Abstract
Degradation of nonylphenol polyethoxylate (NPEOpoly) was examined on coastal sediments collected at Shimonoseki, Japan. The populations of the bacteria that degrade ethylene glycol unit of NPEOpoly ranged from 100 to 103 per g of the sea sediment. When the sediment of station 7 was inoculated into the sterilized seawater enriched with NPEOpoly as a sole organic carbon source, the total count of bacteria showed a two-phased increase and reached the level of 109 cells/ml in the second growth phase. A clear degradation of NPEOpoly was observed in the second growth phase, and the accumulation of NPEO with shorter ethylene glycol units was observed. Of the each 20 strains isolated from the two different growth phase, none of the bacteria of the first phase degraded NPEOpoly, while 17 strains of the second phase did. Gas chromatography suggested that the bacteria hydrolyzed the ethylene glycol chains by the mechanism of hydroxyl shift.
