Nonylphenol biodegradation by the bacterium Raoultella planticola strain f8 isolated from the sediment of gulf of Finland, Baltic Sea

Abstract

Nonylphenol (NP) is an ubiquitous environmental pollutant of major concern due to its toxicity to aquatic organisms, animals and humansand, moreover NP is known as endocrine disruptor. The aim of this study – to screen from the bottom sediments collected in the southern part of the Gulf of Finland (Baltic Sea) and identify the highly-efficient nonylphenol-degrading bacterial strain and to study its NP-degrading capacity at different levels of temperature, initial рН, dissolved oxygen concentrations and initial NP content. The isolated F8 strain was identified by phenotypic traits using standard methods and by Sanger sequencing of a fragment of the 16S rRNA gene sequence (rrs). The content of nonylphenol was determined by high performance liquid chromatography. The novel nonylphenol-degrading bacterium Raoultella planticola F8 was isolated from the bottom sediments collected in the Gulf of Finland. The isolate Raoultella planticola F8 was deposited in the Russian Collection of Agricultural Microorganisms (RCAM) as the strain RCAM 05450. The rrs sequence of the isolate F8 was deposited in the GenBank database No OL831016. This strain is highly efficient for NP degradation in aerobic conditions at different NP concentrations (up to 900 mg∙L^-1), in the temperature range from 5 to 35°С, the initial pH range from 5 to 9 and the dissolved oxygen concentrations range from 0.8 to 2.46 mg∙L^-1. This study is the first demonstrate the ability of Raoultella planticola to degrade nonylphenol. Findings of this study provide useful information for the application of Raoultella planticola F8 in bioremediation processes.

Keywords: Raoultella planticola F8; sediments; identification; nonylphenol; biodegradation