Biological Treatment of Cyanide by Using Klebsiella pneumoniae Species
Nermin Hande Avcioglu* and Isil Seyis Bilkay
Hacettepe University, Faculty of Science, Department of Biology (Biotechnology), Beytepe, TR-06800 Ankara, Turkey
Received November 8, 2015
Accepted May 13, 2016
Klebsiella pneumoniae, cyanide, biodegradation
In this study, optimization conditions for cyanide biodegradation by Klebsiella pneumoniae strain were determined to be 25 °C, pH=7 and 150 rpm at the concentration of 0.5 mM potassium cyanide in the medium. Additionally, it was found that K. pneumoniae strain is not only able to degrade potassium cyanide, but also to degrade potassium hexa cyanoferrate(II) trihydrate and sodium ferrocyanide decahydrate with the efficiencies of 85 and 87.5 %, respectively. Furthermore, this strain degraded potassium cyanide in the presence of different ions such as magnesium, nickel, cobalt, iron, chromium, arsenic and zinc, in variable concentrations (0.1, 0.25 and 0.5 mM) and as a result the amount of the bacteria in the biodegradation media decreased with the increase of ion concentration. Lastly, it was also observed that sterile crude extract of K. pneumoniae strain degraded potassium cyanide on the fifth day of incubation. Based on these results, it is concluded that both culture and sterile crude extract of K. pnemoniae will be used in cyanide removal from different wastes.