Abstract

Moïse Nola*, Ernest Djarmaila, Norbert Kemka, Serge H. Zébazé Togouet, Nour-Eddine Chihib, François Krier, Pierre Servais, Jean-Pierre Hornez and Thomas Njiné

 
The study carried out aimed at assessing the impact of groundwater storage temperature at household conditions on the temporal evolution of electrical conductivity and the future of heterotrophic aerobe bacteria (HAB). The storage duration was 7 days and the considered temperatures were 3, 10, 18 and 25°C. The electrical conductivity during storage reached 829 µS/cm at 3 - 18°C and 850 µS/cm at 25°C. The maximum HAB abundance was 9 x 103 cfu/ml at 3°C, 41 x 103 cfu/ml at 10°C, 44 x 103 cfu/ml at 18°C and 93 x 103 cfu/ml at 25°C. At the 3rd and 7th days storage at 3°C, changes in bacterial abundances values were significantly in the same direction as those of electrical conductivity (P < 0.05). The highest cell apparent growth rate at the 3rd day storage was 0.249 d-1 at 3°C, 0.559 d-1 at 10°C, 0.924 d-1 at 18°C and 1.233 d-1 at 25°C. However, at the 7th day storage, it was 0.362 d-1 at 3°C, 0.497 d-1 at 10°C, 0.690 d-1 at 18°C and 0.672 d-1 at 25°C. At the 3rd day storage, a decrease in cell abundance was noted in 90% of samples at 3°C and the cell apparent inhibitory rate varied from 0.012 to 0.989 d-1. The storage of groundwater in households’ conditions for a long period would alter its bacteriological quality.