Question

Bacteria densities in air are usually positively correlated with the densities of particulates and dust. See this example from Mancinelli and Shulls (1978):

Bacterial parameter Particulates

Micrococcus +0.45^b

Aerococcus +0.31

Staphylococcus +0.38

Total no. of rods isolated +0.41

Total no. of cocci isolated +0.37

Total no. of viable bacteria isolated +0.56^b

^{Why is this?}

Answer 1

In their study, Within the 2-year period, the random samples were taken from the urban areas air and the viable microorganism is tested in that air sample. The next step was to determine the number of bacteria and organism included in this experiment are all identified by their morphological and biochemical characteristics.0.013 to 1.88 organisms, this is the number of bacteria found in per liter of air sampled. In their study, they have found that the number of microorganisms (according to the data given above)influenced by the humidity, temperature and the radiation of the environment. In study 21 samples were taken which represented 19 different genera. We can see that the number of micrococcus and staphylococcus is high the reason behind this raised number is the presence of carotene pigment that pigment allow them to survive in sun radiation exposure better than the survival of other microorganisms. They have used some aerosol and air gases prepared in the laboratory which actually found in urban areas in their samples and found that there are some aerosols and gases that enable the microorganisms to grow fully and the microorganisms found in urban air contain aerosols and pollutants have the complex system than the microorganisms found in the laboratory.