Hydrocarbon degradation at high salinity by a novel extremely halophilic actinomycete

Environmental context. Large areas of arid countries, such as those of the Arabian Peninsula, Central Asia and Australia, are covered by saline sand and gravel deserts, which until recently were considered to be devoid of microbial life. Although in recent times a large number of salt-tolerant and drought-resistant microbes have been described, their metabolism – especially their potential to degrade xenobiotics – is still poorly understood. The ability to degrade xenobiotics is a prerequisite for the use of such organisms for pollution control and environmental field biotechnology. This study describes a potentially to biotechnologically useful actinomycete that is able to degrade some xenobiotics under saline conditions.

Abstract. A new, extremely halophilic, species of Actinopolyspora (Family Pseudonocardiacaea, Order Actinomycetales) was isolated from the saline and arid surroundings of an oil field in the Sultanate of Oman. The strain grows well at salt concentrations up to 250 g L^–1 and is tolerant of the presence of high concentrations of aromatic and aliphatic hydrocarbons. It efficiently degrades alkanes up to C₁₅ and at a slower rate up to C₂₅. Most notable, however, is its fluorene metabolism, which proceeds through several novel metabolites and most likely follows a previously undescribed pathway.