USE OF FILAMENTOUS CYANOBACTERIA FOR BIODEGRADATION OF ORGANIC POLLUTANTS

Biodegradation is increasingly being considered as a less expensive al ternative to physical and chemical means of decomposing organic pollut ants. Pathways of biodegradation have been characterized for a number of heterotrophic microorganisms, mostly soil isolates, some of which h ave been used for remediation of water. Because cyanobacteria are phot oautotrophic and some can fix atmospheric nitrogen, their use for bior emediation of surface waters would circumvent the need to supply biode gradative heterotrophs with organic nutrients. This paper demonstrates that two filamentous cyanobacteria have a natural ability to degrade a highly chlorinated aliphatic pesticide, lindane (gamma-hexachlorocyc lohexane); presents quantitative evidence that this ability can be enh anced by genetic engineering; and provides qualitative evidence that t hose two strains can be genetically engineered to degrade another chlo rinated pollutant, 4-chlorobenzoate.