 19 %에 不過하였으며 108時間後에야 98%가 分解되었다. 이것으로 보아 Strain Ⅲ는, 비록 分解에 長時間을 要하나 2,000㎎/ℓ의 phenol도 sole carbon source로 分解可能한 高活性菌株였다.