Research On The Diversity And Biogeography Of Airborne Microorganisms In Xinjiang Specific Environment

To investigate the effect of partial solar eclipse on airborne microbial diversity in Urumqi, and analyze distribution characteristic and microbial diversity as well as the relation with environmental factors at extreme arid region in Xinjiang, we collected airborne microorganisms before and after partial solar eclipse in Urumqi and extreme region in Xinjiang by using gravity sampling method and liquid impacting method by microbiological aerosol, explored these experiments combined with culture-dependent method and culture-independent method including biolog system and T-RFLP technology. The main results were as follows:(1) Through culture-dependent method and phylogenetic analysis, 81 strains of bacteria were obtained from six days'cultivation and were divided into 4 phyla: Actinobacteria, Firmicutes, Proteobacteria and Bacteroidetes. Actinobacteria was the dominant group that accounted for 54% of total bacteria. Meanwhile, 6 funga isolated from airborne microorganisms identified by using BIOLOG system were Cladosporium sphaerospermum Penz. BGA, Penicillium raistrickii G. Sm., Penicillium viridicatum Westling BGB, Penicillium tricolor, Fusarium verticillioides (Sacc.) Nirenberg BG, Neosartorya fischeri var. fischeri. Along with the advent of partial solar eclipse, both quantity and diversity of airborne microbes increased gradually, and reached the summit on the day, and then decreased in the following time. Clustering analysis, based on different sampling time and their corresponding bacterial community composition, showed that before the partial solar eclipse (July 21) and the day (July 22) were clustered together and separated from the following days'clusters, which formed a joint cluster. The correlation between air environmental factors and microbes were analyzed by Canonical Correlation Analysis (CCA), and the results indicated that the strains belonging to phyla Actinobacteria Proteobacteria and Firmicutes had the positive correlation with all or most of measured air environmental factors, but strains affiliated to phylum Bacteroidetes were positively related to only three factors (temperature, wind speed and solar wind speed). Those results suggested that the changes of air environmental factors caused by partial solar eclipse had positive effects on the quantity and type of cultivable airborne bacteria in Urumqi.(2) To investigate the effect of partial solar eclipse on the carbon metabolic diversity of airborne microorganisms, we used Biolog metabolic fingerprinting method to analyze the variation of the carbon metabolic diversity of airborne microbial community in Urumqi before and after partial solar eclipse. The results suggested that the ability of carbon sources utilization for microbes on the day was higher than other days. The analysis of variance of the microbial community diversity indices showed that Shannon-weiner diversity was the highest on the day, and principal component analysis demonstrated that caoboxylic acids was the mainly carbon sources to the differentiation of the airborne microorganisms. Hence partial solar eclipse may affect the functional diversity of air microbial community in Urumqi.(3) To investigate the effect of partial solar eclipse on diversity of airborne bacteria in Urumqi. we analyzed and compared the changes of diversity of airborne bacteria in Urumqi before and after partial solar eclipse by using T-RFLP technology. most of diversity indices on the day were higher than other day, and the results of enzyme profiles and diversity index showed that microbial diversity by Rsaâ… profile was higher than Hhaâ… . Classified analysis indicated that airborne bacteria before one day and after day and on the day could classified together, while others could classified together. So partial solar eclipse could increase the diversity of airborne bacteria in Urumqi.(4) To investigated differences of airborne microorganisms between extreme arid regions and control regions in Xinjiang by using culture-dependent method, 52 strains of bacteria were obtained from extreme arid regions in Xinjiang and were divided into 5 phyla: Actinobacteria, Firmicutes, Proteobacteria, Bacteroidetes and Deinococcus-Thermus. Actinobacteria was the dominant group that accounted for 44% of total bacteria. Meanwhile, 4 funga isolated from airborne microorganisms identified by using BIOLOG system were Scopulariopsis brumptii Salvanet-Duval, Penicillium herquei Bainier & Sartory, Alternaria alternaria and Phoma glomerata (Corda) Wollenw. & Hochapfel BGA. The similarity of bacterial community compositon at two sites belonging to the same region was higher than different regions, and diversity of airborne microbial community among regions was different as a result of endemic distribution.(5) The distribution characteristic of airborne microbial communities at extreme arid regions in Xinjiang was analyzed by using T-RFLP fingerprinting method, all kinds of diversity indices at extreme arid regions in Xinjiang were higher than controlled region, and the diversity of airborne microorganisms at extreme arid regions in Xinjiang were abundant. There are also the endemic distribution of airborne microorganisms at extreme arid regions in Xinjiang.