Studies on isolation, identification of crude oil degrading bacteria and its degradation capability

Abstract:

[Objective] To identify and characterize a crude oil degrading bacteria 2-9 isolated from a crude oil contaminated marine sponge from Dalian Bay, China. [Methods] According to the 16S rRNA genes sequences analysis, physiological and biochemical characterizations, DNA G+C content assaying, determination of cellular fatty acids and testing of carbon sources. Its capability of degrading crude oil was further determined. [Results] The strain 2-9 was identified as Nitratireductor basaltis. Cells are Gram-negative with catalase-positive and oxidase-positive. The similarity between its 16S rRNA gene and that of its most closely related type strain in GenBank Nitratireductor basaltis J3T was 99%. Growth of strain 2-9 occurred with 0?8% (W/V) NaCl (optimum 2%); strain 2-9 grew at 15 °C?42 °C (optimal 30 °C) and at pH 6.0?10.0 (optimum pH 8.0). It metabolized many carbohydrates and organic acids; the G+C content of its genomic DNA was 57.29 mol%. The major fatty acids were C18:1ω7c (63.61%), C19:0 cycloω8c (16.97%), C18:0 (4.28%) and C16:0 (3.39%). When the initial concentration of crude oil was 1 g/L, the strain 2-9 could consume 63.5% of the crude oil in 14 days. [Conclusion] The strain 2-9 was a crude oil degrading bacteria, holding the potential of being applied in the bioremediation of oil spill.