Effect of Radiation on Bacterial Population During Annular Solar Eclipse

An annular solar eclipse was observed in India on January 15, 2010, with a magnitude of 0.9190 and was most prominently seen in southern parts of Kerala. The effect of radiations especially UV light, produced during different phases of solar eclipse, on bacterial populations was investigated. The bacterial species, E. coli, identified from the normal water samples were inoculated in different test tubes with known aliquots of distilled water and were exposed directly to the eclipse radiations. The samples were observed to have an increased number of viable bacterial colonies in both the pre and post eclipse phases. The samples exposed at the peak hours of eclipse that is phase I (12 -13h) and phase II (13-15h) shows subsequent reduction in bacterial populations. About 51.47% and 63.21% reduction in bacterial populations were observed in first and second phases of eclipse respectively. The restoration of bacterial populations with about 77.46% increase in viability in the post eclipse phase was observed. The major observation made was the development of fluorescence by E. coli colonies on the nutrient agar plates after their exposure to the solar eclipse's radiations. This phenomenon could be attributed to the mutagenic effects of radiations produced during the eclipse. About 82.75% and 94.54% of the bacterial colonies among the total bacterial population developed fluorescence, after their exposure to the radiations in first and second phases of the eclipse respectively.