ABSTRACT
We isolated and identified four spore-forming bacteria from activated sludges and soil, three of which were able to degrade acifluorfen. Biochemical characteristics, DNA base composition and DNA-DNA homology indicated that the degrading strains belonged to the species Bacillus thuringiensis, Clostridium perfringens and Clostridium sphenoides. The fourth strain, identified as C. sphenoides and showing the same characteristics of the corresponding degrading strain, was unable to metabolize acifluorfen. Thus, the plasmid content of these strains was analysed to study the possible correlation between the presence of extrachromosomal elements and the ability to degrade this herbicide.
Subject(s)
Bacillus thuringiensis/isolation & purification , Clostridium perfringens/isolation & purification , Clostridium/isolation & purification , Herbicides/metabolism , Nitrobenzoates/metabolism , Bacillus thuringiensis/genetics , Bacillus thuringiensis/metabolism , Bacillus thuringiensis/physiology , Clostridium/genetics , Clostridium/metabolism , Clostridium/physiology , Clostridium perfringens/genetics , Clostridium perfringens/metabolism , Clostridium perfringens/physiology , DNA, Bacterial/analysis , Electrophoresis, Agar Gel , In Vitro Techniques , Plasmids/analysis , Soil Microbiology , Spores, Bacterial/isolation & purification , Spores, Bacterial/metabolismABSTRACT
A systematic account is offered of a personal series of patients operated for calculosis of the common bile duct, with or without stenosis of Vater's ampulla, over a period of 15 yr. Reference to the clinical and anatomopathological features of these cases is followed by a description of the criteria followed in the choice of the surgical approach. Recent and earlier results are illustrated and some comments are made with regard to the methods employed: ileal choledochotomy, transduodenal papillosphincterotomy, and choledochoduodenostomy). A preference is expressed for papillosphincterotomy in all cases where the correct indications are present.
