For the last several years my research has focused on microbial ecology and the role of microorganisms in safeguarding environmental quality. In Israel, the availability of water and water quality are vital issues. Practical approaches are needed to prevent the contamination of available water resources and to design recycling schemes for wastewater reuse. My current research activities focus primarily on studying ecophysiology and molecular genetics of the chemolithotrophic nitrifying bacteria. The activity of these bacteria is crucial to wastewater (municipal and industrial) purification. The other part of the studies is concerned with bacteria involved in the biodegradation of the environmentally hazardous halo-organics for the remediation of polluted sites.