Question

Can someone please help me with this: I dont have strong opinion about this. Please help me, I really need help with this. It is related to the article "microbes of the upper troposphere" Summarize the opinion about microorganisms in the troposphere in one or two paragraphs. Support your argument with evidence.

Answer 1

Ans. The troposphere and layers above have different microorganisms within. The troposphere acts as their biome. The outer membrane protein (inaZ) acts as a nucleation point for the heterogeneous ice freezing. Their size and concentration which are larger in number helps in the formation of cloud condensation nuclei in the precipitation formation process. However, with increase in altitude the density of the microorganisms is supposed to be lacking due to dearth of sufficient data. The present study analyses microorganisms at mid to high troposphere. The sample collection consisted of cloud free and cloudy days and before and after 2 storms Hurricane Karl and Earl respectively. The purpose was perhaps to study the heterogeneity of the microorganisms and their characterization. The weather and air mass during, before and after 2 hurricanes will definitely be different.

Based on the studies, the bacterial cells were found to be quite large and viable (0.25–1 μm). Some of these species viz., Proteobacteria influence formation of snow and ice droplets in the upper troposphere. More than 85 % of the total bacterial cells found in the upper troposphere were marine in origin, which can be directly correlated to the turbulence caused by the hurricanes. Thus the marine bacteria are quite efficient in promoting carbon nuclei condensation over other bacteria from other ecosystems. The concentration of the bacterial cells were significantly higher than the fngal cells in the upper troposphere. The hurricanes have a key role to play in this since they bring about heterogeneity in both the density and composition of the bacterial community in the upper troposphere, some of which belong to new taxa. Most of the bacteria or even fungal species in the upper troposphere have their roots to the microbial community near the ground surface. After hurricanes the concentrations of the microbial particles were quite high. The reasons could be attributed to their faster growth in favourable conditions in the upper troposphere. However of the available microbes not all species taking part in cloud condensation nuclei are large in number, like Gammaproteobacteria. These organisms have developed their own mechanism of protecting themselves from direct exposure of ultra violet radiations. Certain species like Afipia sp. which are basically marine in nature use carbon in the upper troposphere to survive. The members of the Bradyrhizobiaceae family are found in plethora in the upper troposphere.