Enhancement the recovery of chlorine stressed bacteria from water by using sodium pyruvate

Although classical methods still used for bacterial indicators detection, but some stressed bacteria cannot determined. Thus this study aimed to improve the recovery of stressed bacteria from water by using sodium pyruvate to culture media. Also, to compare between the standard culture media and modified media supplemented by sodium pyruvate. Total bacterial counts (TBC), total coliforms (TC), fecal coliforms (FC) and fecal streptococci (FS) were detected. TC, FC and FC were detected by using two methods including Multiple Tube Fermentation (MTF) and Membrane Filtration (MF). The results showed that, the TBC averages at 37 and 22?C were 34.7 and 28.7% using media supplemented with 0.03% wt/vol of sodium pyruvate. While the recovery value % increase to 54% at 37?C, and 45% at 22?C by using media supplemented with 0.05% wt/vol of sodium pyruvate. The recovery of TC by using MT and MTF methods were 54.9 and 42.4% respectively by using media supplemented with 0.03% wt/vol of sodium pyruvate, While the recovery value % increase to 59.6% by MF method, and 48.9% by MTF, using media supplemented with 0.05% wt/vol of sodium pyruvate. The FC average using selective media was 12.5% using media supplemented with 0.03% wt/vol of sodium pyruvate, While the recovery value % increase to 32% with Selective media using media supplemented with 0.05% wt/vol of sodium pyruvate. It can be concluded that, by addition sodium pyruvate increase capability for stressed bacteria recovery from water samples, these supplemented media with sodium pyruvate are necessary for reducing the threat of false negative results in natural water.