Streptomyces Content of Agricultural Soils Decreases by Methyl Tert -butyl Ether (MTBE) Spills and Leakage, Causing Adverse Change in Soil Micro Flora

摘要

Streptomyceticidal activity of Methyl Tert -butyl ether (MTBE) is being reported for the first time. Adverse effect of Methyl Tert -butyl ether (MTBE), the gasoline additive, against four soil-inhabitant Streptomyces spp. isolates and two plant root-pathogens was investigated. MTBE, an octane enhance is added to gasoline to reduce atmospheric concentrations of carbon monoxide and ozone. It contaminates soil and groundwater by fuel leaks and spills. Streptomyces spp. are of the major contributors to the biological buffering of soils by exerting beneficial and antagonistic activity against wide range of bacteria and fungi. To elucidate antimicrobial activity of MTBE, it was tested against four soil isolates of Streptomyces; a plant bacterial-pathogen, Erwinia carotovora and a plant root fungal-pathogen, Fusarium solani . MTBE did not reveal any growth inhibitory-activity against E. carotovora and F. solani but showed strong inhibitory effect against Streptomyces spp. isolates. The Minimum inhibitory concentration (MIC) was 1/800 of the original MTBE. Fuel leaks and spills can adversely suppress or eliminate the Streptomyces role in the soil causing alteration in the balance of soil micro flora. This change will lead to domination of microorganisms with adverse biological or ecological effects.