Question

Levels of indicator microorganisms (e.g., E. coli) commonly increase in drinking water distribution lines as the water gets farther away from the point of disinfection. Why does this occur?

Explain the importance of functional redundancy with respect to soil and water microbial communities.

Answer 1

Answer-the increase in indicator microorganism in water indicates that the quality of water decreases and it is unable to use as drinking water.It occures as the bod and cod of water increase and the temoerattem of water increase above 15℃ .And high level of Aoc can stimulates bacterial growth in distribution system .And BDOC (Biodegradable dissolved organic carbon)increase stimulates the bacterial growth. Answer-The proper and healthy functioning of the soil depends on the microorganism abundance including the total number of bacteria,and also their diversity.The increase in the biodiversity also increases the functional capabilities of the ecosystem but from a certain point.Soil cores were collected from four sites.Soil from below the canopy of invading pioneer trees ,revegetated soil under new growth on the forest edge ,denuded mine soil,and the forest floor of an adjacent preserved forest.Bacterial population responses were analyzed by amending these soil samples with individual carbon substrate in the presence of BrdU .BrdU labeled DNA was then subjected to a 16s-23s rRNA intergenic analysis to depict the activity growing bacteria from each site.The number and diversity of bacterial groups responding to four carbon substrates increased along the reclamation vegetation gradient such that the preserved forest soil samples contained the highest functional redundancy for each substrate .These data suggest that the bacterial functional redundancy increase in relation to the regrowth of plant communities and may therefore represent an important aspect of the restoration of soil biological functionality to reclaimed mine spoils.