Utilization of Hexadecane and Heptane by Serratia sp. under Different Potassium Nitrate (KNO₃) Concentrations

Authors: Adetitun DO, Owoseni VO, Tomilayo RB

DOI Info: N/A

ABSTRACT

Composition of mineral salts medium vary depending on the scientific protocol used. Potassium nitrate (KNO₃) is one of the components of mineral salts medium (MSM) used in microbiology and other experiment. In this work, the ability of Serratia sp. to degrade hexadecane and heptane at different KNO₃ concentrations was studied. Four experiments were carried out with variations in hexadecane, heptane, salt concentrations and the days of observations. Mineral salts medium composed of 0.125 g/ml of KH₂PO₄, 0.35 g/ml of Na2HPO4, 0.05 g/ml of MgSO2.7H2O, 0.075 g/ml of KNO₃ and 0.25 g/ml of (NH4)₂SO₄ was used. Growth rate using plate count method was assessed during the days of observation. Results showed the ability of Serratia sp. to degrade hexadecane and heptane as the only source of carbon and energy, because the total viable count increased from 79 x 10² to 172 x 10⁶ cfu/ml for the normal MSN with hexadecane as carbon source. In the set up with normal MSM with heptane, total viable count increased from 22 x 10² to 452 x 10⁶ cfu/ml. In the set up with hexadecane and 4 times KNO₃ in normal MSM, the total viable count increased from 26 x 10² to 33 x 10⁶ cfu/ml. In the fourth set up with heptane and 4 times KNO₃ in MSM, the total viable count increased from 117 x 10² to 238 x 10² cfu/ml. It is concluded that the mixture of the hydrocarbons enhanced the degradation efficiency of Serratia sp.

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