| In biosphere, microbial is most closely related to the human being. On one hand, microorganisms involved in industry and life of human, such as: fermentation engineering, medicine engineering, etc. On the other hand, microbes pose impact on human health. Airborne microbes occur in the atmospheric environment. They are not only an important component of atmospheric aerosols, but also affect the process of material recycling and climate change. Consequently, the specific and abundance, especially the distribution in global scale, has received more and more attention.To understand the temporal and spatial distribution of microorganisms in the atmosphere, the sample has collected using FA-1 six-stage airborne microbe sampler during the 3rd China Arctic Research Expedition (2008.7-2008.9) and the 26th Chinese Antarctic Research Expedition (2009.10-2010.4). The sampling locations covered the Arctic Ocean, the Sea of Okhotsk, Sea of Japan., China Yellow sea, East of China Sea, Philippine Sea, Coral Sea, the Southern Ocean, and Antarctica. Microbial was in-situ cultured and then counted. Results were shown below:1. The abundance of total bacteria varied considerably. Bacteria were not detected in some of sample locations, while in some places the value was high up to 919 CFU (Colony Forming Unit/m3). The subgroup of marine source ranged from 4 CFU/m3 to 276 CFU/m3. Generally, the microorganisms declined together with increasing latitude, and the amount of bacterial was higher in Northern Hemisphere than that in Southern Hemisphere, which was more obvious in coarse particle.2. In the size distribution of microorganisms, the largest particle was larger than 8.2μm, and the minimum is less than 1.0μm. The trend of large microorganisms was the same as the total microorganisms. While the number of small size partial reduced slowly than the others in the high latitudes, hence the proportion of fine size over coarse particle increased.3. Two samples collected in Arctic Ocean were selected to identify the genus groups using 16S rDNA microbial technology. The dominance species were Bacillus genus and Deinococcus genus. There were more bacteria of Deinococcus genus in the higher latitude sample site.4. Microorganisms were obviously found as regional distributions.(1) In the Arctic Ocean, the abundance of microorganisms was low with the average value of 102.47 CFU/m3 and change largely with coefficient of variation at 1.73. There was higher proportion of fine particle than that in other region. In some sample location, the microorganisms, less than 1.0μm in diameter, was up to 50%. The dominance species were Bacillus genus (circulaus, firmus, subtilis and alvei) and Deinococcus genus (grandis and murrayi). The distribution of microbial in flocating sea ice region was found to be obviously impacted by the melting of sea ice.(2) In the Northwestern Pacific Ocean, the abundance of microbial changes significantly with the temperature. This region was close to the Asian mainland, and the affect of terrestrial microbes was obvious. When the marine boundary layer was mainly affected by the air-mass from continent, the ratio of terrestrial microbes was higher up to 60%. The microbes were mainly composed by coarse size particle of terrestrial microbes. This phenomenon was more obvious in lower latitude.(3) In the Pacific Ocean and Southern Ocean, the subgroup microbe of marine source has significantly high proportion (60% -80%) and was relatively stable (coefficient of variation 0.87). The microbes in the Pacific Ocean (71 CFU/m3 -147 CFU/m3) were slightly higher than that in the Southern Ocean (56 CFU/m3 - 112 CFU/m3).(4) The amount of microorganisms in the Antarctic inland was very scarce, ranging from 2 CFU/m3 to 24 CFU/m3, and showing random of size distribution.5. The abundance of microbes was potentially impacted by the air mass and meteorological conditions.The impact of airborne meteorological conditions included temperature, precipitation, and UV radiation aspects etc. When the temperatures in ambient air decreased with the increasing latitude, the abundance of microorganisms was correspondingly found to decrease. The role of precipitation including rain or snow was to wash out of micro-organisms. While UV radiation has a significant role in the high latitude region. The rate of species with UV tolerance increased, and the spores and small partial microbes, which were able to hide inside sea salt or snow, increased as well.Air mass has impact on airborne microorganisms as they can carry microorganisms by long distant transportation. In this way, microbe can be taken from continent to the marine boundary layer. The total bacteria thus may be much high than the subgroup of marine source in some sample location.
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