Formation of dimethyloligosulfides in Lake Kinneret

Dimethyloligosulfides were recently identified as a primary source of mild malodorous emissions from Lake Kinneret, Israel. The seasonal odor episodes coincide with a bloom of Peridinium gatunense algae. The possibility that the dimethyloligosulfides are formed by bacterial degradation of Peridinium gatunense lysis products, under oxygen rich conditions was investigated. S everal bacterial strains were isolated from the lake. Addition of Peridiniu m cells to the isolated bacteria cultures yielded dimethyldisulfide and dim ethyltrisulfide. One of the bacteria strains, identified as Acinetobacter l woffii, an obligatory aerobe was singled out for derailed investigation. Ad dition of Peridinium cells or methionine to the Acinetobacter culture yield ed, under aerobic conditions dimethyldisulfide and dimethyltrisulfide. Cyst ein feed yielded only inorganic oligosulfides, which were converted to dime thylsulfides by addition of d(3)-methyliodide. (C) 1999 IAWQ Published by E lsevier Science Ltd. All rights reserved.