Quantitative estimation of Thiosphaera pantotropha from aerobic mixed culture

This paper reports the successful modification of a plate count media to selectively enumerate Thiosphaera pantotropha from mixed culture and suppress the growth of Pseudomonas. Fourteen samples were prepared in the laboratory and analysed for standard plate count (SPC) on a selective medium which was slightly modified by increasing the concentration of MgSO4 from 0.1 to 0.3 g/l to prevent growth of other organisms. The samples were actually contaminated by Pseudomonas, but the results show that the formation of Pseudomonas colonies was prevented, while no inhibition of growth of Thiosphaera pantotropha occurred. This shows that the modified medium can be used for quantitative estimation of Ts. pantotropha. This is important as the aerobic denitrification potential of the organism could prove useful in wastewater treatment. (C) 2000 Elsevier Science Ltd. All rights reserved.