Community Of Airborne Microbes In Bioaerosol In The Qingdao Coastal Region

Bioaerosols are a significant subgroup of atmospheric aerosols. Bioaerosols affect human health, environment quality, global climate and atmospheric process. It is very important to study community structure and diversity of airborne microbes in bioaerosol in the Qingdao coastal region to know the composition characteristics and environmental effect of bioaerosols over the sea. Bioaerosol samples were collected by six-stage sampler from July 2009 to September 2010 in the Qingdao coastal region. The concentrations of culturable microbes and total microbes were analyzed. The community structure and diversity of airborne microbes in bioaerosol in the Qingdao coastal region were discussed. The preponderant microbes were identified for the biaoserosols samples. The impact of dust weather on the ommunity structure and diversity of bioaerosol was also investigated.From July 2009 to September 2010 at Yushan sampling site, the monthly average concentrations of culturable microbes were in the ranges of 50~3120CFU/m~3. The monthly average concentrations of culturable microbes were in the ranges of 283~1901CFU/m~3 at Laoshan sampling site from July 2009 to June 2010. The contribution of marine bacteria to the total bacteria was higher than terrestrial bacteria at Yushan sampling site from July 2009 to July 2010. The contribution of marine bacteria to the total bacteria was high at Laoshan sampling site from Februauy 2009 to June 2010. The contribution of marine fungi to the total fungi was higher than terrestrial fungi in the Qingdao coastal region. The seasonal average concentrations of culturable microbes were highest in the fall, higher in the spring and lowest in the summer of 2009 both at Yushan and Laoshan sampling sites. The contribution of bacteria to culturable microbes was higher than fungi in winter and lower in other seasons in the Qingdao coastal region. The contribution of marine microbes to culturable microbes was higher than terrestrial microbes. From July 2009 to September 2010, the monthly average concentrations of total microbes were in the ranges of 8.11×10~4~1.87×10~5 CFU/m~3 at Yushan sampling site. From July 2009 to June 2010, the monthly average concentrations of total microbes were in the ranges of 8.52×10~4~1.76×10~5 CFU/m~3 at Laoshan sampling site. The monthly average concentrations of total microbes were high from September 2009 to November 2009 and low from December 2009 to February 2010 at the Qingdao coastal region. The seasonal average concentrations of total microbes were highest in the fall and lowest in the winter. The monthly average contribution of culturable microbes to total microbes was 0.6% on average at Yushan sampling site and 0.9% at Laoshan sampling site.The number of microbial species had the same monthly distribution with the concentrations in the Qingdao coastal region. The community structure and diversity of airborne microbes in bioaerosol were affected by concentrations and the number of microbial. Pielou index had the adverse monthly distribution with the concentrations of microbial. When bioaesroosls sample had the high concentrations of microbes in some month, there was higher abundance of some kind of microbe and lower Pielou index. When bioaesroosls sample had the low concentrations of microbes in some month, there was lower abundance of some kind of microbe and higher Pielou index. The community structure and diversity at Yushan sampling site were more complex and higher than that at Laoshan.The average concentrations of total microbes of dust samples at Yushan and Laoshan sampling site were 8542 CFU/m~3 and 8549 CFU/m~3 respectively in March 2010. The numbers of microbial species of total culturable microbes of dust samples were much higher than the common samples. The Pielou index of total culturable microbes of dust samples was much lower than the non-dust samples. The dust samples had the higher abundance microbial species,which were not found in the non-dust samples. The community structure and diversity of dust samples were more complex and higher than that of non-dust samples.The preponderant microbes in bioaerosol samples which collected from Nov 2009 to Jun 2010 in the Qingdao coastal region were identified. The preponderant terrestrial bacteria were Kocuria palustris, Brevibacterium and Bacillus megaterium. The preponderant marine bacteria were Bacillus pumilus and Planococcus citreus. The preponderant marine fungi were Chalaropsis and Cladosporium. Gram-positive bacteria were the main bacteria in the air in the Qingdao coastal region. Tests on drug sensitivity were carried out to the five preponderant bacteria, and the result showed that the bacteria of the high abundance in the Qingdao coastal region had no pathogenic impacts.