Abstract
Some simple testing methods for identification of bacteria in activated sludge by using 511 bacterial isolates were evaluated, and the following results were obtained.
(1) Compared with the Gram staining method, the caustic potash method (Ryu's method) was equally reliable, easier and less troublesome.
(2) Three kinds of motility test methods were compared; (i) cultivation with semi-solid medium, (ii) microscopic examination and (iii) staining of bacterial flagella. The agreement of the test results between (i) and (ii), and between (ii) and (iii) were 89.8% and 69.6%, respectively. The microscopic examination method was the easiest and most reliable.
(3) Three kinds of cytochrome oxidase reagents from different suppliers were tested and compared: one was the dropper-type reagent which seals Kovac's reagent in an ampule and is used by dropping it on a filter paper streaked with bacteria. The other two were filter paper-type reagents which contain Kovac's reagent in a filter paper and are used by rubbing bacteria with a platinum loop. The agreement of the results by three test reagents was 85.4%.
