Automated electrical impedance technique for rapid enumeration of fecal coliforms in effluents from sewage treatment plants.

摘要: Fecal coliforms growing in a selective lactose-based broth medium at 44.5 degrees C generate change the electrical impedance of culture relative to sterile control when populations reach 10(6) 10(7) per ml. The ratio these changes was measured automatically, and data were processed by computer. A linear relation found between log10 number fecal an inoculum time required for signal be detected. Pure inocula consisting 100 log phase or stationary detected 6.5 7.7 h, respectively. Standard curves wastewater versus detection time, based on samples collected sewage treatment plant over 4-month period, vary from one another with time. Nevertheless, times rapid ranged 5.8 7.9 h 200 8.7 11.4 1 coliform. Variations given also among plants. strategy is proposed which takes variations into account allows rapid, automated enumeration technique.