Gaschromatography/mass spectrometry analysis of degradation of ethylacetoacetate achieved in shake flask culture using a previously characterized yeast strain Tichosporon dermatis.

Abstract

Public and regulatory interest regarding the presence of pharmaceutically active compounds in the environment its increasing adverse impact has increased in the recent years. Detection of a wide variety of pharmaceutical compounds in water environment has been a serious and growing concern in the last few decades. Understanding the biological degradation of pharmaceutical compounds is essential for accurately determining their ultimate environmental fate, conducting accurate risk assessments, and improving removal of such micro pollutants.  Present investigation was designed to accomplish biodegradation of ethylacetoacetate in shake flask culture using whole cells of previously isolated and identified yeast strain Trichosporon dermatis, from pharmaceutical effluents using enrichment culture technique. The strain was cultivated for two generations on an orbital shaker at 120 rpm at 28 ± 2⁰C and the biomass was separated by centrifugation at 10,000 rpm for 20 mts. Normal saline washed cells were used in degradation carried out in Erlenmeyer flasks containing 500 ml of mineral medium containing ethylacetoacetate at standard conditions; wet cell weight= 20g/l; ethylacetoacetate concentration = 0.5% in mineral medium (w/v); time of biodegradation= 72 hrs; temperature= 28 ± 2⁰C. Gas chromatography/mass spectrometry (GC-MS) analysis of microbially degraded product revealed that complete degradation of ethylacetoacetate in mineral medium was achieved in 72 hours using whole cells of Trichosporon dermatis yeast strain. Degradation of ethylacetoacetate by this yeast strain has not been reported before the present investigation.

Keywords: ethyl acetoacetate, biodegradation, Gass chromatography/mass spectrometry and effluents,