El-Deeb B A, Ali A M, Ali K A
Department of Botany, Faculty of Science, Sohag, Egypt.
Acta Microbiol Immunol Hung. 2000;47(1):63-73.
Pseudomonas sp. strain Bk8 was isolated from field soil contaminated with different urea-herbicides. This strain is a plasmid (pBkB)-harbouring organism capable of complete degradation of diuron herbicide. Plasmid-cured strain Bk8M was obtained by treatment of Pseudomonas sp. Bk8 with Mitomycin C. This cured strain is capable of only partial degradation of diuron side chain and accumulated a phenolic compound in the medium during growing on diuron as a sole source of carbon and energy. Conjugation experiment was carried out using Bk8M as a recipient and Bk8 as a donor of pBk8 plasmid. The transconjugant was able to degrade a diuron without accumulation of phenolic compound. It was proposed that plasmid pBk8 is self-transmissible and involved in the degradation of diuron aromatic ring but it is not connected with the transformation of diuron into diuron phenol compound.
假单胞菌属菌株Bk8是从受不同尿素除草剂污染的田间土壤中分离出来的。该菌株是一种携带质粒（pBkB）的生物体，能够完全降解敌草隆除草剂。通过用丝裂霉素C处理假单胞菌属Bk8获得了质粒消除菌株Bk8M。这种消除质粒的菌株只能部分降解敌草隆侧链，并且在以敌草隆作为唯一碳源和能源生长期间，在培养基中积累了一种酚类化合物。以Bk8M作为受体，Bk8作为pBk8质粒的供体进行了接合实验。转接合子能够降解敌草隆而不积累酚类化合物。有人提出，质粒pBk8是可自我传递的，并且参与敌草隆芳香环的降解，但它与敌草隆向敌草隆酚类化合物的转化无关。
